tag:theconversation.com,2011:/global/topics/food-contamination-4799/articlesFood contamination – The Conversation2024-02-08T14:09:18Ztag:theconversation.com,2011:article/2205072024-02-08T14:09:18Z2024-02-08T14:09:18ZNigeria’s street food: tasty but toxic? Expert shares advice to make it safer<p>In the lively streets of Nigeria’s cities, where delicious street food is a daily delight, a wide variety of food can be bought and consumed instantly. From the sizzling suya snack in Abuja to the aromatic jollof rice in Lagos, street food has become an integral part of Nigerian life. </p>
<p>However, beneath these enticing flavours lies a critical question of public safety and health regulation. There is growing concern about the chemical and microbiological safety of these foods, as there seems not to be any oversight or control in their production and marketing.</p>
<p>Over 70% of urban dwellers in Africa <a href="https://www.ifpri.org/blog/why-brutalizing-food-vendors-hits-africas-growing-cities-where-it-hurts#:%7E:text=Food%20markets%20in%20the%20informal,meat%2C%20fish%2C%20and%20milk.">rely on street vendors</a>. However, inadequate government regulation in developing nations, such as Nigeria, raises concerns about food safety and public health. Foodborne diseases have been <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">linked</a> with contaminated street foods. Common pathogens include <em>E. coli</em> and <em>Salmonella</em>, which has potential to cause foodborne illnesses such as <a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/gastroenteritis-salmonellosis">gastroenteritis</a>, <a href="https://www.who.int/news-room/fact-sheets/detail/e-coli">haemorrhagic colitis or bloody diarrhoea and life-threatening conditions such as haemolytic uraemic syndrome</a>. Heavy metal contamination is another risk. </p>
<p>This issue is not unique to Nigeria or Africa; it is a <a href="https://link.springer.com/chapter/10.1007/978-981-15-2556-8_7">global challenge</a> in many developing countries where street food is a <a href="https://www.scirp.org/journal/paperinformation?paperid=104389">substantial</a> part of the economy.</p>
<p><a href="https://core.ac.uk/download/pdf/82316865.pdf">Research</a> has explored the role of street-vended foods in meeting socio-economic challenges, particularly in developing nations. Other studies have focused on the microbiological safety of street foods (for example, <a href="https://www.sciencedirect.com/science/article/pii/S0362028X22104229?via%3Dihub">soy wara</a>, a Nigerian curdled soy milk product), and <a href="https://core.ac.uk/download/pdf/82316865.pdf">the risk factors in street food practices</a>. </p>
<p>Our own <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">study</a> analysed gaps in the safety and regulation of street foods in Nigeria. We highlighted gaps in infrastructure, training and vendor awareness, and made recommendations to solve the problems we identified. </p>
<p>We <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">found</a> a gap in food safety standards for street-vended foods in Nigeria. While street food vendors <a href="https://www.ajol.info/index.php/ajfand/article/view/163672/153148">provide</a> affordable and accessible meals, the lack of regulation <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">poses</a> significant health risks. </p>
<h2>Why street food can be unsafe</h2>
<p>The primary concern is hygiene and food handling practices. Inadequate <a href="https://onlinelibrary.wiley.com/doi/full/10.2991/efood.k.200619.001">access to clean water</a>, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8279176/">inappropriate waste disposal</a>, <a href="https://www.sciencedirect.com/science/article/abs/pii/S0956713514004307">temperature abuse</a> and lack of food safety knowledge are common challenges seen among street food vendors. </p>
<p>These conditions can lead to food-borne illnesses, which can be prevented but continue to be a public health issue. The WHO <a href="https://www.who.int/activities/estimating-the-burden-of-foodborne-diseases#:%7E:text=Each%20year%20worldwide%2C%20unsafe%20food,number%20is%20likely%20an%20underestimation.">estimates</a> that each year, there are more than 600 million cases of foodborne illnesses, resulting in over 420,000 deaths, with the greatest burden of these (more than 30%) occuring in children less than 5 years of age. </p>
<p>In Nigeria, there have been pockets of foodborne disease outbreaks over the years which have claimed lives. The Consumer Advocacy for Food Safety and Nutrition Initiative <a href="https://www.gainhealth.org/sites/default/files/publications/documents/report-of-eatsafe-launch-in-nigeria-with-next-steps.pdf#page=3">estimates</a> that 173 million cases of foodborne illnesses occur in Nigeria, resulting in 33,000 deaths annually.</p>
<p>Generally, street food preparation in Nigeria mirrors traditional approaches to food preparation at home. However, <a href="https://jara.org.in/uploads/archivepdf/8025JARA_Vol_03_June_2021_01.pdf">a study in Asaba</a>, Delta State Nigeria highlights that because of the scale and quantity of foods prepared, more than 50% of food processors do not wash raw foods prior to preparation and another 40% of the food processors do not wash their hands. Neither do they practise personal hygiene during the handling of foods. Similarly, many street food vendors <a href="https://pubmed.ncbi.nlm.nih.gov/25258630/">operate in less than perfect environments for food processing</a>: many street food vendor stands have flies, rodents and open waste bins which are risk factors for the contamination of foods. </p>
<p>The lack of a clean and sanitary environment for food processing <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8279176/">has been identified</a> as among the key factors that contribute to the contamination of street foods by microorganisms. </p>
<h2>Checking unsafe practices</h2>
<p>A multifaceted approach to these issues must be adopted. </p>
<ul>
<li><p>Training: First, <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">basic food safety training for vendors</a> is crucial. This training should cover essential hygiene practices, safe food handling and storage procedures. It can be done through local health departments and community organisations. This recommendation draws on <a href="https://www.food.gov.uk/business-guidance/food-hygiene-for-your-business">established principles</a> of hygiene and safe food handling. Continuous training on food safety has <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0287996">proved</a> effective in promoting food safety.</p></li>
<li><p>Enforcement: The government should <a href="https://www.tandfonline.com/doi/full/10.1080/23311932.2023.2266194">develop and enforce</a> food safety regulations specific to street vendors. This requires a balance between ensuring public health and not stifling the livelihoods of the vendors. Subsidising the cost of necessary equipment like portable sinks or refrigeration units could be a part of this initiative. Supplying vendors with hygienic materials has <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0287996">proved</a> to be valuable for preserving and enhancing food safety in low- and middle-income nations.</p></li>
<li><p>Inspection: Regular inspections should be conducted to ensure compliance with these regulations. These should not be punitive but rather supportive, helping vendors to meet the required standards. A <a href="https://www.food.gov.uk/sites/default/files/media/document/Stage%202%20Process_evaluation%20final%20report.pdf">food hygiene rating scheme</a> should be put in place to identify vendors complying with food safety standards as this could motivate them to improve their sanitary conditions.</p></li>
<li><p>Awareness: Public awareness also plays a vital role. Consumers should be educated about the importance of food safety and how to identify vendors who adhere to hygiene standards. <a href="https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-019-7475-9">Consumer awareness</a> can create a demand for safer practices, encouraging vendors to comply with regulations.</p></li>
<li><p>Research and development: Finally, research and collaboration with food scientists and public health experts can lead to innovative solutions that are tailored to the Nigerian context. For instance, exploring low-cost preservation techniques or developing mobile apps for health inspection ratings could revolutionise the way street food is regulated.</p></li>
</ul>
<h2>Regulations will save lives and livelihoods</h2>
<p>Regulating street food in Nigeria is not just about preventing disease; it is about preserving a way of life in a safe and sustainable manner. At the heart of this issue are the vendors and consumers, whose lives and well-being are interconnected with the very essence of street food culture.</p><img src="https://counter.theconversation.com/content/220507/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Onyeaka does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Street food is popular in Nigeria but safety is not regulated.Helen Onyeaka, Associate Professor, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2006892023-06-05T12:09:06Z2023-06-05T12:09:06ZArsenic contamination of food and water is a global public health concern – researchers are studying how it causes cancer<figure><img src="https://images.theconversation.com/files/529435/original/file-20230531-23-iq2312.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C937%2C768&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">One symptom of arsenic poisoning is the growth of plaques on the skin called arsenical keratosis.</span> <span class="attribution"><a class="source" href="https://flic.kr/p/tQzvii">Anita Ghosh/REACH via Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Arsenic is a naturally occurring element found in the Earth’s crust. Exposure to arsenic, often through contaminated food and water, is associated with various negative health effects, <a href="https://www.ncbi.nlm.nih.gov/books/NBK304375/">including cancer</a>. </p>
<p>Arsenic exposure is a global public health issue. A 2020 study estimated that <a href="https://doi.org/10.1126/science.aba1510">up to 200 million people wordwide</a> are exposed to arsenic-contaminated drinking water at levels above the legal limit of <a href="https://www.atsdr.cdc.gov/csem/arsenic/standards.html">10 parts per billion</a> set by the U.S. Environmental Protection Agency and World Health Organization. <a href="https://publications.iarc.fr/Book-And-Report-Series/Iarc-Monographs-On-The-Identification-Of-Carcinogenic-Hazards-To-Humans/Some-Drinking-Water-Disinfectants-And-Contaminants-Including-Arsenic-2004">More than 70 countries</a> are affected, including the United States, Spain, Mexico, Japan, India, China, Canada, Chile, Bangladesh, Bolivia and Argentina.</p>
<p>Since many countries are still affected by high levels of arsenic, we believe arsenic exposure is a global public health issue that requires urgent action. <a href="https://stempel.fiu.edu/research/labs/cancer-research/">We study</a> how <a href="https://www.researchgate.net/profile/Cristina-Andrade-Feraud">exposure to toxic metals</a> like arsenic can <a href="https://scholar.google.com/citations?user=v42J5dMAAAAJ&hl=en">lead to cancer</a> through the formation of <a href="https://theconversation.com/triggering-cancer-cells-to-become-normal-cells-how-stem-cell-therapies-can-provide-new-ways-to-stop-tumors-from-spreading-or-growing-back-191559">cancer stem cells</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ftvJr-BycJY?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Arsenic water contamination predominantly affects communities of color in the U.S.</span></figcaption>
</figure>
<h2>Arsenic contamination of food and water</h2>
<p>Your body can absorb arsenic <a href="https://www.atsdr.cdc.gov/csem/arsenic/what_routes.html">through several routes</a>, such as inhalation and skin contact. However, the most common source of arsenic exposure is through contaminated drinking water or food.</p>
<p>People who live in areas with <a href="https://www.who.int/news-room/fact-sheets/detail/arsenic">naturally high levels of arsenic in the soil and water</a> are at particular risk. In the U.S., for example, that includes regions in the Southwest such as Arizona, Nevada and New Mexico. Additionally, <a href="https://www.wolterskluwer.com/en/solutions/ovid/environmental-and-occupational-medicine-3485">human activities</a> such as mining and agriculture can also increase arsenic in food and water sources.</p>
<p>High levels of arsenic can also be found in <a href="https://theconversation.com/should-we-worry-about-arsenic-in-baby-cereal-and-drinking-water-57948">food and drink products</a>, <a href="https://doi.org/10.1016/j.fct.2018.01.018">particularly rice</a> and rice-based products like rice cereals and crackers. A 2019 Consumer Reports investigation even found that <a href="https://www.consumerreports.org/water-quality/arsenic-in-some-bottled-water-brands-at-unsafe-levels-a1198655241/">some brands of bottled water</a> sold in the U.S. contained levels of arsenic that exceeded the legal limit. Alarmingly, multiple studies have also found that several <a href="https://www.consumerreports.org/food-safety/most-baby-foods-contain-arsenic-lead-and-other-heavy-metals/">popular baby food brands</a> contained arsenic at concentrations much higher than the legal limit.</p>
<h2>Arsenic and cancer stem cells</h2>
<p>Chronic exposure to arsenic increases the <a href="https://doi.org/10.1093/jnci/djx201">risk</a> <a href="https://doi.org/10.1016/j.scitotenv.2019.136071">of</a> <a href="https://doi.org/10.1016/j.scitotenv.2019.134128">developing</a> <a href="https://doi.org/10.1158/1055-9965.epi-13-0234-t">multiple</a> <a href="https://doi.org/10.1016/j.scitotenv.2015.08.070">types</a> <a href="https://doi.org/10.1016/s0041-008x(02)00022-4">of cancer</a>.</p>
<p>The mechanisms by which arsenic causes cancer are complex and not yet fully understood. However, research suggests that <a href="https://doi.org/10.3109%2F10408444.2010.506641">arsenic can</a> <a href="https://doi.org/10.1021%2Facs.chemrestox.9b00464">damage DNA</a>, <a href="https://doi.org/10.1007/s00204-013-1131-4">disrupt cell</a> <a href="https://doi.org/10.1093/toxsci/kfy247">signaling pathways</a> and <a href="https://doi.org/10.1186/1476-069X-12-73">impair the</a> <a href="https://doi.org/10.1016/j.cotox.2018.01.003">immune system</a>, all of which can contribute to cancer development.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/529436/original/file-20230531-17-e8zn68.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Microscopy images of ovarian epithelial cells before and after chronic arsenic exposure" src="https://images.theconversation.com/files/529436/original/file-20230531-17-e8zn68.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/529436/original/file-20230531-17-e8zn68.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=235&fit=crop&dpr=1 600w, https://images.theconversation.com/files/529436/original/file-20230531-17-e8zn68.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=235&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/529436/original/file-20230531-17-e8zn68.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=235&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/529436/original/file-20230531-17-e8zn68.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=295&fit=crop&dpr=1 754w, https://images.theconversation.com/files/529436/original/file-20230531-17-e8zn68.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=295&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/529436/original/file-20230531-17-e8zn68.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=295&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The image on the left shows ovarian epithelial cells under normal conditions. The image on the right shows the cells after three weeks of chronic arsenic exposure at 75 parts per billion.</span>
<span class="attribution"><span class="source">Cristina M. Andrade-Feraud/Azzam Laboratory at FIU</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Scientists <a href="https://doi.org/10.1289%2Fehp.1204987">have also linked</a> <a href="https://doi.org/10.1289%2Fehp.0901059">chronic arsenic exposure</a> to the development of <a href="https://theconversation.com/triggering-cancer-cells-to-become-normal-cells-how-stem-cell-therapies-can-provide-new-ways-to-stop-tumors-from-spreading-or-growing-back-191559">cancer stem cells</a>. These are cells within tumors thought to be responsible for cancer growth and spread. Like normal stem cells in the body, cancer stem cells can develop into many different types of cells. At what stage of cellular development a stem cell acquires the genetic mutation that turns it into a cancer stem cell remains unknown.</p>
<p><a href="https://stempel.fiu.edu/research/labs/cancer-research/">Our research</a> aims to identify what type of cell arsenic targets to form a cancer stem cell. We are currently using cell cultures obtained from the same organ at different stages of cellular development to examine how the origins of cells affect the formation of cancer stem cells.</p>
<p>Preventing chronic arsenic exposure is critical to reducing the burden of arsenic-related health effects. Further research is needed to understand arsenic-induced cancer stem cell formation and develop effective strategies to prevent it. In the meantime, continued monitoring and regulation of this toxic metal in food and water sources could help improve the health of affected communities.</p><img src="https://counter.theconversation.com/content/200689/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Diana Azzam receives funding from the Florida Department of Health and the National Institute of Health.</span></em></p><p class="fine-print"><em><span>Cristina Andrade-Feraud does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Millions of people worldwide are exposed via soil and water to arsenic, whether naturally occurring or related to pollution. Chronic exposure is linked to the formation of cancer stem cells.Cristina Andrade-Feraud, Ph.D. Candidate in Environmental Health Sciences, Florida International UniversityDiana Azzam, Assistant Professor of Environmental Health Sciences, Florida International UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2061242023-06-04T07:46:48Z2023-06-04T07:46:48ZYour snacks may be delicious, but are they safe?<figure><img src="https://images.theconversation.com/files/528790/original/file-20230529-15-wmgf5g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Roasted meat on sticks popularly known as 'Suya' is a common delicacy in Nigeria. </span> <span class="attribution"><span class="source">Pius Utomi Ekpei/AFP via Getty Images</span></span></figcaption></figure><p>Food safety is a concern for Nigerians after <a href="https://guardian.ng/features/600m-people-suffer-from-foodborne-sicknesses-yearly/">increasing reports of food-borne illnesses</a> in recent years. According to the Consumer Advocacy for Food Safety and Nutrition Initiative (CAFSANI), consumption of unsafe food in Nigeria results in about <a href="https://pdf.usaid.gov/pdf_docs/PA00XX8H.pdf#page=3">173 million cases of diarrhoea</a> and approximately 33,000 deaths due to foodborne illnesses. </p>
<p>The country has over the years experienced repeated outbreaks of diseases that can be transmitted through contaminated food, including <a href="https://ncdc.gov.ng/diseases/info/C">cholera</a> and <a href="https://ncdc.gov.ng/diseases/info/L">lassa fever</a>. </p>
<p>Food safety is a global issue affecting everyone, regardless of location or social status. According to the <a href="https://www.who.int/news-room/fact-sheets/detail/food-safety">World Health Organization</a>, food-borne diseases affect an estimated 600 million people annually, resulting in 420,000 deaths globally.<br>
Nigeria has significant challenges <a href="https://www.mdpi.com/2304-8158/10/8/1878#B17-foods-10-01878">when it comes to food safety</a> – behaviour around food hygiene. For most developing countries, it can be difficult to practise food safety when clean water and sanitation aren’t available. Some of the other factors that influence food safety in Nigeria are population growth, income inequality, long food supply chains, education gaps and poor regulation.<br>
As a <a href="https://sciprofiles.com/profile/951517">microbiological expert</a>, I am often asked, “how safe is my snack?” The answer to this is not straightforward. It depends on various factors like where the ingredients come from, and how snacks are prepared and stored. </p>
<p>In Nigeria, snacks are small food items that are eaten between meals – a quick bite, as a stand-alone treat or with a beverage. They may be savoury or sweet. Examples include chin-chin, meat pie, <a href="https://theconversation.com/you-love-amagwinya-puff-puff-bofrot-heres-a-healthier-version-of-africas-favourite-snack-170845">puff-puff</a> (deep fried dough), sausage rolls (gala), suya (grilled meat), akara (bean cake), kilishi (dried beef jerky), roasted corn, plantain and groundnuts. </p>
<p>These are usually available from street vendors, in local markets and from supermarkets. Supermarket snacks usually come pre-packaged from the factories while snacks purchased from street vendors and open markets are packaged in a variety of materials such as newspapers for suya and kilishi, polyethylene bags for chin-chin and puff-puff and reused plastic bottles for groundnuts. This unconventional packaging may increase the risk of <a href="https://doi.org/10.18034/ra.v5i3.315">contamination with microorganisms</a>.</p>
<p>There are simple and effective ways to make snacks safer for everyone. Choosing ingredients from trusted sources and following proper food preparation and storage methods can make a big difference. </p>
<figure class="align-center ">
<img alt="men standing behind piles of fruits and vegetables arranged on tables" src="https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&rect=14%2C22%2C4905%2C3201&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/528410/original/file-20230525-25-7fvjqu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Raw fruits and vegetables can be contaminated at the point of sale. Photo by:Pius Utomi Ekpei/AFP.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/roadside-vendors-display-fruits-for-sale-in-lagos-nigerias-news-photo/1239230464?adppopup=true">from www,gettyimages.com</a></span>
</figcaption>
</figure>
<p>By following the tips I offer here, you can enjoy your snacks and reduce the risk of foodborne diseases. Remember, “an ounce of prevention is worth a pound of cure”.</p>
<h2>Managing the risks</h2>
<p><strong>The source of ingredients:</strong> One of the main things that affect the safety of your snack is where its ingredients come from. Raw materials, including fruits, vegetables and animal products, can be <a href="https://www.sciencedirect.com/science/article/pii/S0740002017310158?via%3Dihub">contaminated with harmful microorganisms</a>, such as bacteria, viruses, and parasites. </p>
<p>These microorganisms can cause food-borne illnesses if they are not properly handled and cooked.</p>
<p>To reduce the risk of contamination, it is important to buy <a href="https://www.betterhealth.vic.gov.au/health/healthyliving/food-safety-when-shopping">ingredients from trusted suppliers</a> who have good hygiene practices. </p>
<p>When buying fresh produce, look for signs of spoilage, such as mould, discolouration and foul odours. Avoid buying pre-cut fruits and vegetables, as they are more susceptible to contamination. Always wash fruits and vegetables thoroughly with clean running water before using them.</p>
<p>There are also things to watch out for when buying processed food. Food processing, such as canning and freezing, can kill harmful microorganisms and <a href="https://www.betterhealth.vic.gov.au/health/healthyliving/food-processing-and-nutrition">extend the shelf life of products</a>. But poor processing and handling can lead to contamination and spoilage. </p>
<p><strong>Safe handling and storage:</strong> It’s important to follow <a href="https://www.cdc.gov/handwashing/handwashing-kitchen.html">good hygiene practices</a>, such as washing your hands thoroughly with soap and water before handling food and using clean utensils and equipment. To avoid <a href="https://www.food.gov.uk/safety-hygiene/avoiding-cross-contamination">cross-contamination</a>, separate raw and cooked foods and use different cutting boards for different types of food. Cook food to the <a href="https://www.healthline.com/health/what-temperature-kills-bacteria">appropriate temperature</a> to kill any harmful microorganisms present.</p>
<p>Proper storage can prevent the growth of harmful microorganisms and extend the shelf life of products. <a href="https://opentextbc.ca/foodsafety/chapter/storage-temperatures-and-procedures/">Store perishable items</a>, such as meats, dairy products and cooked foods, in the refrigerator at temperatures of 40°F (4°C) or below. </p>
<p><a href="https://countrylifefoods.com/blogs/country-life-feed/a-quick-guide-on-how-to-store-dried-beans-nuts-and-other-pantry-items">Keep dry foods</a>, such as crackers, cookies and chips, in a cool, dry place away from moisture and heat.</p>
<p><strong>Packaging and labelling:</strong> The <a href="https://www.nafdac.gov.ng/wp-content/uploads/Files/Resources/Guidelines/FOOD/Guidelines%20For%20Food%20Labelling_Labelling.pdf">packaging and labelling</a> of snacks provide important and valuable information about their safety. Look out for products with clear, easy-to-read labels that include information about the <a href="https://www.inecta.com/blog/food-labeling-requirements-what-you-should-know">ingredients, nutritional content and allergens</a>. </p>
<p>Products with damaged or bulging packaging should be avoided as this could be a sign of contamination or spoilage.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/nigerias-street-food-adds-to-the-plastic-problem-green-leaves-offer-a-solution-203618">Nigeria’s street food adds to the plastic problem – green leaves offer a solution</a>
</strong>
</em>
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<h2>Symptoms of food-borne diseases</h2>
<p>Knowing the <a href="http://www.aimspress.com/article/10.3934/microbiol.2017.3.529">most common types of foodborne illnesses</a> and their symptoms is very important. The most common microorganisms that cause food-borne illnesses include salmonella, E. coli, listeria and norovirus. </p>
<p>Symptoms of food-borne illness can range from mild, such as nausea and diarrhoea, to severe, such as kidney failure and paralysis – the inability to move some or all parts of your body.</p>
<p>If you experience or observe any symptoms of food-borne illness after eating a snack, seek medical attention immediately. Food-borne infections can spread quickly, and it is important to take preventive measures to avoid the spread. <a href="https://www.cdc.gov/handwashing/when-how-handwashing.html">Wash your hands</a> frequently and avoid food preparation or handling until you fully recover.</p>
<p>In conclusion, ensuring the safety of your snack requires careful consideration of various factors that can affect its quality and safety. These include the source of ingredients, processing and preparation methods, storage, packaging, labelling, and awareness of common food-borne illnesses.</p><img src="https://counter.theconversation.com/content/206124/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Onyeaka does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Food safety means checking the source and paying attention to hygiene and storage.Helen Onyeaka, Associate Professor, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2050872023-05-16T14:41:27Z2023-05-16T14:41:27ZHow does food get contaminated? The unsafe habits that kill more than 400,000 people a year<figure><img src="https://images.theconversation.com/files/526039/original/file-20230514-182951-p8iehb.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Food-borne illnesses usually present as diarrhoea, vomiting and stomach pains. </span> <span class="attribution"><span class="source">Getty Images</span></span></figcaption></figure><p><em>Unsafe foods, according to the <a href="https://www.who.int/news/item/07-03-2022-world-food-safety-day-2022-theme-highlights-the-role-that-safe-nutritional-food-plays-in-ensuring-human-health">World Health Organization</a> (WHO), contribute to poor health, including impaired growth and development, micro-nutrient deficiencies, noncommunicable and infectious diseases, and mental illness. Globally, one in ten people are affected by food-borne diseases each year. Antonina Mutoro, a nutrition researcher at the African Population and Health Research Center, explains what causes food contamination and how we can lower the risk of disease.</em></p>
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<h2>What is food contamination?</h2>
<p>Access to safe and nutritious food is a basic human right which many do not enjoy, partly because of food contamination. This is defined as the presence of harmful chemicals and microorganisms in food that can cause illness. According to the WHO, food contamination affects about <a href="https://www.who.int/news-room/fact-sheets/detail/food-safety">one in every ten people</a> globally and causes about <a href="https://www.who.int/news-room/fact-sheets/detail/food-safety">420,000 deaths annually</a>. </p>
<p>Food contamination can be:</p>
<ul>
<li><p><strong>physical:</strong> foreign objects in food can potentially cause injury or carry disease-causing microorganisms. Pieces of metal, glass and stones can be choking hazards, or cause cuts or damage to teeth. Hair is another physical contaminant.</p></li>
<li><p><strong>biological:</strong> living organisms in food, including microorganisms (bacteria, viruses and protozoa), pests (weevils, cockroaches and rats) or parasites (worms), can cause disease. </p></li>
<li><p><strong>chemical:</strong> substances like soap residue, pesticide residue and toxins produced by microorganisms such as <a href="https://theconversation.com/what-must-be-done-to-get-toxin-out-of-kenyas-food-supply-127137">aflatoxins</a> can lead to poisoning.</p></li>
</ul>
<h2>What are the most common causes of food contamination?</h2>
<p>The most common cause of food contamination is poor food handling. This includes not washing your hands at the appropriate time – before eating and preparing food, after using the toilet, or after blowing your nose, coughing or sneezing. Using dirty utensils, not washing fruits and vegetables with clean water, and storing raw and cooked food in the same place can also be harmful. Sick people should not handle food. And you should avoid consuming under-cooked foods, particularly meat.</p>
<p>Poor <a href="https://theconversation.com/vegetable-farmers-in-urban-ghana-dont-worry-much-about-food-safety-but-they-should-143706">farming practices</a> can also contaminate food. This includes the heavy use of pesticides and <a href="https://theconversation.com/chickens-from-live-poultry-markets-in-nigeria-could-be-bad-for-your-health-scientists-explain-why-192646">antibiotics</a>, or growing fruits and vegetables using contaminated soil and water. The use of inadequately composted or raw animal manure or sewage is also harmful. </p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/power-cuts-and-food-safety-how-to-avoid-illness-during-loadshedding-200586">Power cuts and food safety: how to avoid illness during loadshedding </a>
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</em>
</p>
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<p>Fresh foods can lead to a number of illnesses. In Kenya, for instance, the <a href="https://bmcresnotes.biomedcentral.com/articles/10.1186/1756-0500-7-627">contamination of meat</a>, <a href="https://www.researchgate.net/publication/329170819_Consumer_Risk_Exposure_to_Chemical_and_Microbial_Hazards_Through_Consumption_of_Fruits_and_Vegetables_in_Kenya">fruits</a> and <a href="https://pubmed.ncbi.nlm.nih.gov/24968591/">vegetables</a> with human waste is relatively common. This is attributed to the use of contaminated water to wash food. Flies carrying contaminants can also directly transfer faecal matter and bacteria onto plant leaves or fruits.</p>
<p><a href="https://theconversation.com/informal-food-markets-what-it-takes-to-make-them-safer-161601">Street foods</a> are another common source of food contamination. These foods are widely consumed in low- and middle-income countries because they’re cheap and easily accessible. </p>
<h2>What are the signs that you’ve eaten contaminated food?</h2>
<p>Biological and chemical substances are the most common food contaminants. They account for <a href="https://www.who.int/news-room/fact-sheets/detail/food-safety">more than 200 food-borne illnesses</a>, including <a href="https://theconversation.com/explainer-causes-symptoms-and-cures-of-typhoid-fever-53645">typhoid</a>, <a href="https://theconversation.com/explainer-why-cholera-remains-a-public-health-threat-74444">cholera</a> and <a href="https://theconversation.com/what-led-to-worlds-worst-listeriosis-outbreak-in-south-africa-92947">listeriosis</a>. Food-borne illnesses usually present as diarrhoea, vomiting and stomach pains.</p>
<p>In severe cases, food-borne illnesses can lead to neurological disorders, organ failure and even death. It’s therefore advisable to seek immediate medical attention if you begin to experience symptoms like persistent diarrhoea and vomiting after eating or drinking.</p>
<p>Children aged under five are the most vulnerable to food-borne illnesses. They bear <a href="https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1001923">40%</a> of the food-borne disease burden. A child’s immune system is still developing and can’t fight off infections as effectively as an adult’s. </p>
<p>In low- and middle-income countries, reduced immunity in children can also occur as a result of malnutrition and frequent exposure to infections due to poor hygiene and sanitation, including a lack of access to safe water and toilets. Additionally, when children are ill, they tend to have poor appetites. This translates to reduced food intake. Coupled with increased nutrient losses through diarrhoea and vomiting, this can lead to a cycle of infection and malnutrition and, in extreme cases, death. </p>
<p>Pregnant women and people with <a href="https://theconversation.com/how-do-i-improve-my-immunity-expert-shares-tips-on-what-to-do-and-what-to-avoid-198537">reduced immunity</a> due to illness or age are equally vulnerable and extra care should, therefore, be taken to prevent food-borne illnesses among these groups.</p>
<h2>What can we do to prevent food contamination?</h2>
<p>Food-borne illnesses also have negative economic impacts, especially in low- and middle-income countries. The World Bank estimates it costs more than <a href="https://www.worldbank.org/en/news/press-release/2018/10/23/food-borne-illnesses-cost-us-110-billion-per-year-in-low-and-middle-income-countries#:%7E:text=The%20total%20productivity%20loss%20associated,estimated%20at%20US%24%2015%20billion.">US$15 billion</a> annually to treat these illnesses in these countries. So it’s important to have preventive strategies in place.</p>
<p>Food contamination can be prevented through simple measures:</p>
<ul>
<li><p>washing your hands at key times (before preparing, serving or eating meals; before feeding children, after using the toilet or after disposing of faeces) </p></li>
<li><p>wearing clean, protective clothing during food preparation </p></li>
<li><p>storing food properly</p></li>
<li><p>washing raw foods with clean water</p></li>
<li><p>keeping raw and cooked foods separate</p></li>
<li><p>using separate utensils for meats and for food meant to be eaten raw. </p></li>
</ul>
<p>Good farming practices, such as the use of clean water and application of approved pesticides in recommended amounts, can help prevent food contamination. </p>
<p>Food vendors also need to be trained on food safety, and provided with clean water and proper sanitation. </p>
<p>As part of the research team at the African Population and Health Research Center, I’m working on the <a href="https://healthyfoodafrica.eu/blog/promoting-access-to-nutritious-food-in-nairobi-urban-poor-settings/">Healthy Food Africa project</a>, which aims to boost food security in urban informal settlements through the promotion of food safety. In Kenya, the project is working closely with the Nairobi county government to develop a food safety training manual targeting street food vendors. This will go a long way towards improving food safety in the city.</p><img src="https://counter.theconversation.com/content/205087/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Antonina Mutoro does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Biological and chemical substances are the most common food contaminants and account for over 200 food-borne illnesses.Antonina Mutoro, Postdoctoral Research Scientist, African Population and Health Research CenterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2015532023-03-16T19:11:18Z2023-03-16T19:11:18ZPFAS for dinner? Study of ‘forever chemicals’ build-up in cattle points to ways to reduce risks<figure><img src="https://images.theconversation.com/files/515054/original/file-20230314-2080-1forbm.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5424%2C3605&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>PFAS, known as “forever chemicals”, have been found just about <a href="https://www.ewg.org/interactive-maps/pfas_in_wildlife/map/">everywhere on Earth</a>, including in <a href="https://www.theguardian.com/environment/2023/mar/13/toxic-forever-chemicals-pfas-toilet-paper">toilet paper</a>.</p>
<p>These chemicals are a group of artificial compounds based on carbon and fluorine – per- and polyfluoroalkyl substances, or PFAS. They comprise thousands of individual chemicals with hundreds of documented uses, including <a href="https://doi.org/10.1039/D0EM00291G">water proofing and fire suppression</a>. It is likely every household has products or textiles that contain or were treated with a product that contained PFAS (including some <a href="https://theconversation.com/youve-read-the-scary-headlines-but-rest-assured-your-cookware-is-safe-199967">non-stick cookware</a> and stain-resistant fabrics). </p>
<p>Studies have shown most people have one or more <a href="https://doi.org/10.1016/j.envint.2014.05.019">PFAS compounds in their blood</a>. We live in a world full of chemicals, so why do we care about these ones? Well, some PFAS have been associated with a wide range of <a href="https://www.health.gov.au/sites/default/files/documents/2022/07/enhealth-guidance-health-effects-and-exposure-pathways-per--and-polyfluoroalkyl-substances-pfas.pdf">adverse human health effects</a>, such as cancer and immune problems. However, there is limited evidence of human disease resulting from environmental exposures. </p>
<p><a href="https://doi.org/10.1016/j.envres.2023.115518">Our study</a> investigated the uptake of PFAS into livestock at ten PFAS-impacted farms in Victoria. Our analysis also shows how risks can be reduced. </p>
<p>Our findings show the land and livestock can be managed to reduce PFAS levels in the animals before they enter the food chain. This means good management practices can protect food quality and reduce consumer exposure.</p>
<figure class="align-center ">
<img alt="Farmer closes the gate behind a herd of beef cattle" src="https://images.theconversation.com/files/515051/original/file-20230314-22-d1yrt0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/515051/original/file-20230314-22-d1yrt0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/515051/original/file-20230314-22-d1yrt0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/515051/original/file-20230314-22-d1yrt0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/515051/original/file-20230314-22-d1yrt0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/515051/original/file-20230314-22-d1yrt0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/515051/original/file-20230314-22-d1yrt0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The bad news is PFAS builds up in cattle when their pasture or water is contaminated. The good news is the land and livestock can be managed to reduce the risks.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/pfas-might-be-everywhere-including-toilet-paper-but-lets-keep-the-health-risks-in-context-201785">PFAS might be everywhere – including toilet paper – but let's keep the health risks in context</a>
</strong>
</em>
</p>
<hr>
<h2>How do PFAS get in your blood?</h2>
<p>Exposure to household <a href="https://www.sciencedirect.com/science/article/pii/S0160412022000757?via%3Dihub">dust and consumption of contaminated food</a> or <a href="https://doi.org/10.1016/j.envres.2019.108648">water</a> are major contributors to human exposure to PFAS. It then <a href="https://doi.org/10.1016/j.envres.2019.108648;%20https://doi.org/10.1016/j.envint.2022.107149">accumulates in our blood</a>. </p>
<p>As the name would suggest, forever chemicals persist in the environment. As a result, when released into the environment, they disperse and over time can contaminate surrounding areas. </p>
<p>Firefighting and training activities have historically resulted in large releases of PFAS into the environment. This includes farming areas. </p>
<p>As livestock feed and drink from contaminated sources, this leads to PFAS accumulation in tissues. From there, PFAS can be transferred into the food chain, including products we eat such as <a href="https://doi.org/10.1016/j.scitotenv.2020.144795">meat and milk</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/forever-chemicals-have-made-their-way-to-farms-for-now-levels-in-your-food-are-low-but-theres-no-time-to-waste-192402">'Forever chemicals' have made their way to farms. For now, levels in your food are low – but there's no time to waste</a>
</strong>
</em>
</p>
<hr>
<p>The causal links and what levels of PFAS exposure are harmful are <a href="https://nceph.anu.edu.au/research/projects/pfas-health-study#acton-tabs-link--tabs-0-footer-4">still being investigated</a>. The scientific community has yet to reach a consensus on how “bad” these compounds are, or conversely what the safe exposure levels are. </p>
<p>In the meantime, it is important to <a href="http://chm.pops.int/Implementation/IndustrialPOPs/PFAS/Overview/tabid/5221/Default.aspx">limit exposure through regulation</a>. Australia has adopted environmental and <a href="https://www.dcceew.gov.au/environment/protection/publications/pfas-nemp-2">health-based guideline values</a> for three PFAS of concern: perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexane sulfonate (PFHxS).</p>
<p>Australian food quality is high. In a 2021 study, scientists tested for 30 different PFAS in a broad range of Australian foods and beverages. Only one specific PFAS (PFOS) was detectable. It was found in just five out of 112 commonly consumed foods and beverages <a href="https://www.foodstandards.gov.au/publications/Documents/27th%20ATDS%20report.pdf">at levels below concern</a>. </p>
<p>These findings would suggest PFAS contamination is not an issue at most farms in Australia. The risks are likely to be higher from food produced at PFAS-contaminated sites. At such locations, PFAS can affect a range of foods, including <a href="https://www.efsa.europa.eu/en/efsajournal/pub/6223">eggs, vegetables and livestock</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1571230263702683650"}"></div></p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/backyard-hens-eggs-contain-40-times-more-lead-on-average-than-shop-eggs-research-finds-187442">Backyard hens' eggs contain 40 times more lead on average than shop eggs, research finds</a>
</strong>
</em>
</p>
<hr>
<h2>What did the study investigate?</h2>
<p>We collated data from environmental investigations at ten PFAS-impacted farms in Victoria. This included testing about 1,000 samples of soil, water, pasture and livestock blood for concentrations of 28 types of PFAS. Our analysis also included information about farm practices, including livestock rotation, access to clean pasture and water. </p>
<p>We found:</p>
<ul>
<li><p>two specific PFAS compounds (PFOS and PFHxS) made up more than 98% of total PFAS detected in livestock blood</p></li>
<li><p>PFAS concentrations in water were correlated to concentrations in livestock blood, implying water was a critical exposure pathway, while the relationships between livestock and PFAS levels for soil and pasture were weaker</p></li>
<li><p>livestock exposure to PFAS varies over time and across paddocks. Seasonal patterns in PFAS blood concentrations were linked to seasonal grazing behaviours and the animals’ need for drinking water. </p></li>
</ul>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/515045/original/file-20230314-2603-vl3pg1.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Graphic showing how PFAS exposures in livestock vary according to farmland management practices" src="https://images.theconversation.com/files/515045/original/file-20230314-2603-vl3pg1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/515045/original/file-20230314-2603-vl3pg1.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=412&fit=crop&dpr=1 600w, https://images.theconversation.com/files/515045/original/file-20230314-2603-vl3pg1.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=412&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/515045/original/file-20230314-2603-vl3pg1.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=412&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/515045/original/file-20230314-2603-vl3pg1.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/515045/original/file-20230314-2603-vl3pg1.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/515045/original/file-20230314-2603-vl3pg1.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=518&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">PFAS exposures in livestock vary according to farmland management practices.</span>
<span class="attribution"><a class="source" href="https://doi.org/10.1016/j.envres.2023.115518">Mikkonen et al 2023</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>What’s the next step?</h2>
<p>Environment Protection Authority Victoria (EPA) is leading research and policy to understand how environmental PFAS risks can be better managed. In this regard, EPA along with research partners, is working to develop predictive models to estimate PFAS accumulation in livestock over their lifetime. This research will help determine when a site is too contaminated for livestock production and which ones to prioritise for PFAS remediation in soil and water.</p>
<p>Ultimately, this will allow more effective management of PFAS accumulation and reduce the likelihood of having PFAS for dinner.</p><img src="https://counter.theconversation.com/content/201553/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Antti Mikkonen is an employee of EPA Victoria, in the role of Principal Health Risk Advisor for chemicals. This work is part of Antti's PhD research at the University of South Australia where his candidature was supported by the Australian Government, Department of Education, Skills and Employment Research Training Program scholarship.</span></em></p><p class="fine-print"><em><span>Mark Patrick Taylor is a full-time employee of EPA Victoria, appointed to the statutory role of Chief Environmental Scientist. He is also an Honorary Professor at Macquarie University. </span></em></p>Most food in Australia remains free of PFAS, but a new study has found it can build up in cattle on PFAS-affected farms. But there are ways to manage the land and livestock to reduce the risks.Antti Mikkonen, Principal Health Risk Advisor – Chemicals, EPA Victoria, and PhD Candidate, School of Pharmacy and Medical Sciences, University of South AustraliaMark Patrick Taylor, Victoria's Chief Environmental Scientist, EPA Victoria; Honorary Professor, School of Natural Sciences, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1879052022-08-19T12:42:26Z2022-08-19T12:42:26ZWhat is listeria? A microbiologist explains the bacterium behind recent deadly food poisoning outbreaks<figure><img src="https://images.theconversation.com/files/479719/original/file-20220817-21-a18luh.jpg?ixlib=rb-1.1.0&rect=132%2C0%2C3875%2C2951&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Investigators in Florida traced a listeria outbreak to ice cream.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/ice-cream-jar-with-4-flavors-strawberry-vanilla-royalty-free-image/1279372828?adppopup=true">Graiki/Moment via Getty Images</a></span></figcaption></figure><p>Bacteria do, and will, end up in food. Everyone eats – intentionally or unintentionally – <a href="https://doi.org/10.7717/peerj.659">millions to billions</a> of live microbes every day. </p>
<p>Most are completely harmless, but some can cause serious illnesses in humans. Because of these potential pathogens, there is a long <a href="https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/pregnancy-nutrition/art-20043844">list of foods to avoid</a>, including uncooked eggs, raw fish and unwashed fruits and vegetables, particularly for pregnant women. The foods themselves are not bad, but the same cannot be said for certain bacterial passengers, such as <em>Listeria monocytogenes</em>, or listeria for short. </p>
<p>This particular pathogen has found ways to indiscriminately get into our foods. While deli and dairy foods like cold cuts, cheese, milk and eggs are frequently culprits for causing listeriosis – the general name for listeria-caused infections – fresh vegetables and fruits have also been implicated.</p>
<p>The variety of foods responsible for <a href="https://www.cdc.gov/listeria/outbreaks/index.html">U.S. listeria outbreaks in the past decade</a> shows just how easily these bacteria get around. Listeria has turned up in <a href="https://www.cdc.gov/listeria/outbreaks/eggs-12-19/index.html">hard-boiled eggs</a>, <a href="https://www.cdc.gov/listeria/outbreaks/enoki-mushrooms-03-20/index.html">enoki mushrooms</a>, <a href="https://www.cdc.gov/listeria/outbreaks/precooked-chicken-07-21/index.html">cooked chicken</a> and, <a href="https://www.cdc.gov/listeria/outbreaks/packaged-salad-12-21-b/index.html">in 2021, packaged salad</a> – <a href="https://www.cdc.gov/listeria/outbreaks/packaged-salad-mix-12-21/index.html">twice</a>.</p>
<p>Even the frozen aisle is not spared from listeria contamination. Contaminated ice cream in Florida was behind this year’s listeria outbreak, with 25 reported cases spanning 11 states since January 2021, according to <a href="https://www.cdc.gov/listeria/outbreaks/monocytogenes-06-22/details.html">an early August 2022 report</a> from the Centers for Disease Control and Prevention. Those who fell ill ranged in age from less than 1 to 92 years old, and 24 of the cases have involved hospitalizations.</p>
<p>How can such a tiny organism bypass extensive disinfection efforts and wreak such havoc? <a href="https://scholar.google.com/citations?user=G_tH2rUAAAAJ&hl=en">As a microbiologist</a> who has been working with listeria and trying to solve these mysteries, I’d like to share some insider secrets about this unique little pathogen and its strategies of survival inside and outside our bodies.</p>
<h2>Farm to table</h2>
<p>To prevent consumer exposure to listeria, the food industries follow <a href="https://www.fda.gov/files/food/published/Draft-Guidance-for-Industry--Control-of-Listeria-monocytogenes-in-Ready-To-Eat-Foods-%28PDF%29.pdf">stringent disinfection and surveillance guidelines</a> from the Food and Drug Administration and the U.S. Department of Agriculture. Any detection of listeria triggers a recall of potentially contaminated food products. </p>
<p>Since 2017, there have been <a href="https://www.fsis.usda.gov/recalls">over 270 listeria-related food recalls</a>. These are incredibly costly and can sometimes lead to fears in consumers <a href="https://www.npr.org/sections/thetwo-way/2018/01/29/581531318/panera-bread-recalls-cream-cheese-across-u-s-over-listeria-fears">as well as nationwide disruptions in food services</a>. However, the recalls represent one of the few tools that the food industry has to protect consumers from foodborne infections. </p>
<p>Not all listeria strains are created equal. <a href="https://doi.org/10.1016/j.ijmm.2010.05.002">Genetic variations</a> in listeria make a big difference in whether the pathogen ends up being involved in multistate outbreaks or simply hitching a ride harmlessly through our digestive tract. Essentially, based on the <a href="https://doi.org/10.1093/jaoac/85.2.524">different methods used</a>, listeria can be subtyped into different lineages, with some associated with outbreaks more frequently than others.</p>
<p>Researchers are investigating ways to tell these listeria strains apart, distinguishing the less harmful ones from those that are particularly dangerous, or hypervirulent. Being able to accurately identify them can help policymakers assess risks and make economically feasible decisions to improve food safety.</p>
<figure class="align-center ">
<img alt="Illustration of red-orange rod-shaped Listeria bacteria." src="https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3979&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/477025/original/file-20220801-70681-jygdr6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Listeria is an intracellular pathogen. Inside the body, it can grow inside a cell and spread to neighboring cells.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/listeria-monocytogenes-illustration-royalty-free-illustration/685023881">Kateryna Kon/Science Photo Library via Getty Images</a></span>
</figcaption>
</figure>
<h2>Listeria is tough</h2>
<p>Listeria can live in any place where food is grown, packaged, stored, transported, prepared or served. Our research team has even found listeria in <a href="https://doi.org/10.3390/pathogens7030060">organic lettuce harvested from a backyard garden</a>. </p>
<p>Listeria can survive and grow in temperatures as cold as <a href="https://ask.usda.gov/s/article/Can-Listeria-grow-at-refrigerator-temperatures">24 degrees Fahrenheit</a> (-4.4 Celsius) because it has <a href="https://doi.org/10.1080/10408390701856272">adapted to cold temperatures</a> and developed <a href="https://doi.org/10.4315/0362-028X-69.6.1473">tricks for overcoming cold stress</a>. Considering the average refrigerator maintains a temperature range of 35 F to 38 F (1.7 C to 3.3 C), even when the food is stored properly at refrigeration temperatures, a harmless few listeria can grow to dangerous levels of contamination over time.</p>
<p>Listeria is also extremely versatile in adapting to and surviving all kinds of disinfection processes. When it grows on surfaces, listeria protects itself with <a href="https://doi.org/10.3390%2Fpathogens6030041">a biofilm structure</a>, a kind of coating that forms a physical and chemical barrier and prevents disinfectants from reaching the bacteria within.</p>
<p>Surviving the harsh conditions outside our body is only the first part of the story. Before even beginning to cause infections, listeria needs to get to the intestines without getting caught and destroyed by the body’s defenses.</p>
<p>Traveling and surviving passage through a <a href="https://doi.org/10.3389%2Ffcimb.2014.00009">human digestive tract is not easy</a> for bacteria. Saliva enzymes can degrade bacterial cell walls. So can stomach acids and bile salts. Antibodies in our digestive tract can recognize and target bacteria for degradation. Moreover, <a href="https://doi.org/10.1084%2Fjem.20170495">resident gut microbes</a> are strong competitors for the limited amount of space and nutrients in our intestines.</p>
<p>After digestion, the body’s intestinal movement sends traffic one way – out of the body. In order to stick around and cause infections, bacteria have to attach themselves and hang on against the bowel movement while competing for nutrients. Successful pathogens can establish these survival and attachment tasks while undermining our immune defenses. </p>
<p>Listeria that manage to stick around in our intestines can trigger an immune response. In healthy people, that might manifest as <a href="https://www.cdc.gov/listeria/symptoms.html">minor diarrhea or vomiting that goes away without medical attention</a>. </p>
<p>However, those with compromised immune systems or immune systems temporarily weakened as a result of medication or <a href="https://doi.org/10.3389/fimmu.2020.575197">pregnancy</a> can be more susceptible to severe infections. In the absence of an effective immune system, listeria can invade other tissues and organs by creating an efficient niche for growth.</p>
<h2>Listeria in stealth mode</h2>
<p>Listeria is what we microbiologists call an intracellular pathogen. In an infected individual, listeria can grow inside a cell and <a href="https://doi.org/10.1083%2Fjcb.146.6.1333">spread to neighboring cells</a>. Hiding inside our cells this way, listeria avoids detection by antibodies or other immune defenses that are designed to detect and destroy threats that exist outside of our cells.</p>
<p>Once in stealth mode, listeria can move into and infect different organs. Wherever it goes, inflammation follows as the body’s immune system tries to go after the bacteria. The inflammation eventually results in collateral damage in nearby tissues. </p>
<p>In fact, deaths from listeria infections are often associated with the more invasive forms of the disease in which the microbes have breached the intestinal barriers and moved to other body parts. <a href="https://www.cdc.gov/listeria/symptoms.html">Life-threatening illnesses</a> that can result from listeria include meningitis – inflammation around the brain and spinal cord that can occur when these microbes infect the brain – or <a href="https://doi.org/10.1016/j.ijantimicag.2017.12.032">endocarditis</a>, infection of the heart’s inner lining. And in pregnant individuals, if the pathogen reaches the placenta, it can spread to the fetus and cause stillbirth or miscarriage.</p>
<p>As such, invasive listeria cases often have an alarmingly high <a href="https://www.fda.gov/animal-veterinary/animal-health-literacy/get-facts-about-listeria#">hospitalization rate of more than 90% and a fatality rate that can reach 30%</a>. </p>
<p>The scary statistics argue for a proactive and effective infection control to protect vulnerable populations, such as elderly or pregnant individuals, from listeria exposure. </p>
<h2>Think, cook and eat</h2>
<p>If you have risk factors and want to take extra precautions, maybe turn that unpasteurized cider into a hot, mulled cider to kill the bacteria with boiling and simmering. Eat soft cheeses on foods that get cooked, such as pizzas or grilled sandwiches, instead of eating them cold, straight from the refrigerator. Essentially, use heat to bring out the delicious flavors and eliminate potential listeria contamination in your food. </p>
<p>Ultimately, it’s nearly impossible to live in a completely sterile environment, eating food devoid of all living microorganisms. So enjoy your favorites, but <a href="https://www.fsis.usda.gov/food-safety">stay up to date with ongoing recalls</a> and follow the expiration guidelines, especially for ready-to-eat food.</p><img src="https://counter.theconversation.com/content/187905/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Yvonne Sun does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Listeria causes serious illness and food recalls nearly every year.Yvonne Sun, Assistant Professor of Microbiology, University of DaytonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1311552020-02-07T03:16:08Z2020-02-07T03:16:08ZChocolate contains cadmium that can increase cancer risk<figure><img src="https://images.theconversation.com/files/313664/original/file-20200205-149802-1gai64i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The amount of cadmium content in cocoa beans depends on the location and soil conditions where the chocolate plant is grown and type of chocolate plant itself.</span> <span class="attribution"><span class="source">iravgustin/Shutterstock</span></span></figcaption></figure><p>Children and adults all over the world love chocolate, either enjoying it by eating chocolate bars or sipping warm cocoa drinks. </p>
<p>But behind its delicious taste, cacao contains cadmium, a chemical substance <a href="https://www.who.int/water_sanitation_health/dwq/chemicals/cadmium.pdf">harmful to kidneys</a>. It also increases the <a href="https://www.who.int/water_sanitation_health/dwq/chemicals/cadmium.pdf">risk of cancer</a>. </p>
<p>If we compare it to other harmful heavy metals like <a href="https://www.who.int/news-room/fact-sheets/detail/arsenic">arsenic</a>, cadmium may not seem to be that bad. But, exposure to cadmium for a long time, even in small amounts, can be dangerous as it accumulates in the body. Our body needs <a href="https://www.sciencedirect.com/science/article/pii/S0041008X09001690">ten to thirty years to digest cadmium</a>.</p>
<p>This is why the European Commission last year decreased the safety threshold of the amount of cadmium in processed chocolate in the region. The <a href="https://ec.europa.eu/food/sites/food/files/safety/docs/cs_contaminants_catalogue_cadmium_chocolate_en.pdf">cadmium threshold</a> is between 0.1 and 0.8 milligrams per kilogram of chocolate, depending on the type of chocolate.</p>
<p>Dark chocolate, for instance, has a lower ceiling than milk chocolate. All chocolate imported to Europe have to comply with the limit. </p>
<p>Europe’s decision was <a href="https://www.chemistryworld.com/news/why-cadmium-is-a-problem-for-chocoholics/3009994.article">based on research that showed</a> even though cadmium exposure in adult non-smokers in the region is still below WHO’s upper limit, exposure through food in children reaches twice the safe limit.</p>
<p>Meanwhile in Indonesia, the maximum limit on cadmium is <a href="http://sertifikasibbia.com/upload/logam_berat.pdf">0.5 milligram per kilogram of chocolate and cacao product</a>. The amount is roughly the same as the new European regulation for processed chocolate with over 30% cacao. </p>
<h2>Cadmium levels</h2>
<p>Chocolate is not the only food that contains cadmium. But because chocolate is often consumed by people of all ages, including children, its amount of cadmium must be regulated. This chemical is often associated with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3248365/">bone density problems</a>. </p>
<p>Cadmium levels in processed chocolate on the market vary depending on the production process and the producers. </p>
<p>Generally, the cadmium rate in processed chocolate is minimal because of the mixing of raw chocolate with milk, sugar and syrup during production. The chocolate level in a product is between 10% (for milk chocolate) and 70-100% (for dark chocolate). However, if you eat too much chocolate for a long time, the cadmium amount in your body will increase.</p>
<p>A 2010 study on cadmium levels in chocolate powder from various countries showed chocolate powder from Venezuela <a href="https://www.tandfonline.com/doi/abs/10.1080/0265203031000077888">was up to 1.8 milligrams per kilogram of powder</a>. It’s higher than the European Commission standard. </p>
<p>Meanwhile, several studies on cadmium in processed chocolate in <a href="https://pubs.acs.org/doi/abs/10.1021/jf5026604">Brazil</a>, the <a href="https://www.tandfonline.com/doi/full/10.1080/19393210.2017.1420700">United States</a> and <a href="https://www.sciencedirect.com/science/article/pii/S0889157504000900">India</a> concluded the level of cadmium was under the safety limit. </p>
<p>Even in chocolate containing 100% chocolate, some processing has been carried out. Mixing cocoa beans from several sources, for example, can reduce the levels of cadmium in processed chocolate. The amount of cadmium content in cacao beans <a href="https://ec.europa.eu/food/sites/food/files/safety/docs/cs_contaminants_catalogue_cadmium_chocolate_en.pdf">depends on the location and soil conditions where the chocolate plant is grown</a>, as well as on the type of the chocolate plant itself.</p>
<p>WHO only has a limit on the amount of cadmium for dried cacao beans – <a href="https://www.berkeleywellness.com/healthy-eating/food-safety/article/there-cadmium-your-cocoa">0.3 milligrams per kg</a>. The maximum level of cadmium that can be tolerated by the human body, according to WHO, is <a href="https://iopscience.iop.org/article/10.1088/1755-1315/259/1/012005/pdf">0.025 milligrams per kg of body mass</a>. This is equivalent to 1.25 milligrams of cadmium for a person with a body weight of 50 kilograms per month.</p>
<p>By the WHO’s standard, it is potentially dangerous for a person who weighs 50 kilograms to consume more than 12.5 kilograms of 30% cocoa processed chocolate, that is under the European Commission’s ceiling, in a month; or to consume 2.5 kilograms of processed chocolate according to Indonesia’s ceiling.</p>
<h2>Cadmium exposure</h2>
<p>Exposure to excessive cadmium through food has <a href="https://www.who.int/water_sanitation_health/dwq/chemicals/cadmium.pdf">a significant effect on kidney health</a>, disrupting <a href="https://mcb.berkeley.edu/courses/mcb135e/kidneyprocess.html">reabsorption (such as the reabsorption of protein salt the body still needs)</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5596182/">in the kidney’s</a> filtering unit.</p>
<p>Apart from food, cadmium exposure through <a href="https://www.who.int/water_sanitation_health/dwq/chemicals/cadmium.pdf">air is known to increase cancer risk</a>, causing <a href="https://occup-med.biomedcentral.com/articles/10.1186/1745-6673-1-22">shortness of breath, lung irritation and mucous membrane damage</a>. Cadmium exposure through the air in daily life, for example, occurs <a href="https://err.ersjournals.com/content/27/147/170122.short">through cigarette smoke</a>.</p>
<p>In the 1960s, Japan experienced cadmium contamination in its water. <a href="https://link.springer.com/article/10.1007/BF00381306">A study of a decades-long strange illness</a> in residents in Toyama Prefecture reveals “itai-itai” disease, caused by heavy metal pollution, especially cadmium, from mines in the upper reaches of the Jinzu River. <a href="https://www.who.int/water_sanitation_health/dwq/chemicals/cadmium.pdf">Itai-itai disease is marked</a> by bone softening, bone loss and kidney damage.</p>
<p>People with this disease complain of pain in the spine and joints due to reduced bone density associated with the toxic effects of cadmium. However, keep in mind this is an extreme case caused by chronically large amounts of cadmium poisoning.</p>
<h2>Why does food contain cadmium</h2>
<p>Plants can absorb and accumulate cadmium from water in the soil.</p>
<p>Chocolate plants can absorb cadmium through its roots and store it in chocolate leaves and seeds. This absorption can be influenced by <a href="https://ief.ee.ethz.ch/content/main/en/news-and-events/eth-news/news/2016/11/cadmium-cocoa-beans-and-chocolate.html">soil acidity and the amount of cadmium available in the soil</a>.</p>
<p>Therefore, geographical location can affect the cadmium content in plants. Volcanic soils, for instance, can contain higher amounts of cadmium. Environmental pollution and excessive use of fertilisers containing cadmium are also <a href="http://ejournal.forda-mof.org/ejournal-litbang/index.php/JKLH/article/view/4911/4371">factors affecting cadmium levels in the soil</a>.</p>
<p>In the case of itai-itai disease in Japan, cadmium in wastewater from mines flows and pollutes water sources used for irrigation by residents. Water pollution also pollutes aquatic ecosystems such as rivers and seas.</p>
<p>In addition to preventive action, remediation is <a href="https://publikasiilmiah.ums.ac.id/xmlui/bitstream/handle/11617/9326/fix%20prosiding%20SNPBS%202017%20Final%20Akhir%20fix%20deal%2023%20AGUSTUS_p188-p198.pdf?sequence=1&isAllowed=y">one of the solutions to reduce levels of cadmium in the environment</a>.</p>
<h2>Reducing cadmium exposing</h2>
<p>The easiest way to reduce the risk of cadmium exposure in everyday life is to avoid materials that have the potential to contain large amounts of it.</p>
<p>For example, you should limit consumption of chocolate, <a href="https://www.republika.co.id/berita/nasional/daerah/18/02/27/p4t1m9335-rentetan-kejadian-keracunan-penyu-di-mentawai">shellfish taken from contaminated waters</a> and <a href="https://www.popsci.com/heavy-metals-baby-food/">plants harvested from contaminated soil</a>. You should stop smoking and keep away from secondhand smoke exposure to avoid cadmium through the air.</p>
<p>Environmental pollution causes a high amount of cadmium in various foods. Therefore, the most appropriate way to reduce cadmium exposure is to protect the environment from the potential for cadmium pollution.</p>
<p>Disposing of NiCd (nickel-cadmium) batteries properly, using fertilisers that contain cadmium at appropriate levels, and monitoring the content of cadmium in the environment around waste disposal are some examples of preventive measures that can reduce exposure to cadmium in the community.</p><img src="https://counter.theconversation.com/content/131155/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mila Sari tidak bekerja, menjadi konsultan, memiliki saham, atau menerima dana dari perusahaan atau organisasi mana pun yang akan mengambil untung dari artikel ini, dan telah mengungkapkan bahwa ia tidak memiliki afiliasi selain yang telah disebut di atas.</span></em></p>Chocolate plants can absorb cadmium through their roots and store it in chocolate leaves and seeds. Cadmium levels in processed chocolate depending on the production process and the producers.Mila Sari, PhD Researcher in Chemistry, University of HullLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1035162018-09-26T20:13:42Z2018-09-26T20:13:42ZGrowers are in a jam now, but strawberry sabotage may well end up helping the industry<figure><img src="https://images.theconversation.com/files/238031/original/file-20180926-149982-bjbiyk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">original</span> </figcaption></figure><p>Is it act of malicious stupidity or evil genius? The strawberry sabotage crisis is no doubt hurting individual growers in the short term, but in the long term it may prove a huge win for the industry. </p>
<p>Few crimes are as easy to commit, yet so seriously endanger public safety and threaten such commercial damage, as <a href="https://foodmag.com.au/thinking-the-unthinkable-product-contamination-risk-and-response/">malicious food tampering</a>.
The perpetrators’ motivation is typically to create fear and hurt a company or industry. Yet history illustrates that, over time, the opposite occurs. </p>
<p>This crisis began in early September with the discovery of sewing needles embedded in strawberries bought at <a href="http://www.abc.net.au/news/2018-09-12/strawberry-investigation-after-sewing-needles-found-inside/10237954">a Woolworths store in Brisbane</a>. What started as an isolated incident thought to involve a disgruntled employee at one Queensland farm quickly turned to national crisis. Consumers were <a href="https://www.health.qld.gov.au/news-alerts/doh-media-releases/releases/contaminated-strawberries-queensland-update-5">advised</a> to dispose of, or return strawberries bought from supermarkets in Queensland, New South Wales and Victoria. Then needles showed up in strawberries <a href="http://www.abc.net.au/news/2018-09-17/wa-has-first-reported-strawberry-contamination-case/10257554">in Western Australia</a> <a href="https://thenewdaily.com.au/money/consumer/2018/09/16/needles-in-strawberries-south-australia/">and Tasmania</a>. Within a week, dozens of cases of fruit contamination had been reported around the country, <a href="https://www.theage.com.au/national/queensland/new-zealand-supermarket-withdraws-australian-strawberry-brand-over-needles-20180923-p505j4.html">as well as in New Zealand</a>. </p>
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Read more:
<a href="https://theconversation.com/strawberry-sabotage-what-are-copycat-crimes-and-who-commits-them-103423">Strawberry sabotage: what are copycat crimes and who commits them?</a>
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<h2>Product tampering’s long and pointless history</h2>
<p>One of the earliest recorded incidents of product tampering was in 1982. Seven people in Chicago died after taking tablets of <a href="https://www.pbs.org/newshour/health/tylenol-murders-1982">Tylenol laced with potassium cyanide</a>. Though a man was convicted of attempting to extort US$1 million from Tylenol’s maker, Johnson & Johnson, he was never charged over the deaths. </p>
<p>Johnson & Johnson <a href="https://www.ou.edu/deptcomm/dodjcc/groups/02C2/Johnson%20&%20Johnson.htm">responded to the crisis quickly</a>. It withdrew more than 30 million bottles of the medication, advertised widely to warn consumers of the danger, suspended production and changed its packaging to make it tamper-proof. It cost the company more than US$100 million. But its commitment to customers’ safety ended up enhancing <a href="https://bizgovsocfive.wordpress.com/2012/11/14/social-and-economic-benefits-can-a-company-do-both/">its brand reputation</a>. Tylenol regained its market share within a year. </p>
<p>There have also been attempts to hold pharmaceutical companies to ransom in Australia. In 2000, paracetamol capsules made by Herron Pharmaceuticals were <a href="http://www.abc.net.au/pm/stories/s225830.htm">laced with strychnine</a>. Following Johnson & Johnson’s example, Herron immediately pulled the product from store shelves.
A few months later SmithKline Beecham International (now GlaxoSmithKline) <a href="https://www.icis.com/resources/news/2000/06/06/113788/australia-sbi-recalls-panadol-capsules-on-extortion-threat/">was threatened</a>. It recalled its best-selling Panadol paracetamol capsules as a precaution. In both cases public trust in each company was enhanced. </p>
<h2>Food scares make hearts grow fonder</h2>
<p>If extortion is the motivation, threatening a pharmaceutical company has some logic. Contaminating food seems to make less sense.</p>
<p>In 1977 Australia’s biggest biscuit maker, Arnott’s, dumped $10 million of biscuits due to the threat of poisoned biscuits. In this case, bizarrely, the extortionists were demanding a convicted criminal be released from prison. </p>
<p>In 2007, Masterfoods pulled Mars and Snickers chocolate bars from the shelves due to fears <a href="http://www.abc.net.au/am/content/2005/s1405381.htm">some might have been poisoned</a>.</p>
<p>In both cases, by acting quickly and following textbook <a href="http://www.ethics.org.au/on-ethics/blog/august-1997/arnott-s-doesn-t-crumble-under-pressure">crisis management</a> – protect customers first, brand second and shareholder interest third – neither company suffered long-term damage. Australians continue to buy their biscuits and bars by the millions.</p>
<p>In every case, history illustrates the targets of product contamination bounce back, often with sales even stronger than before.</p>
<p>There is good reason to believe, therefore, that the enduring result of the strawberry contamination crisis is that Australians will grow fonder of the fruit. </p>
<h2>How consumers respond to group trauma</h2>
<p>Research suggests there is a four-stage pattern of social behaviour after traumatic social events, such as a natural disaster or <a href="http://journals.sagepub.com/doi/10.1111/j.1467-9558.2004.00204.x">terrorist act</a>. </p>
<ul>
<li><p>first, a few days of shock and idiosyncratic individual reactions to attack</p></li>
<li><p>second, one to two weeks of establishing standardised displays of solidarity</p></li>
<li><p>third, two to three months of high solidarity</p></li>
<li><p>fourth, a gradual decline toward normalcy in six to nine months. </p></li>
</ul>
<p>The <a href="http://www.abc.net.au/news/2018-09-19/social-media-shares-strawberry-recipes-after-needle-scare/10280260">“cut them up, don’t cut them out”</a> pro-strawberry campaign fits into the second stage. What we are observing now is a move into a phase of strong national consumer solidarity.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/video-michelle-grattan-on-strawberries-sudmalis-schools-and-the-au-pair-affair-103685">VIDEO: Michelle Grattan on strawberries, Sudmalis, schools, and the au pair affair</a>
</strong>
</em>
</p>
<hr>
<p>While strawberry growers suffered a few weeks of devastating losses, <a href="http://www.abc.net.au/news/rural/2018-09-21/strawberry-sales-bounce-back-consumers-support-farmers/10289856">sales have bounced back quickly</a>. In some cases people are making a concerted effort to <a href="https://www.moreechampion.com.au/story/5657013/queenslanders-turn-out-in-droves-to-support-strawberry-farmers/">buy even more strawberries</a> than they would have.</p>
<h2>An outpouring of strawberry solidarity</h2>
<p>Already searches for the recipes using strawberries have risen markedly on the popular <a href="https://www.sunshinecoastdaily.com.au/news/strawberries-soar-in-popularity-despite-contaminat/3527031/">cooking website taste.com.au</a>. Social media hashtags #SmashaStrawb and #saveourstrawberries have trended. Celebrities and politicians have appeared in the media happily eating strawberries. Media outlets are hosting <a href="http://www.abc.net.au/radio/brisbane/ekka-strawberry-sundae-fundraiser-for-our-farmers/10287386">special awareness and fundraising events</a>.</p>
<p>Strawberry festivals are attracting strong crowds <a href="https://thewest.com.au/news/fremantle/city-of-fremantle-to-host-strawberry-sunday-festival-to-support-growers-amid-needle-crisis-ng-b88966734z">from Fremantle</a> to <a href="http://www.abc.net.au/news/2018-09-23/strawberry-celebration-in-time-of-crisis/10294122">Bundaberg in Queensland</a> Farmers have opened their gates to families wanting to <a href="https://thewest.com.au/business/agriculture/strawberry-needle-crisis-perths-pick-your-own-strawberry-farms-attract-huge-crowds-ng-b88969467z">pick their own fruit</a>.
This is the sort of emotional connection other primary producers can only dream about. It helps that strawberry farms are generally close to towns and cities, and that you don’t need to climb or dig to harvest the fruit. </p>
<p>Because we are creatures of habit – the reason we return so quickly to <a href="https://www.nytimes.com/2010/12/05/business/05metricstext.html">buying products after a contamination scare</a> – there is a good chance this enthusiasm for strawberries, if sustained for a few months, will translate into higher habitualised consumption in the longer term. </p>
<p>So if the intention of the original strawberry saboteur was to damage a specific strawberry grower, it is likely to prove an intensely stupid scheme. On the other hand, as a perverse act of strategic marketing it has a touch of evil genius.</p><img src="https://counter.theconversation.com/content/103516/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>History shows the targets of product tampering bounce back, often with sales stronger than before.Gary Mortimer, Associate Professor in Marketing and International Business, Queensland University of TechnologyLouise Grimmer, Lecturer in Marketing, Tasmanian School of Business and Economics, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/926512018-03-01T06:10:23Z2018-03-01T06:10:23ZWhat is listeria and how does it spread in rockmelons?<figure><img src="https://images.theconversation.com/files/208403/original/file-20180301-36693-16m2x6y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Ten cases have been reported so far, including two deaths. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/1034959780?src=M8OlxeHD5z7h4Kw2RVyVVA-1-72&size=huge_jpg">Shutterstock/Doug J Moore</a></span></figcaption></figure><p>Two people have died after eating rockmelon (cantaloupe) contaminated with listeria. A total of <a href="http://www.abc.net.au/news/rural/2018-02-28/two-dead-national-rockmelon-listeria-outbreak/9494576">ten cases have been confirmed</a> in New South Wales, Queensland and Victoria between January 17 and February 9, and more are expected. </p>
<p>Listeriosis is caused by eating food contaminated with a bacterium called <em>Listeria monocytogenes</em>. It’s an <a href="http://www.health.nsw.gov.au/Infectious/factsheets/Pages/listeriosis.aspx">uncommon illness</a> but can be deadly if it causes septicaemia (blood poisoning) or meningitis (inflammation of the membranes around the brain). </p>
<p>The ten reported cases are among people aged over 70. The elderly are <a href="http://www.foodstandards.gov.au/consumer/safety/listeria/Pages/default.aspx">particularly susceptible</a> to listeriosis, as are pregnant women and their fetuses, and those with weakened immune systems.</p>
<p>Past outbreaks <a href="http://www.health.nsw.gov.au/Infectious/factsheets/Pages/listeriosis.aspx">have been linked with</a> raw milk, soft cheeses, salads, unwashed raw vegetables, cold diced chicken, pre-cut fruit and fruit salad.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/understanding-the-recent-listeria-linked-cheese-recall-12213">Understanding the recent listeria-linked cheese recall </a>
</strong>
</em>
</p>
<hr>
<h2>How does it spread?</h2>
<p>Listeria is found widely in soil, water and vegetation, and can be carried by pets and wild animals. </p>
<p>A vegetable or fruit food product can become contaminated anywhere along the chain of food production: planting, harvesting, packing, distribution, preparation and serving. </p>
<p>Even on a farm, sources of contamination can include irrigated waters, wash waters and soil. Listeria <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0075969">can survive</a> for up to 84 days in some soils.</p>
<p>Heavy rains on a crop can splash listeria from soils onto the surface or skin of the vegetable, especially those that grow low to the ground, such as rockmelons. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/scary-berries-how-food-gets-contaminated-and-what-to-do-37629">Scary berries: how food gets contaminated and what to do</a>
</strong>
</em>
</p>
<hr>
<p>Listeria contamination can also occur in restaurants and home kitchens, where the bacterium can be found – and spread – in areas where foods are being handled. </p>
<p><em>Listeria monocytogenes</em> is quite a hardy bacterium. It <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3913888/">can survive</a> at refrigerated temperatures and has adapted mechanisms to survive acidic environments such as the stomach.</p>
<h2>What are the symptoms?</h2>
<p>First, it’s important to note that eating foods that contain listeria bacteria <a href="http://www.foodstandards.gov.au/publications/pages/listeriabrochuretext.aspx">won’t necessarily make you sick</a>.</p>
<p><em>Listeria monocytogenes</em> can survive in the body, moving between cells (human phagocytes) for a long time. This is, in part, why there can be a long “incubation period” between ingestion and onset of illness. This <a href="https://www.ncbi.nlm.nih.gov/pubmed/3137471">can be as long as 70 days</a> but is usually around three weeks.</p>
<p>Symptoms include fever, muscle aches and gastrointestinal problems such as nausea, vomiting and diarrhoea. </p>
<p>In severe cases, symptoms can include collapse and shock, particularly if there is septicaemia. If the infection has spread to the central nervous system, more worrying symptoms will occur, such as headache, stiff neck, confusion, seizures and the person may go into a coma. In such cases, the fatality rate is <a href="https://www2.health.vic.gov.au/public-health/infectious-diseases/disease-information-advice/listeriosis">as high as 30%</a>.</p>
<p>In pregnant women, the bacteria are <a href="https://www.ncbi.nlm.nih.gov/pubmed/22417207">thought to</a> cross the lining of maternal blood vessels and then enter the fetal circulation of the placenta. Infection during pregnancy <a href="http://www.sahealth.sa.gov.au/wps/wcm/connect/Public+Content/SA+Health+Internet/Health+topics/Health+conditions+prevention+and+treatment/Infectious+diseases/Listeria+infection/">can lead to</a> miscarriage, stillbirth and newborn infections. </p>
<p>Treatment for confirmed infections involves <a href="https://www.ncbi.nlm.nih.gov/pubmed/10852095">antibiotics</a> and supportive measures such as intravenous fluids for dehydration. </p>
<p>When infection does occur in pregnancy, the early use of antibiotics can often prevent infection of the fetus or newborn. </p>
<p>But even with very prompt treatment, infections can be deadly in high-risk groups.</p>
<h2>Why are some groups at higher risk?</h2>
<p>Pregnant women are a special group known to be at higher risk for listeriosis. The underlying mechanisms for why pregnant women are susceptible to listeriosis <a href="https://www.ncbi.nlm.nih.gov/pubmed/28398675">are not well understood</a> but it’s thought an altered immune system is involved. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-to-keep-school-lunches-safe-in-the-heat-89868">How to keep school lunches safe in the heat</a>
</strong>
</em>
</p>
<hr>
<p>People with weakened immune systems, such as those on cancer treatment or medications that suppress the immune system, are more susceptible to developing listeriosis because their bodies are less able to fight off the bug. </p>
<p>Newborn babies are also extremely vulnerable as their immune systems have not yet matured, as are the elderly, whose immune systems are declining. </p>
<h2>Tracking and finding the source</h2>
<p>The <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3562139/">life cycle of the bacteria</a> can make it difficult to track the source of the outbreak. Listeria is able to contaminate a variety of foods, which may have a long shelf life, and listeriosis has a long incubation period. </p>
<p>All ten people in the current outbreak <a href="http://www.abc.net.au/news/rural/2018-02-28/two-dead-national-rockmelon-listeria-outbreak/9494576">consumed rockmelon</a> before they fell sick and state and territory health departments were able to pinpoint the source to a farm in the NSW Riverina district. </p>
<p>But it’s not always that easy. The current <a href="http://www.foodsafetynews.com/2018/01/south-africa-hit-by-deadliest-listeriosis-outbreak-in-history/">South African listeriosis outbreak</a> is the worst outbreak in recorded history with <a href="http://ewn.co.za/2018/02/28/listeriosis-outbreaks-difficult-to-investigate-says-nicd">172 deaths recorded to date</a>. The source has not yet been identified. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-we-can-prevent-more-listeria-deaths-91475">How we can prevent more Listeria deaths</a>
</strong>
</em>
</p>
<hr>
<h2>How can you prevent listeriosis?</h2>
<p>Here are some <a href="http://www.health.nsw.gov.au/Infectious/factsheets/Pages/listeriosis.aspx">practical things</a> you can do to prevent the spread of listeria:</p>
<ul>
<li>thoroughly cook raw food from animal sources, such as beef, lamb, pork and poultry</li>
<li>wash raw vegetables and fruit thoroughly before eating</li>
<li>use separate cutting boards for raw meat and foods that are ready to eat </li>
<li>wash your hands with soapy water before and after preparing food</li>
<li>wash knives and cutting boards after handling uncooked foods</li>
<li>wash your hands after handling animals.</li>
</ul>
<p>If you are at greater risk for listeriosis, consider <a href="http://www.health.nsw.gov.au/news/Pages/20180223_01.aspx">avoiding</a>:</p>
<ul>
<li>pre-cut melons such as rockmelon or watermelon</li>
<li>pre-packed cold salads including coleslaw and fresh fruit salad</li>
<li>pre-cooked cold chicken, cold delicatessen meats, pâté</li>
<li>raw and uncooked smoked seafood (such as smoked salmon)</li>
<li>unpasteurised milk or milk products, soft cheeses (such as brie, camembert, ricotta or blue-vein)</li>
<li>sprouted seeds</li>
<li>raw mushrooms.</li>
</ul>
<p>The NSW Food Authority is also <a href="http://www.foodauthority.nsw.gov.au/news/newsandmedia/departmental/2018-02-28-listeriosis-outbreak-link-to-rockmelon">advising consumers who are most at risk</a> of listeriosis to avoid eating rockmelon and discard any rockmelon they already have at home.</p><img src="https://counter.theconversation.com/content/92651/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Vincent Ho does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Two people have died after eating rockmelon contaminated with listeria. A total of ten cases have been confirmed in NSW, Queensland and Victoria between Jan 17 and Feb 9, and more are expected.Vincent Ho, Senior Lecturer and clinical academic gastroenterologist, Western Sydney UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/902302018-01-22T22:27:33Z2018-01-22T22:27:33ZEverything you need to know about fresh produce and E. coli<figure><img src="https://images.theconversation.com/files/202669/original/file-20180120-110094-se5g8w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A worker harvests romaine lettuce in Salinas, Calif. </span> <span class="attribution"><span class="source">(AP Photo/Paul Sakuma)</span></span></figcaption></figure><p>While the recent outbreak of <em>E. coli</em> infections linked to romaine lettuce <a href="https://www.canada.ca/en/public-health/services/public-health-notices/2017/public-health-notice-outbreak-e-coli-infections-linked-romaine-lettuce.html">has been declared over</a>, Canadian public health officials are still working to determine the cause of the contamination.</p>
<p><a href="https://www.nytimes.com/2018/01/05/health/e-coli-romaine-lettuce.html">Several people in the U.S. and eastern Canada</a> were sickened after eating romaine, with two reported deaths.</p>
<p>I am a food safety expert. Here’s what consumers need to know about <em>E. coli</em> and produce:</p>
<h2>Why produce and why E. coli?</h2>
<p><a href="https://www.cdc.gov/ecoli/general/index.html"><em>E. coli</em> are bacteria</a> that live naturally in the intestines of cattle, poultry and other animals. For the most part, they co-exist with these animals, and hence they don’t become sick.</p>
<p>Most of the <em>E. coli</em> strains associated with humans are harmless, and, in fact, are an important part of a healthy human intestinal tract. However, some <em>E. coli</em> strains are pathogenic, meaning they can cause human illness. Pathogenic <em>E. coli</em> that can cause diarrhea can be transmitted through contaminated water or food, or through contact with animals or people.</p>
<h2>How does produce become contaminated?</h2>
<p>There are many different ways that produce can become contaminated. Firstly, in the farmer’s field, it can become contaminated with pathogenic <em>E. coli</em> through direct contact with animal feces.</p>
<p>For example, wild animals, like feral pigs and deer rummaging through farm fields, have previously been found to be linked to cases of illness due to spinach and strawberries, respectively. </p>
<p>In fact, any time produce in the field makes contact with animal feces, it could lead to the contamination of that produce with a pathogen. Contaminated irrigation water, bird feces or improperly composted manure are other potential sources of pathogenic bacteria. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/202853/original/file-20180122-182976-1otuvae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/202853/original/file-20180122-182976-1otuvae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202853/original/file-20180122-182976-1otuvae.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202853/original/file-20180122-182976-1otuvae.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202853/original/file-20180122-182976-1otuvae.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=507&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202853/original/file-20180122-182976-1otuvae.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=507&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202853/original/file-20180122-182976-1otuvae.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=507&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A red-winged blackbird rests on the head of a deer as it looks up from grazing in a sun-drenched farmer’s field in Vermont in 2011.</span>
<span class="attribution"><span class="source">(AP Photo/Toby Talbot)</span></span>
</figcaption>
</figure>
<p>Once produce is sent from the farmers’ fields to processing plants, there are other potential sources of microbial contamination, including the water used to wash the produce and the equipment used to cut up the leafy greens. </p>
<p>Further along the food chain, at the retail store, if the produce is not bagged, there is also the chance for cross-contamination in the store from raw foods — for example, from cutting boards and counters that have been in contact with raw meat, and which haven’t been properly disinfected between uses. </p>
<h2>More produce-related outbreaks now?</h2>
<p>It appears that there are now more cases of illness due to produce. There are a few reasons for this.</p>
<p>Firstly, there has been a large increase in the sale of bagged greens and salad kits as consumers are making an effort to try to eat more fruits and vegetables.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/202671/original/file-20180120-110113-fvw7m8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202671/original/file-20180120-110113-fvw7m8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202671/original/file-20180120-110113-fvw7m8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202671/original/file-20180120-110113-fvw7m8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202671/original/file-20180120-110113-fvw7m8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202671/original/file-20180120-110113-fvw7m8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202671/original/file-20180120-110113-fvw7m8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A grocery store worker stocks prepackaged salads at a Toronto shop.</span>
<span class="attribution"><span class="source">(CP PHOTO/Frank Gunn)</span></span>
</figcaption>
</figure>
<p>Secondly, we’re getting much better at detecting and stopping food-borne outbreaks in their tracks due to a new molecular typing technique referred to as <a href="https://www.fda.gov/Food/FoodScienceResearch/WholeGenomeSequencingProgramWGS/">whole genome sequencing (WGS)</a>, which is a much more sensitive typing method than ones public health officials have been using. </p>
<p>WGS identifies pathogens isolated from food or environmental samples. These can then be compared to clinical samples isolated from patients. </p>
<p>The technology has proven to be extremely valuable in making a link between a food-borne illness and a contaminated food. Previously, outbreaks caused by contaminated produce were either missed, or a food product could not be linked to illnesses because of the poor sensitivity of the typing method. Thanks to WGS, those links are now more quickly identified and tied to a specific fruit or vegetable.</p>
<h2>Trace an outbreak back to a certain farm</h2>
<p>In some cases, it may be straightforward to trace a contaminated produce item back to a certain field or farm. However, in other cases, because of the complex distribution systems, there may be a co-mingling of products from many different farms going into one central farm distribution centre, which then ships products to Canada. </p>
<p>This can make it extremely difficult to trace a product back to its source. </p>
<p>A lot of progress, however, has been made toward the ambitious goal of being able to quickly trace contaminated produce back to its field of origin. One example of this is the <a href="https://www.producetraceability.org/">Produce Traceability Initiative</a>, an organization sponsored by North American produce associations that helps the industry track fruits and vegetables.</p>
<h2>Why no romaine recall?</h2>
<p>In the most recent outbreak, there was epidemiological evidence collected initially that found an association between the human cases and the consumption of romaine lettuce. </p>
<p>However, in spite of all the evidence that was gathered during the outbreak in Canada, no common supplier, distributor or retailer of romaine lettuce was identified <a href="https://consumersunion.org/news/cu-urges-health-officials-to-take-more-aggressive-steps-to-identify-source-of-e-coli-outbreak-as-cdc-reports-more-illnesses/">as a possible source of the outbreak. </a></p>
<p>In fact, people reported eating romaine lettuce at home, restaurants, fast-food chains and from prepared salads bought at grocery stores, further complicating the picture. </p>
<p>In addition, all test samples of romaine lettuce in question were negative. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/202855/original/file-20180122-182955-s9ebqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/202855/original/file-20180122-182955-s9ebqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202855/original/file-20180122-182955-s9ebqg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202855/original/file-20180122-182955-s9ebqg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202855/original/file-20180122-182955-s9ebqg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202855/original/file-20180122-182955-s9ebqg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202855/original/file-20180122-182955-s9ebqg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In the e. Coli recent outbreak, those who became ill reported eating romaine lettuce at home, in restaurants and at fast-food outlets.</span>
<span class="attribution"><span class="source">(AP Photo/Matthew Mead)</span></span>
</figcaption>
</figure>
<p>It therefore becomes difficult for regulatory agencies to do a recall when they can’t pinpoint the actual origin of the product. Further complicating the issue is lettuce’s relatively short shelf life. In most cases much of the product that caused the illnesses has already been consumed or spoiled, and so isn’t available for tracing information or microbiological analysis.</p>
<p>Furthermore, regulatory agencies don’t want to issue a recall too quickly because of public pressure. </p>
<p>For example, in the late 1990s, a big food-borne outbreak occurred due a protozoan parasite called <em>Cyclospora</em>, and the outbreak was quickly blamed on Californian strawberries. </p>
<p>However, the outbreak was later linked to <a href="http://www.foodsafetynews.com/2013/07/last-big-cyclospora-outbreak-was-traced-to-guatemalan-raspberries/#.WmSjIbQ-fq0">Guatemalan raspberries</a>. The mistake caused the California strawberry industry millions of dollars. </p>
<h2>Did Canadian health officials do the right thing?</h2>
<p>On Dec. 11, 2017, officials at the Public Health Agency of Canada said that they were investigating the outbreak of <em>E. coli</em> 0157 linked to the consumption of romaine lettuce, which was occurring in three provinces. </p>
<p>On Dec. 14, the notice was updated to include two additional provinces, Ontario and Nova Scotia, which had reported illnesses linked to the outbreak, bringing the total number of cases to 30 cases, including one death.</p>
<p>On Dec. 21, the notice was updated to include 10 additional cases (a total of 40 cases) and advised consumers in Ontario, Quebec, New Brunswick, Nova Scotia and Newfoundland and Labrador that they should consider consuming other types of lettuce instead of romaine until more was known about the outbreak and the cause of contamination.</p>
<p>Furthermore, on Dec. 28, the notice was again updated to include one additional case, and stated that there is still an ongoing risk of <em>E. coli</em> infections associated with the consumption of romaine lettuce in Canada’s eastern provinces.</p>
<p>Finally, on Jan. 10 of this year, <a href="https://www.theglobeandmail.com/news/national/e-coli-outbreak-linked-to-romaine-lettuce-appears-to-be-over-health-agency/article37568371/">federal officials put out a notice stating that the outbreak appeared to be over</a> and that the overall risk to Canadians had returned to low. At this point, they were no longer advising individuals in affected provinces to avoid romaine lettuce.</p>
<p>Thus, consumers in Canada’s eastern provinces were told for about 20 days not to eat romaine, and it took about 10 days from the start of the outbreak until they were told this. </p>
<p>Is this a reasonable time period? Should there have been a recall of romaine lettuce in the affected provinces? </p>
<p>I think so. </p>
<p>Some stores pulled romaine lettuce and others kept it on the shelves, confusing the consumer. </p>
<p>This outbreak in particular would benefit from a post-mortem analysis to see what, if anything, could have been done better and what consumers truly understood in light of all the warnings and social media chatter.</p>
<h2>Should consumers wash their pre-washed bags of produce?</h2>
<p>Consumers do not need to wash their packaged triple-washed bags of leafy greens, and can actually make things worse if they do, as during the course of washing, they can cross-contaminate the product. </p>
<p>If consumers feel better doing the extra wash, they should use safe-handling practices to avoid any cross-contamination. Start with hand-washing for 20 seconds with warm water and soap before and after handling the product.</p>
<p>Then it’s critical that consumers wash their cutting boards before using (of course as well as dishes, salad spinners, utensils, and countertops) to avoid cross-contamination between, for example, raw meats and ready-to-eat leafy greens. Plastic cutting boards can be placed in the dishwasher to be disinfected. </p>
<p>When you’re washing your cutting board by hand, you should first rinse off any visible debris and then scrub the cutting board with soap and water. Finally, you should <a href="http://www.eatright.org/resource/homefoodsafety/four-steps/wash/safe-care-and-washing-of-cutting-boards">be sanitizing the cutting board.</a></p>
<p>Bagged leafy greens should of course also be refrigerated, and consumers should consume the product before its best-before date. </p>
<h2>Reducing consumer risk</h2>
<p>Firstly, consumers should buy their produce from reputable retail operations. </p>
<p>When shopping, keep your fruits and vegetables separated from raw meat, poultry and fish to prevent cross-contamination</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/202672/original/file-20180120-110121-s2ih6w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/202672/original/file-20180120-110121-s2ih6w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202672/original/file-20180120-110121-s2ih6w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202672/original/file-20180120-110121-s2ih6w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202672/original/file-20180120-110121-s2ih6w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202672/original/file-20180120-110121-s2ih6w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202672/original/file-20180120-110121-s2ih6w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Wash your produce under running water.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>At home, store your fruits and vegetables in the refrigerator in a produce drawer separate from the raw meat, poultry or fish. Follow the aforementioned washing techniques.</p>
<p>Wash your hands with hot, soapy water for at least 20 seconds before and after handling fresh fruits and vegetables, and wash them well under running water (do not use soap or chemicals), including those that come from farmers’ markets, roadside stands or your home garden.</p><img src="https://counter.theconversation.com/content/90230/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jeffrey M. Farber does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The recent E. coli outbreak in North America was linked to romaine lettuce. Many such outbreaks are often linked to fresh produce. Here’s what you need to know to keep your family safe.Jeffrey M. Farber, Professor of Food Safety, University of GuelphLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/794812017-06-16T00:42:05Z2017-06-16T00:42:05ZIs lead in the US food supply decreasing our IQ?<figure><img src="https://images.theconversation.com/files/174088/original/file-20170615-24915-1i3j0lg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A baby plays with blocks spelling out one of the most famous formulas in history. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/genius-baby-high-iq-playing-cubes-461058916?src=ygHBdVvcs9OKo5WBzS4ZZg-1-16">vchal/From www.shutterstock.com</a></span></figcaption></figure><p>The environmental advocacy group Environmental Defense Fund (EDF) on June 15 released a <a href="https://www.edf.org/health/lead-food-hidden-health-threat?_ga=2.61184942.363465047.1497539228-274183335.1497539228">study</a> about dietary lead exposure, with a focus on food intended for babies and young children. </p>
<p>Using a Federal Drug Administration (FDA) database of food samples, EDF reported some pretty worrying numbers, most remarkably in fruit juice samples intended for children. For example, 89 percent of the baby food grape juice samples had detectable levels of lead in them.</p>
<p>As researchers who served as independent reviewers on the EDF report, we think it raises important concerns about the safety of our food supply. Since EDF primarily focused on exposure (whether lead was detectable or not), we were interested to see if we could get a better sense of the magnitude of risk. Specifically, we examined potential IQ loss and the percentage of samples with high lead concentrations.</p>
<h2>Why is lead in our food and beverages?</h2>
<p>Most of us are probably familiar with the dangers of chipping and peeling <a href="https://www.epa.gov/lead">lead paint</a>. And the Flint water crisis has brought <a href="https://theconversation.com/piping-as-poison-the-flint-water-crisis-and-americas-toxic-infrastructure-53473">lead pipes</a> to the forefront of our minds.</p>
<p>But food is a source of lead exposure most of us probably aren’t thinking about. <a href="https://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm557424.htm">Soil contamination</a> is a known source of lead in food, but the EDF report also raised the possibility of contamination occurring via the use of lead-containing materials during food processing. </p>
<p>Eating lead-contaminated food increases the level of lead in the blood. Chronic, low-level exposure to lead during childhood can harm <a href="https://www.atsdr.cdc.gov/phs/phs.asp?id=92&tid=22#bookmark06">mental and physical development</a>. For each microgram (µg) per day of dietary lead intake, blood lead levels increase by about .16 micrograms per deciliter (µg/dL), though there is individual <a href="http://onlinelibrary.wiley.com/doi/10.2903/j.efsa.2010.1570/epdf">variation in how much lead is absorbed through the gastroinestical tract</a>. A microgram is one millionth of a gram – a very small unit of measure. </p>
<p>There is <a href="http://www.who.int/mediacentre/factsheets/fs379/en/">no known level of lead exposure</a> that is considered safe. Even <a href="https://ntp.niehs.nih.gov/pubhealth/hat/noms/lead/index.html">low blood lead levels</a> can harm child development and behavior. In 2012, the Centers for Disease Control and Prevention (CDC) reduced the <a href="https://www.cdc.gov/nceh/lead/acclpp/lead_levels_in_children_fact_sheet.pdf">definition of elevated blood levels in children</a> from 10 to 5 μg/dL.</p>
<p>This revised definition reflects findings from a <a href="https://ntp.niehs.nih.gov/pubhealth/hat/noms/lead/index.html">2012 National Toxicology Program Report</a> that concluded a wide range of adverse health effects are associated with blood lead levels less than 5 μg/dL. These included “decreased academic achievement, IQ, and specific cognitive measures; increased incidence of attention-related behaviors and problem behaviors.”</p>
<p>The FDA has set <a href="https://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm557424.htm">limits for lead</a> in the form of maximum parts per billion (ppb) for certain foods. The FDA reports that these differences in limits are due to what is considered <a href="https://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm557424.htm">achievable</a> after food processing. The American Academy of Pediatrics has the lowest recommended limit at <a href="http://pediatrics.aappublications.org/content/pediatrics/early/2016/06/16/peds.2016-1493.full.pdf">1 ppb for school drinking water</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/173915/original/file-20170615-26091-16ilnpm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/173915/original/file-20170615-26091-16ilnpm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=433&fit=crop&dpr=1 600w, https://images.theconversation.com/files/173915/original/file-20170615-26091-16ilnpm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=433&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/173915/original/file-20170615-26091-16ilnpm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=433&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/173915/original/file-20170615-26091-16ilnpm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=545&fit=crop&dpr=1 754w, https://images.theconversation.com/files/173915/original/file-20170615-26091-16ilnpm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=545&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/173915/original/file-20170615-26091-16ilnpm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=545&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Lead Limits in Juice and Water.</span>
<span class="attribution"><span class="source">Environmental Defense Fund</span></span>
</figcaption>
</figure>
<h2>How many of the samples had detectable levels of lead?</h2>
<p>EDF analyzed more than 12,000 test results from the 2003-2013 FDA national composite food sample data (the <a href="https://www.fda.gov/Food/FoodScienceResearch/TotalDietStudy/ucm184232.htm">Total Diet Study</a>). The Total Diet Study is an FDA “<a href="https://www.fda.gov/Food/FoodScienceResearch/TotalDietStudy/ucm494299.htm">market-basket</a>” survey of typical foods eaten by U.S. consumers and is used to assess average nutrient intake and exposure to chemical contaminants. </p>
<p>EDF did an exposure analysis (detection/nondetection), and reported the percentage of samples within different food types that tested positive for lead. Twenty percent of the samples designated by the FDA as baby food had detectable levels of lead in them, compared to 14 percent for regular foods.</p>
<p>This type of analysis is similar to measuring accident rates in workplaces, or even visits by children to the medical staff in schools. As with the lead data, increases in these numbers alert organizations to potential problems, but they don’t give enough indication to pinpoint the exact nature of the problem. </p>
<p>Even without specifics on the magnitude of the risks involved, when a lead exposure issue is flagged, it’s good practice to reduce the exposure – as a way to guard against associated negative health impacts such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1257652/">decreased intellectual function</a>.</p>
<h2>How might this be affecting our IQ?</h2>
<p>These data alone aren’t enough to indicate what the likely health effects are. Ultimately, the risk depends on how much contaminated food a child will eat through his or her childhood, and how much neurological damage this ends up causing.</p>
<p>Based on <a href="https://www.epa.gov/sites/production/files/2017-01/documents/report_proposed_modeling_approaches_for_a_health_based_benchmark_for_lead_in_drinking_water_final_0.pdf">EPA estimates</a> of average childhood dietary lead exposure, we are roughly dealing with a less than 1-point decrease in IQ in the adult population than it might otherwise be. </p>
<p>In its analysis, EDF calculated an 0.38 average IQ loss from dietary lead based on the following assumptions: </p>
<ul>
<li><p>Average dietary lead exposure for young children is 2.9 µg/day. This calculation is based on a <a href="https://www.epa.gov/sites/production/files/2017-01/documents/report_proposed_modeling_approaches_for_a_health_based_benchmark_for_lead_in_drinking_water_final_0.pdf">2017 EPA dietary lead intake estimate</a> for children ages 1-7 years.</p></li>
<li><p>2.9 µg/day dietary exposure elevates blood lead levels by 0.46 µg/dL. This calculation is based on a <a href="http://www.sciencedirect.com/science/article/pii/027323009290008W?via%3Dihub">ratio of dietary lead intake to the increase in blood lead levels</a> (for every 1 µg/day lead consumed in the diet, lead increases in the blood by 0.16 µg/dL).</p></li>
<li><p>This 0.46 µg/dL elevation in lead in the blood decreases IQ by an estimated 0.38 IQ points. This calculation is based on a <a href="http://onlinelibrary.wiley.com/doi/10.2903/j.efsa.2010.1570/epdf">2013 European Food Safety Authority (EFSA) ratio of blood lead level increase to IQ loss</a> (1.2 µg/dL lead in blood to a 1 point IQ loss).</p></li>
</ul>
<p>Recall that the <a href="https://ntp.niehs.nih.gov/pubhealth/hat/noms/lead/index.html">2012 National Toxicology Program Report</a> cited a wide range of measurable health effects occurring with blood lead levels less than 5 μg/dL. For comparison, we are talking about an average increase of 0.46 μg/dL blood lead levels from dietary exposure alone.</p>
<p>Though the estimated reductions in IQ here may seem low, they are not insignificant – in some cases, small losses in IQ might make the difference, for example, in the type of career one leads and subsequent <a href="http://www.nber.org/papers/w22470">lifetime earnings</a>. </p>
<h2>How many of the samples tested above specific lead concentrations?</h2>
<p>We went back to the same FDA data EDF used, looked at the measured amounts of lead, and then plotted the percentage of tested baby food products with lead concentrations above certain amounts.</p>
<p>This type of plot gives a ballpark idea of the percentage of the baby food being sold in the U.S. for certain levels of lead. But the data need to be treated with caution, as many of the measurements were below the Limit of Quantification (LOQ), meaning that they may not be particularly accurate.</p>
<p>Average dietary lead exposure for young children is around <a href="https://www.epa.gov/sites/production/files/2017-01/documents/report_proposed_modeling_approaches_for_a_health_based_benchmark_for_lead_in_drinking_water_final_0.pdf">2.9 µg/day</a>, which approximately equates to daily levels in food at about 2.9 ppb (assuming <a href="https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=236252">average consumption of about 1 kg of food</a>). Our analysis shows the percentage of baby food samples testing at higher levels. Eighteen percent of the baby food samples tested above 5 ppb lead, which is the amount the FDA allows in drinking water. This percentage decreased in accordance with the lead concentration: 9 percent of the samples tested above 10 ppb lead; 2 percent tested above 20 ppb lead; and less than 1 percent tested above 30 ppb lead. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/173948/original/file-20170615-25014-v467x7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/173948/original/file-20170615-25014-v467x7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/173948/original/file-20170615-25014-v467x7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/173948/original/file-20170615-25014-v467x7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/173948/original/file-20170615-25014-v467x7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/173948/original/file-20170615-25014-v467x7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/173948/original/file-20170615-25014-v467x7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Percentage of baby food samples with lead concentrations greater than a given level.</span>
</figcaption>
</figure>
<h2>Where do we go from here?</h2>
<p>Even though these are not life-and-death type risks, we believe there is no room for complacency. The FDA sets limits for lead in food, but the current limits are based on levels that can be reliably measured and are considered achievable after manufacturing processes. However, a May 2017 <a href="https://www.fda.gov/Food/FoodborneIllnessContaminants/Metals/ucm557424.htm">FDA fact sheet on lead in foods</a> states that a Toxic Elements Working Group will be developing a risk-based approach. Establishing limits based on risk would help further curb the impacts of lead on society. </p>
<p>The good news is that this is possible. Many of the samples tested by FDA are already either lead-free (according to the limits of detection in the analyses used) or have low lead content. It should be possible to expand the number of products that fit into these categories, simply by understanding what some companies do right and replicating it.</p>
<p>The bottom line is that, even with relatively few products on the market with relatively high quantities of lead, the health risks from this metal are insidious, which means the more we do to eliminate it from our food supply, the better off we’ll be.</p>
<p><em>This story was updated on June 16 to correct the date of CDC recommendations and also to clarify that the 2017 EPA dietary lead exposure estimate is based on data from 2007-2013.</em></p><img src="https://counter.theconversation.com/content/79481/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Szejda's position is funded by the Center for Research on Ingredient Safety (CRIS) at Michigan State University.
She served as an independent reviewer on the EDF Lead in Food Report.</span></em></p><p class="fine-print"><em><span>Andrew Maynard receives funding support from the Center for Research on Ingredient Safety (CRIS) at Michigan State University. He is also on the Board of Trustees of the International Life Sciences Association North America. He served as an independent reviewer on the EDF Lead in Food Report.</span></em></p>A new report from the Environmental Defense Fund raises concerns about lead in our food supply. Here are some things you should consider.Keri Szejda, Postdoctoral Research Associate, Arizona State UniversityAndrew Maynard, Director, Risk Innovation Lab, Arizona State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/508952015-12-23T21:14:30Z2015-12-23T21:14:30ZShould I throw away food once a fly has landed on it?<figure><img src="https://images.theconversation.com/files/104553/original/image-20151206-4710-1ogwugi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">They land on dead animals and poop, and then on our food. If we see a fly on our Christmas lunch, should we throw it away?</span> <span class="attribution"><span class="source">Author Provided</span></span></figcaption></figure><p>It only takes a single fly to alight on your picnic lunch to make you uneasy about what germs may have landed with it. But what harm can come from a fly landing on your food? Should you throw it away?</p>
<p>There are hundreds of different <a href="http://australianmuseum.net.au/flies-and-mosquitoes-order-diptera">fly species</a> in Australia. This diverse group of insects ranges from mosquitoes and biting midges to bush flies and blowflies.</p>
<p>They play an important role in the environment by assisting decomposition, pollinating plants and providing food for insectivorous predators. They can help <a href="http://www.australianpolice.com.au/forensic-scientists/forensic-entomology/">solve crimes</a> and treat <a href="http://www.theaustralian.com.au/news/health-science/medical-maggot-makes-a-comeback/story-e6frg8y6-1226217574891">infected wounds</a>. </p>
<p>Many of these flies pose a health risk but none hang about our homes more than the house fly. It’s a ubiquitous presence during the warmer months, can be a substantial annoyance and may also be a potential health risk.</p>
<p><em>Musca domestica</em>, commonly known as the house fly, is one of the most widespread nuisance insects in the world. It has found a place in and around our homes. It is closely associated with rotting organic waste, including dead animals and faeces. It’s no surprise they’re commonly known as “filth flies”.</p>
<p>After laying eggs, maggots will hatch out and eat their way through the decaying organic material before pupating and then emerging as an adult fly a few days later. The adult flies can live up to a month and may lay hundreds of eggs over that time.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/104559/original/image-20151206-29720-hioeho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/104559/original/image-20151206-29720-hioeho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=446&fit=crop&dpr=1 600w, https://images.theconversation.com/files/104559/original/image-20151206-29720-hioeho.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=446&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/104559/original/image-20151206-29720-hioeho.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=446&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/104559/original/image-20151206-29720-hioeho.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=560&fit=crop&dpr=1 754w, https://images.theconversation.com/files/104559/original/image-20151206-29720-hioeho.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=560&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/104559/original/image-20151206-29720-hioeho.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=560&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The house fly (<em>Musca domestica</em>).</span>
<span class="attribution"><span class="source">Image: Stephen Doggett (NSW Health Pathology)</span></span>
</figcaption>
</figure>
<h2>From poop to plate</h2>
<p>When it comes to passing on pathogens, it’s not necessarily the fly itself but where it’s come from that matters. Flies don’t just visit freshly made sandwiches. They spend far more of their time in rotting animal and plant waste. Among this waste can be a range of pathogens and parasites. </p>
<p>House flies don’t bite. Unlike mosquitoes that transmit pathogens of human health importance in their saliva, house flies transmit pathogens on their feet and body. As well as leaving behind pathogen-filled footprints, the flies leave their poop on our food. They vomit too.</p>
<p>Flies don’t have teeth. They can’t take a bite out of our food, so they have to spit out some enzyme-rich saliva that dissolves the food, allowing them to suck up the resulting soup of regurgitated digestive fluids and partially dissolved food. If a fly has plenty of time to walk around on our food vomiting up, sucking in and defecating out, the chances of leaving behind a healthy population of pathogens are high.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/104555/original/image-20151206-4710-tmzm02.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/104555/original/image-20151206-4710-tmzm02.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=537&fit=crop&dpr=1 600w, https://images.theconversation.com/files/104555/original/image-20151206-4710-tmzm02.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=537&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/104555/original/image-20151206-4710-tmzm02.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=537&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/104555/original/image-20151206-4710-tmzm02.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=675&fit=crop&dpr=1 754w, https://images.theconversation.com/files/104555/original/image-20151206-4710-tmzm02.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=675&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/104555/original/image-20151206-4710-tmzm02.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=675&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Fly swats are a cheap way to control flies around the home.</span>
</figcaption>
</figure>
<h2>Brush off or toss out?</h2>
<p>In most instances, spotting a fly on your food doesn’t mean you need to throw it out. While there is little doubt that flies can carry bacteria, viruses and parasites from <a href="http://www.sciencedirect.com/science/article/pii/S1286457901013715">waste to our food</a>, a single touchdown is unlikely to trigger a chain reaction leading to illness for the average healthy person. </p>
<p>Flies that land out of sight and wander about for a few minutes vomiting and pooping on your food or food preparation area are more of a concern. The more time passes, the greater the chance of pathogens left behind by the flies growing and multiplying on our food. That’s when health risks increase.</p>
<p>Having plenty of flies about can be a concern but risk is generally higher in regions <a href="http://online.liebertpub.com/doi/abs/10.1089/fpd.2009.0366">away from the city</a>. There are not only likely to be higher numbers of flies but a greater chance they’ll be in contact with dead animals and animal waste. </p>
<p>There is no shortage of opportunities for flies in the city either but, for the most part, insecticides and improved hygiene standards assist in fly control and minimising the risk of contact with contaminated substances.</p>
<p>Ensure your food is covered while preparing, cooking and serving outdoors and don’t leave “leftovers” sitting about outside for the flies. There are plenty of other reasons <a href="https://theconversation.com/health-check-how-to-avoid-food-poisoning-at-summer-picnics-34483">food safety is important</a> over the summer, not just to stop flies touching down. </p>
<p>Screening windows and doors will help block flies from coming inside, but also minimising garbage around the house is critical. Ensure bins are cleaned regularly, household garbage is covered and animal waste is routinely cleaned up. The addition of insecticidal surface sprays around bin areas will help and, inside the home, a range of knockdown sprays will keep the numbers of flies down.</p>
<p>An old-school <a href="http://www.nytimes.com/2012/05/27/magazine/who-made-that-fly-swatter.html?_r=0">fly swat</a> works a treat too.</p><img src="https://counter.theconversation.com/content/50895/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Cameron Webb and the Department of Medical Entomology (NSW Health pathology and University of Sydney) have been engaged by a wide range of insect repellent and insecticide manufacturers to provide testing of products and provide expert advice on the biology and control of pest insects.</span></em></p>It only takes a single fly to alight on your picnic lunch to make you uneasy about what germs may have landed with it. But what harm can come from a fly landing on your food? Should you throw it away?Cameron Webb, Clinical Lecturer and Principal Hospital Scientist, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/510142015-11-24T10:17:33Z2015-11-24T10:17:33ZIs double-dipping a food safety problem or just a nasty habit?<figure><img src="https://images.theconversation.com/files/102705/original/image-20151122-404-7i9xn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">One dip and done.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-282254456/stock-photo-female-hand-holding-a-tortilla-chip-with-salsa-on-it.html?src=zI-uJ_Uztefw8gvxIAqy0w-1-10">Chip and dip via www.shutterstock.com.</a></span></figcaption></figure><p>What do you do when you are left with half a chip in your hand after dipping? Admit it, you’ve wondered whether it’s OK to double dip the chip.</p>
<p>Maybe you’re the sort who dips their chip only once. Maybe you look around the room before loading your half-eaten chip with a bit more dip, hoping that no one will notice. </p>
<p>If you’ve seen that classic episode of Seinfeld, “The Implant,” where George Costanza <a href="http://worldofseinfeld.blogspot.com/2007/08/double-dip-seinfeld-quote.html">double-dips</a> a chip at a wake, maybe you’ve wondered if double-dipping is really like “putting your whole mouth right in the dip!”</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/RfprRZQxWps?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">‘You doubled-dipped the chip.’</span></figcaption>
</figure>
<p>But is it, really? Can the bacteria in your mouth make it onto the chip then into the dip? Is this habit simply bad manners, or are you actively contaminating communal snacks with your particular germs?</p>
<p>This question intrigued our undergraduate research team at Clemson University, so we designed <a href="http://dx.doi.org/10.1111/j.1745-4565.2008.00137.x">a series of experiments</a> to find out just what happens when you double-dip. Testing to see if there is bacterial transfer seems straightforward, but there are more subtle questions to be answered. How does the acidity of the dip affect bacteria, and do different dips affect the outcome? Members of the no-double-dipping enforcement squad, prepare to have your worst, most repulsive suspicions confirmed.</p>
<h2>Start with a cracker</h2>
<p>Presumably some of your mouth’s bacteria transfer to a food when you take a bite. But the question of the day is whether that happens, and if so, how much bacteria makes it from mouth to dip. Students started by comparing bitten versus unbitten crackers, measuring how much bacteria could transfer from the cracker to a cup of water.</p>
<p>We found about 1,000 more bacteria per milliliter of water when crackers were bitten before dipping than solutions where unbitten crackers were dipped.</p>
<p>In a second experiment, students tested bitten and unbitten crackers in water solutions with pH levels typical of food dips (pH levels of 4, 5 and 6, which are all toward the more acidic end of the pH scale). They tested for bacteria right after the bitten and unbitten crackers were dipped, then measured the solutions again two hours later. More acidic solutions tended to lower the bacterial numbers over time.</p>
<p>The time had come to turn our attention to real food. </p>
<h2>But what about the dip?</h2>
<p>We compared three kinds of dip: salsa, chocolate and cheese dips, which happen to differ in pH and thickness (viscosity). Again, we tested bacterial populations in the dips after already-bitten crackers were dipped, and after dipping with unbitten crackers. We also tested the dips two hours after dipping to see how bacterial populations were growing. </p>
<p>We tested All Natural Tostitos Chunky Hot Salsa (pH 4), Genuine Chocolate Flavor Hershey’s Syrup (pH 5.3) and Fritos Mild Cheddar Flavor Cheese Dip (pH 6.0).</p>
<p>So, how dirty is your dip? We found that in the absence of double-dipping, our foods had no detectable bacteria present. Once subjected to double-dipping, the salsa took on about five times more bacteria (1,000 bacteria/ml of dip) from the bitten chip when compared to chocolate and cheese dips (150-200 bacteria/ml of dip). But two hours after double-dipping, the salsa bacterial numbers dropped to about the same levels as the chocolate and cheese. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/102914/original/image-20151123-18257-1dhttmi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/102914/original/image-20151123-18257-1dhttmi.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=390&fit=crop&dpr=1 600w, https://images.theconversation.com/files/102914/original/image-20151123-18257-1dhttmi.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=390&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/102914/original/image-20151123-18257-1dhttmi.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=390&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/102914/original/image-20151123-18257-1dhttmi.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=490&fit=crop&dpr=1 754w, https://images.theconversation.com/files/102914/original/image-20151123-18257-1dhttmi.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=490&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/102914/original/image-20151123-18257-1dhttmi.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=490&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">After two hours, levels of bacteria in the salsa were similar to levels in the cheese and chocolate dips.</span>
<span class="attribution"><span class="source">Paul Dawson</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We can explain these phenomena using some basic food science. Chocolate and cheese dips are both pretty thick. Salsa isn’t as thick. The lower viscosity means that more of the dip touching the bitten cracker falls back into the dipping bowl rather than sticking to the cracker. And as it drops back into the communal container, it brings with it bacteria from the mouth of the double-dipper. </p>
<p>Salsa is also more acidic. After two hours, the acidity of the salsa had killed some of the bacteria (most bacteria don’t like acid). So it’s a combination of viscosity and acidity that will determine how much bacteria gets into the dip from double-dipping. As a side note about party hosting: cheese dip will run out faster than salsa since more of the cheese sticks to the cracker or chip on each dip. That could reduce the chances of people double-dipping. And yes, this is something we discovered during the experiment.</p>
<h2>Should I freak out about double-dipping?</h2>
<p>Double-dipping can transfer bacteria from mouth to dip, but is this something you need to worry about?</p>
<p>Anywhere from hundreds to thousands of different bacterial types and viruses live in the human oral cavity, most of which are harmless. But some aren’t so good. Pneumonic plague, tuberculosis, influenza virus, Legionnaires’ disease and severe acute respiratory syndrome (SARS) are known to spread through saliva, with coughing and sneezing aerosolizing up to 1,000 and 3,600 bacterial cells per minute. These tiny germ-containing droplets from a cough or a sneeze can settle on surfaces such as desks and doorknobs. Germs can be spread when a person touches a contaminated surface and then touches their eyes, nose or mouth.</p>
<p>That’s why the Centers for Disease Control and Prevention <a href="http://www.cdc.gov/flu/protect/covercough.htm">strongly recommends</a> covering the mouth and nose when coughing and sneezing to prevent spreading “serious respiratory illnesses like influenza, respiratory syncytial virus (RSV), whooping cough, and severe acute respiratory syndrome (SARS).” With that in mind, there may be a concern over the spread of oral bacteria from person to person thanks to double-dipping. And a person doesn’t have to be sick to pass on germs.</p>
<p>One of the most infamous examples of spreading disease while being asymptomatic is household cook Mary Mallon (Typhoid Mary), who spread typhoid to numerous families in 19th-century New England during food preparation. Science has left unanswered whether she was tasting the food as she went along and, in effect, double-dipping. Typhoid Mary is obviously an extreme example, but your fellow dippers might very well be carrying cold or flu germs and passing them right into the bowl you’re about to dig into. </p>
<p>If you detect double-dippers in the midst of a festive gathering, you might want to steer clear of their favored snack. And if you yourself are sick, do the rest of us a favor and don’t double-dip.</p><img src="https://counter.theconversation.com/content/51014/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Paul Dawson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Should you double-dip? A food scientist explains what’s lurking in the depths of your salsa.Paul Dawson, Professor of Food Science, Clemson UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/377522015-02-26T01:48:52Z2015-02-26T01:48:52ZFor safety’s sake, make food labels say what companies already know<figure><img src="https://images.theconversation.com/files/73124/original/image-20150226-1758-kqcht6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Unclear and sometimes misleading country-of-origin labelling in Australia is a source of confusion for consumers.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/dsevilla/14297747541">Diego Sevilla Ruiz/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>Prime Minister <a href="http://www.sbs.com.au/news/article/2015/02/26/pm-orders-imported-food-label-review">Tony Abbott has called on</a> two senior ministers to prepare a cabinet submission on country-of-origin labelling laws. The move follows a <a href="https://theconversation.com/berry-scare-heres-what-you-need-to-know-about-hepatitis-a-37758">national outbreak of hepatitis A</a> linked to <a href="https://theconversation.com/scary-berries-how-food-gets-contaminated-and-what-to-do-37629">frozen berries</a> from China and Chile. </p>
<p><a href="https://theconversation.com/angst-over-berries-makes-case-for-good-clean-fair-food-37892">The outbreak</a> was a strong reminder that all is not well in Australia’s food supply. Once the alleged offending ingredient was identified and <a href="http://www.foodstandards.gov.au/industry/foodrecalls/recalls/Pages/Nanna's-Mixed-Berries.aspx">relevant products recalled</a>, consumers claimed <a href="http://www.heraldsun.com.au/news/opinion/consumers-have-right-to-know-if-its-made-in-australia-or-not/story-fni0fhie-1227223949217">they were not aware</a> the berries they were choosing to eat were from China.</p>
<p>But labelling on the berry products complied with <a href="http://www.foodstandards.gov.au/consumer/labelling/coo/Pages/default.aspx">current labelling</a> and <a href="http://www.accc.gov.au/consumers/groceries/country-of-origin">consumer information</a> laws. And despite the recall highlighting the inadequacy of the labelling, the <a href="http://www.theguardian.com/australia-news/2015/feb/18/tony-abbott-says-no-to-tougher-food-tests-labels-after-hepatitis-a-outbreak?CMP=share_btn_tw">prime minister dismissed initial calls for changes</a>. He said it would make life very hard for business, would raise the cost of food and that it was the responsibility of business “not to poison their customers”. </p>
<p>That changed this morning when Abbott asked Agriculture Minister Barnaby Joyce and Industry Minister Ian MacFarlane to submit a proposal to cabinet in March. MacFarlane has already warned <a href="http://www.sbs.com.au/news/article/2015/02/26/pm-orders-imported-food-label-review">consumers may have to bear the cost of the change</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/75041/original/image-20150317-13682-1czs2l8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/75041/original/image-20150317-13682-1czs2l8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/75041/original/image-20150317-13682-1czs2l8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=849&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75041/original/image-20150317-13682-1czs2l8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=849&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75041/original/image-20150317-13682-1czs2l8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=849&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75041/original/image-20150317-13682-1czs2l8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1067&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75041/original/image-20150317-13682-1czs2l8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1067&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75041/original/image-20150317-13682-1czs2l8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1067&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>Here’s one problem with this current food-labelling system: “Made in Australia from local and imported ingredients” does not actually reveal where the food comes from. A company can claim a product is made in Australia if at least half the cost of manufacturing that product is incurred here. </p>
<p>Consider a jar of jam: the total cost of production includes the cost of producing the lid, the jar, the label, as well as the jam. Half the cost of production could easily be attributed to the jar itself, leaving room for jam ingredients to be imported and still allowing the label to say it was made in Australia. </p>
<p>The <a href="http://www.foodlabellingreview.gov.au/internet/foodlabelling/publishing.nsf/content/48C0548D80E715BCCA257825001E5DC0/$File/Labelling%20Logic_2011.pdf">2011 report</a> on the effectiveness of Australia’s food-labelling system <a href="http://www.foodlabellingreview.gov.au/internet/foodlabelling/publishing.nsf/content/48C0548D80E715BCCA257825001E5DC0/$File/Labelling%20Logic_2011.pdf">described the challenges</a> for improving transparency. It identified country-of-origin labelling as a particularly contentious issue, and recommended:</p>
<blockquote>
<p>That for foods bearing some form of Australian claim, a consumer-friendly, food-specific country-of-origin labelling framework, based primarily on the ingoing weight of the ingredients and components (excluding water), be developed. </p>
</blockquote>
<h2>Other options</h2>
<p>This recommendation was taken up by Greens leader Christine Milne. She <a href="http://www.comlaw.gov.au/Details/C2013B00117/b6b51a4c-df0c-4f3d-9b64-3ccb0b2f0f28">introduced a bill</a> to improve transparency of country-of-origin labelling just before the berry scare. It calls for <a href="http://greens.org.au/country-of-origin">three items on labels</a> that cover where a product is grown, where it’s manufactured and where it is packaged.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/75040/original/image-20150317-13674-1ndgd40.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/75040/original/image-20150317-13674-1ndgd40.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/75040/original/image-20150317-13674-1ndgd40.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=793&fit=crop&dpr=1 600w, https://images.theconversation.com/files/75040/original/image-20150317-13674-1ndgd40.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=793&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/75040/original/image-20150317-13674-1ndgd40.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=793&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/75040/original/image-20150317-13674-1ndgd40.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=997&fit=crop&dpr=1 754w, https://images.theconversation.com/files/75040/original/image-20150317-13674-1ndgd40.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=997&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/75040/original/image-20150317-13674-1ndgd40.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=997&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<p>Even before this, consumer organisation Choice launched a <a href="http://www.choice.com.au/consumer-action/food-labelling/country-of-origin/better-country-of-origin-labelling.aspx">campaign about country-of-origin labelling</a> in January 2012 after a survey showed 86% of respondents found such labels unclear. </p>
<p>Choice proposes a three-tiered system that specifies “product of” for primary produce such as fruit and vegetables, “manufactured in” and “packaged in”. This last one would cover foods with input from multiple companies, which makes it difficult to isolate single ingredients, and products such as mixed frozen vegetables where each vegetable is from a different country. Choice plans to develop exact wording through consumer testing.</p>
<p>Another simple and practical way to resolve the problem is to include the origin of imported ingredients in the “ingredient list”. Labelling laws mandate that ingredient lists appear on every product. Individual ingredients are listed in order of volume, from most to least. </p>
<p>Take peanut butter as an example. Its ingredients list says roasted peanuts, vegetable oil, sugar and salt. If labelling laws mandated the listing of country of origin for imported ingredients, the list might say roasted peanuts (China), vegetable oil (Chile), sugar (Phillipines) and salt. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/73129/original/image-20150226-1758-17i4cai.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/73129/original/image-20150226-1758-17i4cai.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/73129/original/image-20150226-1758-17i4cai.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=416&fit=crop&dpr=1 600w, https://images.theconversation.com/files/73129/original/image-20150226-1758-17i4cai.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=416&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/73129/original/image-20150226-1758-17i4cai.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=416&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/73129/original/image-20150226-1758-17i4cai.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=523&fit=crop&dpr=1 754w, https://images.theconversation.com/files/73129/original/image-20150226-1758-17i4cai.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=523&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/73129/original/image-20150226-1758-17i4cai.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=523&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
</figcaption>
</figure>
<p>Ingredients sourced locally wouldn’t need to be declared as made in Australia would the default position; only imported ingredients would need to state the country of origin. </p>
<h2>It’s about time</h2>
<p>Milne’s bill has <a href="http://ausfoodnews.com.au/2013/02/20/country-of-origin-bill-ignites-afgc-anger.html">attracted the ire of the Australian Food and Grocery Council</a>, the peak food, drink and grocery manufacturing body. And food manufacturers have already responded to the prime minister’s announcement. They say <a href="http://ausveg.com.au/media-release/label-change-double-standard-puts-food-manufacturers-to-shame">changing the labelling system</a> would place an unreasonable burden on them.</p>
<p>But changing the wording of a label is different from adding a regime of <a href="http://www.abc.net.au/news/2015-02-17/nick-xenophon-calls-for-food-safety-review-berries-hepatitis-a/6131754">increased testing and reporting</a>. And although <a href="http://www.abc.net.au/news/2015-02-19/how-australia-checks-imported-food/6148576">risk assessment and testing</a> of imported foods is vital, what we now need for consumer confidence is the more cost-effective option of label change. </p>
<p>Food companies track the exact point of origin of each ingredient because of quality-control procedures, supported by Australia’s food laws. All consumers want is for the companies to tell them what they already know. </p>
<p>Changing Australia’s country-of-origin labelling system will effectively give consumers power to make informed decisions in the free market. And it will overcome the current information asymmetry, which keeps them in the dark.</p><img src="https://counter.theconversation.com/content/37752/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Melanie Voevodin has been the recipient of an NHMRC Public Health Scholarship (2011-2013).</span></em></p>Prime Minister Tony Abbott has called on two ministers to prepare a cabinet submission about country-of-origin food labelling despite initial reluctance about change.Melanie Voevodin, NHMRC Public Health PhD Scholar, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/290152014-07-16T05:14:55Z2014-07-16T05:14:55ZThe top ten parasites that could be lurking in your food<figure><img src="https://images.theconversation.com/files/53889/original/3vh4xz5f-1405420547.jpg?ixlib=rb-1.1.0&rect=0%2C37%2C800%2C562&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Hey! You got a friend in Taenia solium.</span> <span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Taenia_solium_scolex.JPG">Roberto J. Galindo</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">CC BY-NC-SA</a></span></figcaption></figure><p>Most people are fascinated, and probably equally repulsed, by parasites. And it may be something you think <a href="https://theconversation.com/six-human-parasites-you-definitely-dont-want-to-host-17332">you only need to worry about</a> if you go on holiday somewhere exotic. However, increasing globalisation and transportation of food products across the globe means we are all increasingly at risk of catching something unwanted from our favourite foods. </p>
<p>Many infections can be thwarted with proper hygiene – washing fruit and vegetables, including “ready-washed” lettuce, cooking meat properly and avoiding contamination from domestic or wild animals. A <a href="http://www.fao.org/publications/card/en/c/ee07c6ae-b86c-4d5f-915c-94c93ded7d9e/">joint UN/WHO report</a> said better farming and global food trade standards could also prevent parasites entering the food chain. Experts have ranked the 24 most damaging food-borne parasites according to number of cases, global distribution and health impact. Here are the top ten: </p>
<h2>1. <em>Taenia solium</em></h2>
<p><em>T.solium</em>, also known as pork tapeworms, can measure up to 10m when mature and are among the biggest of these ribbon-like worms to infect humans. They do this through larval cysts in undercooked pork that hatch in the stomach and quickly grow into adult worms which inhabit the intestine, feeding on the nutrients you eat. </p>
<p>Disease is generally restricted to malnutrition as the worm competes with you for food – unless you ingest eggs rather than a cyst. These migrate around the body before forming larval cysts – a condition called cysticercosis – just like they do in the pigs. This can cause severe problems, particularly in the central nervous system (neurocysticercosis) where they can cause epileptic seizures. This <a href="http://jnnp.bmj.com/content/68/2/137.long">is believed to be</a> a main cause of epilepsy in many poorer parts of the world. </p>
<h2>2. <em>Echinococcus granulosus</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53891/original/qmzz4fkm-1405420918.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53891/original/qmzz4fkm-1405420918.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53891/original/qmzz4fkm-1405420918.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=407&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53891/original/qmzz4fkm-1405420918.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=407&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53891/original/qmzz4fkm-1405420918.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=407&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53891/original/qmzz4fkm-1405420918.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=512&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53891/original/qmzz4fkm-1405420918.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=512&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53891/original/qmzz4fkm-1405420918.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=512&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Growing up with not a care in the world.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Echinococcus_granulosus_scolex.jpg">CDC/L.L.A. Moore, Jr</a></span>
</figcaption>
</figure>
<p>Another tapeworm, but only 3-7mm long, which causes a nasty disease called cystic echinococcosis (CE). The worm has a life cycle that normally cycles between carnivores (usually dogs), and sheep or other livestock. Humans become infected through accidental ingestion of eggs from dog faeces, either through contaminated food products or from direct contact, or contaminated soil. The worm’s eggs are tough – they can remain infective for months, even in freezing temperatures. </p>
<p><a href="http://www.plosntds.org/article/info%3Adoi%2F10.1371%2Fjournal.pntd.0002249">More than a million</a> cases of CE occur every year worldwide, mainly in areas where livestock, including camels, come in to close contact with dogs. After ingesting eggs, the parasite migrates, primarily to the liver. Slow-growing cysts form and symptoms may not be obvious until several years later. Cysts can contain several litres of fluid and are full of infectious larval stages called protoscoleces. Spontaneous rupture of the cysts can be very dangerous and lead to fatal shock.</p>
<h2>3. <em>Echinococcus multilocularis</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53894/original/5zm727sd-1405421076.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53894/original/5zm727sd-1405421076.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53894/original/5zm727sd-1405421076.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=307&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53894/original/5zm727sd-1405421076.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=307&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53894/original/5zm727sd-1405421076.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=307&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53894/original/5zm727sd-1405421076.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=385&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53894/original/5zm727sd-1405421076.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=385&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53894/original/5zm727sd-1405421076.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=385&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">No, I encyst.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Cotton_rat_infected_with_Echinococcus_multilocularis_3MG0020_lores.jpg">CDC/I. Kagan</a></span>
</figcaption>
</figure>
<p>Geographical distribution of this tapeworm is patchy but it’s found in both North America and Europe where prevalence is slowly <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2792858/">increasing</a>. Its life cycle normally involves foxes and small rodents but can happen in domestic dogs and even cats. In humans it causes a disease called alveolar echinococcosis, which forms cysts in internal organs. The cysts can reproduce and spread like tumours and be fatal if untreated. This infection is considered a risk factor for hunters who handle infected fox carcasses and people foraging for berries and mushrooms contaminated by fox faeces. </p>
<h2>4. <em>Toxoplasma gondii</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53895/original/pcjtgs5j-1405421195.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53895/original/pcjtgs5j-1405421195.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53895/original/pcjtgs5j-1405421195.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53895/original/pcjtgs5j-1405421195.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53895/original/pcjtgs5j-1405421195.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53895/original/pcjtgs5j-1405421195.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53895/original/pcjtgs5j-1405421195.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53895/original/pcjtgs5j-1405421195.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Secreted away.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Toxoplasma_gondii.jpg"> Ke Hu/John Murray/PLOS</a></span>
</figcaption>
</figure>
<p><em>T.gondii</em> is a single-cell parasitic animal (protozoa) that can infect practically all warm-blooded mammals, but its life cycle normally takes place between cats and rodents. <em>T.gondii</em> is present in most countries and is one of the most widespread protozoan parasites affecting humans. Infection rate in humans varies between 10-80% of the population in different parts <a href="http://www.ncbi.nlm.nih.gov/pubmed/19433092">of the world</a> and the parasite usually stays dormant in the tissues for the lifetime of the host – most infected people have no symptoms and never know they’re infected. </p>
<p>The most serious problems arise in pregnant women because the parasite can cross the placenta and cause foetal abnormalities or even miscarriage, which is why its advisable for them to avoid cleaning cat litter. Immunosuppressed individuals, such as HIV/AIDS and organ transplant patients, are also at risk because the parasite can start multiplying uncontrollably.</p>
<h2>5. <em>Cryptosporidium spp.</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53896/original/99dggw6f-1405421441.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53896/original/99dggw6f-1405421441.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53896/original/99dggw6f-1405421441.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53896/original/99dggw6f-1405421441.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53896/original/99dggw6f-1405421441.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53896/original/99dggw6f-1405421441.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=455&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53896/original/99dggw6f-1405421441.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=455&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53896/original/99dggw6f-1405421441.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=455&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Not the eggs you want in the morning.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Cryptosporidium_Ziehl_Alae_Gati.jpg">Alae-eddine GATI</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>These protozoan parasites are mainly transmitted via contaminated water or food washed in contaminated water. Unpasteurised cider and milk, and contaminated shellfish have been implicated in several outbreaks. The parasite is present worldwide, including the UK, and infection is often caused by foecal contamination of water supplies by infected livestock. In healthy individuals the disease causes severe watery diarrhoea, which often rights itself. Thorough washing of fresh produce – including “ready washed” lettuces – is recommended. </p>
<h2>6. <em>Entamoeba histolytica</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53897/original/qfj7rvbj-1405421635.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53897/original/qfj7rvbj-1405421635.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53897/original/qfj7rvbj-1405421635.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=404&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53897/original/qfj7rvbj-1405421635.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=404&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53897/original/qfj7rvbj-1405421635.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=404&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53897/original/qfj7rvbj-1405421635.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=507&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53897/original/qfj7rvbj-1405421635.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=507&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53897/original/qfj7rvbj-1405421635.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=507&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Cyst-ematic infection.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Entamoeba_histolytica_01.jpg">CDC/George Healy</a></span>
</figcaption>
</figure>
<p>Another protozoan parasite that infects the digestive tract causes amoebic dysentery. The disease is characterised by bloody diarrhoea and abdominal pain that can become life threatening. More severe problems can occur if the parasite starts spreading from the intestine out into the body, causing abscesses in the liver and other organs. </p>
<h2>7. <em>Trichinella spiralis</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53898/original/vghf3sp3-1405421784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53898/original/vghf3sp3-1405421784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53898/original/vghf3sp3-1405421784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53898/original/vghf3sp3-1405421784.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53898/original/vghf3sp3-1405421784.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53898/original/vghf3sp3-1405421784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53898/original/vghf3sp3-1405421784.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53898/original/vghf3sp3-1405421784.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Spiraling problem.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Clinical_appearance_of_eyes_in_trichinosis_by_trichinella_3MG0027_lores.jpg">CDC</a></span>
</figcaption>
</figure>
<p><em>Trichinella spiralis</em>, is an intracellular “pork roundworm” responsible for trichinellosis, a muscle infection caught from eating raw or undercooked pork, or pork products such as smoked sausages. Other sources include game such as wild boar, and even walrus. Infected meat is contaminated with cysts, invisible to the eye, that contain a small larvae. When the meat is digested, these grow into adult worms that mate and produce thousands of new larvae, which travel out into the muscle tissues where they encyst, awaiting the current host to be eaten.</p>
<h2>8. <em>Opisthorchiidae</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53899/original/j54t2csh-1405421913.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53899/original/j54t2csh-1405421913.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53899/original/j54t2csh-1405421913.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53899/original/j54t2csh-1405421913.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53899/original/j54t2csh-1405421913.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53899/original/j54t2csh-1405421913.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=469&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53899/original/j54t2csh-1405421913.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=469&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53899/original/j54t2csh-1405421913.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=469&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Clonorchis: from the Chinese branch of the family.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Clonorchis_anterior_showing_Stoma_and_oral_sucker.jpg">Circa24</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>This is a family of flatworms, or flukes, mainly present in south-east Asia (though some species are also present in Europe and Russia). The infection is contracted through eating raw or undercooked freshwater fish that have themselves been snails infected with larvae. These develop into another type of larvae in fish, and when they are eaten by a mammal (such as a human) they turn into adult worms that make themselves at home in the bile duct and gall bladder. It then produces eggs that are excreted in faeces, which hatch to infect new snails when they reach a fresh water source. </p>
<p>Infected dogs and cats roaming freely in villages are often significant reservoirs of infection. Chronic long-term Opisthorchis infections are significantly <a href="http://www.ncbi.nlm.nih.gov/pubmed/22947297">associated with cancer</a> of the liver and bile ducts. Freezing or cooking fish prevents infection – pickling, drying, salting or smoking fish won’t.</p>
<h2>9. <em>Ascaris spp.</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53902/original/mck4jc36-1405422223.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53902/original/mck4jc36-1405422223.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53902/original/mck4jc36-1405422223.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=418&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53902/original/mck4jc36-1405422223.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=418&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53902/original/mck4jc36-1405422223.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=418&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53902/original/mck4jc36-1405422223.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=525&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53902/original/mck4jc36-1405422223.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=525&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53902/original/mck4jc36-1405422223.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=525&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Do not swallow.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Ascaris-suum.jpg">Alan R Walker</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>These are the largest of the human intestinal roundworms (up to 35cm) and with 25% of the world <a href="http://www.ncbi.nlm.nih.gov/pubmed/19450374">infected</a>, is the most common parasite in humans. After ingestion, the eggs hatch into larvae in the intestine before undergoing a remarkable migration: they travel out of the intestine via the blood to the lungs, then migrate up the airways to the throat, where they get swallowed down into the stomach and back to the intestine again, where they finally develop into adult worms. </p>
<p>Each female worm produces hundreds of thousands of eggs per day which are excreted in the faeces, contaminating the environment and further spreading the disease. A second species, <em>Ascaris suum</em>, was until recently believed to only infect pigs but is also able to infect humans. The level and symptoms of disease depends on the number of worms the individual is infected with, and intestinal blockage can happen because of the size of the worms. </p>
<h2>10. <em>Trypanosoma cruzi</em></h2>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/53903/original/kmzz3dvd-1405422398.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/53903/original/kmzz3dvd-1405422398.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/53903/original/kmzz3dvd-1405422398.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/53903/original/kmzz3dvd-1405422398.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/53903/original/kmzz3dvd-1405422398.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/53903/original/kmzz3dvd-1405422398.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/53903/original/kmzz3dvd-1405422398.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/53903/original/kmzz3dvd-1405422398.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Some flowers would do.</span>
<span class="attribution"><a class="source" href="http://commons.wikimedia.org/wiki/File:Triatoma_infestans.jpg">CDC/WHO</a></span>
</figcaption>
</figure>
<p><em>T.cruzi</em> is a protozoan parasite which causes a disease called Chagas disease. The disease is characterised by slow progression where the parasite infects various cells and organs in the body, including the heart, over many years, often with no or only mild symptoms present. Eventually the disease manifests itself through serious, and sometime fatal, cardiac or intestinal problems. </p>
<p>The infection is normally transmitted though contact with the faeces of triatomine beetles (“kissing bugs”), which seek nightly human contact to feed on human blood. When it feeds, the beetle defecates on the host’s skin. Bug faeces are often then scratched into the bite wound. <em>T.cruzi</em> is on the top ten list because it was recently discovered that humans can be infected by simply <a href="http://www.ncbi.nlm.nih.gov/pubmed/23010131">ingesting foods</a> contaminated with bug faeces – several outbreaks in recent years were caused by contaminated fruit and sugar cane juices – causing concern that it could become a global pathogen.</p><img src="https://counter.theconversation.com/content/29015/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helena receives funding from Bill and Melinda Gates Foundation for her research on immunity to intestinal nematode infections</span></em></p>Most people are fascinated, and probably equally repulsed, by parasites. And it may be something you think you only need to worry about if you go on holiday somewhere exotic. However, increasing globalisation…Helena Helmby, Senior Lecturer, London School of Hygiene & Tropical MedicineLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/228502014-02-16T19:13:08Z2014-02-16T19:13:08ZSPC Ardmona’s bailout is crucial given China’s food safety record<figure><img src="https://images.theconversation.com/files/41542/original/nsmmmp2y-1392353282.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In 2008, Chinese baby formula and milk products were tainted
with melamine, killing six babies and hospitalising many more.</span> <span class="attribution"><span class="source">EPA/Wu Hong</span></span></figcaption></figure><p>SPC Ardmona’s <a href="http://www.abc.net.au/news/2014-02-13/victorian-government-announces-package-for-spc-ardmona/5257564">$22 million lifeline</a> from the Victorian government seems to have saved Australia’s largest food packaging company.</p>
<p>Yet the firm’s <a href="http://ccamatil.com/InvestorRelations/ASX/2014/SPCA%20announcement.pdf">recent tribulations</a> are a reminder of why I regularly choose to buy products at the supermarket that are more expensive than the alternative. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/41554/original/dsvkhvv2-1392362420.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/41554/original/dsvkhvv2-1392362420.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=388&fit=crop&dpr=1 600w, https://images.theconversation.com/files/41554/original/dsvkhvv2-1392362420.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=388&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/41554/original/dsvkhvv2-1392362420.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=388&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/41554/original/dsvkhvv2-1392362420.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=487&fit=crop&dpr=1 754w, https://images.theconversation.com/files/41554/original/dsvkhvv2-1392362420.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=487&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/41554/original/dsvkhvv2-1392362420.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=487&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Local produce: Victorian workers and politicians have rallied behind the SPC brand.</span>
<span class="attribution"><span class="source">AAP</span></span>
</figcaption>
</figure>
<p>One reason is that Australian food standards are generally world-class when it comes to the amount of contamination allowed from metals such as lead and cadmium. Although it is not always possible to police this perfectly, these standards allow a high degree of confidence that Australian food is free from contamination.</p>
<h2>Contamination issues</h2>
<p>The story is different elsewhere. In China, for example, the past decade has seen a host of food-contamination issues. Besides the notorious <a href="http://www.scientificamerican.com/blog/post/why-is-melamine-in-baby-formula-you-2008-09-24/">melamine baby formula scandal</a>, there were also rice products with <a href="http://online.wsj.com/news/articles/SB10001424127887324787004578494583962413470">toxic levels of cadmium</a>, and vegetables tainted with <a href="http://www.scmp.com/news/china/article/1267541/heavy-metals-poison-vegetables-pearl-river-delta">other industrial heavy metals</a> such as lead, chromium, zinc and nickel. </p>
<p>In March last year, up to <a href="http://www.theguardian.com/world/2013/mar/29/dead-pigs-china-water-supply">16,000 diseased pig carcasses</a> were found rotting in Shanghai’s Huangpu River, after a crackdown on black-market sales of substandard meat prompted the animals’ owners to dump them. </p>
<p>There have also been fears over <a href="http://www.scmp.com/article/440079/firm-uses-human-hair-soya-sauce-breakthrough">soy sauce made using human hair</a>, and slaughtered sheep <a href="http://www.news.com.au/lifestyle/food/pond-water-injected-into-chinese-sheep/story-fneuz8wn-1226796188856">injected with filthy pondwater</a> to boost the weight of the meat.</p>
<h2>Rapid growth, but at what cost?</h2>
<p>Last year, my colleagues and I released a <a href="http://sydney.edu.au/arts/ciss/downloads/CISS_Food_Security_Policy_Report.pdf">report</a> on the state of food security in Asia. It highlighted serious environmental issues related to China’s food supply, stemming in part from the chronic pollution of China’s water and farmland. </p>
<p>Among other things, it showed that China’s rampant economic growth has come at a severe cost to its environment, effectively turning its rivers and lakes into industrial dumping grounds. As a result, 90% of groundwater in China is polluted, 65% severely so, with contaminants such as pesticides, fertilisers, and petrochemicals. </p>
<p>According to China’s Vice-Minister for Land and Resources, <a href="http://news.xinhuanet.com/english/china/2014-01/22/c_133066345.htm">3.3 million hectares of agricultural land are moderately or severely polluted</a>, an area roughly the size of The Netherlands. This results in the contamination with heavy metals of 12 million tonnes of grain per year; an amount greater than the entire cereal production of Japan. </p>
<p>Along China’s vast coastline, 68,000 square kilometres of coastal waters are now classified as severely polluted. <a href="http://www.chinadaily.com.cn/cndy/2013-03/21/content_16326460.htm">Figures</a> from China’s National Marine Environmental Monitoring Centre show that in 2012, some 17 million tonnes of pollutants flowed through 72 of China’s rivers, including 93,000 tonnes of oil and a staggering 46,000 tonnes of heavy metals such as lead and cadmium. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/41577/original/xfkqfsq7-1392381211.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/41577/original/xfkqfsq7-1392381211.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/41577/original/xfkqfsq7-1392381211.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=395&fit=crop&dpr=1 600w, https://images.theconversation.com/files/41577/original/xfkqfsq7-1392381211.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=395&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/41577/original/xfkqfsq7-1392381211.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=395&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/41577/original/xfkqfsq7-1392381211.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=496&fit=crop&dpr=1 754w, https://images.theconversation.com/files/41577/original/xfkqfsq7-1392381211.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=496&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/41577/original/xfkqfsq7-1392381211.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=496&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A woman collecting water from the Yangtze River, China.</span>
<span class="attribution"><span class="source">Lu Guang/Greenpeace</span></span>
</figcaption>
</figure>
<p>The deadly combination of food, water and air pollution in China has led to a dramatic increase in the number of <a href="http://news.xinhuanet.com/english/china/2013-09/11/c_132712669.htm">“cancer villages”</a>, where high rates of cancer have risen in line with water and soil contamination. </p>
<h2>Poor track record</h2>
<p>This is not to say that all Chinese canned food is necessarily contaminated. Nor does it suggest that it is only China facing these issues. India, Bangladesh and Vietnam, to name a few, are also facing serious challenges to clean up pollution and contamination. </p>
<p>But for importers of Chinese food, China’s track record on food safety, and its systemic problem with severe and chronic pollution, should raise serious concerns. </p>
<p>Several reports have shown how deadly chemicals have infiltrated the Chinese food system, such as through the <a href="http://www.sciencedirect.com/science/article/pii/S0269749107003351">use of waste water</a> to irrigate crops, and the <a href="http://www.sciencedirect.com/science/article/pii/S0308814612018602">presence of pesticides</a> in market food. A <a href="http://www.tandfonline.com/doi/abs/10.1080/10643389.2012.671738?journalCode=best20#preview">2012 review</a> of the extent of lead contamination in China concluded that “the problem of lead pollution in China is a global problem”. </p>
<p>Of greatest concern to Australian consumers of canned fruit should be a <a href="http://www.sciencedirect.com/science/article/pii/S0956713513005719">recent study</a> in Zhejiang province, showing that oranges, grapes, pears and plums were contaminated with levels of chromium, copper, cadmium, mercury and lead well in excess of Chinese safety standards. It is worth noting that Chinese safety standards allow twice the level of lead permitted in Australian fruit.</p>
<p>Although <a href="https://theconversation.com/spc-ardmona-and-the-cheap-chinese-food-challenge-22579">a recent article in The Conversation</a> suggested that the label of “cheap, dumped and frequently contaminated” attached to Chinese food is a shortsighted view, I would argue exactly the opposite.</p>
<p>China is attempting to make changes to the amount of pollution in its food chain, and clean up its environment. Yet the reality is that as the pressure for food and water continues to ramp up, food contamination is also likely to increase. </p>
<p>China’s environmental problems border on insurmountable, and when combined with systemic corruption in environmental monitoring and the greater profits to be gained from industrial output over agriculture, it makes for a bleak long-term outlook.</p>
<h2>What does this mean for Australia?</h2>
<p>China is already Australia’s largest supplier of prepared fruit. According to data from the UN Food and Agriculture Organisation, Australia imported just 3,000 tonnes of packaged Chinese fruit in 2001, rising to 27,000 tonnes a decade later. As a comparison, <a href="http://www.pc.gov.au/__data/assets/pdf_file/0018/125181/sub039-fruit-safeguards.pdf">statistics prepared for the Australian Productivity Commission</a> show that SPC Ardmona sold just over 36,000 tonnes of packaged fruit in 2012.</p>
<p>Australia’s last fresh fruit cannery is <a href="http://www.abc.net.au/news/2014-02-13/victorian-government-announces-package-for-spc-ardmona/5257564">safe for now</a>. But its demise would have caused a shortfall in packaged fruit that would need to be sourced from overseas. Given that China is Australia and the world’s largest supplier of prepared fruit, it’s likely that much of the shortfall would be sourced from China. </p>
<p>The challenges facing SPC Ardmona highlight the risks confronting both Australian food producers and consumers. The steady increase in cheap food imports means that Australian producers of food face an increasingly uneven playing field: one in which it is harder every day to stay profitable.</p>
<p>For Australian consumers, the increase of food imports from countries facing severe contamination issues - such as China - creates a difficult choice between the superior and more expensive Australian product and the often much cheaper import. Unfortunately, there are far too many consumers who are unaware of the potentially serious risks to their health of buying the import. </p>
<p>In <a href="http://www.news.com.au/finance/tony-abbott-says-no-taxpayers-money-to-rescue-spc-ardmona/story-e6frfm1i-1226814102074">denying federal assistance</a> to SPC Ardmona, Prime Minister Tony Abbott has said he wants to signal the end of the corporate “free ride”. But he should bear in mind that the consequences of leaving Australian food manufacturing by the roadside are far greater than any short-term economic agenda.</p><img src="https://counter.theconversation.com/content/22850/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Christopher G. Baker does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>SPC Ardmona’s $22 million lifeline from the Victorian government seems to have saved Australia’s largest food packaging company. Yet the firm’s recent tribulations are a reminder of why I regularly choose…Christopher G. Baker, Research Analyst, Centre for International Security Studies, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/122132013-02-21T19:34:13Z2013-02-21T19:34:13ZUnderstanding the recent listeria-linked cheese recall<figure><img src="https://images.theconversation.com/files/20449/original/gjcb65hg-1361333017.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Soft, surface-ripened cheeses, such as Brie and Camembert, are most likely to transmit listeriosis.</span> <span class="attribution"><span class="source">Shutterstock/Jiri Hera</span></span></figcaption></figure><p>Soft cheeses made by <a href="http://www.jindi.com.au/">Jindi</a> were recently recalled in Victoria, after they were <a href="http://www.theage.com.au/victoria/infected-cheeses-claim-third-victim-20130209-2e5dh.html">linked to the deaths</a> of three adults, a miscarriage, and a score of other cases of “listeriosis”. The case is a reminder of the need for public health authorities to be vigilant about educating at-risk people about this disease and for the food industry to minimise the risk from contaminated food.</p>
<h2>Deadly disease</h2>
<p>Listeriosis is almost always acquired by eating contaminated foods. While listeria monocytogenes are quite common in the environment (and at low levels in many fresh foods), the disease itself is rare. There are about 60 reported cases a year in Australia, and that rate is similar to other developed nations, although it’s possible that as many cases again go undetected. </p>
<p>If detected early enough, infections can be treated successfully with antibiotics. Despite being uncommon, listeriosis is very serious and will be fatal for 20% to 30% of infected people. This statistic is repeated in the current outbreak, which has seen four deaths out of about 20 cases.</p>
<p>Listeria monocytogenes is harmless to most people, even when ingested at high levels. Many of us will have the bacteria in our guts at some time and they usually pass through without harming us. People at high risk are those with reduced immune function, such as those on drugs to stop rejection of an organ transplant, or to control an autoimmune disease, such as <a href="https://theconversation.com/why-its-never-lupus-television-illness-and-the-making-of-a-meme-1198">lupus</a>, those receiving anti-cancer treatments, the aged, those with diabetes, liver or kidney disease, and the unborn or very young babies. </p>
<p>Indeed, a person with liver cancer is nearly 1000 times more likely to get listeriosis than a healthy young adult, while pregnant women and their foetuses are at about 100 times greater risk. Virtually every person who gets listeriosis has some underlying condition that predisposes them to infection.</p>
<p>If people susceptible to listeriosis ingest a large amount of listeria, some may cross from the intestine into the cells of the body, where they can “hide” from the immune system. They then increase in number, moving from cell to cell, and spreading to susceptible sites in the body, where they cause damage to host cells. This results in disease symptoms. The most common sites of overt infection and damage are the central nervous system and the uterus of pregnant women and foetuses.</p>
<h2>Mitigating risk</h2>
<p>Health authorities have produced information pamphlets for pregnant women to alert them to the risk from eating certain foods, while also giving advice about alternative foods to meet nutritional needs. Such advice is equally relevant to people with reduced immunity.</p>
<p>Since listeriosis was first recognised in the 1980s as a food-borne disease capable of causing outbreaks with deadly consequences, research has shown how best to reduce the risk. Listeria is common in nature, preferring moist habitats where there’s decaying organic matter, such as rotting vegetation. Unusually among bacteria that can cause human infection, it can grow at refrigeration temperatures and tolerates quite salty conditions. As such, it can grow in foods that have traditionally relied on added salt and chilling to extend shelf life. </p>
<p>Some of these foods allow listeria to grow to dangerous levels, albeit slowly. Foods most at risk of transmitting listeriosis are those that have a long shelf life but that still require refrigeration, such as “ready-to-eat” processed meats (for example ham, cold meats and paté), cheeses (particularly soft, surface-ripened cheeses, such as Brie, or Camembert), smoked fish and other lightly preserved seafood, and some types of pre-prepared salads.</p>
<p>Listeria’s lifestyle means it likes to set up house in food factories, because they often have nooks and crannies that are cool, remain wet and have traces of food to sustain populations of the bacteria. For the food industry, understanding that lifestyle has led to increased vigilance and steps to prevent listeria from becoming established factories, to detect it if it has, and to prevent if from contaminating foods. </p>
<p>This increased vigilance has also meant that potential problems are more reliably detected before contaminated foods are released or people become ill. Foods are also sometimes recalled to minimise risk to consumers.</p><img src="https://counter.theconversation.com/content/12213/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tom Ross receives funding from Meat and Livestock Australia, and NZ Ministry of Primary Industries. </span></em></p>Soft cheeses made by Jindi were recently recalled in Victoria, after they were linked to the deaths of three adults, a miscarriage, and a score of other cases of “listeriosis”. The case is a reminder of…Tom Ross, Associate Professor in Food Microbiology, Food Safety Centre, School of Agricultural Science, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/121922013-02-15T03:53:01Z2013-02-15T03:53:01ZHorse-meat scandal is about breach of consumer trust<figure><img src="https://images.theconversation.com/files/20225/original/hrhwjgv7-1360731378.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The plot thickened when some Findus and Aldi products were found to contain 100% horse meat.</span> <span class="attribution"><span class="source">Ian Langsdon/AAP</span></span></figcaption></figure><p>Woolworths has announced it will <a href="http://finance.ninemsn.com.au/newsbusiness/8609639/woolies-checking-meals-for-horse-meat">conduct DNA tests</a> on its home-brand meals in response to horse meat contamination in Europe. The uproar follows revelations by Irish food inspectors in mid-January that horse meat had been detected in burgers sold in UK supermarket chains.</p>
<p>The story intensified when some Findus and Aldi products labelled as beef were found to be <a href="http://www.guardian.co.uk/money/2013/feb/08/horsemeat-findus-lasagne-consumer">100% horse meat</a> and may now involve as many as <a href="http://www.bbc.co.uk/news/world-europe-21437317">16 European countries</a>. In response to the growing evidence for <a href="http://www.bbc.co.uk/news/world-21412590">widespread mislabelling</a>, the EU Health Commissioner Tonio Borg has now urged all EU member states to <a href="http://www.neurope.eu/article/dna-tests-be-carried-out-european-meat">implement random DNA testing</a> of processed beef products, for a three-month period beginning March 1.</p>
<p>By saying it will test what it sells here, <a href="http://www.woolworths.com.au/wps/wcm/connect/webSite/Woolworths/">Woolworths</a> is indicating to both the government and the public that it recognises the issue has become an identifiable risk. And it wants to assure customers that its products are legitimate.</p>
<p>Still, there’s no sign of a problem in Australia that’s similar to what’s happening in Europe, which seems to be in the grip of what is ostensibly economic fraud – the substitution of horse meat in products sold as beef. There don’t seem to be any specific food safety issues involved, although some commentators have raised the possibility of contamination with veterinary pharmaceuticals, which could have a negative impact on human health.</p>
<p>The issue is economic rather than nutritional. People eat meat because they enjoy it – they enjoy the texture and the flavour. Often people become accustomed to the flavour of the meat they eat, so horse meat may taste different, possibly “gamey”, but it’s easy to become accustomed to this. </p>
<p>Horse meat is generally very lean but otherwise nutritionally similar to beef or sheep. It’s a good source of protein, vitamins, minerals (especially iron) and healthy fatty acids (omega-3).</p>
<p>So, at the heart of the issue is a breach of trust for economic gain rather than being fed something unthinkable. Products have been labelled as containing beef, when they may in fact contain up to 100% horse meat. But let’s go back to the problem of veterinary pharmaceuticals. Some of these compounds are painkillers and since the human body responds differently to such drugs compared to horses, we get into dangerous territory for human health.</p>
<p>The substance causing the most concern is <a href="http://www.bbc.co.uk/news/uk-21455419">phenylbutazone</a>, an anti-inflammatory drug given to horses for the treatment of lameness, pain and fever. It’s no longer used to treat humans and is not supposed to enter the food chain because it may cause a range of side effects. Some of these are quite serious, such as aplastic anaemia (bone marrow failure) in some people. But authorities in the United Kingdom have declared the illegal horse meat in the food safe to eat.</p>
<p>The difficulty for any regulator, such as the <a href="http://www.food.gov.uk/">UK Food Standards Agency</a>, is the same as the public faces. There has to be some degree of trust, let’s say, truth in labelling. If a supplier indicates that a food contains particular ingredients, then one can expect it will. Once again, what we’re talking about here is a breach of trust and that’s what’s unacceptable.</p>
<p>For food standards authorities around the world, the question is, does any agency have the ability to test everything? We think that’s what lies at the heart of the matter here. No agency has the resources to test everything and compliance with accepted food standard codes and labelling is vital.</p>
<p>But Europe will recover. Generally speaking, recovery from a scandal of this kind begins with a phase of greater accountability, and a requirement for food manufacturers to provide more independent evidence substantiating the authenticity of ingredients. Rogue operators shown to be breaching trust and behaving fraudulently are punished and banned. This is what we can expect to happen in the coming weeks. The EU Health Commissioner’s announcement suggests that the cleanout has begun.</p><img src="https://counter.theconversation.com/content/12192/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>CSIRO receives funding from Meat and Livestock Australia for research concerning the safety and quality of beef and sheepmeat.</span></em></p><p class="fine-print"><em><span>Robyn Warner does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Woolworths has announced it will conduct DNA tests on its home-brand meals in response to horse meat contamination in Europe. The uproar follows revelations by Irish food inspectors in mid-January that…Kari Gobius, Theme Leader - Food Safety and Stability, CSIRORobyn Warner, Senior Principal Research Scientist, Team Leader Food Chemistry and Biochemistry, Animal, Food and Health Sciences, CSIROLicensed as Creative Commons – attribution, no derivatives.