tag:theconversation.com,2011:/columns/ian-musgrave-1808Paracelsus' poison – The Conversation2017-10-10T05:58:00Ztag:theconversation.com,2011:article/854612017-10-10T05:58:00Z2017-10-10T05:58:00ZThe chemicals in firefighting foam aren’t the new asbestos<figure><img src="https://images.theconversation.com/files/189506/original/file-20171010-4228-13qfcm8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Firefighting foams used to contain large quantities of PFAAs chemicals, but their use has been phased out.</span> <span class="attribution"><span class="source">from shutterstock.com</span></span></figcaption></figure><p>This week’s ABC <a href="http://www.abc.net.au/4corners/contamination/9032140">Four Corners episode</a> investigated contamination at defence force sites and surrounding aquifers with chemicals called perfluoroalkyl acids or PFAAs. Around 18 sites are reported to be affected, with the concern being the PFAAs have entered groundwater and contaminated water used for drinking, cleaning and watering plants for human consumption. </p>
<p>PFAAs include compounds such as <a href="https://en.wikipedia.org/wiki/Perfluorooctanoic_acid">perfluorooctanoic acid</a> (PFOA) and <a href="https://en.wikipedia.org/wiki/Perfluorooctanesulfonic_acid">perfluorooctane sulfonate</a> (PFOS), which have been used in a wide variety of applications. In the case of the defence force, the application was in firefighting foams. These contained large quantities of PFFAs which then entered the soil and stormwater drains. </p>
<p>PFAAs are persistent organic pollutants which are not readily broken down and can accumulate in the environment including in food, although most people are exposed to PFAAs from drinking water. Once in the body, these compounds persist for a long time. For instance, it <a href="https://www.epa.gov/sites/production/files/2015-09/documents/pfoa-pfos-provisional.pdf">takes around five years</a> for half of an ingested dose of PFOA to be removed. So, these compounds have the potential to reach levels which can affect our health.</p>
<p>As a result the use of these compounds started to be <a href="http://www.nsf.org/consumer-resources/health-and-safety-tips/water-quality-treatment-tips/perfluorooctanoic-acid-and-perfluorooctanesulfonic-acid-in-drinking-water">phased out in 2000</a>, although the defence department did not completely replace the PFAA firefighting foams <a href="http://www.abc.net.au/news/2017-10-09/defence-admits-delay-in-informing-residents-of-contamination/9027706">until 2012</a>. While PFAAs are ubiquitous in the environment, data from the <a href="https://www.cdc.gov/exposurereport/index.html">US National Report on Human Exposure to Environmental Chemicals</a> shows their levels have consistently fallen in line with the phase-out of their use.</p>
<p>There are several potential health concerns. The Persistent Organic Pollutants Review Committee to the Stockholm Convention listed PFOA and PFOS as persistent organic pollutants, linking <a href="http://chm.pops.int/TheConvention/POPsReviewCommittee/Meetings/POPRC11/POPRC11Documents/tabid/4573/">them to six human diseases</a>. These include cancer, low birth-weight, effects on the heart and blood vessels and on the immune system. But what does “linking” actually mean and how strong is the evidence?</p>
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<img alt="" src="https://images.theconversation.com/files/189507/original/file-20171010-4256-1a45cge.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/189507/original/file-20171010-4256-1a45cge.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/189507/original/file-20171010-4256-1a45cge.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/189507/original/file-20171010-4256-1a45cge.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/189507/original/file-20171010-4256-1a45cge.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/189507/original/file-20171010-4256-1a45cge.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/189507/original/file-20171010-4256-1a45cge.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 concern is that PFAA chemicals have seeped into the ground and drinking water.</span>
<span class="attribution"><span class="source">from shutterstock.com</span></span>
</figcaption>
</figure>
<h2>How strong is the evidence?</h2>
<p>The evidence comes from animal studies, human community studies, and studies of industrial workers exposed to high environmental levels. The strength of the evidence depends on a number of factors. </p>
<p>There is presumptive evidence that PFFAs could have health effects. PFFAs (particularly PFOA and PFOS) bind to a class of receptors for fats called <a href="https://en.wikipedia.org/wiki/Peroxisome_proliferator-activated_receptor">peroxisome proliferator receptors</a>. These can alter fat metabolism, and potentially have effects on heart function and foetal development.</p>
<p>However, the effects on the peroxisome proliferation receptors in rodents occur at concentrations typically a <a href="https://academic.oup.com/toxsci/article-lookup/doi/10.1093/toxsci/kfn166">thousand times higher</a> than average human blood concentrations and around 100 times the blood concentrations in <a href="https://www.ncbi.nlm.nih.gov/pubmed/17605032">contaminated workers</a>. And human receptors are less sensitive than mouse receptors, so mouse and rat studies may overestimate human toxicity.</p>
<h2>Cancer</h2>
<p>This is the risk most people are worried about, and there is good evidence in rats long-term exposure to high levels of PFOA induces benign liver tumours (called adenomas), Leydig cell adenomas (tumours associated with ovaries and testes), rare types of pancreatic tumors (called acinar cell tumours), and that PFOS also induces liver adenomas. But the <a href="http://www.tandfonline.com/doi/full/10.3109/10408444.2014.905767">relevance of this evidence to humans</a> is limited. </p>
<p>It’s important to note activation of peroxisome proliferation receptors plays a role in these actions, and the lower responsiveness of these receptors activated in rodents are not present in humans. </p>
<p>A recent review of all the available epidemiological (exploring incidence across populations) studies, including community and worker exposure, of the association between PFAAs and cancer found <a href="http://www.tandfonline.com/doi/full/10.3109/10408444.2014.905767">studies were inconsistent</a> in terms of both degree of exposure, dose-response and site of cancer. One study found exposure to PFOA <a href="https://www.ncbi.nlm.nih.gov/pubmed/24468211">decreased the incidence of bowel cancer</a>. Overall the review noted:</p>
<blockquote>
<p>Taken together, the epidemiological evidence does not support the hypothesis of a causal association between PFOA or PFOS exposure and cancer in humans.</p>
</blockquote>
<h2>Low birthweight</h2>
<p>As with cancer, there is reasonable evidence <a href="https://www.ncbi.nlm.nih.gov/pubmed/24968374">PFAA exposure in animals</a> produces low birth weight. However, the concentrations animals were exposed to were <a href="https://www.ncbi.nlm.nih.gov/pubmed/28617200">100-1000 times greater</a> than high human exposure. </p>
<p>Despite some early suggestive studies, more comprehensive human epidemiological studies have failed to find significant effects on <a href="https://www.ncbi.nlm.nih.gov/pubmed/19049861">birth weight</a>, <a href="https://www.ncbi.nlm.nih.gov/pubmed/22370857">birth outcomes</a> or <a href="https://www.ncbi.nlm.nih.gov/pubmed/23825166">growth and development</a> to at least seven years of age. </p>
<p>It is also unlikely there is any causal relationship between <a href="https://www.ncbi.nlm.nih.gov/pubmed/27268162">PFAA exposure and fertility</a>.</p>
<h2>Cardiovascular (heart and blood vessels) disease</h2>
<p>There is very limited evidence that PFAAs affect the heart and blood vessels. There is some limited evidence that there may be effects on cholesterol levels (consistent with their effects on peroxisome proliferation activation receptors), but these effects <a href="http://www.tandfonline.com/doi/full/10.3109/01480545.2011.582502">are small and may be of doubtful significance</a>. </p>
<p>Some epidemiological studies suggested there may be an <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1356533">association between PFAAs and cardiovascular disease</a>. Again, these are limited by the possible interference of other lifestyle factors, one-time measurements of PFAAs which may not reflect overall exposure, and limitations in how cardiovascular disease was reported. Overall whether PFAAs cause cardiovasular disease is not well established. </p>
<p>You can see a pattern here. Animal models exposed to high levels of PFAAs have suggestive indications of disease, but evidence in the exposed human population is equivocal or negative. This is true for several proposed effects, such as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4819831/">immune system dysfunction</a>.</p>
<p>I previously discussed a cardiovascular study <a href="https://theconversation.com/perfluorooctanoic-acid-does-it-really-cause-heart-disease-9324">here</a> and an immune system study cited in the Four Corners report <a href="https://theconversation.com/is-your-health-at-risk-from-fish-and-frying-pans-5000">here</a>.</p>
<h2>Estimating risk</h2>
<p>While hard evidence of PFAAs and significant human disease is elusive, we should not be cavalier about the risk and try to minimise our exposure to them as a matter of course.</p>
<p>This is where the <a href="http://www.abc.net.au/4corners/contamination/9032140">Four Corners report</a> is important. Even if the risks are low, they have been placed on people who rely on the aquifers without their consent.</p>
<p>Th information provided to affected consumers has been inconsistent as well. A reported statement by a defence employee that “[PFAAs are] the new asbestos” was unnecessarily alarmist, given what we know about the risk. However, in their tardiness in informing the public, the defence department has damaged, potentially irretrievably, any trust in statements they make.</p>
<p>It is hard to find concrete values for the <a href="http://www.defence.gov.au/Environment/PFAS/docs/General/PSPReports/PSPTindal.pdf">levels of contamination in various aquifers</a> in question. While some areas exceed the current safety values, trying to estimate the risk to people exposed is difficult. </p>
<p>The <a href="http://www.health.gov.au/internet/main/publishing.nsf/content/ohp-pfas-hbgv.htm">reference consumption values</a> have built-in safety margins, typically <a href="https://www.epa.gov/sites/production/files/2015-09/documents/pfoa-pfos-provisional.pdf">50 times lower than the levels that have no effect in animals</a>, which as we have seen, overestimate cancer risk in humans. Several sites appear to be within the margin of safety, but others appear to be well outside the 50-times margin. </p>
<p>But really, that is beside the point. Regardless of the risk, residents should have been informed in a timely manner of the contamination. As a result of the department’s reticence and anodyne statements about health, residents are unnecessarily alarmed and will have lost trust in any health messages.</p><img src="https://counter.theconversation.com/content/85461/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave receives funding from the National Health and Medical Research Council to study adverse reaction to herbal medicines and has previously been funded by the Australian Research Council to study potential natural product treatments for Alzheimer's disease. He has collaborated with SA water on studies of cyanobacterial toxins and their implication for drinking water quality.</span></em></p>This week’s ABC Four Corners episode investigated contamination at defence force sites and surrounding aquifers with chemicals called perfluoroalkyl acids or PFAAs. Around 18 sites are reported to be affected…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/807962017-07-11T06:03:12Z2017-07-11T06:03:12ZHow worried should you be about lead from Aldi taps?<p>If you have bought an Aldi “<a href="http://www.abc.net.au/news/2017-07-10/aldi-spiral-spring-mixer-tap/8695150">The Spiral Spring Mixer Tap</a>” you should <em>not</em> use water from it for drinking or cooking until investigations of <a href="http://www.smh.com.au/business/consumer-affairs/aldi-tap-found-to-be-contaminated-with-lead-being-investigated-with-urgency-20170710-gx83c2.html">reported lead contamination</a> is complete. </p>
<h2>What we know</h2>
<p>The <a href="http://www.news.com.au/finance/business/retail/customers-warned-to-beware-of-cheap-aldi-tap/news-story/9be3c4f8aa5e04e0ef031d08d1aa7443">media reports</a> that water passing through the tap has up to 15 times the <a href="https://www.nhmrc.gov.au/guidelines-publications/eh52">lead levels</a> allowed in Australian drinking water (<a href="https://www.hunterwater.com.au/Water-and-Sewer/Water-Supply/Water-Quality/Guidelines-for-Drinking-Water-Quality.aspx">maximum 0.01 milligrams per litre</a>). <a href="https://www.health.qld.gov.au/qhcss/qhss">Queensland Health’s Forensic and Scientific Services</a> conducted the tests, so the results are credible. </p>
<h2>What we don’t know</h2>
<p>We don’t know how extensive the contamination is. So far, only one tap has been tested and I haven’t seen the actual results. So, we need a larger sample of taps to determine if this was a one-off contamination (unlikely) or represents a wider problem. </p>
<p>Aldi confirmed the taps were tested by a <a href="https://www.nata.com.au/nata/">National Association of Testing Authorities</a> accredited laboratory and passed Australian standards for lead leakage into water before going on sale. But it is not clear why the current tested tap exceeds the Australian standards by so much. </p>
<p>Is it a problem with a particular batch? Or did <a href="http://www.couriermail.com.au/news/queensland/how-aldi-tap-with-dangerous-levels-of-lead-may-have-passed-safety-tests/news-story/b94a7187ae7b4dfa4ccdaf91d58bb372">substitution of high lead components occur after the first samples were tested</a> as some media reports claim? Australia permits <a href="https://www.newscientist.com/article/2100806-lead-in-australias-drinking-water-is-leaching-from-brass-taps/">higher levels of lead in brass used in Australia’s plumbing fittings</a> than the US, for example. However, the reported lead levels seem too high for this to explain the current situation. </p>
<p>Aldi has suspended sales of the tap and is currently having the taps tested at an independent accredited laboratory. Answers to the questions should be available by the end of the month.</p>
<p>Another issue is the report of “up to 15 times the permitted lead level”. We don’t know if the level of lead is declining with each use of the tap, or if this is just simple assay variability. If the levels decline over time the risk to consumers are less (but still concerning). </p>
<h2>What is the risk if I have one of these taps?</h2>
<p>While the levels involved are substantially higher than the Australian guideline, they are still low and not likely to cause acute lead poisoning. One or two glasses will not poison you.</p>
<p>But lead is <a href="http://www.who.int/mediacentre/factsheets/fs379/en/">a cumulative toxin</a>. Continued consumption of low levels of lead (over weeks, months and years) can have adverse effects. </p>
<p>The major concern is in babies, young children and unborn babies. Babies and young children absorb more lead than adults, with significant effects on their developing bodies. Effects include <a href="https://ntp.niehs.nih.gov/pubhealth/hat/noms/lead/index.html">disruption of red blood cell production, kidney damage, behavioural disturbances and other nervous system effects</a>. The behavioural and nervous system effects are of most concern.</p>
<p>Exactly which effects occur will depend on how long and how much water has been consumed (and whether the reported lead levels are typical). For adults, <a href="https://ntp.niehs.nih.gov/pubhealth/hat/noms/lead/index.html">anaemia, high blood pressure, tremor, tiredness, sleeplessness, irritability, headache and joint pain</a> may be signs of long-term exposure to low levels of lead. </p>
<h2>What should I do if I have one of these taps?</h2>
<p>Until it is determined if other taps of this brand are similarly contaminated (again, previous test samples had complied with Australian regulations) people who have bought these taps should <em>not</em> use water from them for drinking or cooking. </p>
<p>Anyone who has any health concerns should consult their doctor.</p>
<hr>
<p><em>Aldi confirmed the taps were undergoing independent testing, which is expected to be completed by 31 July. “If these results present any indication that a health risk exists for our customers, we will take appropriate action,” a company statement said.</em></p>
<p><em>In the meantime the company recommends customers who have bought the taps register their <a href="http://www.productregistration.aldi.com.au/">product</a> to receive updates and the results of the testing.</em></p>
<hr>
<p><em>Updated July 26, 2017: Aldi says independent testing of its Spiral Spring Mixer Tap confirms it is safe to use. The company says the tap passed testing against the AS/NZS 4020:2005 standard, which was conducted at a laboratory accredited by the National Association of Testing Authorities.</em></p><img src="https://counter.theconversation.com/content/80796/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave receives funding from the National Health and Medical Research Council to study adverse reaction to herbal medicines and has previously been funded by the Australian Research Council to study potential natural product treatments for Alzheimer's disease. He has used workshops on lead contamination as a teaching tool for environmental toxicology.</span></em></p>If you have bought an Aldi “The Spiral Spring Mixer Tap” you should not use water from it for drinking or cooking until investigations of reported lead contamination is complete. What we know The media…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/804032017-07-04T01:35:51Z2017-07-04T01:35:51ZNo, nanoparticles in baby formula will not harm your baby<figure><img src="https://images.theconversation.com/files/176674/original/file-20170704-12293-t2rt7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The health scare surrounding nanoparticles might lead to people abandoning formula unnecessarily, with serious impacts on babies' health.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/392125570?size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>If you watched Channel 7 news this week, you would have learnt about a <a href="http://www.smh.com.au/business/consumer-affairs/study-finds-potentially-toxic-nanoparticles-in-australian-baby-formula-20170622-gwwb2j.html">study</a> commissioned by <a href="http://www.foe.org/projects/food-and-technology/nanotechnology/baby-formula">Friends of the Earth</a> that found “potentially toxic” <a href="https://theconversation.com/nanoparticles-and-nanosafety-the-big-picture-22061">nanoparticles</a> in Australian baby formula.</p>
<p>The study’s spokesperson said calcium phosphate nanoparticles (nano-hydroxyapatite, also known as nano-hydroxylapatite) caused kidney and liver damage. That claim was, how shall I put it kindly, just a little <em>misleading</em>.</p>
<iframe src="https://www.facebook.com/plugins/video.php?href=https%3A%2F%2Fwww.facebook.com%2F7NewsAdelaide%2Fvideos%2F1606605372703445%2F&show_text=0&width=560" width="100%" height="450" style="border:none;overflow:hidden" scrolling="no" frameborder="0" allowtransparency="true" allowfullscreen="true"></iframe>
<p>I have the <a href="http://pubs.rsc.org/en/content/articlepdf/2012/nr/c2nr00044j">study</a> the spokesperson mentioned before me, which was conducted in rats, not humans.</p>
<p>The researchers injected calcium phosphate nanoparticles directly into rats’ body cavities (instead of oral administration as happens with baby formula) at concentrations around a million times higher than found in the baby formula.</p>
<p>Let me quote from the study’s findings:</p>
<blockquote>
<p>The normal levels of AST, ALT and A/G [liver enzymes indicating liver damage] in the n-HA [nano-hydroxyapatite] group suggested no inflammation and necrosis induced by accumulation of 100 mg of n-HA particles. In the liver function there was almost no damage. Moreover, no significant change on values of BUN and CR [urea and creatine] than the control, which also suggested n-HA has no effect on renal function.</p>
</blockquote>
<p>In other words, there were <em>no</em> ill effects on liver or kidney function, the direct opposite of what the media reports were claiming.</p>
<p>Even <em>if</em> you injected 100 milligrams of pure nano-hydroxyapatite directly into a newborn baby’s body (equivalent in baby terms to the dose given to the rats) there would be <em>no</em> significant effect on liver or kidney function.</p>
<p>The spokesperson’s misleading message caused unwarranted concern. On a now deleted <a href="https://www.facebook.com/Sunrise">Sunrise Facebook</a> post discussing this report, the commentors’ concern and fear was palpable. Causing unreasonable fear is irresponsible.</p>
<h2>Nanoparticles occur naturally</h2>
<p>Nanoparticles have become the latest bogeyman, despite nanoparticles occurring naturally. The <a href="http://www.smh.com.au/business/consumer-affairs/study-finds-potentially-toxic-nanoparticles-in-australian-baby-formula-20170622-gwwb2j.html">media report</a> that fuelled the controversy failed to put nanoparticles in their natural biological context, provide any significant support that particles detected in milk are engineered nanomaterials, nor provide evidence of harm for the levels found.</p>
<p>Infant formula is based on milk, which naturally contains calcium and phosphorus (as calcium phosphates). Milk is an important source of calcium, which forms the basis of bones and teeth. The calcium and phosphates are in a complex balance between soluble and protein-bound forms.</p>
<p>One of the forms of calcium phosphate in milk is <a href="https://hal.archives-ouvertes.fr/hal-00900570/document">hydroxyapatite</a> (also found in <a href="https://en.wikipedia.org/wiki/Hydroxylapatite">tooth enamel</a>). So it is unsurprising that hydroxyapatite is found in dried infant formula, which is mainly dried milk powder. </p>
<p>Nanometre-sized particles of calcium phosphate also <a href="https://www.ncbi.nlm.nih.gov/pubmed/6626580">form naturally</a> in drying milk.</p>
<h2>Other studies have found no effect</h2>
<p>Researchers have studied the safety of consuming hydroxyapatite nanoparticles before.</p>
<p>Animals who ate the nanoparticles (added to their food, as opposed to having them injected) showed <a href="http://www.sciencedirect.com/science/article/pii/S0928493116315703">no toxicity</a> at levels well above those present in milk (up to 100 milligrams per kilogram of body weight a day for a year). </p>
<p>Even if you inject them (into veins or into body cavities), you need levels well above those found in infant formulas to <a href="http://onlinelibrary.wiley.com/doi/10.1002/jat.3073/full">cause damage</a> (50 milligrams nano-hydroxyapatite per kilogram body weight in rats).</p>
<p>To give you an idea of how much higher this is with respect to infant formula, the highest levels of hydroxyapatite nanoparticles in any formula is 287 particles in 10 grams of formula.</p>
<p>Yes, that’s <em>particles</em> not milligrams, not micrograms but actual particles. We are talking nano- to femtograms here, amounts so small it is hard to visualise. These levels are a million times or more less than levels found to have produced no effects in animals (and even lower than levels that do cause damage).</p>
<p>Hydroxyapatite nanoparticles have been widely developed to aid bone repair, deliver drugs and have been extensively tested. All results suggest that even <a href="http://onlinelibrary.wiley.com/doi/10.1002/cphc.201200080/full">levels required to be drug delivery agents</a>, well above those found in baby formula, have no significant adverse effects.</p>
<h2>The body dissolves the nanoparticles anyway</h2>
<p>These nanoparticles will also not stay nanoparticles: they dissolve in the stomach fluids, allowing their calcium to be absorbed. </p>
<p>Newborns and very young babies’ stomach fluids are less acidic than older babies and young children (pH5), but <a href="http://www.sciencedirect.com/science/article/pii/S0003996997000447">still acidic enough to dissolve hydroxyapatite</a>. </p>
<p>And particles are more easily dissolved the smaller they are. So, nanoparticles are likely to be even more rapidly dissolved into their component calcium and phosphate ions than larger particles.</p>
<h2>What’s the take-home message?</h2>
<p>There are no significant public health implications for these small crystals of naturally occurring calcium phosphates in milk-based baby formula. </p>
<p>The way the Friends of the Earth study results have been presented, with misleading references to irrelevant studies, has caused unnecessary fear and concern, and may lead some to abandon formula unnecessarily, with negative impacts on baby health.</p><img src="https://counter.theconversation.com/content/80403/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave receives funding from the National Health and Medical Research Council to study adverse reaction to herbal medicines, and has previously been funded by the Australian Research Council to study potential natural product treatments for Alzheimer's disease. In previous years he has collaborated on work on the formation of amyloids from milk proteins. </span></em></p>A widely publicised study that cast doubt on the safety of milk formula was misleading, based on dubiously reported studies and may have serious consequences.Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/712702017-01-13T03:42:45Z2017-01-13T03:42:45ZShould over 50’s avoid that afternoon coffee? Maybe.<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/152607/original/image-20170113-8677-d1akpq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/152607/original/image-20170113-8677-d1akpq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/152607/original/image-20170113-8677-d1akpq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/152607/original/image-20170113-8677-d1akpq.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/152607/original/image-20170113-8677-d1akpq.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/152607/original/image-20170113-8677-d1akpq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/152607/original/image-20170113-8677-d1akpq.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/152607/original/image-20170113-8677-d1akpq.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"></a>
<figcaption>
<span class="caption">Coffee, one of our favourite sources of caffeine.</span>
<span class="attribution"><span class="source">Ian Musgrave</span></span>
</figcaption>
</figure>
<p>Sleep is good. This is one thing both experts and the person in the street can agree on about that knitter up of the unravelled sleeve of care <a href="#1"><sup>[1]</sup></a>. Getting decent sleep not only leaves you feeling refreshed, but lack of good quality sleep is associated not just with fatigue and lower life quality, but can also increase the risk of diseases such as Alzheimer’s and type II diabetes. </p>
<p>Sadly, as we age we are less likely to get good sleep, we sleep less deeply than when we were younger, wake more and are more likely to be disturbed in our sleep.
Recently the <a href="http://www.aarp.org/health/brain-health/global-council-on-brain-health/">Global Council on Brain Health</a> (GCBH) published <a href="http://www.aarp.org/content/dam/aarp/health/healthy-living/2017/01/gcbh-recommendations-sleep-and-brain-health-aarp.pdf">20 recommendations</a> that would help people over 50 years of age to have better sleep. </p>
<p>Now in reporting this did the newspapers focus on the recommendations to not drink alcohol three hours before bed time, keeping mobile phones and tablet devices out of the bedroom or keeping pets out of the bedroom?</p>
<p>No, they focused on the recommendation to avoid caffeine after lunch time, with headlines such as “<a href="http://www.bbc.com/news/health-38573835">Sleep tips: Avoid afternoon coffee, over-50s advised</a>” and “<a href="http://www.dailymail.co.uk/health/article-4107668/Middle-aged-want-good-night-s-sleep-Don-t-cuppa-lunch-Stimulants-drinks-takes-longer-absorb-50s.html">Middle aged and want a good night’s sleep? Don’t have a cuppa after lunch</a>”.</p>
<h2>Well, that’s disappointing, I like my afternoon cuppa</h2>
<p>Yes, as does my Mum and thousands of Australians rich in years.</p>
<p>The advice is sensible though. After all, caffeine is a stimulant, and who amongst us has not used strong coffee to try and <a href="http://www.sciencedirect.com/science/article/pii/B9780444538178000062">stave off sleep</a>. Ironically enough, moderate coffee consumption is associated with lower risks of <a href="https://www.ncbi.nlm.nih.gov/pubmed/26944757">Dementia</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898757/">type II diabetes</a>.</p>
<p>The effects of caffeine can persist some time, taking 400 milligrams of caffeine can cause you to lose <a href="http://www.aasmnet.org/jcsm/ViewAbstract.aspx?pid=29198">up to an hours sleep</a> and have to have more disturbed sleep up to six hours after you have taken it.</p>
<h2>But, you are going to say “But …” aren’t you</h2>
<p>But, 400 milligrams of caffeine is roughly the equivalent of chugging four espressos at once, and is the <a href="https://www.efsa.europa.eu/en/efsajournal/pub/4102">maximum recommended daily caffeine intake</a>. And you really shouldn’t consume more than 300 milligrams in one go. </p>
<p>A typical afternoon cuppa will have between 50-100 milligram caffeine, depending on whether it is tea or coffee, instant or brewed. This is 1/8th to ¼ the amount used in the sleep study. Here are some representative levels of a variety of caffeinated beverages per typical serve.
</p><pre>375 ml Iced Coffee: 68 mg caffeine
Average espresso: 75-85 mg Caffeine
Instant coffee: ~ 65 mg Caffeine
Tea: 50-80 mg caffeine
Colas: 30- 70 mg caffeine
Energy Drinks: 80-160 mg caffeine
</pre><p></p>
<p>Now, you won’t drink 400 milligrams of caffeine in one hit usually, people typically have between 2-4 cups per day. This makes calculating the amount of caffeine in your body a little tricky, as the amount present in your body accumulates to different levels depending on how often you drink it.</p>
<p>Simulations I have run suggest that the level of caffeine in your body six hours after consuming 400 milligrams of caffeine (the amount that can lose you an hour of sleep) is a bit under the maximum amount of caffeine in your body after consuming 100 milligrams of caffeine <a href="#1"><sup>[2]</sup></a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/152611/original/image-20170113-8672-xez3hw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/152611/original/image-20170113-8672-xez3hw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/152611/original/image-20170113-8672-xez3hw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=441&fit=crop&dpr=1 600w, https://images.theconversation.com/files/152611/original/image-20170113-8672-xez3hw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=441&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/152611/original/image-20170113-8672-xez3hw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=441&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/152611/original/image-20170113-8672-xez3hw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=555&fit=crop&dpr=1 754w, https://images.theconversation.com/files/152611/original/image-20170113-8672-xez3hw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=555&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/152611/original/image-20170113-8672-xez3hw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=555&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Bllod levels of caffeine simulated after one 400 mg dose of caffeine (top line) or three 100 mg doses taken every three hours (bottom line)</span>
<span class="attribution"><span class="source">Ian Musgrave</span></span>
</figcaption>
</figure>
<p>If you drink you last caffeinated drink with 100 milligrams of caffeine in it at 4 pm, then you need to wait around four hours for the caffeine levels to fall below the levels associated with the loss of one hours sleep, make it six hours to be safe and if you have had a beverage with 100 milligrams of caffeine in it at 4 pm, you should be going to bed at 10 pm (or put it another way, if you want to go to bed at 10pm, you last caffeinated drink with 100 milligrams caffeine should be at 4 pm).</p>
<p>Of course I have calculated these values based on the average amount of time it takes the body to absorb caffeine and break it down.</p>
<h2>You are going to say “It’s complicated” now, aren’t you</h2>
<p>Well, yes. The amount of time peoples bodies take to break down caffeine is roughly 4 hours on average, but this can vary from as little as 2.5 hours to as much as 9 hours. This can produce huge differences in the amount of caffeine in the body (roughly three fold between the slowest and fastest rate of breakdown.</p>
<p>As well, the pathways in the brain that are responsible for the stimulant effect of caffeine can vary in sensitivity.</p>
<p>So you can have someone like me who can drink espresso late at night with no apparent effect on sleep, and my partner, who cannot drink a cup of tea after 3 pm without having disturbed sleep. </p>
<h2>So what about age, which is the whole point of this</h2>
<p>As you age, your body’s ability to break down drugs and natural products is reduced.</p>
<p>However, it turns out that caffeine is not affected; in fact <a href="https://www.ncbi.nlm.nih.gov/pubmed/6886969">older folk break caffeine down slightly faster than young people</a>. But they also absorb it more slowly, so the effects basically cancel out and older people and young people have very similar levels of caffeine after consuming it.</p>
<p>On the basis of caffeine concentrations alone, the recommendation to avoid caffeine after lunch is being a little over cautious <a href="#1"><sup>[3]</sup></a>. </p>
<p>On the other hand the brain systems that caffeine interacts with to cause stimulation alter with age, and this may make older people more sensitive to caffeine’s effects.</p>
<p><strong>What is the bottom line then?</strong></p>
<p>Getting good sleep is about more than cutting out tea and coffee after lunch.</p>
<p>The Global Council on Brain Health has suggested <a href="http://www.aarp.org/content/dam/aarp/health/healthy-living/2017/01/gcbh-recommendations-sleep-and-brain-health-aarp.pdf">several approaches</a> to improving sleep quality, so that you can get about 7- 8 hours of sleep in a 24-hour period.</p>
<p>These include not drinking alcohol three hours before bedtime (this recommendation will disturb my in-laws most), not eating or drinking generally for three hours before bed <a href="#1"><sup>[4]</sup></a>, getting regular exercise, getting more outdoor light exposure, losing weight if you are overweight, having a regular bedtime routine and not having smart phones and tablet devices in the bedroom at night as the screens light is distracting.</p>
<p>Avoiding (NOT do not drink tea or coffee at all all) caffeine is sensible advice as part of a coordinated approach to better sleep. Slamming back double espressos late at night is guaranteed to disturb your sleep, but an afternoon cuppa is unlikely to bother you (unless of course you are caffeine sensitive).</p>
<p>Be sensible, use a coordinated approach to the recommendations rather than fixating on one thing and hopefully you will sleep better. </p>
<p><a>[1]</a> Sleeping in the street is not recommended.</p>
<p>[2] These are simplistic simulations, using the data on caffeine breakdown by young and old men from <a href="https://www.ncbi.nlm.nih.gov/pubmed/6886969">https://www.ncbi.nlm.nih.gov/pubmed/6886969</a>
Comparative pharmacokinetics of caffeine in young and elderly men and assuming you drink 100 milligrams of caffeine at 10 am, 1 pm and 4 pm.</p>
<p>[3] The recommendation to <em>avoid</em> caffeine after lunch has been widely <strong>misinterpreted</strong> as to mean having <em>no</em> caffeinated beverages after lunch.</p>
<p>[4] As I write this a large part of Australia is in the grip of a massive heat wave, keeping hydrated, especially for older people, is essential in the conditions, so make sure you are getting plenty of fluids even at night.</p><img src="https://counter.theconversation.com/content/71270/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>an Musgrave receives funding from the National Health and Medical Research Council to study adverse reaction to herbal medicines, and has previously been funded by the Australian Research Council to study potential natural product treatments for Alzheimer's disease. He does enjoy a good esspresso, but does not get paid by or own shares in any caffeinated food of beverage company.</span></em></p>Sleep is good. This is one thing both experts and the person in the street can agree on about that knitter up of the unravelled sleeve of care [1]. Getting decent sleep not only leaves you feeling refreshed…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/626082016-07-17T14:33:52Z2016-07-17T14:33:52ZNew evidence for BPA and obesity? Not so fast!<p>The headline image of the University of Melbourne’s Facebook link to its press release about <a href="https://pursuit.unimelb.edu.au/articles/obesity-link-to-packaging-chemical">recent research on Bisphenol A (BPA)</a> is of a takeaway coffee cup. The kind that <a href="https://en.wikipedia.org/wiki/Paper_cup#Waterproofing">does not have any BPA</a> in it at all <sup>[1]</sup>. The headline “Obesity Link to BPA” directly below the image of the cup is guaranteed to cause unwarranted consternation in consumers of our favourite takeaway beverage which I’m sure the researchers did not intend. </p>
<p><a href="https://en.wikipedia.org/wiki/Bisphenol_A">Bisphenol A</a> (BPA) is one of the most recognizable chemicals to the general public. A component of some kinds of hard plastics, plastic liners for tins (but not paper cups) and certain kinds of <a href="https://theconversation.com/will-holding-thermal-printer-paper-really-send-your-bisphenol-a-levels-soaring-33328">thermal paper</a>, it has generated quite a lot of concern as BPA is a mimic of the hormone estrogen. </p>
<p>However, it is a very weak mimic of estrogen (and some other hormones). BPA is typically 10,000 to 100,000 times weaker than estrogen (see for example <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3443136/">here</a>). BPA may also act through some other pathways, but again it is not very strong. Studies of our exposure to BPA have <a href="http://www.ncbi.nlm.nih.gov/pubmed/26656411">consistently shown</a> that we have <a href="http://www.ncbi.nlm.nih.gov/pubmed/26121292">a safety margin of about 100-1,000 fold</a> between the threshold for BPA to produce biological effects and the levels in our bodies.</p>
<p>Still, we are not cavalier about BPA’s presence in our environment and studies continuously reevaluate BPA’s potential for harm, which is where <a href="http://www.nature.com/articles/srep29318">this latest study</a> from the University of Melbourne comes in.</p>
<h2>So what did the researchers do?</h2>
<p>They took <a href="http://www.nature.com/articles/srep29318#materials-and-methods">cow embryos and placed them in tissue culture conditions</a>. They then exposed them for four days to either BPA at 1 or 10 nanogram per millilitre of tissue culture solution (1ng/mL) or estrogen at 1 or 10 ng/mL <sup>[2]</sup>. To make sure that BPA was working through estrogen receptors they also exposed some of the embryos to a combination of BPA and a specific blocker of estrogen receptors.</p>
<h2>What did they find?</h2>
<p><a href="http://www.nature.com/articles/srep29318#results">Both 10 ng/mL BPA and estrogen</a> reduced the number of 8 cell embryos that progressed to blastocysts by around 7% (1 ng/ml of BPA and estrogen had no significant effect). Roughly 10% fewer of the 10 ng/mL treated blastocysts were of implantation quality.</p>
<h2>What about obesity – where does that fit in?</h2>
<p>In embryos treated 10 ng/mL of either BPA or estrogen, there was a roughly 50% increase in glucose uptake and lactate production. This increase was prevented by the selective estrogen receptor blocker (the 1 ng/mL concentration of BPA had no effect). </p>
<h2>That’s it?</h2>
<p>While there is no direct evidence that increased glucose uptake and utilisation in the embryo will cause obesity later in life, it is at least plausible that this could somehow predispose organisms to obesity later in life.</p>
<h2>So should we be worried?</h2>
<p>Not really, as well as the link being weak, there are two key issues which means that the relevance to humans is limited. </p>
<p>One is that the concentrations used in the study are very unlikely to be achieved in the human body under normal conditions. 10 ng/mL is a really tiny quantity, and it is hard to visualise this <sup>[2]</sup>, but the quantities in the human body are even smaller, on the <a href="http://www.ncbi.nlm.nih.gov/pubmed/27038865">order of picograms/mL</a> (that is a thousand times less). </p>
<p>Measuring the levels of BPA in blood and biological fluid accurately is very difficult. BPA is very rapidly metabolised, most of BPA in the circulation is inactive metabolites. Not only do the low levels stretch the limits of our measuring devices, but BPA present in the plastics that are used to draw and store blood and other biological fluids can contaminate these fluids, giving spuriously high readings. </p>
<p>Very careful measurements and <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4510366/#s0070">studies using BPA</a> where the hydrogen atoms have been replaced with a heavier isotope of hydrogen (deuterium) have shown that levels of BPA in blood (and hence other body fluids) <a href="http://www.ncbi.nlm.nih.gov/pubmed/26522835">are well below</a> the 1ng/mL concentration that had no effect in this study (see also <a href="http://www.sciencedirect.com/science/article/pii/S027869151300536X">here</a>). This is backed up by back calculation from measurement of urinary excretion of BPA and its metabolites. </p>
<p>Another check is calculation of intake from foods and the environment. These show that intake of BPA is 100 to 1,000 times less than the new, temporary European Food Safety <a href="http://www.health.gov.au/internet/main/publishing.nsf/content/ocs-adi-list.htm">tolerably daily intake</a> of 4 micrograms per kilogram body weight (which is 1,000 times lower than the lowest levels that show no effect in animal studies).</p>
<p>Recent studies of food exposure from Australian foods showed <a href="https://theconversation.com/good-news-we-are-not-at-risk-from-our-food-packaging-53489">very low intake levels</a> (with the new limits, you only need to consume 10 cans of soup a day of the soups with the highest BPA content to reach the tolerably daily intake).</p>
<p>So, altogether the evidence is that human levels of BPA are well below the levels that produce these metabolic effects in these cow embryos.</p>
<p>Another issue is the response to BPA. Remember how I said that <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3443136/">BPA is 10,000-100,000 times weaker than estrogen?</a> This has been shown in numerous receptor and functional studies, including studies on human estrogen receptors. In the current cow embryo studies BPA and estrogen were approximately equally effective, and the blocker study confirmed that the effect of BPA was through the estrogen receptor, not some novel mechanism (as in <a href="https://theconversation.com/a-fishy-story-zebra-fish-bisphenol-a-and-hyperactivity-36224">this study</a>). </p>
<p>This implies that cow embryo estrogen receptors are different to human receptors and that any extrapolation to humans must be made very carefully. </p>
<h2>The take home message?</h2>
<p>Don’t panic over BPA and obesity. You are very unlikely to reach the bodily levels of BPA that will cause disruption of glucose metabolism in early embryos. Of course, as I have said before, the best way to reduce BPA intake is to eat fresh, rather than pre-prepared foods, especially fresh fruit and vegetables as Australians in general do not eat enough fresh fruit an vegetables (and <a href="https://theconversation.com/too-much-salt-and-sugar-and-not-enough-exercise-why-australians-health-is-lagging-61165">eat too many calories, and don’t exercise enough</a>).</p>
<p>Another take home message is to make sure the containers you use to illustrate your press release actually do have BPA in them. You may be consuming too many calories from the milk and sugar in your takeaway coffee, but BPA? No.</p>
<p><strong>[1]</strong> I can’t link directly to the Facebook advertisement. The main illustration on the University of Melbourne press release webpage is cans of soft drink, these do not <a href="http://www.ncbi.nlm.nih.gov/pubmed/27362993">measurably contribute to BPA intake</a>. It also has the takeaway coffee cup, which is lined with <a href="https://en.wikipedia.org/wiki/Polyethylene">polyethylene</a>, not BPA containing plastic. </p>
<p><strong>[2]</strong> A milligram will cover the head of a pin, a microgram would be a single speck on the head of a pin, you would need a microscope to see a nanogram. In contrast, a teaspoon full of sugar is around 4 grams, one teaspoon in a 250 mL coffee will result in 20 milligrams per millilitre (mg/mL) coffee. Now dilute that a million times and you will get 20 ng/mL.</p><img src="https://counter.theconversation.com/content/62608/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave receives funding from the National health and Medical Research Council to study contaminants in herbal medicines. He has recieved ARC funding for studying Alzheimer's disease in the recent past.He is a member of the Science Communicators South Australian Branch. </span></em></p>The headline image of the University of Melbourne’s Facebook link to its press release about recent research on Bisphenol A (BPA) is of a takeaway coffee cup. The kind that does not have any BPA in it…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/549042016-02-17T07:22:26Z2016-02-17T07:22:26ZNo, pesticides are not causing microcephaly in Brazil<p>The explosive expansion of the <a href="http://www.cdc.gov/zika/">Zika virus</a> in the Americas has only been exceeded by the rise of <a href="http://scienceblogs.com/insolence/2016/02/05/zika-virus-the-conspiracy-theories-flow-fast-and-furious/">conspiracy theories</a> blaming everything from vaccines to genetically modified mosquitoes. While not a conspiracy theory, recently the <a href="http://secondnexus.com/ecology-and-sustainability/zika-is-not-to-blame/">internet</a> and news media have been running with <a href="http://www.reduas.com.ar/wp-content/uploads/downloads/2016/02/Informe-Zika-de-Reduas_TRAD.pdf">a report</a> that claims the birth defects attributed to the Zika virus is in fact due to pesticides.</p>
<p><strong>Short summary:</strong> this claim is not plausible. </p>
<p>Just to remind you, the <a href="http://www.cdc.gov/zika/disease-qa.html">Zika virus</a> is a generally mild, <a href="http://www.cdc.gov/zika/transmission/index.html">mosquito-borne</a> virus that has <a href="http://www.cdc.gov/zika/geo/index.html">recently arrived in the Americas</a> and is spreading rapidly. The virus has been linked to the rise of <a href="http://www.cdc.gov/ncbddd/birthdefects/microcephaly.html">microcephaly</a>, where babies are born with very small heads, in Brazil and its rapid spread is the focus of international concern. </p>
<p>However, a recent report from the group “<a href="http://www.reduas.com.ar/wp-content/uploads/downloads/2016/02/Informe-Zika-de-Reduas_TRAD.pdf">Physicians in the Crop-Sprayed Villages</a>” has claimed that the outbreak of microcephaly is due to a pesticide used to control the mosquitoes that carry Zika virus (and Dengue fever). </p>
<h2>How does pyriproxyfen work?</h2>
<p>The pesticide in question is <a href="https://en.wikipedia.org/wiki/Pyriproxyfen">pyriproxyfen</a>, a replacement for the organophosphate pesticides originally used for mosquito control that the mosquitoes are becoming resistant to. <a href="http://npic.orst.edu/factsheets/pyriprogen.html">Pyriproxyfen</a> acts by interfering with the hormonal control of the <a href="http://www.cdc.gov/dengue/entomologyEcology/m_lifecycle.html">insect growth cycle</a>. Most insects do not hatch as small adults and get bigger, but go thorough successive stages of larvae, to pupa, then to adult. </p>
<p>Pyriproxyfen mimics one of the key hormones in this process, <a href="https://en.wikipedia.org/wiki/Juvenile_hormone">juvenile hormone</a>, killing insects at very low concentrations. This hormone control system does not exist in organisms with backbones, such as humans, and pyriproxyfen has <a href="http://www.who.int/whopes/quality/en/pyriproxyfen_eval_specs_WHO_jul2006.pdf">very low toxicity in mammals</a> as a result. </p>
<h2>How toxic is pyriproxyfen?</h2>
<p>This isn’t taken on faith though, pyriproxyfen has been extensively tested in animals for both <a href="http://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfen2ndadd.pdf">acute and chronic toxicity</a>. We have also learnt from the DDT story, and test extensively for reproductive and birth defects in animals exposed to any chemicals that are brought onto the market.</p>
<p>Based on animal studies, an adult human would need to eat a teaspoon full of the raw pesticide to reach the threshold levels for toxicity seen in long-term feeding experiments in animals. Regulatory levels are of course set much lower than this (0.1 milligram per kilogram body weight).</p>
<p>At the regulatory levels that are permitted in drinking water, a 60 kilogram person would need to drink <a href="http://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfen.pdf">200 litres of water to reach the toxic threshold</a><sup>[1]</sup>. In terms of how much is <a href="http://www.icup.org.uk/reports%5CICUP886.pdf">actually present in water reservoirs</a> that have been sprayed with pyriproxyfen to control mosquito larvae, a person would have to drink well over 1,000 litres of water a day, every day, to achieve the threshold toxicity levels seen in animals.</p>
<h2>Does pyriproxyfen cause brain defects in animals?</h2>
<p>The effect of pyriproxyfen on reproduction and foetal abnormalities is <a href="http://www.who.int/water_sanitation_health/dwq/chemicals/pyriproxyfen2ndadd.pdf">well studied in animals</a>. In a variety of animal species large quantities of pyriproxyfen are required produce either small body weight or some changes in the skeleton. Importantly, pyriproxyfen does not cause the defects seen during the recent Zika outbreak. Neither brain abnormalities nor effects on neurodevelopment have been seen in animals exposed to pyriproxyfen during foetal development. </p>
<p>We have quite a lot of experience with pyriproxyfen, it is used extensively world-wide. It has been trialled for controlling <a href="http://www.bioone.org/doi/abs/10.2987/11-6139.1?journalCode=moco">Salt Marsh mosquitoes</a> in Australia, and is present in many of the <a href="http://www.exelpet.com.au/products/dogs/flea-treatment/palatable-flea-control-tablets-for-small-dogs,-puppies,-cats-and-kittens/">flea control preparations</a> we use on our pets. Despite animals ingesting 100 milligrams of pyriproxyfen in tablet form, we haven’t seen outbreaks of microcephaly (or brain abnormalities) in our pets<sup>[2]</sup>. </p>
<p>Pyriproxyfen is poorly absorbed by humans and rapidly broken down so even the minute amounts humans would be exposed to via water treatment would be reduced even further. As well, pyriproxyfen is <a href="http://www.cdpr.ca.gov/docs/emon/pubs/fatememo/pyrprxfn.pdf">relatively rapidly removed from the environment</a>, so overall exposure will be low (certainly thousands of times lower than what our pets are exposed to with no sign of ill health or brain developmental abnormalities). </p>
<h2>What is the evidence for Zika virus?</h2>
<p>The “<a href="http://www.reduas.com.ar/wp-content/uploads/downloads/2016/02/Informe-Zika-de-Reduas_TRAD.pdf">Physicians in the Crop-Sprayed Villages</a>’” only evidence for the role of pyriproxyfen is that spraying began in 2014. </p>
<p>Yes, that’s it.</p>
<p>While the evidence that Zika virus is responsible for the rise in microcephaly in Brazil is <a href="http://www.sciencemag.org/news/2016/01/zika-virus-your-questions-answered">not conclusive</a>, it is substantial. As well as the coincidence of the outbreak and the rise of microcephaly, there are several reports of the Zika virus being found baby and <a href="http://www.cdc.gov/mmwr/volumes/65/wr/mm6506e1er.htm?s_cid=mm6506e1er.htm_w">foetal tissues</a>. The latest report, where the complete genome of the Zika virus was found in a microcephalic foetus’s brain, <a href="http://www.nejm.org/doi/full/10.1056/NEJMoa1600651">is here</a>. </p>
<p>In contrast, the role of pyriproxyfen, with at least a decade of safe use, is simply not plausible. </p>
<h2>The importance of mosquito control</h2>
<p>If there is one thing the “Physicians in the Crop-Sprayed Villages” gets right, is that for mosquito control, you need to involve the local communities.</p>
<p>Mosquito control is a significant public health issue. In the Americas, the mosquitoes carry not only Zika virus, but dengue and yellow fever and others. </p>
<p>I grew up in Brisbane in the late 50s and 60s, when the would come around and fog the local waterways behind our house, and I remember the rainbow slick in the local waterholes from kerosene put on the water to control mosquito larvae (my father-in-law learnt about dosing the hard way when he put too much kerosene in his water tank, the water tasted of kerosene for a long time after). And I remember the mosquito fish released into the creeks to help control mosquito larvae.</p>
<p>Public involvement to reduce standing water sources where disease-carrying mosquitoes breed, and to prevent breeding in drinking water supplies is critical. But as well as mosquito fish you need spraying programs to control mosquitoes where people can’t reach. </p>
<h2>Summary</h2>
<p>Pyriproxyfen is simply not plausible as the cause of microcephaly seen in Brazil. If the current panic over pyriproxyfen interrupts mosquito control programs, this will only help spread disease and decrease the health of the local communities.</p>
<p>[<strong>1</strong>] In some interviews I used 300 litres, based on heavier body weights, here I’m using the international reference body weight.</p>
<p>[<strong>2</strong>] Seriously, our pets are exposed to around 10 milligrams of pyriproxyfen per kilogram body weight, exposures from drinking water (or spraying or other forms of administration) is on the order of nanograms per kilogram body weight, around 10,000,000 times lower. Did the “Physicians in the Crop-Sprayed Villages” not do any dose checking?</p><img src="https://counter.theconversation.com/content/54904/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave receives funding from the National Health and Medical Research Council to study contaminants in herbal medicines. He has received ARC funding for studying Alzheimer's disease in the recent past. He hopes to study the effects of Alzheimer's amyloid in Drosophila. He has never recieved any funding or payments from pesticide or herbicide manufacturers, it is unlikely they even know he exists. </span></em></p>The explosive expansion of the Zika virus in the Americas has only been exceeded by the rise of conspiracy theories blaming everything from vaccines to genetically modified mosquitoes. While not a conspiracy…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/535082016-01-21T08:39:06Z2016-01-21T08:39:06ZEven better news; Australian honey is not likely to make you sick.<p>Those of us who consume honey as a tastier alternative to refined sugar would have been disturbed to see headlines proclaiming <a href="http://www.smh.com.au/national/australian-honey-could-be-making-us-sick-20160120-gm9u6f.html">Australian honey could be making us sick</a>. Why, you might wonder, could this wholesome and all natural product be a threat to our health?</p>
<p>It is all because plants, famously, can’t run away from predators. </p>
<p>To stop animals eating them plants often use toxic chemicals. An example is the bitter alkaloid caffeine, which deters or can even kill insects trying to munch on the plants that contain it. A far less pleasant herbivore deterrent is the class of toxic chemicals are the <a href="https://en.wikipedia.org/wiki/Pyrrolizidine_alkaloid">pyrrolizidine alkaloids</a>. These are a large group of related compounds that can cause <a href="http://www.tandfonline.com/doi/pdf/10.1080/19440049.2010.547520">severe liver and lung damage</a>. Long term consumption of pyrrolizidine alkaloids may increase the risk of cancer. </p>
<p>Pyrrolizidine alkaloids are present in many plants ranging from comfrey to <a href="https://data.environment.sa.gov.au/Content/Publications/pests_salvation_jane.pdf">Patterson’s curse (Salvation Jane)</a>, and small amounts of pyrrolizidine alkaloids may be found in comfrey containing salads and <a href="http://www.itmonline.org/arts/pas.htm">herbal medicines</a>. Importantly, one source is <a href="http://www.honeybee.org.au/pdf/INFORMATION_SHEET_on_PAs.pdf">honey</a>. </p>
<p>In many parts of Australia, <a href="http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:apni.taxon:308797">especially southern Australia</a>, the weed Patterson’s Curse/Salvation Jane is a significant source of nectar for foraging bees. Patterson’s Curse produces high levels of pyrrolizidine alkaloids<sup>[2]</sup>. Indeed it is called Patterson’s Curse in part because of it poisoning stock. Honey produced from Patterson’s Curse nectar can have high levels of pyrrolizidine alkaloids, and must be diluted with honey from other sources to reduce the levels. </p>
<p>To date no adverse health effects, either acute or chronic, have been attributed to consumption of Australian honey. </p>
<p>The headlines were generated by <a href="http://www.tandfonline.com/doi/full/10.1080/19440049.2014.996789">a recent report</a> that shows that Australian honey has on average four times more pyrrolizidine alkaloids than European honeys. Depending on how much you ate, consumption of some of the honeys would exceed recommended European intake guidelines.</p>
<p>Several <a href="http://onlinelibrary.wiley.com/doi/10.1002/mnfr.200900529/pdf">European guidelines</a> recommend that people be exposed to no more than 0.007 micrograms pyrrolizidine alkaloid per kilogram body weight per day, while <a href="http://www.foodstandards.gov.au/publications/documents/TR2.pdf">Australian guidelines</a> state that people should consume no more than 1 microgram pyrrolizidine alkaloid per kilogram body weight. Australian guidelines have set the intake limits as one hundred times lower than levels that show no evidence of toxicity or carcinogenicity in animal studies. Thus there is a substantial safety factor.</p>
<p>European guidelines are more stringent than Australian guidelines, due to a more conservative estimate of cancer risk. While pyrrolizidine alkaloids are able to <a href="http://www.foodstandards.gov.au/publications/documents/TR2.pdf">produce cancer in rats</a>, evidence for cancer in <a href="http://www.sciencedirect.com/science/article/pii/S0887233315001575">humans is indirect</a>. As well, the human risk is likely lower as the mechanism of carcinogenicity are likely different to that in rats. However, the European guidelines take a “zero tolerance approach” and thus have lower intake limits.</p>
<p>Even with this more stringent approach for most Australian honeys the risk is low. Australian honey has on average <a href="http://www.tandfonline.com/doi/full/10.1080/19440049.2014.996789">149 micrograms of pyrrolizidine alkaloids per kilogram honey</a> (compared to 40 micrograms per kilogram for European honeys, to give you an idea of how small that is, a single grain of sugar weighs around 600 micrograms, now imagine a third of a single grain of sugar dissolved in a kilogram of honey). </p>
<p>For a 70 Kg person eating the average amount of honey (around three grams per day, <strike>roughly three teaspoons</strike><sup>[1]</sup>, this is around double the average European consumption) consumption of most of the Australian honeys would be safe at both European and Australian guidelines. </p>
<p>There were a few exceptions where the levels were quite high, and would have exceeded the EU, but not Australian, limits substantially. <a href="http://www.tandfonline.com/doi/full/10.1080/19440049.2014.996789">Out of 59 honeys tested five had double the EU limit and one had nearly ten times the EU limit</a> (ironically this was an “organic” honey) these honeys are of concern.</p>
<p>While for the average consumer the risk is low, people who are high consumers of honey are at much greater risk. The average Australian may consume only three grams <strike>teaspoons</strike> of honey a day, but a small proportion of Australians consume much more.</p>
<p>Around 5% of Australians consume around 57 grams of honey a day. When consumed at these levels several honeys come close to the current Australian limits and substantially exceed the European guideline limits. The impact on children with lower body mass is likely to be greater as well. </p>
<p>On a brighter note the honey that was assayed in the headline-generating study was purchased in 2011 and 2012. Since then there has been a <a href="http://www.pir.sa.gov.au/__data/assets/pdf_file/0006/145599/Fact_Sheet_salvation_Jane.pdf">substantial campaign to reduce Patterson’s Curse</a> infestation. While Patterson’s curse is not the only source of pyrrolizidine alkaloids (eg. weeds of the <a href="https://en.wikipedia.org/wiki/Heliotropium"><em>Heliotropium</em> genus</a> also contribute) this should reduce the amount of pyrrolizidine alkaloids entering into our honeys.</p>
<p>To reiterate, for the average consumer the risk from honey is low. However, further investigation and assays of more recent honey supplies will be needed to understand the risk to more vulnerable groups. </p>
<p>The bottom line is that there is no need to throw away your honey, but do eat sensible amounts of it, and make sure the kids are not eating too much.</p>
<p>[1] As pointed out in the comments, this may not be correct, I took this value from a FSANZ document, however, honey from different sources has different densities, according to what I can find, 2.74 grams of European honey will be two teaspoons, and 2.74 grams of Manuka honey will be around half a teaspoon.</p>
<p>[2] Updated 25/01/2016 Patterson’s Curse has a distinctive chemical fingerprint of the proportions of the different types of pyrrolizidine alkaloids it produces. The paper looked at a number of these pyrrolizidine alkaloids, enough to get a good idea of the range of sources. 10 of the 56 honeys tested clearly contain Patterson’s Curse Honey (for the technically minded, from the Echimidine/Lycopsamine ratio. This identification holds unless there are mega fields of Comfrey nearby), but six of the honeys with highest levels of pyrrolizidine alkaloids, including the honey with the highest level, have higher levels of Lycopsamine than anything else, often by a wide margin (the most problematic honey especially). This rules out Patterson’s Curse, Comfery, Borrage<sup>[3]</sup>, the Heliotropium family (which were my best guess for sources of pyrrolizidine alkaloids, but virtually no honey had high levels of Heliotrine), it also rules out the orchid family, the legume family and whole range of flowering plants including sunflowers. I have no idea what this source could be. On the plus side Lycopsamine is less toxic than other pyrrolizidine alkaloids. On the minus side controlling Patterson’s Curse is unlikely to reduce pyrrolizidine alkaloids in all honeys.
[3] The herb Borage is different from the plant called Blue Borage in New Zealand, and Vipers Bugloss in Australia. Blue Borage is a relative of Patterson’s Curse and has a similar ratio of pyrrolizidine alkaloids as Patterson’s Curse.</p><img src="https://counter.theconversation.com/content/53508/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave receives funding from the National Health and Medical Research Council to study contaminants in herbal medicines. He has recieved ARC funding for studying Alzheimer's disease in the recent past. He hopes to study the effects of Alzheimer's amyloid in Drosophila, but the Australian Bee Council is unlikely to be interested in funding him. </span></em></p>Those of us who consume honey as a tastier alternative to refined sugar would have been disturbed to see headlines proclaiming Australian honey could be making us sick. Why, you might wonder, could this…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/534892016-01-21T04:05:20Z2016-01-21T04:05:20ZGood news, we are not at risk from our food packaging<p>For most of us, food is more than fuel, it is a source of delight and an important part of healthy living. Also for most of us, our food must travel substantial distances from producer to our plate, with many opportunities for the foodstuff to be contaminated with extraneous substances like bacteria. </p>
<p>Like it or not, food packaging is an important part of food safety. Proper food packaging prevents foods being contaminated during transport storage and sale, as well as improving their shelf life. Ironically, in this modern age we are often more concerned about the packaging that shields our food from these contaminants than the contaminants themselves. However, <a href="http://www.foodstandards.gov.au/publications/Pages/24th-ATDS-Phase-2.aspx">a new study</a> has confirmed that the health risks from packaging are minuscule. </p>
<p>Why is there concern? The very clever, modern materials that shield our food from contamination may contain chemicals that could migrate into these foods to levels that could potentially affect our health. Some of these materials, including <a href="https://theconversation.com/should-the-latest-research-about-plastics-exposure-worry-us-6922">bisphenol A (BPA)</a> and <a href="http://phthalates.americanchemistry.com/Phthalates-Basics/Food-Containers-and-Packaging">phthalates</a>, mimic the effects of our bodies’ endocrine hormones and could possibly affect the endocrine system at low levels. </p>
<p><a href="http://www.foodstandards.gov.au/">Food Standards Australia New Zealand</a> is the regulatory body in charge of food safety. It <a href="http://www.foodstandards.gov.au/science/surveillance/Pages/australiantotaldiets1914.aspx">routinely surveys foods</a> to ensure exposure to health risks from food contamination is low to negligible. The <a href="http://www.foodstandards.gov.au/publications/Pages/24th-ATDS-Phase-2.aspx">recently released study</a> looks at chemicals that can migrate into foods from packaging, following up a <a href="http://www.foodstandards.gov.au/science/surveillance/pages/surveyofchemicalmigr5148.aspx">previous survey in 2010</a>. </p>
<p>81 typical foods were tested for levels of 30 chemicals (BPA, epoxidised soybean oil, di-2-ethylhexyl adipate (DEHA), two perfluorinated compounds, 14 phthalates, and 11 chemicals used in printing inks). </p>
<p>The good news is that half of the 30 chemicals tested for were <em>not detected at all</em> by sensitive analytical techniques. Of the 15 remaining chemicals, very few foods had detectable levels of these chemicals, and all but two of those that did fell well below the accepted international <a href="http://www.health.gov.au/internet/main/publishing.nsf/content/ocs-adi-list.htm">Tolerable Daily Intake</a> (TDI) levels. </p>
<p>TDI levels are set on the basis of a wide variety of information about exposure, but typically the levels are set to 100 times lower than the amount that produces no effects in animals that have been fed the substance for over 80% of that animals lifetime.</p>
<p>The compounds that had levels below the acceptable TDI levels included <a href="http://www.foodstandards.gov.au/consumer/chemicals/bpa/Pages/default.aspx">Bisphenol A</a>, which has been the focus of recent public concern. For Bisphenol A, only eight of the tested food had detectable levels. To give an idea of how little risk there is, you would need to consume over <strong>100 Kg</strong> of the baked beans with the highest levels of BPA a day, every day, to reach the TDI threshold. </p>
<p>These results are consistent with the <a href="http://www.foodstandards.gov.au/science/surveillance/pages/surveyofchemicalmigr5148.aspx">findings of the 2010 survey</a>. </p>
<p>Two exceptions were the phthalates <a href="https://www.nicnas.gov.au/communications/publications/information-sheets/existing-chemical-info-sheets/diethylhexyl-phthalate-dehp-factsheet">di(2-ethylhexyl) phthalate</a> (DEHP) and <a href="https://www.nicnas.gov.au/communications/publications/information-sheets/existing-chemical-info-sheets/diisononyl-phthalate-dinp-factsheet">diisononyl phthalate</a> (DINP), which were found at higher that recommended levels in a very few foods, and further studies will be undertaken as well as consultation with industry to ensure reduced levels. </p>
<p>Even so, the risks from these two phthalates are low. In the case of DINP, out of 48 foods tested, high levels were found in a single sample of peanut butter, four hamburgers and one pizza. You would need to consume <strong>200 grams</strong> of that peanut butter or <strong>0.6kg</strong> of that pizza daily to exceed the tolerable daily intake level. While this is possible, it is very unlikely<sup>[1]</sup>. Nonetheless these findings will be followed up to see why these samples had high levels, and to reduce the levels in future.</p>
<p>Overall, <a href="http://www.smh.com.au/business/retail/fsanz-detects-potentially-concerning-amounts-of-phthalates-in-food-from-packaging-20160119-gm9033.html">despite some headlines</a>, the study again confirms that our foods are generally safe, and we do very well by international standards.</p>
<hr>
<p><em>Update 23-01-2016: In response to an emailed comment I weighed large pizzas from one of our local take-aways. A single large weighed 0.6 kg. Yes, it is possible for some people to consume a large pizza by themselves (I can do that when hungry). But to do that daily for weeks on end, or a large proportion of your lifetime is unlikely.</em></p><img src="https://counter.theconversation.com/content/53489/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave receives funding from the National health and Medical Research Council to study contaminants in herbal medicines. he has recieved ARC funding for studying Alzheimer's disease in the recent past.</span></em></p>For most of us, food is more than fuel, it is a source of delight and an important part of healthy living. Also for most of us, our food must travel substantial distances from producer to our plate, with…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/526392015-12-23T13:03:48Z2015-12-23T13:03:48ZA Rare Christmas Full Moon, and other Astronomical Treats of the Festive Season<p>While not much spectacular is going on in the Southern Hemisphere skies, Christmas day will see the first Christmas Full Moon for 38 years and Mars and bright star Spica close in the morning skies.<br>
<a href="http://2.bp.blogspot.com/-30B_VUbLfbk/VngBnLAG9mI/AAAAAAAANqk/8PQCT2yoUrQ/s1600/Mars_Spica_25-12-15_0500.png"><img height="240" src="http://2.bp.blogspot.com/-30B_VUbLfbk/VngBnLAG9mI/AAAAAAAANqk/8PQCT2yoUrQ/s320/Mars_Spica_25-12-15_0500.png" width="320" align="left"></a>
Early morning sky on Friday December 25 looking east as seen from
Adelaide at 5:00 ACDST showing Jupiter, Mars, Venus and comet C/2013 US10. Similar views will be seen elsewhere in Australia at the equivalent local time. (click to embiggen). <br>
<br>
If you are one of being Santa’s Helpers and are up in the early morning on the 25th around 5 am distributing presents and helping Santa eat all those biscuits, then you will see 4 bright planets, Jupiter, Mars, Venus (and if you
have a level horizon) Saturn.<br>
<br>
As an added bonus on Christmas morning Mars and the Bright star Spica are at their closest (strictly speaking, they were at their closest on Thursday, but what is a mere 0.01 arc minutes between friends.<br>
<br>
<a href="http://4.bp.blogspot.com/-QAJ11n01Enk/VngETn_aSCI/AAAAAAAANqw/czbYQWE8AUw/s1600/Full_Moon_25-12-15_2200.png"><img height="241" src="http://4.bp.blogspot.com/-QAJ11n01Enk/VngETn_aSCI/AAAAAAAANqw/czbYQWE8AUw/s320/Full_Moon_25-12-15_2200.png" width="320" align="left"></a>
The Christmas Moon rises under the constellation of Orion, with Taurus, the Pleiades and Canis Major nearby. This shows the north-eastern horizon at around 10:00 pm local daylight saving time. (click to embiggen).<br>
<br>
If the beautiful morning planets are not enough, the evening is rather special.<br>
<br>
As you are contemplating your evening barbie and Christmas pud, the rising full moon is the first Christmas Full Moon since 1977, a gap of 38 years. The next will not be until 2034, 19 years later.<br>
<br>
Put it another way, the last time we had a full Moon on Christmas, the first Star Wars movie “A new Hope” was playing in cinemas, this Christmas Full Moon sees “The Force Awakens”. <br>
<br>
While this is a long time between Full Moons, there are much longer gaps. People had to wait 57 years from 1920 to 1977’s Christmas Full Moon.<br>
<br>
And Christmas is not special, December 23 will see only 3 Full Moons between 1900 and 2100, with gaps of 19, 46 and 76 years between full Moons. September 3 and May 24 only saw 3 Full Moons too. Indeed, if you saw the Full Moon on May 24, 1956, you will have to wait 133 years until 2089 to see the next Full Moon on May 24. <br>
<br>
Exactly why there are these long gaps, I do not know. As the time from Full Moon to Full Moon is 29.5 days, whereas the months are 30-31 days (Excepting February, which is 28, and 29 in leap years), the date of the full Moon will slowly drift over the course of the year.<br>
<br>
Typically, it takes 19 years for a Full Moon to fall on the same date again, however, gaps can occur in multiples of 19 (133 is 7 x 19 and 114 is 6x 19), but I’m not sure why. There are also weird fractions of 19 (46 years is 2.42 x 19). Again, I have no idea why this is.<br>
<br>
After Christmas, New Years holds a small celestial treat.
<br>
<a href="http://3.bp.blogspot.com/-FDSeUOHRQBo/VngMubN5wZI/AAAAAAAANrA/6F_jghaOF80/s1600/Jupiter_Moon_01-01-16_0030.png"><img height="240" src="http://3.bp.blogspot.com/-FDSeUOHRQBo/VngMubN5wZI/AAAAAAAANrA/6F_jghaOF80/s320/Jupiter_Moon_01-01-16_0030.png" width="320" align="left"></a>
On the morning of New Years Day, if you are up celebrating, you will see
Jupiter and the waning Moon rise shortly before (non-daylight saving) or shortly after (daylight saving) midnight.<br>
<br>
If you have bought binoculars or a low powered telescope to the New Years celebration you can see both the Moon and
Jupiter’s moons (along with Jupiter) in the binocular or telescope field of view on New Years morning.<br>
<br>
Jupiter and the Moon will be at their closest a couple of hours after midnight, so if you have a long celebration it is well worth watching the pair during the proceedings.<br>
<br>
<a href="http://4.bp.blogspot.com/-9R9Y4frFsHg/VngQSjG-QuI/AAAAAAAANrM/vphDtgShly4/s1600/Telescope_Jupiter_Moon_01-01-16_0030.png"><img height="240" src="http://4.bp.blogspot.com/-9R9Y4frFsHg/VngQSjG-QuI/AAAAAAAANrM/vphDtgShly4/s320/Telescope_Jupiter_Moon_01-01-16_0030.png" width="320" align="left"></a>
Telescopic view of the Moon and Jupiter, simulating the view through a 25 mm eyepiece on a 4" Newtonian Reflector at 2:30 pm daylight saving time.<br>
<br>
After New Years the Moon visits the rest of the planets. <br>
<br>
On the mornings of January 4th
Mars and crescent Moon are close, on the 7th, Venus Saturn and crescent
Moon are close and on the morning of the 9th, Venus and Saturn
spectacularly close (also visible together in a low power telescope).<br>
<br>
<a href="http://1.bp.blogspot.com/-gT4CjG9p-K4/VnAb-MHdcOI/AAAAAAAANqU/nrE1VDDp-pA/s1600/Venus_07-12-15_0500.png"><img height="240" src="http://1.bp.blogspot.com/-gT4CjG9p-K4/VnAb-MHdcOI/AAAAAAAANqU/nrE1VDDp-pA/s320/Venus_07-12-15_0500.png" width="320" align="left"></a>
The line-up of Jupiter, crescent Moon, Mars and Venus as seen from
Adelaide on the morning of 7 December at 5:00 am. (click to embiggen)
<br></p><img src="https://counter.theconversation.com/content/52639/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave receives funding from the NHMRC for biomedical research which has nothing to do with his love of amateur astronomy</span></em></p>While not much spectacular is going on in the Southern Hemisphere skies, Christmas day will see the first Christmas Full Moon for 38 years and Mars and bright star Spica close in the morning skies. Early…Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/521442015-12-10T20:09:27Z2015-12-10T20:09:27ZWhat’s in your herbal medicines?<figure><img src="https://images.theconversation.com/files/105183/original/image-20151210-7428-j8b0yp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The most concerning finding was leopard DNA.</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-72466159/stock-photo-traditional-chinese-medicine-herbs-and-remedies-in-jars.html?src=HIr8BTFSvoXmoCsud7eENg-1-14">Elena Elisseeva/Shutterstock</a></span></figcaption></figure><p>by Ian Musgrave and <a href="https://theconversation.com/profiles/michael-bunce-8333">Michael Bunce</a></p>
<p>Many people take herbal medicines, including traditional Chinese medicine (TCM) thinking they are doing something positive for their health. Ironically, in many cases they may be doing just the opposite.</p>
<p>Have you ever wondered what is actually in the herbal medicine products you buy? Has the herb on the label been replaced with another herb? Have pharmaceuticals been snuck in? </p>
<p>Making sure that a tablet claiming to have 500 milligrams of paracetamol really does contain 500 milligrams of paracetamol is relatively easy, there are established assays to measure paracetamol routinely. But how do you test for herbs? </p>
<p>Most herbal medicines are pills or powders that have removed all trace of structure we would normally use to identify plants, and many plants have no chemical signature that is able to definitively identify them. And what about all the other possible contaminants and adulterants that could hide in the complex brew of chemicals from herbal medicines?</p>
<p><a href="http://www.nature.com/articles/srep17475">Our research</a>, which has just been published in the journal <a href="http://www.nature.com/srep/">Nature Scientific Reports</a>, goes a long way to answering that.</p>
<p>For the first time, our group of researchers from <a href="http://www.curtin.edu.au/">Curtin University</a>, <a href="http://www.murdoch.edu.au/">Murdoch University</a> and the <a href="http://www.adelaide.edu.au/">University of Adelaide</a> have combined some of the most cutting-edge and sensitive analytical techniques to screen a set of traditional Chinese medicines available in Australia. </p>
<p>We used a three-pronged approach, combining DNA sequencing, toxicology and heavy metal testing to elucidate the true composition of 26 TCMs purchased at random from the Adelaide Markets; most were either for colds and flu’s or for general wellness. </p>
<h2>What did we find?</h2>
<figure class="align-left zoomable">
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<figcaption>
<span class="caption">Summary of the contaminants in traditional Chinese medicines (TCMs) tested in this study that contained toxic metals, undeclared or illegal contents as determined by DNA, toxicological, and heavy metal screening methods. Each TCM tested is represented in the diagram as a tablet; blue shading on tablets indicate AUST L listed medicines, red shading are not-listed with the TGA regulatory body. TCMs deemed non-compliant.
for DNA (green), toxicology (pink) and heavy metals (yellow) or a combination thereof, are represented within the Venn diagram.</span>
<span class="attribution"><span class="source">Coglan et al.,Sci Reports 2015</span></span>
</figcaption>
</figure>
<p>Nearly nine in ten of these medicines had some form of undeclared substance in them as either adulteration or contamination. Sixteen of TCM’s had more than one contaminant or adulterant. </p>
<p>While around half of these medicines were not listed with the <a href="http://www.tga.gov.au/index.htm">Therapeutic Goods Administration</a> (TGA), and should not have been available for purchase, contaminants were found in both TGA-listed and non-listed medicines. These adulterants/contaminants included pharmaceuticals and toxic heavy metals. </p>
<p>Plant and/or animal DNA from species not listed on the labels were also found. The most concerning finding was snow leopard DNA (snow leopards are an endangered species), which was detected in one medicine. DNA from pit viper, frog, rat, cat and dog was also detected in several medicines. </p>
<p>Among the pharmaceuticals found were paracetamol, antihistamines, anti-inflammatories and antibiotics, and stimulants such as pseudoephedrine. Of particular concern were drugs such as warfarin, which have significant potential for harm if not taken under medical supervision, and ephedrine, which is banned in Australia.</p>
<p>Significant levels of toxic heavy metals such as arsenic, cadmium and lead were found in over half the medicines. In at least four of these medicines following the directions on the label would expose you to over ten times the TGA’s regulatory limit for heavy metals in medicines.</p>
<h2>What does this mean?</h2>
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<img alt="" src="https://images.theconversation.com/files/105222/original/image-20151210-7431-1oi14lx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/105222/original/image-20151210-7431-1oi14lx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=513&fit=crop&dpr=1 600w, https://images.theconversation.com/files/105222/original/image-20151210-7431-1oi14lx.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=513&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/105222/original/image-20151210-7431-1oi14lx.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=513&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/105222/original/image-20151210-7431-1oi14lx.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=645&fit=crop&dpr=1 754w, https://images.theconversation.com/files/105222/original/image-20151210-7431-1oi14lx.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=645&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/105222/original/image-20151210-7431-1oi14lx.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=645&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Herbal Medicines.</span>
<span class="attribution"><span class="source">Megan Coglan</span></span>
</figcaption>
</figure>
<p>Are the levels of undeclared materials in these products adulteration or contamination? In <em>adulteration</em>, the material is added deliberately. In <em>contamination</em>, the material is added inadvertently, for example, through unclean workplaces or herbs grown on contaminated soil. </p>
<p>Whether a compound is a result of deliberate adulteration or contamination has different regulatory implications. It can mean the difference between banning a substance or cleaning up the workplace. </p>
<p>It can be tricky to decide which is which. In TCM materials, for instance, <a href="http://www.cnbc.com/id/100992436">heavy metals</a> or <a href="http://www.ncbi.nlm.nih.gov/pubmed/12866383">toad venom</a> may be added as part of the treatment. However, by looking at the patterns of materials we found, we can get some hints. </p>
<p>One TCM claiming to enhance weight gain with appetite stimulation contained pharmaceutically relevant levels of the drug <a href="https://en.wikipedia.org/wiki/Cyproheptadine">cyproheptadine</a>, a known appetite enhancer. </p>
<p>In another, <a href="https://en.wikipedia.org/wiki/Ephedrine">ephedrine</a> was found without any evidence of DNA from plants of the <a href="https://en.wikipedia.org/wiki/Ephedra_sinica">Ephedra</a> genus, suggesting that in both cases the drug was deliberately added. </p>
<p>Intriguingly, high levels of arsenic were often found with similar levels of lead. <a href="https://www.lead.org.au/lanv10n3/lanv10n3-7.html">Lead arsenate</a> has been used as a pesticide, and the high levels may come from persistently contaminated soils.</p>
<p>What this means is that you should be very careful about choosing and purchasing TCMs. Definitely avoid any medicine that does not have an <a href="https://www.ebs.tga.gov.au/">ARTG listing</a> (it should have a number like AUST L 123456 on the front of the bottle). But even medicines with these AUST L labels are no guarantee of safety.</p>
<p>This also highlights the importance of informing your health practitioner if you are taking TCMs as adulterants might interact with conventional medication to cause adverse effects. </p>
<h2>What are the regulatory implications?</h2>
<p>Unlike countries such as the United States, where many herbal medicines are regulated as dietary supplements, in Australia, herbal medicines are regulated through the TGA as medicines.</p>
<p>TGA-regulated medicines can be approved as either <a href="https://www.tga.gov.au/registered-and-listed-medicines">“registered” or “listed”</a>. Most herbal medicines are classified as <a href="https://www.tga.gov.au/listed-medicines">“listed”</a>. Unlike registered medicines such as paracetamol and <a href="http://www.nps.org.au/medicines/heart-blood-and-blood-vessels/anti-clotting-medicines/for-individuals/anticoagulant-medicines/for-individuals/active-ingredients/warfarin">warfarin</a>, the evidence required for approval is much less stringent. </p>
<p>In many ways it is an honour system, where the herbal medicines sponsor says there’s no evidence of harm, and they hold documentation that shows this. Mostly, the evidence is historical, claiming that people have been using it for generations without evidence of harm. As well, if the compounds are on the TGA’s list of “generally recognised are safe” materials extensive safety testing is not required.</p>
<p>The TGA uses post marketing follow-up to check for compliance with the “listed” medicine regulations. This follow-up consists of <a href="http://www.anao.gov.au/Publications/Audit-Reports/2011-2012/Therapeutic-Goods-Regulation-Complementary-Medicines/Audit-brochure">random surveys as well as targeted surveys</a> from concerns raised by consumers. </p>
<p>In Australia, nearly 2,000 new herbal medicines are registered each year.
In a <a href="http://www.tga.gov.au/behind-news/complementary-medicines-compliance-reviews-2013">TGA survey in 2012-2013</a>, 145 complementary medicines were tested. Around 83% of complimentary medicines surveyed were deemed to be non-compliant, with 6% failing due to product composition, formulation or manufacturing.</p>
<p>Using a combination of new molecular approaches, our survey found a much higher level of adulteration and contamination in TCMs than found in the TGA’s surveys. Adding DNA ingredient screening to the TGA’s armoury of analytical methods would help ensure that undeclared ingredients are not included in the herbal medicines we consume. </p>
<h2>And Finally:</h2>
<p>The herbal medicine industry is a billion dollar international industry, with products travelling all over the world. </p>
<p>Globally, we need a better auditing “toolkit” to ensure consumers of herbal medicines, as well as people testing their efficacy, are not being misled. </p>
<p>This research, we think, provides a roadmap to more effective regulation of the herbal medicine sector. </p>
<p><em>* The results of our screening have been passed on to the TGA, which is following this up.</em></p><img src="https://counter.theconversation.com/content/52144/count.gif" alt="The Conversation" width="1" height="1" />
<h4 class="border">Disclosure</h4><p class="fine-print"><em><span>Ian Musgrave and Michael Bunce receive funding from the National Health and Medical research Council to study adulteration and Contamination of herbal medicine. Ian Musgrave is a board member of the Australasian Society of Clinical and Experimental Pharmacology and Toxicoloy</span></em></p>Making sure that a tablet claiming to have 500 mg of paracetamol really does contain 500 mg of paracetamol is relatively easy. But how do you test for herbs?Ian Musgrave, Senior lecturer in Pharmacology, University of AdelaideLicensed as Creative Commons – attribution, no derivatives.