tag:theconversation.com,2011:/fr/topics/indoor-pollution-10709/articlesIndoor pollution – The Conversation2023-01-29T19:09:20Ztag:theconversation.com,2011:article/1979082023-01-29T19:09:20Z2023-01-29T19:09:20ZToxic pollutants can build up inside our homes. Here are 8 ways to reduce the risks<figure><img src="https://images.theconversation.com/files/506044/original/file-20230124-15-cgwl3k.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3988&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>We know everything in our homes gathers dust. What you probably don’t know is whether there are toxic contaminants in your house dust, and where these might come from. </p>
<p>Our <a href="https://doi.org/10.1016/j.envres.2022.115173">newly published research</a> found most of the dust inside homes came from outside and contains potentially toxic trace metals such as lead, arsenic and chromium. </p>
<p>Worryingly, we found some contaminants can accumulate at higher concentrations inside homes than outside. This happened in homes with certain characteristics: older properties, metal construction materials enriched in zinc, recent renovations and deteriorating paint. </p>
<p>Fortunately, you can take some simple steps to reduce your exposure, which we explain later.</p>
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Read more:
<a href="https://theconversation.com/what-is-dust-and-where-does-it-all-come-from-168265">What is dust? And where does it all come from?</a>
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<h2>What’s in house dust?</h2>
<p>Our study explored the connected sources, pathways and potentially harmful exposures to trace metals at homes across Sydney. We collected and analysed 383 samples from nearby road dust (51 samples) and garden soil (166), as well as indoor dust (166).</p>
<p>We found the dust in homes comes from a range of sources including outdoor environments and soil, skin, cleaning products, pet hair and cooking particles.<br>
Nearly 60% of dust particles inside the homes originated from their immediate outdoor environment – it was <a href="https://theconversation.com/wearing-shoes-in-the-house-is-just-plain-gross-the-verdict-from-scientists-who-study-indoor-contaminants-177542">dirt from outside</a>! Wind, your shoes or your pets can carry in <a href="https://www.sciencedirect.com/science/article/pii/S0160412021002075?via%3Dihub">soil</a> and <a href="https://pubs.acs.org/doi/10.1021/acs.est.1c04494">dust</a>-related contaminants. </p>
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Read more:
<a href="https://theconversation.com/wearing-shoes-in-the-house-is-just-plain-gross-the-verdict-from-scientists-who-study-indoor-contaminants-177542">Wearing shoes in the house is just plain gross. The verdict from scientists who study indoor contaminants</a>
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<figure class="align-center ">
<img alt="Dog looks back after leaving muddy paw prints on carpet" src="https://images.theconversation.com/files/506038/original/file-20230124-13-dx8set.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506038/original/file-20230124-13-dx8set.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506038/original/file-20230124-13-dx8set.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506038/original/file-20230124-13-dx8set.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506038/original/file-20230124-13-dx8set.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506038/original/file-20230124-13-dx8set.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506038/original/file-20230124-13-dx8set.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">
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<span class="caption">Wind, your shoes or your pets can all carry contaminants into your home.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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</figure>
<p>The remaining 40% of home dust came from indoor sources. These included <a href="https://theconversation.com/microplastics-are-common-in-homes-across-29-countries-new-research-shows-whos-most-at-risk-189051">fibres from clothes, carpets and furnishings</a>, cleaning products, skin and hair.</p>
<p>Some dust sources can carry a cocktail of potentially harmful contaminants including:</p>
<ul>
<li><p><a href="https://doi.org/10.1016/j.envpol.2021.117064">microplastics</a></p></li>
<li><p><a href="https://doi.org/10.1016/j.envres.2014.10.009">persistent organic pollutants</a></p></li>
<li><p><a href="https://doi.org/10.1016/j.scitotenv.2019.05.463">perfluorinated chemicals</a> (PFAS)</p></li>
<li><p><a href="https://doi.org/10.1016/j.envpol.2021.117593">trace metals</a></p></li>
<li><p><a href="https://doi.org/10.3389/fenvs.2021.754657">bacterial communities</a></p></li>
<li><p><a href="https://doi.org/10.1016/j.envint.2021.106501">antimicrobial resistance genes</a>. </p></li>
</ul>
<p>The nature of the risk is related to how much of the contaminant you’re exposed to and for how long. The risks are greatest in children under the age of five. This is because they are small, closer to the floor and have frequent hand-mouth contact, which increases ingestion of contaminants. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/506043/original/file-20230124-19-v1sh36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506043/original/file-20230124-19-v1sh36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506043/original/file-20230124-19-v1sh36.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506043/original/file-20230124-19-v1sh36.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506043/original/file-20230124-19-v1sh36.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506043/original/file-20230124-19-v1sh36.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506043/original/file-20230124-19-v1sh36.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Young children’s size and behaviour leave them more at risk of exposure to indoor contaminants.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/microplastics-are-common-in-homes-across-29-countries-new-research-shows-whos-most-at-risk-189051">Microplastics are common in homes across 29 countries. New research shows who's most at risk</a>
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<h2>How do contaminants build up in homes?</h2>
<p>Industrial activity has left a marked legacy of contaminants in many city neighbourhoods. We analysed road dust, garden soil and vacuum dust samples from 166 homes in Sydney to see how this risk translated to inside homes. We used high-magnification microscopy and <a href="https://www.climate-policy-watcher.org/earth-sciences/lead-isotopes-as-tools-for-source-identification.html">lead isotopic ratios</a> to understand trace metal composition in the samples. </p>
<p>On average, concentrations of trace metals arsenic, chromium, copper, manganese, lead and zinc were all higher inside homes than outside. This means homes are not only “accumulators” of trace metal contaminants but also important sources of a significant proportion of harmful contaminants that we can be exposed to. </p>
<p>The lead isotopic ratios, or the lead “fingerprints”, of each home and its garden soil matched. This confirms the soil is the main source of lead inside homes. </p>
<p>Most of this lead is the result of the pre-1970s use of high concentrations of lead in <a href="https://www.dcceew.gov.au/environment/protection/chemicals-management/lead/lead-in-house-paint">paints</a> and <a href="http://dx.doi.org/10.1016/j.apgeochem.2017.02.007">petrol</a>, which contaminated many garden soils. Even <a href="https://theconversation.com/why-lead-is-dangerous-and-the-damage-it-does-116506">low levels of lead exposure</a> can be harmful. Lead levels in some <a href="https://theconversation.com/elevated-lead-levels-in-sydney-back-yards-heres-what-you-can-do-68499">Sydney backyards</a> pose a risk for <a href="https://doi.org/10.1016/j.dib.2021.107151">urban veggie growers</a> and <a href="https://theconversation.com/backyard-hens-eggs-contain-40-times-more-lead-on-averagethan-shop-eggs-research-finds-187442">backyard chickens and their eggs</a>. </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>
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<p>High-magnification images of house dust showed mineral particles that have been blown in or tracked in on shoes. The rest of the dust was elongated fibres and hair from indoor sources.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/505802/original/file-20230123-23-4i7gf6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/505802/original/file-20230123-23-4i7gf6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505802/original/file-20230123-23-4i7gf6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=638&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505802/original/file-20230123-23-4i7gf6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=638&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505802/original/file-20230123-23-4i7gf6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=638&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505802/original/file-20230123-23-4i7gf6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=801&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505802/original/file-20230123-23-4i7gf6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=801&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505802/original/file-20230123-23-4i7gf6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=801&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In this high-magnification image of indoor dust, the long particles are fibres and the angular particles are of mineralogical origin from outdoors.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Which homes are most at risk?</h2>
<p>We also collected information about each house, relevant activities and renovations at the property. We found house age, proximity to the city centre and renovations had the greatest influence on levels of lead and other trace metals in the home. </p>
<p>All homes more than 50 years old had higher concentrations of arsenic, copper, lead and zinc in their garden soil and house dust. They are typically <a href="https://iupui-earth-science.shinyapps.io/MME_Sydney/">located closer to city centres</a>, where early industrial activity has contaminated soils. </p>
<p>As older homes in former industrial areas are renovated, trace metal loads in these homes and gardens can increase. Walls and ceilings contain decades of dust. Old paint buried under more recent layers can also be released, causing <a href="https://www.abc.net.au/radionational/programs/backgroundbriefing/3983094">lead exposure risks</a>. </p>
<p>It is critical that home renovators take appropriate remediation steps or <a href="https://painters.edu.au/Training-Courses/CPCCPD3031-Work-safely-with-lead-painted-surfaces-in-the-painting-industry.htm">employ a qualified paint professional</a> so lead dust isn’t spread across the area. </p>
<figure class="align-center ">
<img alt="Old red paint peeling of weatherboards and a windowframe" src="https://images.theconversation.com/files/506041/original/file-20230124-11-mrdiel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506041/original/file-20230124-11-mrdiel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=454&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506041/original/file-20230124-11-mrdiel.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=454&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506041/original/file-20230124-11-mrdiel.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=454&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506041/original/file-20230124-11-mrdiel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=571&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506041/original/file-20230124-11-mrdiel.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=571&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506041/original/file-20230124-11-mrdiel.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=571&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Old lead-based paint is a major source of contamination, especially if it’s deteriorating or proper precautions aren’t taken when removing it.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>8 ways to reduce your risk</h2>
<p>We spend about <a href="https://escholarship.org/uc/item/1zg3q68x#main">70% of our time at home</a>, which the pandemic has increased. Understanding the environmental <a href="https://www.cdc.gov/niosh/topics/exposome/default.html">conditions and contaminants we encounter</a> and their effects on our health is more important than ever. </p>
<p>Armed with this knowledge, though, you can take some simple steps to reduce your exposure to contaminants in your home and garden:</p>
<ol>
<li><p>regularly vacuum carpeted areas with a good vacuum cleaner fitted with a <a href="https://www2.education.vic.gov.au/pal/ventilation-air-purification/print-all">HEPA filter</a></p></li>
<li><p>wet mop and wet dust hard surfaces</p></li>
<li><p>mulch areas of exposed soil in your garden</p></li>
<li><p>use a quality doormat and wash it regularly, which can roughly <a href="https://nrl.northumbria.ac.uk/id/eprint/51148/1/Manuscript_File_Global_Pb_Modeling_Final_clean_1%20%281%29.pdf">halve the amount of lead</a> in your home within three months</p></li>
<li><p>leave your shoes at the door as they can <a href="https://theconversation.com/wearing-shoes-in-the-house-is-just-plain-gross-the-verdict-from-scientists-who-study-indoor-contaminants-177542">bring all sorts of nasties into the home</a></p></li>
<li><p>wash your hands and your veggies thoroughly </p></li>
<li><p>close windows on windy days</p></li>
<li><p>when renovating, use dust-mitigation strategies and personal protective equipment (PPE).</p></li>
</ol>
<p>You can dig a little deeper into what’s in your own home environment by sending your soil to <a href="https://www.360dustanalysis.com">VegeSafe Australia</a> or <a href="https://www.epa.vic.gov.au/for-community/get-involved/citizen-science-program/gardensafe">EPA Victoria’s GardenSafe</a> for analysis. If you live in the United States, Canada, United Kingdom or Australia you can also send your vacuum dust to <a href="https://www.360dustanalysis.com">DustSafe</a> for testing. You will receive a report outlining what was in your sample, with links and advice on what to do next where necessary.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/house-dust-from-35-countries-reveals-our-global-toxic-contaminant-exposure-and-health-risk-172499">House dust from 35 countries reveals our global toxic contaminant exposure and health risk</a>
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</p>
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<img src="https://counter.theconversation.com/content/197908/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Patrick Taylor received funding via an Australian Government Citizen Science Grant (2017-2020), CSG55984 ‘Citizen insights to the composition and risks of household dust’ (the DustSafe project). The VegeSafe and DustSafe programs are supported by publication donations to Macquarie University. He is a full-time employee of EPA Victoria, appointed to the statutory role of Chief Environmental Scientist.</span></em></p><p class="fine-print"><em><span>Carlos Ibañez del Rivero receives funding from Macquarie University and National Council on Science and Technology, Mexico (CONACYT) support number 739570 in the form of graduate stipends for his PhD program and partial funding for his tuition costs.</span></em></p><p class="fine-print"><em><span>Kara Fry is a Senior Research and Development Officer at EPA Victoria. Previously, Kara was a research assistant for VegeSafe and DustSafe, supported by public donations to Macquarie University and an Australian Government Citizen Science Grant (2017-2020), CSG55984 ‘Citizen insights to the composition and risks of household dust’.</span></em></p>Levels of trace metals inside can be higher than the sources of contamination outside. It underscores the need for households to take care to prevent those contaminants being brought indoors.Mark Patrick Taylor, Victoria's Chief Environmental Scientist, EPA Victoria; Honorary Professor, School of Natural Sciences, Macquarie UniversityCarlos Ibañez del Rivero, PhD candidate, School of Natural Sciences, Macquarie UniversityKara Fry, Adjunct Fellow, School of Natural Sciences, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1775422022-03-16T03:57:09Z2022-03-16T03:57:09ZWearing shoes in the house is just plain gross. The verdict from scientists who study indoor contaminants<figure><img src="https://images.theconversation.com/files/450599/original/file-20220308-109743-ujxk6x.jpg?ixlib=rb-1.1.0&rect=0%2C31%2C5280%2C3498&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>You probably clean your shoes if you step in something muddy or disgusting (please pick up after your dog!). But when you get home, do you always de-shoe at the door?</p>
<p>Plenty of Australians don’t. For many, what you <a href="https://sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/jam.13250">drag in on the bottom of your shoes</a> is the last thing on the mind as one gets home.</p>
<p>We are environmental chemists who have spent a decade examining the indoor environment and the contaminants people are exposed to in their own homes. Although our examination of the indoor environment, via our <a href="https://www.360dustanalysis.com">DustSafe program</a>, is far from complete, on the question of whether to shoe or de-shoe in the home, the science leans toward the latter. </p>
<p>It is best to leave your filth outside the door.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/447469/original/file-20220221-18-1h8q5jy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A woman removes shoes at the front door." src="https://images.theconversation.com/files/447469/original/file-20220221-18-1h8q5jy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/447469/original/file-20220221-18-1h8q5jy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/447469/original/file-20220221-18-1h8q5jy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/447469/original/file-20220221-18-1h8q5jy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/447469/original/file-20220221-18-1h8q5jy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/447469/original/file-20220221-18-1h8q5jy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/447469/original/file-20220221-18-1h8q5jy.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"></a>
<figcaption>
<span class="caption">It is best to leave your filth outside the door.</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/house-dust-from-35-countries-reveals-our-global-toxic-contaminant-exposure-and-health-risk-172499">House dust from 35 countries reveals our global toxic contaminant exposure and health risk</a>
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<h2>What contaminants are in your home, and how did they get there?</h2>
<p>People spend up to 90% of their time indoors, so the question of whether or not to wear shoes in the house is not a trivial one.</p>
<p>The policy focus is typically on the outdoor environment for soil, air quality and environmental public health risks. However, there is growing regulatory interest in the question of <a href="https://ncc.abcb.gov.au/sites/default/files/resources/2021/Handbook-Indoor-Air-Quality.pdf">indoor</a> <a href="https://www.euro.who.int/en/media-centre/sections/press-releases/2021/new-who-global-air-quality-guidelines-aim-to-save-millions-of-lives-from-air-pollution">air quality</a>. </p>
<p>The matter <a href="https://www.tandfonline.com/doi/abs/10.1080/09603123.2018.1457141?journalCode=cije2">building up</a> inside your home includes not just dust and dirt from people and pets shedding hair and skin.</p>
<p>About a third of it is <a href="https://pubs.acs.org/doi/10.1021/es9003735">from outside</a>, either blown in or <a href="https://www.washingtonpost.com/health/how-the-dust-in-your-home-may-affect-your-health/2019/07/19/9f716068-a351-11e9-bd56-eac6bb02d01d_story.html">tramped</a> in on those offensive shoe bottoms.</p>
<p>Some of the microorganisms present on shoes and floors are <a href="https://www.cambridge.org/core/journals/epidemiology-and-infection/article/mechanisms-for-floor-surfaces-or-environmental-ground-contamination-to-cause-human-infection-a-systematic-review/37BF6318BD1473C4918A23C843B25D05">drug-resistant pathogens</a>, including hospital-associated infectious agents (germs) that are very difficult to treat.</p>
<p>Add in cancer-causing toxins from <a href="https://www.tandfonline.com/doi/full/10.1080/10408444.2018.1528208">asphalt road residue</a> and endocrine-disrupting <a href="https://www.tandfonline.com/doi/full/10.1080/23273747.2016.1148803">lawn chemicals</a>, and you might view the filth on your shoes in a new light.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/447472/original/file-20220221-24-z7zsx5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A woman rests her feet on the couch" src="https://images.theconversation.com/files/447472/original/file-20220221-24-z7zsx5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/447472/original/file-20220221-24-z7zsx5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/447472/original/file-20220221-24-z7zsx5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/447472/original/file-20220221-24-z7zsx5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/447472/original/file-20220221-24-z7zsx5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/447472/original/file-20220221-24-z7zsx5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/447472/original/file-20220221-24-z7zsx5.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"></a>
<figcaption>
<span class="caption">Please don’t do this.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>A roll-call of indoor nasties</h2>
<p>Our work has involved the measurement and assessment of exposure to a range of harmful substances found inside homes including:</p>
<ul>
<li><p><a href="https://www.newscientist.com/article/2231210-antibiotic-resistance-genes-can-be-passed-around-by-bacteria-in-dust/">antibiotic-resistant genes</a> (genes that make bacteria resistant to antibiotics)</p></li>
<li><p><a href="https://pubs.acs.org/doi/10.1021/acs.estlett.0c00587">disinfectant chemicals in the home environment</a> </p></li>
<li><p><a href="https://doi.org/10.1016/j.envpol.2021.117064">microplastics</a></p></li>
<li><p>the <a href="https://bmjopen.bmj.com/content/11/5/e044833.citation-tools">perfluorinated chemicals</a> (also known as PFAS or “forever chemicals” because of their tendency to remain in the body and not break down) used ubiquitously in a multitude of industrial, domestic and food packaging products</p></li>
<li><p><a href="http://hdl.handle.net/1959.14/1276977">radioactive elements</a>.</p></li>
</ul>
<p>A strong focus of our work has involved assessing levels of <a href="https://theconversation.com/house-dust-from-35-countries-reveals-our-global-toxic-contaminant-exposure-and-health-risk-172499">potentially toxic metals (such as arsenic, cadmium and lead)</a> inside homes across <a href="https://doi.org/10.1021/acs.est.1c04494">35 nations (including Australia)</a>.</p>
<p>These contaminants – and most importantly the dangerous neurotoxin lead – are odourless and colourless. So there is no way of knowing whether the dangers of lead exposure are only in your <a href="https://doi.org/10.1016/j.envint.2021.106582">soils</a> or your <a href="https://www.abcb.gov.au/sites/default/files/resources/2020/Lead_in_Plumbing_Products_and_Materials.pdf">water pipes</a>, or if they are also on your <a href="https://theconversation.com/house-dust-from-35-countries-reveals-our-global-toxic-contaminant-exposure-and-health-risk-172499">living room floor</a>.</p>
<p>The <a href="https://theconversation.com/house-dust-from-35-countries-reveals-our-global-toxic-contaminant-exposure-and-health-risk-172499">science</a> suggests a very strong connection between the lead inside your <a href="https://www.mapmyenvironment.com">home and that in your yard soil</a>.</p>
<p>The most likely reason for this connection is dirt blown in from your yard or trodden in on your shoes, and on the furry paws of your adorable pets. </p>
<p>This connection speaks to the priority of making sure matter from your outdoor environment stays exactly there (we have tips <a href="https://www.360dustanalysis.com/pages/interpreting-your-results">here</a>).</p>
<p>A recent Wall Street Journal <a href="https://www.wsj.com/articles/heres-why-ill-be-keeping-my-shoes-on-in-your-shoeless-home-11644503227">article</a> argued shoes in the home aren’t so bad. The author made the point that <em>E. coli</em> – dangerous bacteria that develop in the intestines of many mammals, including humans – is so widely distributed that it’s pretty much everywhere. So it should be no surprise it can be swabbed on shoe bottoms (96% of shoe bottoms, as the article pointed out). </p>
<p>But let’s be clear. Although it’s nice to be scientific and stick with the term <em>E. coli</em>, this stuff is, put more simply, the bacteria associated with poo. </p>
<p>Whether it is ours or Fido’s, it has the potential to make us very sick if we are exposed at high levels. And let’s face it – it is just plain gross.</p>
<p>Why walk it around inside your house if you have a very simple alternative – to take your shoes off at the door?</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/447449/original/file-20220221-26-1xza5z0.jpg?ixlib=rb-1.1.0&rect=0%2C1518%2C4541%2C2090&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/447449/original/file-20220221-26-1xza5z0.jpg?ixlib=rb-1.1.0&rect=0%2C1518%2C4541%2C2090&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/447449/original/file-20220221-26-1xza5z0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=477&fit=crop&dpr=1 600w, https://images.theconversation.com/files/447449/original/file-20220221-26-1xza5z0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=477&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/447449/original/file-20220221-26-1xza5z0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=477&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/447449/original/file-20220221-26-1xza5z0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=599&fit=crop&dpr=1 754w, https://images.theconversation.com/files/447449/original/file-20220221-26-1xza5z0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=599&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/447449/original/file-20220221-26-1xza5z0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=599&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Why walk muck around inside your house if you have a very simple alternative – to take your shoes off at the door?</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>On balance, shoeless wins</h2>
<p>So are there disadvantages to having a shoe-free household? </p>
<p>Beyond the <a href="https://www.washingtonpost.com/lifestyle/wellness/feet-toes-broken-pain-covid/2021/01/11/470d2efa-4a05-11eb-a9f4-0e668b9772ba_story.html">occasional stubbed toe</a>, from an environmental health standpoint there aren’t many downsides to having a shoe-free house. Leaving your shoes at the entry mat also leaves potentially harmful pathogens there as well.</p>
<p>We all know prevention is far better than treatment and taking shoes off at the door is a basic and easy prevention activity for many of us. </p>
<p>Need shoes for foot support? Easy – just have some “indoor shoes” that never get worn outside.</p>
<p>There remains the issue of the “sterile house syndrome,” which refers to increased rates of allergies among children. Some argue it’s related to overly sterile households.</p>
<p>Indeed, some dirt is probably beneficial as <a href="https://www.jacionline.org/article/S0091-6749(10)00907-3/fulltext">studies</a> have indicated it helps develop your immune system and reduce allergy risk.</p>
<p>But there are better and less gross ways to do that than walking around inside with your filthy shoes on. Get outside, go for a bushwalk, enjoy the great outdoors. </p>
<p>Just don’t bring the muckier parts of it inside to build up and contaminate our homes.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/what-is-dust-and-where-does-it-all-come-from-168265">What is dust? And where does it all come from?</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/177542/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Patrick Taylor received funding via an Australian Government Citizen Science Grant (2017-2020), CSG55984 ‘Citizen insights to the composition and risks of household dust’ (the DustSafe project). He is an Honorary Professor at Macquarie University and a full time employee of EPA Victoria, appointed to the statutory role of Chief Environmental Scientist.</span></em></p><p class="fine-print"><em><span>Gabriel Filippelli 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>It is best to leave your filth outside the door.Mark Patrick Taylor, Chief Environmental Scientist, EPA Victoria; Honorary Professor, Macquarie UniversityGabriel Filippelli, Chancellor's Professor of Earth Sciences and Executive Director, Indiana University Environmental Resilience Institute, IUPUILicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/706112016-12-21T11:17:28Z2016-12-21T11:17:28ZAir pollution expert: why Christmas may be the most toxic day of the year<figure><img src="https://images.theconversation.com/files/151011/original/image-20161220-9515-1puihuz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source"> Goncharenya Tanya / shutterstock</span></span></figcaption></figure><p>On Christmas Day in 1879 the combination of fog and smoke was so dense over London that it was <a href="http://www.victorianlondon.org/weather/londonfogs.htm">virtually dark</a> at noon. Nowadays, with many people staying at home and fewer vehicles on the road, the ambient air quality on Christmas Day is typically very good. However air in the home may be at its worst. </p>
<p>On Christmas, indoor sources of air pollution can generate particles that, in terms of number and mass concentrations, significantly exceed background levels. Here are a few reasons why.</p>
<h2>Turkey pollution</h2>
<p>Cooking the traditional Christmas dinner can result in elevated levels of a number of pollutants. Ultrafine particles (UFP) smaller than 100 nanometres are of special interest from a health perspective, since they can penetrate deep into the respiratory system and cause inflammatory effects. A number of studies have reported increased UFP concentrations associated with electric stoves and cooking utensils, perhaps from <a href="http://onlinelibrary.wiley.com/doi/10.1111/ina.12163/full">heating detergent residues</a>.</p>
<p>The number of particles emitted during cooking depends upon factors such as the raw food composition, cooking temperature and style – stirring food has been shown to <a href="http://www.tandfonline.com/doi/pdf/10.1080/10473289.2000.10464154">produce larger aerosols</a> as the ingredients are splashed about and tiny specs fly into the atmosphere.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151014/original/image-20161220-26729-ukff1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151014/original/image-20161220-26729-ukff1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151014/original/image-20161220-26729-ukff1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151014/original/image-20161220-26729-ukff1w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151014/original/image-20161220-26729-ukff1w.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151014/original/image-20161220-26729-ukff1w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151014/original/image-20161220-26729-ukff1w.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151014/original/image-20161220-26729-ukff1w.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"></a>
<figcaption>
<span class="caption">Santa’s little polluters.</span>
<span class="attribution"><span class="source">Sergey kamenskykh / shutterstock</span></span>
</figcaption>
</figure>
<p>Gas cooking is a major source of both nitrogen dioxide (a harmful gas) and particulate matter (tiny, often hazardous particles suspended in the air). Kitchens with gas cooking can have higher levels of nitrogen dioxide than even a busy roadside.</p>
<p>In fact it has been shown that gas cooking is associated with increased risk of both <a href="http://ije.oxfordjournals.org/content/early/2013/08/20/ije.dyt150.full.pdf">current and lifetime asthma</a>.</p>
<p>The health risks associated with cooking are poorly understood, although UK regulations require <a href="https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/468871/ADF_LOCKED.pdf">extractor fans in kitchens</a>. Given that it takes <a href="http://www.dailymail.co.uk/femail/article-417821/The-13-days-Christmas-spent-average-mum-preparing-big-meal.html#ixzz4SM61jzp7">more than four hours</a> to prepare and cook the average Christmas dinner, people with asthma or cardiovascular disease may want to avoid the kitchen. When cooking, especially with gas, it is important to keep the extractor fan on or open a window. </p>
<h2>See the blazing yule before us</h2>
<p>Wood burning is becoming more popular – often for aesthetic reasons – and this releases significant amounts of particulate pollution into the outdoor environment. Wood smoke is a significant reason why many cities are <a href="https://www.theguardian.com/cities/2016/jan/19/log-fires-traffic-fumes-cause-bergen-air-pollution">exceeding European air quality limits</a> during winter. In Denmark, emissions from wood-burning stoves are calculated to cause <a href="https://ideas.repec.org/p/foi/wpaper/2016_11.html">400 premature deaths</a> every year, while in London it accounts for <a href="http://www.atmos-chem-phys.net/15/3149/2015/">between 7% and 9%</a> of wintertime particle pollution.</p>
<p>Studies have also shown wood smoke can enter neighbouring homes. Even if wood is burnt in modern stoves rather than open fires, <a href="http://www.telegraph.co.uk/news/earth/environment/12175306/Is-my-wood-burning-stove-really-killing-me-What-happened-when-I-monitored-my-exposure-to-pollution.html">start-up, stoking and reloading</a> can still cause high emissions. Smoke from firewood contains hundreds of compounds which can cause <a href="http://www.dailymail.co.uk/news/article-3972966/Inconvenient-truth-wood-burning-stove-bad-environment-health.html">cancer, mutations or defective pregnancies</a>. </p>
<p>To reduce emissions allow wood to season before burning it. Keep it dry as it burns most efficiently when its moisture content is <a href="http://www.firewood.co.uk/heating-qualities/">below 20%</a>.</p>
<h2>The dark side of candles</h2>
<p>The use of candles to create a warm, festive atmosphere is common in homes over Christmas. While they look attractive, once lit, they emit ultrafine particles which may contain metals released from the colour pigments. Soot can also be produced, typically when the candle flame flickers due varying air flows. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151012/original/image-20161220-26738-cqeiic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151012/original/image-20161220-26738-cqeiic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151012/original/image-20161220-26738-cqeiic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151012/original/image-20161220-26738-cqeiic.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151012/original/image-20161220-26738-cqeiic.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151012/original/image-20161220-26738-cqeiic.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151012/original/image-20161220-26738-cqeiic.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151012/original/image-20161220-26738-cqeiic.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">Let’s hope these crackers contain gas masks.</span>
<span class="attribution"><span class="source">Rawpixel.com / shutterstock</span></span>
</figcaption>
</figure>
<p>Scented candles are even worse as they release various <a href="http://ec.europa.eu/environment/archives/air/stationary/solvents/legislation.htm">volatile organic compounds</a> (VOCs), identified by the EU as priority indoor pollutants. However <a href="https://theconversation.com/clearing-the-air-the-hidden-wonders-of-indoor-plants-15339">certain house plants</a> can help clean up these compounds.</p>
<p>Party poppers are an often overlooked source of indoor air pollution. In Britain, they are classified as fireworks. While the impact of fireworks outdoors is <a href="https://www.theguardian.com/environment/2015/nov/15/fireworks-bonfire-night-diwali-pollution">well documented</a> detailed knowledge of how it affects the indoor environment is lacking. Although party poppers are short lived, they can generate large concentrations of ultrafine particles. </p>
<p>The figure below shows the result of 10 party poppers in a typical dining room. Particle concentrations are more than 100 times higher than those <a href="http://www.sciencedirect.com/science/article/pii/S1352231011013409">at the roadside</a> and these levels can persist for some time. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/151235/original/image-20161221-3340-83qe76.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/151235/original/image-20161221-3340-83qe76.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/151235/original/image-20161221-3340-83qe76.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=351&fit=crop&dpr=1 600w, https://images.theconversation.com/files/151235/original/image-20161221-3340-83qe76.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=351&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/151235/original/image-20161221-3340-83qe76.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=351&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/151235/original/image-20161221-3340-83qe76.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=442&fit=crop&dpr=1 754w, https://images.theconversation.com/files/151235/original/image-20161221-3340-83qe76.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=442&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/151235/original/image-20161221-3340-83qe76.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=442&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Popper pollution peaks at more than 800,000 tiny particles per cubic centimetre (busy roadsides peak at around 2,000).</span>
<span class="attribution"><span class="source">Ian Colbeck (own measurements)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>It also needs to be remembered that many household activities such as sweeping, hoovering, or even simply moving about, can generate larger particles – although hopefully no one is cleaning the house on Christmas Day. But if you are particularly worried about indoor air pollution a <a href="http://www.nature.com/news/validate-personal-air-pollution-sensors-1.20195">low-cost sensor</a> would make an excellent scientific stocking-filler.</p><img src="https://counter.theconversation.com/content/70611/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Colbeck receives funding from NERC, EU</span></em></p>Party poppers, candles and wood fires will get you feeling festive – and breathing pollution.Ian Colbeck, Professor of Environmental Science, University of EssexLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/547432016-02-16T18:24:02Z2016-02-16T18:24:02ZHidden housemates: meet the moulds growing in your home<figure><img src="https://images.theconversation.com/files/111575/original/image-20160215-8211-15wm44y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Your home is full of fungi. </span> <span class="attribution"><span class="source">Mould image from www.shutterstock.com</span></span></figcaption></figure><p><em>Home alone? Hardly. Our homes are positively swarming with creatures of all kinds. In our new series, we’ll be profiling the “hidden housemates” that live with us.</em> </p>
<p>Our offices and homes are full of airborne spores from fungi, and for the most part we never even notice them.</p>
<p>Whether you like to think about it or not, you’re covered in microorganisms. Absolutely teeming with them from head to toe. Your body is covered and filled with bacteria called commensals, which inhabit the microscopic valleys of your skin and recesses of your gut. These organisms for the most part never cause you any harm, and in fact protect you from being colonised by disease-causing organisms. </p>
<p>In the same way that you’re a walking zoo of microbes, the world around you is peppered with invisible microorganisms. </p>
<h2>Ancient relationship</h2>
<p>This isn’t a new relationship though. Humans have been cohabiting with fungi for a very long time. </p>
<p>Ancient Egyptian bakers and brewers were harnessing natural yeasts more than <a href="http://search.proquest.com/docview/213552171?pq-origsite=gscholar">4,000 years ago</a>, but it was only in the 1850s that we realised it was microbes that were responsible for <a href="http://onlinelibrary.wiley.com/doi/10.1002/1097-0061(20000615)16:8%3C755::AID-YEA587%3E3.0.CO;2-4/full">leavening bread and making alcohol</a>.</p>
<p>We’ve also known for a very long time that unpreserved foods spoil, growing conspicuously fuzzy tufts of blue and green mould. The kinds of moulds that make our bread and make forgotten oranges go fluffy are really the weeds of the fungal world.</p>
<p><em>Penicillium</em> (this is the same fungus involved in the discovery of the first antibiotics, but that’s another story) and <em>Aspergillus</em> are the microscopic equivalent of soursobs and dandelions, and look fairly similar in a lot of ways. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/111592/original/image-20160216-6548-1fbxe2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111592/original/image-20160216-6548-1fbxe2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=449&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111592/original/image-20160216-6548-1fbxe2z.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=449&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111592/original/image-20160216-6548-1fbxe2z.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=449&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111592/original/image-20160216-6548-1fbxe2z.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=564&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111592/original/image-20160216-6548-1fbxe2z.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=564&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111592/original/image-20160216-6548-1fbxe2z.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=564&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Aspergillus niger, the fungal dandelion.</span>
<span class="attribution"><span class="source">Michael Taylor</span></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/111613/original/image-20160216-8211-e8jows.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111613/original/image-20160216-8211-e8jows.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111613/original/image-20160216-8211-e8jows.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111613/original/image-20160216-8211-e8jows.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111613/original/image-20160216-8211-e8jows.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111613/original/image-20160216-8211-e8jows.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111613/original/image-20160216-8211-e8jows.png?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">Penicillium, the source of the antibiotic penicillin.</span>
<span class="attribution"><span class="source">Michael Taylor</span></span>
</figcaption>
</figure>
<p>Walk through any park, or into any building the world over and you’ll probably be picking up spores from <em>Penicillium</em> and <em>Aspergillus</em>; up to a <a href="http://ibe.sagepub.com/content/23/7/1002.short">several hundred per cubic metre of air is normal</a>. In fact when you’re looking at indoor fungi, if you don’t find these two floating around you often question if you’ve taken your samples correctly.</p>
<h2>Is your house ‘killing you’?</h2>
<p>Indoor airborne fungi have become implicated in “<a href="https://en.wikipedia.org/wiki/Sick_building_syndrome">sick building syndrome</a>” and claims that our homes are “<a href="https://www.youtube.com/watch?v=2q6OqA7_Etc">killing us</a>”. </p>
<p>There is some sense mixed in with the scare here. These kinds of organisms can colonise our houses and <a href="https://theconversation.com/health-check-how-does-household-mould-affect-your-health-48341">cause serious illness</a> but it’s unlikely that you’re in imminent danger. </p>
<p>Mould becomes a problem when there is moisture, or the inability for it to escape. After large rainfall or flood events, porous materials in buildings like wood, insulation, carpet and furnishings absorb a lot of water. </p>
<p>This water can then support the growth of fungi and fill cavities and hidden areas with very humid and stagnant air – perfect conditions for problem moulds such as <em>Stachybotrys</em>, the <a href="http://toxsci.oxfordjournals.org/content/104/1/4.long">toxic black mould</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/111612/original/image-20160216-8211-1j2jqed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111612/original/image-20160216-8211-1j2jqed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111612/original/image-20160216-8211-1j2jqed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111612/original/image-20160216-8211-1j2jqed.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111612/original/image-20160216-8211-1j2jqed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111612/original/image-20160216-8211-1j2jqed.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111612/original/image-20160216-8211-1j2jqed.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">Stachybotrys, or Black mould.</span>
<span class="attribution"><span class="source">Unknown</span></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/111617/original/image-20160216-22545-1t6zr4u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/111617/original/image-20160216-22545-1t6zr4u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/111617/original/image-20160216-22545-1t6zr4u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/111617/original/image-20160216-22545-1t6zr4u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/111617/original/image-20160216-22545-1t6zr4u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/111617/original/image-20160216-22545-1t6zr4u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/111617/original/image-20160216-22545-1t6zr4u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/111617/original/image-20160216-22545-1t6zr4u.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"></a>
<figcaption>
<span class="caption">If your bathroom is looking like this, you may have a problem…</span>
<span class="attribution"><span class="source">Black mould image from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>Most of the time though the fungi that turn up after water damage shouldn’t poison you or cause infection, but will probably smell musty and cause allergy-like symptoms until the problem is fixed. </p>
<p>In many cases fixing the root cause may be relatively simple, with the first step always being to ensure that whatever caused the water to accumulate is fixed and any excess moisture is dried out. Non-porous surfaces are often simply able to be wiped clean of all visible mould with a detergent or cleaning spray. </p>
<p>Soft furnishings, clothes and carpets should be thoroughly vacuumed and washed if possible, or thrown out if extensively contaminated. Porous surfaces are increasingly more difficult as wiping the surface clean may not actually remove the mould and will likely need to be replaced to fully solve the problem. Extensively damaged homes after a flood may be beyond remediation, and any clean-up operations on this scale should always involve a professional.</p>
<p>But it’s not just leaky roofs that encourage fungi to come indoors though, our push towards ultra-efficient green buildings can <a href="http://link.springer.com/article/10.1023/A:1015592224368">cause similar problems</a>. </p>
<p>To reduce energy costs, we often design our air-conditioning systems to recycle as much of the indoor air as possible, which over the course of the day can slowly push up carbon dioxide and moisture in the air. </p>
<p>If this isn’t removed, it can leave you feeling sleepy and the air feeling heavy whilst providing an opportunity for fungi to take over.</p>
<h2>The fungal garden in your home</h2>
<p>We’re often told to aim for a lifestyle with “balance”. The same is true for our microscopic housemates. </p>
<p>If you end up with one single species dominating <a href="http://www.who.int/indoorair/publications/7989289041683/en/">you may have a problem</a>. On the other hand a mixture of species shows that everything is relatively in order and is an indicator of a healthy environment.</p>
<p>The mixture of airborne fungi does change from place to place, but not as dramatically as you’d expect. The same specimens tend to turn up the world over: <em>Penicillium</em>, <em>Aspergillus</em> and <em>Cladosporium</em>, alongside a handful of other common fungi. </p>
<p>If you live near agricultural pastures, you may find a greater abundance of plant pathogens like <em>Alternaria</em>, <em>Stemphylium</em> and <em>Fusarium</em>. The species may change if you’re in different regions of the world, but overall your lungs probably contain similar spores to your relatives in Spain or Japan. </p>
<p>If you live in California’s San Joaquin Valley, however, you are in the unlucky position of being tens of thousands of times more likely to be exposed to infectious spores from the fungi <a href="http://jcm.asm.org/content/45/1/26.short"><em>Coccidioides immitis</em></a>, which cause the otherwise relatively rare condition of fungal pneumonia. </p>
<p>But if it makes you uncomfortable to think about the invisible world pulsing with life around you, relax. Generally a healthy mixture of fungi can indicate a healthy home, and I promise you that life is better with fungi in it than without. </p>
<p><em>Are you a researcher with an idea for a “hidden housemates” story? <a href="mailto:james.whitmore@theconversation.edu.au">Get in touch</a></em>.</p><img src="https://counter.theconversation.com/content/54743/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Taylor 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>Moulds and fungi have been living with us for thousands of years - you just might not think about them until they become a problem.Michael Taylor, Lecturer, School of the Environment, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/407932015-05-11T05:43:32Z2015-05-11T05:43:32ZScientists at work: studying indoor microbial ecology means sampling in public restrooms<figure><img src="https://images.theconversation.com/files/81050/original/image-20150508-22733-1y89xer.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The author, collecting dust via vacuum for lab analysis.</span> <span class="attribution"><span class="source">Clarisse Betancourt Román</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span></figcaption></figure><p>“Ok, Clarisse, you stand guard and I’ll go in. Just… make sure no one comes in after me.”</p>
<p>When most people talk about the challenges facing women in science, I bet they don’t have sneaking into the boys’ bathroom in mind. But today, that is precisely the challenge that my colleague Clarisse Betancourt Román and I have to deal with.</p>
<p><a href="http://biobe.uoregon.edu/">We’re interested</a> in the microbial ecology in the spaces where we live – the so-called built environment. People have been studying ecology for centuries – the way organisms relate to each other and their surroundings. But until recently, most ecologists focused on creatures in their natural habitats in the great outdoors. Now my field of indoor microbial ecology is starting to look at what kinds of <a href="https://vimeo.com/80317131">microbes live in the buildings</a> we inhabit, which is important since we spend an awful lot of time indoors. </p>
<figure class="align-left zoomable">
<a href="https://images.theconversation.com/files/81091/original/image-20150509-22730-lhueyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/81091/original/image-20150509-22730-lhueyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/81091/original/image-20150509-22730-lhueyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=712&fit=crop&dpr=1 600w, https://images.theconversation.com/files/81091/original/image-20150509-22730-lhueyi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=712&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/81091/original/image-20150509-22730-lhueyi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=712&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/81091/original/image-20150509-22730-lhueyi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=895&fit=crop&dpr=1 754w, https://images.theconversation.com/files/81091/original/image-20150509-22730-lhueyi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=895&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/81091/original/image-20150509-22730-lhueyi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=895&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Stocking up on antimicrobial cleaners might have some serious side effects.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/elwillo/4458596543">Keith Williamson</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The knee-jerk reaction to the idea that there are <a href="https://vimeo.com/90059732">microbes (germs!) in our homes</a> is to load up on antimicrobial hand soaps, and maybe even to embed flooring, paints and other household products with antimicrobial chemicals. But no one has actually looked at the effect of all of those antimicrobial chemicals on indoor bacteria.</p>
<p>I’m concerned that by constantly exposing the bacteria in our buildings to these chemicals, we might actually be <a href="http://dx.doi.org/10.3389/fmicb.2014.00780">increasing the spread of antibiotic resistance</a>. When I came to this field, I saw that some people had looked at what kinds of <a href="http://dx.doi.org/10.1021/es200925h">antimicrobial chemicals</a> were present in buildings, because we know they can have serious negative effects on indoor air quality and human health. Others had looked at what kinds of <a href="http://dx.doi.org/10.1371/journal.pone.0087093">bacteria were in buildings</a>. But no one had put the two together. It seemed like an obvious next step, so I decided to investigate, starting with one of the buildings on campus here at the University of Oregon.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/81051/original/image-20150508-22727-16bwpxi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/81051/original/image-20150508-22727-16bwpxi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/81051/original/image-20150508-22727-16bwpxi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1003&fit=crop&dpr=1 600w, https://images.theconversation.com/files/81051/original/image-20150508-22727-16bwpxi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1003&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/81051/original/image-20150508-22727-16bwpxi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1003&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/81051/original/image-20150508-22727-16bwpxi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1261&fit=crop&dpr=1 754w, https://images.theconversation.com/files/81051/original/image-20150508-22727-16bwpxi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1261&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/81051/original/image-20150508-22727-16bwpxi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1261&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Clarisse collects dust from the tops of bathroom stalls with a touch of class.</span>
<span class="attribution"><span class="source">Erica Hartmann</span>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>I feel like I’m in 2nd grade again, when we used to dare each other to go into the boys’ bathroom. Only this time, the goal isn’t just to run in and run out. We have to collect dust to extract bacteria and chemicals, and this dust is precious. It’s the key to finding out if there’s a link between antimicrobial chemicals and antibiotic resistance indoors. And this is why I’m standing in the hallway armed with purple nitrile gloves (think Johnny Depp in <em>Charlie and the Chocolate Factory</em>) and a handheld vacuum equipped with special filters to collect our samples. I’ll have to scour the corners, the pipes under the sinks and behind the toilets, the tops of the walls of the cubicles to get enough. And that’s just in the bathrooms! It’ll take days to go through the whole building. We actually have a whole other project planned to look at homes, but for now we’re concentrating on public spaces.</p>
<p>We’re currently in the thick of this research. The goal is to see whether the bacteria in dust that contains high levels of antimicrobial chemicals have genes that make them resistant to the antimicrobial cleaning products we use to kill them – or even antibiotics we use to treat infections.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/81092/original/image-20150509-22785-hvxxzs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/81092/original/image-20150509-22785-hvxxzs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/81092/original/image-20150509-22785-hvxxzs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=428&fit=crop&dpr=1 600w, https://images.theconversation.com/files/81092/original/image-20150509-22785-hvxxzs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=428&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/81092/original/image-20150509-22785-hvxxzs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=428&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/81092/original/image-20150509-22785-hvxxzs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=538&fit=crop&dpr=1 754w, https://images.theconversation.com/files/81092/original/image-20150509-22785-hvxxzs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=538&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/81092/original/image-20150509-22785-hvxxzs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=538&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Antibiotic-resistant bacteria – including methicillin-resistant <em>Staphylococcus aureus</em> (MRSA) are a threat to human health.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/niaid/8436193898">NIAID</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Once we get the dust, it will take a small army to process the samples. Clarisse will take care of the DNA extraction and preparation, but then we’ll send it off to be sequenced by someone else. The same goes for the chemicals. And the computational tools to pull information out of our results and put everything together are pretty specialized, so I’ll need a lot of training with that as well. In the end, this project will directly involve about 15 people from four different disciplines and probably take over a year, from the time it was conceived to the time the results are peer-reviewed and published. It will cost tens of thousands of dollars, not counting people’s salaries and indirect costs that go to the university. So, in addition to designing and performing this study, I am working with the team to help secure funding for it, too.</p>
<p>Working on the grant proposals to get that funding, I’m always struck by the odd juxtapositions of our research: the sophisticated next-generation DNA-sequencing techniques to assess the microbial community composition, the high accuracy, high-resolution mass spectrometry for analytical chemistry, the complicated and not user-friendly bioinformatics analysis to make sense of the data – and the simple, childish fun of climbing around buildings, getting up on the furniture and hanging from the rafters looking for fat dust bunnies, ripe for the picking. In scientific writing, the whole thing comes across as so serious.</p>
<p>And it is serious. We’re looking for reservoirs of antibiotic-resistant pathogens, germs that could land you in the hospital, infections for which we have no more cures. If I can find a particular source, one thing that we’re doing that increases antibiotic resistance, maybe we can use my discovery to help curb the spread of antibiotic resistance and preserve our arsenal of antibiotics, preventing the return of fatal infectious diseases. But first, I have to get into the boys’ bathroom.</p><img src="https://counter.theconversation.com/content/40793/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Erica Hartmann receives funding from the Alfred P. Sloan Foundation.</span></em></p>We spend much of our time inside buildings. What chemicals and microbes are in here with us? And how do they affect each other? One scientist collects dust to find out.Erica Hartmann, Postdoctoral Research Associate in Microbiology at the Biology and the Built Environment Center, University of OregonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/262032014-05-29T16:40:01Z2014-05-29T16:40:01ZRural networks can help prevent deaths from indoor pollution<figure><img src="https://images.theconversation.com/files/49787/original/9y4y7k56-1401363670.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">One of the biggest killers.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/eileendelhi/185462923">eileendelhi</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>The ineffective burning of wood in traditional stoves means that more people die around the world from pollution indoors than outdoors. There are simple, cleaner alternatives for sale, but encouraging the purchase of them has proved difficult. A project in India, however, is using rural women’s social networks to successfully change the situation and those selling improved stoves can learn from that project.</p>
<p>A <a href="http://www.cleancookstoves.org/blog/who-estimates-increased-hap-deaths.html">recent report</a> from the World Health Organisation (WHO) estimates around 4.3m deaths globally in 2012 due to indoor air pollution and almost all of them in low and middle income countries. In comparison, outdoor air pollution led to <a href="http://www.cleancookstoves.org/media-and-events/news/who-7-million-deaths.html">2.6m deaths</a>. </p>
<p>The WHO report believes that nearly <a href="http://www.cleancookstoves.org/blog/who-estimates-increased-hap-deaths.html">three billion poor people</a>, who rely on solid fuels for cooking and heating, are at risk of being affected by indoor pollution. Nearly <a href="http://www.who.int/mediacentre/factsheets/fs292/en/">50% deaths among children under five</a> in underdeveloped countries are the result of acute lower respiratory infections caused by indoor pollution in the form of carbon monoxide and particulate matter generated by burning biomass. Such biomass is the cheapest and most widely available fuel. Continuous exposure to such indoor pollution can lead to other health problems. Women – who spend more time near stoves – are particularly badly affected.</p>
<p>One solution to changing this is to use improved stoves. In most countries, these are available from governments and charities. Some provide them for free, but most places offer it at subsidised prices. </p>
<p>Improved stoves come in different designs, but the main idea is to ensure that the fuel is burned effectively, so that it does not create soot or toxic carbon monoxide. This is achieved by improving airflow near the site where the fuel is burnt. Some designs allow the removal of gases released from the burning fuel away from the person sitting near the stove.</p>
<p>The health benefits are usually long term, so people don’t always opt for the purchase even at subsidised rates. Even when they are provided for free, a lot of the people quickly <a href="http://ehs.sph.berkeley.edu/krsmith/publications/2011/ruiz_adoption.pdf">stop using them</a>. </p>
<p>The Indian government’s National Program on Improved Cookstoves is <a href="http://practicalaction.org/docs/energy/docs48/bp48_pp23-26.pdf">a good example</a> of the kind of government-led stove interventions that can go wrong. Although there was money available for the program, it failed because of poor stove design, misunderstanding of the community’s needs and poor distribution networks. NGOs do better, but often don’t have enough financial support.</p>
<h2>Power of networks</h2>
<p><a href="http://www.unilever.com/images/es_Project_Shakti_tcm13-141088.pdf">Project Shakti</a>, a programme launched by Hindustan Unilever, has found a way to use women’s social networks to bring about behaviour change and drive communities to adopt new products. Important insights can be drawn through this case and can be applied for sustained dissemination of improved cookstoves among such poor communities.</p>
<p>The project recruits influential women in rural communities who are called Shakti Ammas, where Shakti means “power” and Amma means “mother”. These Shakti Ammas have strong social network partnership with the other women in their communities. While earning a living from this programme, these Shakti Ammas influence the opinions of the peers in their networks. </p>
<p>In a country with the largest informal labour market, women often don’t find decent wages for their work. That is why even a small income can be a good driver. In this case, the influence leads to the purchase of Hindustan Unilever’s products, such as washing powders, soaps, shampoos or toothpastes, among the rural women in their networks. But there is much to learn from this marketing strategy to help other not-for-profit ideas to spread.</p>
<p>Penetrating the rural market in India has remained a big challenge because that population tends not to consume media and advertising in the way that urban folks do. But Project Shakti has been successful where most have failed. The strategy has been so effective that by 2013, more than 40,000 Shakti Ammas are working in 15 Indian states and these informal networks are changing behaviour in more than 100,000 villages.</p>
<p>Project Shakti provides two important insights for an effective dissemination of ideas and products. First, the influence of the group leader in informal community based networks has a marked prominence in dissemination of new products. Second, influential women within these social networks can become powerful agents to change traditions, culture, and social norms and can facilitate the uptake of new, cleaner products. These insights and cases such as Project Shakti are highly relevant to research studies focusing on the dissemination of improved cookstoves and eventually for causing a behavioural change among the rural communities to sustainably use these improved stoves. </p><img src="https://counter.theconversation.com/content/26203/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Praveen Kumar 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 ineffective burning of wood in traditional stoves means that more people die around the world from pollution indoors than outdoors. There are simple, cleaner alternatives for sale, but encouraging…Praveen Kumar, Ph.D. Student, Washington University in St. LouisLicensed as Creative Commons – attribution, no derivatives.