tag:theconversation.com,2011:/fr/topics/cyanide-26530/articlescyanide – The Conversation2023-01-12T04:14:50Ztag:theconversation.com,2011:article/1960512023-01-12T04:14:50Z2023-01-12T04:14:50Z‘More potent than cyanide’: how to stay safe from blue-ringed octopus this summer<figure><img src="https://images.theconversation.com/files/504135/original/file-20230112-13-yk30h3.jpg?ixlib=rb-1.1.0&rect=26%2C22%2C2968%2C1661&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Kris Mikael Krister/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>As an octopus biologist, I get a call from the media every summer because someone has had an encounter with a blue-ringed octopus. Thankfully, everyone has been OK. </p>
<p>Blue-ringed octopus are famed for being one of the most venomous animals on the planet, and the symptoms from a bite are the stuff of nightmares. But how worried do you need to be?</p>
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Read more:
<a href="https://theconversation.com/who-would-win-in-a-fight-between-an-octopus-and-a-seabird-two-marine-biologists-place-their-bets-158520">Who would win in a fight between an octopus and a seabird? Two marine biologists place their bets</a>
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<h2>1,000 times more powerful than cyanide</h2>
<p>It’s a common myth that blue-ringed octopus are found only in the tropics. These tiny marine animals are, in fact, found all around Australia, including Tasmania.</p>
<p>There are <a href="https://www.publish.csiro.au/book/6526/">three official species</a> in Australia, with a maximum size ranging from 12 to 22 centimetres, and they are all extremely venomous. There are <a href="https://museumsvictoria.com.au/article/blue-ringed-octopus/">also many</a> scientifically “undescribed” species, which have yet to be named and officially added to the blue-ringed family.</p>
<p>The venom of blue-ringed octopus contains tetrodotoxin, a potent neurotoxin <a href="https://www.mdpi.com/2072-6651/6/2/693">claimed to be</a> a thousand times more potent to humans than cyanide. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/504137/original/file-20230112-24-xqf111.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/504137/original/file-20230112-24-xqf111.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/504137/original/file-20230112-24-xqf111.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504137/original/file-20230112-24-xqf111.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504137/original/file-20230112-24-xqf111.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504137/original/file-20230112-24-xqf111.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504137/original/file-20230112-24-xqf111.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504137/original/file-20230112-24-xqf111.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>
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<span class="caption">Blue-ringed octopus are found all over Australia.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>First discovered in pufferfish, tetrodotoxin <a href="https://www.cell.com/current-biology/pdf/S0960-9822(16)30596-6.pdf">is actually found in</a> more than 100 species including the Panamanian golden frog and rough-skinned newt. But levels of the toxin varies hugely between species, and levels in blue-ringed octopus are high. </p>
<p>Surprisingly, scientists are debating where blue-ringed octopus and other marine animals source their tetrodotoxin. <a href="https://www.sciencedirect.com/science/article/pii/S0166445X1830465X">One theory</a> is that it’s produced by bacteria that live inside the host species, the other is that it’s sourced from the diet. </p>
<p>Most of these animals use tetrodotoxin for defence, but blue-ringed octopus also use it to hunt and kill their prey, such as fish and crabs. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/504138/original/file-20230112-4958-hwkux8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Pufferfish" src="https://images.theconversation.com/files/504138/original/file-20230112-4958-hwkux8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/504138/original/file-20230112-4958-hwkux8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504138/original/file-20230112-4958-hwkux8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504138/original/file-20230112-4958-hwkux8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504138/original/file-20230112-4958-hwkux8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504138/original/file-20230112-4958-hwkux8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504138/original/file-20230112-4958-hwkux8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Tetrodotoxin is found in over 100 species, including pufferfish.</span>
<span class="attribution"><span class="source">Stelio Puccinelli/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
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<h2>Are blue-ringed octopus proliferating?</h2>
<p>The <a href="https://www.dailymail.co.uk/news/article-5397513/Record-number-blue-ringed-octopus-sightings-Adelaide.html">media often report</a> spikes or record numbers in blue-ringed octopus sightings. </p>
<p>While we don’t have the long-term data to confirm this, the populations of some octopus species <a href="https://www.sciencedirect.com/science/article/pii/S0960982216303190">are increasing</a>. For example, there <a href="https://reporterre.net/Il-n-y-a-plus-que-ca-En-Bretagne-l-inquietante-invasion-des-poulpes">are reports</a> the common European octopus is proliferating in France right now. </p>
<p>Octopus are short-lived – the blue-ringed octopus only lives for <a href="https://link.springer.com/article/10.1007/BF00348686">a few months</a> – and are highly responsive to changing environmental conditions. </p>
<p>Hypothetically, some human-made habitats, such as breakwalls and lobster pots, or marine litter, such as bottles and cans, could be providing additional habitat for blue-ringed octopus. Likewise, climate change could confer an advantage to some octopus species that can better adapt to <a href="https://www.publish.csiro.au/mf/pdf/MF14126">warming waters</a>.</p>
<p>But we simply do not know if this is the case for blue-ringed octopus. Octopus populations may also undergo natural “boom and bust” cycles in response to fluctuations in temperature, food, and other factors in their environment, resulting in rapid increases and decreases in population numbers. </p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/tv/CZVjyUYqnTy/?utm_source=ig_web_copy_link","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>How to keep safe</h2>
<p>Blue-ringed octopus deliver venom by biting using their parrot-like beak, which is found at the base of the arms. </p>
<p>Blue-ringed octopus bites are rare – they are docile, shy animals and are not interested in people. But they may bite when they are threatened or provoked, so <em>NEVER, EVER</em> pick them up. </p>
<p>And remember, these octopus <a href="https://journals.biologists.com/jeb/article/215/21/3752/19182/How-does-the-blue-ringed-octopus-Hapalochlaena">only flash</a> their characteristic blue rings when upset, so stay clear of any small octopus, no matter what they look like. </p>
<p>Blue-ringed octopus are found in shallow coastal waters, including the foreshore, so accidental encounters do happen. Their <a href="https://www.publish.csiro.au/book/6526/">preferred habitats</a> include rocky reefs and coral reefs, seagrass and algal beds, and rubble. Given they’re found throughout the Indo-West Pacific, you may encounter them while on holiday.</p>
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<a href="https://images.theconversation.com/files/504139/original/file-20230112-34767-8nyu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Blue-ringed octopus in a shallow tide pool" src="https://images.theconversation.com/files/504139/original/file-20230112-34767-8nyu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/504139/original/file-20230112-34767-8nyu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504139/original/file-20230112-34767-8nyu7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504139/original/file-20230112-34767-8nyu7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504139/original/file-20230112-34767-8nyu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504139/original/file-20230112-34767-8nyu7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504139/original/file-20230112-34767-8nyu7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A blue-ringed octopus in a shallow tide pool.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Be careful exploring rock pools, cracks or crevices, or picking up empty shells or bottles at the beach, where the octopus may make a home or den, or even when retrieving fishing gear, such as octopus pots or lobster pots.</p>
<p>Curious, young children may also be at risk of an encounter as they explore the beach environment – I know my own toddler would seek out the ideal octopus habitat if given a chance. </p>
<p>This month also, many dead blue-ringed octopus were found on the beach after a mass death event of marine critters in <a href="https://www.abc.net.au/news/2023-01-06/carnage-of-dead-marine-life-on-beaches-near-murray-mouth/101831330">South Australia</a>. It’s best not to pick them up as they could be dying and stressed. Please also keep pets and young children well away as ingestion could lead to poisoning. </p>
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Read more:
<a href="https://theconversation.com/curious-kids-could-octopuses-evolve-until-they-take-over-the-world-and-travel-to-space-156493">Curious Kids: could octopuses evolve until they take over the world and travel to space?</a>
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<h2>What to do if bitten, and symptoms to watch for</h2>
<p>All three blue-ringed octopus species in Australia <a href="https://www.publish.csiro.au/book/6526/">have killed people</a>, but cases are extremely rare. The severity of symptoms <a href="http://www.toxinology.com/generic_static_files/A%20Clinician's%20Guide%20to%20Venomous%20Bites%20&%20Stings%202013.pdf">depends on</a> how much venom someone receives.</p>
<p>A mild case of envenomation may result in tingling around the mouth and mild weakness. A <a href="http://www.toxinology.com/generic_static_files/A%20Clinician's%20Guide%20to%20Venomous%20Bites%20&%20Stings%202013.pdf">severe case</a> may lead to flaccid paralysis (weak or limp muscles), including respiratory paralysis and the inability to breathe. </p>
<p>A tricky thing with blue-ringed octopus is that bites may be painless, so people can be unaware they have been bitten. But the onset of symptoms can be rapid (within minutes) and so an equally rapid first-aid response is crucial.</p>
<p>If you believe someone has been bitten by a blue-ringed octopus, remove them from water immediately and seek urgent medical care. You do not need to put anything on the bite, such as vinegar or hot water. Rather, pressure bandaging and immobilisation is <a href="http://www.toxinology.com/generic_static_files/A%20Clinician's%20Guide%20to%20Venomous%20Bites%20&%20Stings%202013.pdf">recommended, as for snake bites</a>.</p>
<p>If the envenomation is severe, first aid is also focused on providing basic life support, particularly breathing support. <strong>Full first aid response details <a href="http://www.toxinology.com/fusebox.cfm?fuseaction=main.first_aid.firstaid&id=FAD-14">can be found here</a> and <a href="http://www.toxinology.com/generic_static_files/A%20Clinician's%20Guide%20to%20Venomous%20Bites%20&%20Stings%202013.pdf">here</a>.</strong></p>
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Read more:
<a href="https://theconversation.com/the-hidden-world-of-octopus-cities-and-culture-shows-why-its-wrong-to-farm-them-180536">The hidden world of octopus cities and culture shows why it’s wrong to farm them</a>
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<p>Importantly, undertaking a first-aid course may help equip you with some of the skills to support a person who has been bitten before medical help arrives. </p>
<p>While there is no antivenom available for a blue-ringed octopus bite, the venom has <a href="http://www.toxinology.com/generic_static_files/A%20Clinician's%20Guide%20to%20Venomous%20Bites%20&%20Stings%202013.pdf">short-lived effects</a> (usually hours). </p>
<p>At the end of the day, enjoy the ocean. But if you see any small octopus, whatever you do, do not pick it up. </p>
<p><em>The author gratefully acknowledges clinical toxinologist, Professor Julian White AM (Women’s & Children’s Hospital, Adelaide), who provided advice on this article.</em></p><img src="https://counter.theconversation.com/content/196051/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Zoe Doubleday receives funding from the Australian Research Council, Australian Academy of Science, and Fisheries Research and Development Corporation. </span></em></p>Ranging from 12 to 22 centimetres, these tiny octopus are extremely venomous and found all over Australia. Here’s what to do if you see someone get bitten.Zoe Doubleday, Marine Ecologist and ARC Future Fellow, University of South AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1489202020-11-23T19:03:09Z2020-11-23T19:03:09ZSilky oaks are older than dinosaurs and literally drip nectar – but watch out for the cyanide<figure><img src="https://images.theconversation.com/files/370726/original/file-20201123-19-x1qpx0.jpg?ixlib=rb-1.1.0&rect=83%2C251%2C3904%2C1988&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>As we come to the end of spring, look up from the footpath or at the park, and you may spot the fiery flowers of the silky oak, <em>Grevillea robusta</em>. </p>
<p>You may already be familiar with <a href="http://anpsa.org.au/APOL2009/mar09-s1.html">grevilleas</a> – perhaps you have low- growing ground cover and shrub species in your garden. </p>
<p>Some people love the brilliant red, yellow, orange or white flowers of grevilleas. They’re also nesting and roosting havens for small native birds, and so people may plant them to attract wildlife.</p>
<p>Of all the grevillias, the silky oak is the one that catches my eye. It’s the largest and tallest of the species, reaching up to 30 metres. They’re now blooming along the east coast and in some inland places – like huge orange light bulbs dominating the skyline.</p>
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<img alt="A bird feeding on silky oak flower" src="https://images.theconversation.com/files/370727/original/file-20201123-17-1n2zq6s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/370727/original/file-20201123-17-1n2zq6s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/370727/original/file-20201123-17-1n2zq6s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/370727/original/file-20201123-17-1n2zq6s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/370727/original/file-20201123-17-1n2zq6s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/370727/original/file-20201123-17-1n2zq6s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/370727/original/file-20201123-17-1n2zq6s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Silky oaks flowers are a magnet for birds and insects.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<h2>Strong like oak</h2>
<p>Grevilleas have an ancestry older than dinosaurs. They originated on the super-continent Gondwana, and are closely related to banksias, waratahs and proteas.</p>
<p>Today, the 360 species of grevilleas occur in Indonesia and Australia and are a diverse group. Their colourful, distinctive flowers lack petals and instead consist of a long tube known as a “calyx”, which splits into four “lobes”.</p>
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Read more:
<a href="https://theconversation.com/once-again-wattles-are-out-in-bloom-heres-what-makes-our-iconic-flowers-so-special-146109">Once again, wattles are out in bloom: here's what makes our iconic flowers so special</a>
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<p>Like most other grevillea, silky oak possesses proteoid or cluster roots, which are dense and fine. These roots greatly increase the absorbing surface area and <a href="http://www.plantphysiol.org/content/121/2/317">allow plants to thrive</a> in nutrient-deprived soils.</p>
<p>The word “robusta” refers to the fact that the timber is strong like real oak. The freshly split wood has a silky texture, and a pattern and light colour resembling English oak – hence the common name “silky oak”.</p>
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<img alt="Silky oak timber" src="https://images.theconversation.com/files/370729/original/file-20201123-13-4i08av.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/370729/original/file-20201123-13-4i08av.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/370729/original/file-20201123-13-4i08av.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/370729/original/file-20201123-13-4i08av.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/370729/original/file-20201123-13-4i08av.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/370729/original/file-20201123-13-4i08av.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/370729/original/file-20201123-13-4i08av.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Grevillia robusta has a silky texture when split for timber.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<h2>Watch out for the cyanide</h2>
<p>Grevilleas literally drip nectar, much to the delight of native birds and bees. <a href="https://www.rbg.vic.gov.au/documents/Top_10_Australian_bush_tucker_plants_FINAL.pdf">Aboriginal people enjoyed</a> the sweet nectar straight from the plant or mixed with water — the original lolly water. </p>
<p>But you have to know which species to taste as some, including the silky oak, <a href="https://landcare.nsw.gov.au/groups/maclean-landcare-group/projects/signs-plant-labels-fact-sheets-for-community-education/australian-native-plant-factsheets/Silky%20Oak.pdf">contain hydrogen cyanide</a> that could make you ill.</p>
<p>Like other grevilleas the silky oak also contains <a href="https://www.publish.csiro.au/ch/CH9682979">tridecyl resorcinol</a>, which causes an allergic reaction leading to contact dermatitis. The chemical is similar to the <a href="http://anpsa.org.au/APOL2009/mar09-s1.html">toxicodendron</a> in poison ivy. </p>
<p>So when working with silky oaks, you’d be wise to wear gloves, a face mask, protective eye wear (or face shield) and long sleeved clothing. Washing hands and showering at the end of the day is also recommended.</p>
<figure class="align-center ">
<img alt="gardening gloves" src="https://images.theconversation.com/files/370731/original/file-20201123-23-1h5hjjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/370731/original/file-20201123-23-1h5hjjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/370731/original/file-20201123-23-1h5hjjr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/370731/original/file-20201123-23-1h5hjjr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/370731/original/file-20201123-23-1h5hjjr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/370731/original/file-20201123-23-1h5hjjr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/370731/original/file-20201123-23-1h5hjjr.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">Wear gardening gloves when handling silky oak, just to be one the safe side.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>A prized timber</h2>
<p>Silky oak timber was widely used in colonial times. Then it was <a href="http://www.agroforestry.net.au/main.asp?_=Silky%20Oak">marketed as</a> “lacewood”, and that name persists today among some who use it.</p>
<p>Silky oak veneer was used widely in colonial table tops and other furniture. Over the years, silky oak has also been used to make window frames because it is resistant to wood rot.</p>
<p>Overseas, silky oak timber is still <a href="https://bie.ala.org.au/species/https://id.biodiversity.org.au/node/apni/2918082">widely grown</a>, in timber plantations and as windbreaks.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/here-are-5-practical-ways-trees-can-help-us-survive-climate-change-129753">Here are 5 practical ways trees can help us survive climate change</a>
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<p>But it’s not widely available in Australia, due to low market demand – the allergens and cyanide it contains means people are generally reluctant to work with it. However silky oak is still highly prized by those who make guitars, and wood turners who make bowls and cabinets.</p>
<figure class="align-center ">
<img alt="Painted silky oak window frames" src="https://images.theconversation.com/files/370732/original/file-20201123-21-17f79g0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/370732/original/file-20201123-21-17f79g0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/370732/original/file-20201123-21-17f79g0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/370732/original/file-20201123-21-17f79g0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/370732/original/file-20201123-21-17f79g0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/370732/original/file-20201123-21-17f79g0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/370732/original/file-20201123-21-17f79g0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Silky oak timber is rot-resistant and was often used in window frames.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>In the garden</h2>
<p>Although an evergreen tree, some specimens are almost semi-deciduous, losing most of their foliage just prior to flowering.</p>
<p>Some specimens of silky oak can be a bit scraggly in their canopy form. They can benefit enormously from a bit of formative pruning when they are young, and perhaps some structural pruning from a good arborist as they get older. A little attention at the right time will be amply rewarded with a safe and great looking tree that can live for 150 years or more.</p>
<p>Silky oak is <a href="https://www.cabi.org/isc/datasheet/25866">drought-tolerant</a>. In dry times they often flower a bit later than their usual October blooming, providing a big splash of colour in otherwise drab and difficult years. </p>
<p>The trees can be vulnerable to frost when young, but grow well once taller. This makes the silky oak a potential winner as climate change brings warmer, drier weather. </p>
<p>Silky oaks have been declared an <a href="https://weeds.dpi.nsw.gov.au/WeedImages/Details/1324">environmental weed</a> in parts of New South Wales and Victoria where it grows outside its native distribution range. They’re also considered an invasive or invader plant in Hawaii and South Africa. However <em>Grevillea robusta</em> <a href="https://keyserver.lucidcentral.org/weeds/data/media/Html/grevillea_robusta.htm">is declining</a> in its natural rainforest/wet forest habitat. </p>
<p>In some cities in China, silky oaks have been planted along roadsides with great success. The tree has also gained the <a href="https://en.wikipedia.org/wiki/Royal_Horticultural_Society">Royal Horticultural Society</a>’s <a href="https://en.wikipedia.org/wiki/Award_of_Garden_Merit">Award of Garden Merit</a> for its performance in growing under United Kingdom conditions. That just shows you how one person’s weed is another’s treasure.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-river-red-gum-is-an-icon-of-the-driest-continent-118839">The river red gum is an icon of the driest continent</a>
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<img src="https://counter.theconversation.com/content/148920/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gregory Moore does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Silky oaks, or Grevillea robusta, are in bloom. These hardy, attractive trees light up the sky in late spring – but handle with care.Gregory Moore, Doctor of Botany, The University of MelbourneLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/835152017-09-05T14:44:13Z2017-09-05T14:44:13ZAcid drainage: the global environmental crisis you’ve never heard of<figure><img src="https://images.theconversation.com/files/184713/original/file-20170905-13709-196idx5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">alredosaz / shutterstock</span></span></figcaption></figure><p>Romania’s prime minister, Mihai Tudose, recently raised the prospect of <a href="https://www.theguardian.com/environment/2017/aug/31/romania-may-seek-to-pull-gold-mine-from-unesco-protected-list#img-1">reopening</a> the country’s huge Roșia Montană goldfield. The area had been mined from Roman times until the last state-run operation closed in 2006. An application by a previous government to make the area a UNESCO world heritage site has now been withdrawn, paving the way for new development. </p>
<p>Roșia Montană is nestled in the Carpathian mountains and, with 314 tonnes of gold, has Europe’s largest known deposits. A short-term mining bonanza promises employment for thousands of labourers and hundreds of millions of Romanian Leu in investment in the EU’s <a href="https://www.reuters.com/article/us-cee-summit-romania-economy/romanias-strong-economic-growth-not-reflected-in-budget-revenue-watchdog-idUSKBN18I20W">fastest-growing economy</a>. But is the boom really worth it? After all, gold mining has historically resulted in long-term, chronic environmental problems. Roșia Montană is big, but the threats posed by acid mine drainage are bigger.</p>
<p>The problem is, if completed, the so-called Roșia Montană project would use “cyanide amalgamation” to extract the gold from its ore body. This is the same cyanide used to poison people, fish and <a href="https://phys.org/news/2013-10-elephants-poisoned-zimbabwe.html">elephants</a>. It has a toxic past in Roșia Montană, too: back in the 1970s, a copper mine in the area needed somewhere to store its cyanide-contaminated waste and the nearby <a href="https://6thfloor.blogs.nytimes.com/2012/05/22/the-shared-fate-of-treece-kan-and-geamana-romania/">village of Geamana</a> was evacuated and flooded. It has been submerged under toxic waters ever since. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/184717/original/file-20170905-13714-1gxzgk7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/184717/original/file-20170905-13714-1gxzgk7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/184717/original/file-20170905-13714-1gxzgk7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=449&fit=crop&dpr=1 600w, https://images.theconversation.com/files/184717/original/file-20170905-13714-1gxzgk7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=449&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/184717/original/file-20170905-13714-1gxzgk7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=449&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/184717/original/file-20170905-13714-1gxzgk7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/184717/original/file-20170905-13714-1gxzgk7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/184717/original/file-20170905-13714-1gxzgk7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A single church spire pokes through the toxic waters: all that remains of Geamana.</span>
<span class="attribution"><span class="source">Calin Stan / shutterstock</span></span>
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</figure>
<p>Geamana is one of Romania’s <a href="https://www.opendemocracy.net/can-europe-make-it/raluca-besliu/romania%27s-unsolved-communist-ecological-disaster">greatest ecological disasters</a>, surpassed only in 2000 when a gold mine in Baia Mare in the north of the country spilled an estimated 100 tonnes of cyanide into a river. The latter incident was described as Europe’s <a href="http://news.bbc.co.uk/1/hi/world/europe/642880.stm">worst environmental disaster since Chernobyl</a>. No wonder that when the government first mooted the resumption of mining in 2013, it led to <a href="http://www.dw.com/en/protests-erupt-in-romania-over-gold-mine/a-17068049">weeks of protests</a> – protests which now threaten to erupt again.</p>
<h2>Gold’s dirty secret</h2>
<p>Cyanidation was the breakthrough gold mining technology of the 1890s, when it enabled Anglo mining conglomerates to make colossal profits from low grade ores. Simply put: cyanidation involves mixing finely crushed ores (referred to as “sands” or, when water-based, “slimes”) in a weak cyanide solution (usually calcium cyanide). This solution is then mixed in large tanks and the gold separated from its ore body. </p>
<p>The process increases yields of gold but produces immense quantities of highly-toxic waste that releases acid and metals into the environment. Around <a href="http://www.e-mj.com/features/1656-the-current-status-of-cyanide-regulations.html">90% of all gold</a> extracted worldwide uses this method.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/184722/original/file-20170905-13755-124ll6g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/184722/original/file-20170905-13755-124ll6g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/184722/original/file-20170905-13755-124ll6g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/184722/original/file-20170905-13755-124ll6g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/184722/original/file-20170905-13755-124ll6g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/184722/original/file-20170905-13755-124ll6g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/184722/original/file-20170905-13755-124ll6g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/184722/original/file-20170905-13755-124ll6g.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>
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<span class="caption">Waste water from a gold mine flows into the forest. Guyana, South America.</span>
<span class="attribution"><span class="source">kakteen / shutterstock</span></span>
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</figure>
<p>The waste from cyanidation is a fine rock solution that is left in open air ponds while the concentration of acid is reduced to legal limits. The risk here is from dam failure or breakages in the lining of waste ponds, which can lead to <a href="http://www.toxipedia.org/display/toxipedia/Baia+Mare+Cyanide+Spill">catastrophic spills</a> or leakage through the porous land surface into the water table. </p>
<p>In nearly all metal mines, and some coal mines, acid drainage occurs because of the oxidation of iron ore found alongside precious mineral deposits. Uncovered by the mining process, the iron reacts with the air and releases sulphuric acid into the water. This process can last centuries. Spills from cyanidation waste are more short-lived, but more highly toxic than acid mine drainage occurring through iron oxidation. </p>
<p>The ratio of waste to metal recovered in gold mining is vastly disproportionate: the Fimiston Super Pit, near the West Australian town of Kalgoorlie, and until recently the largest open cut mine in the world, has returned approximately 1,640 tonnes of gold since operations began there in 1989. But that’s only a small portion of the <a href="https://www.miningpeople.com.au/news/10-fast-facts-about-kalgoorlies-massive-super-pit">15m tonnes of rock extracted per year</a>. On a more personal scale, a single gold wedding ring generates <a href="http://nodirtygold.earthworksaction.org/impacts#.Wa698EqGPbh">20 tonnes of waste</a>.</p>
<h2>The river runs yellow</h2>
<p>Cyanidation poses catastrophic ecological risks because cyanide leaks so easily into groundwater. Historical parallels suggest the Romanian proposal will most likely leave a toxic legacy.</p>
<p>In 2015, as the US Environmental Protection Agency attempted to drain polluted water from the Gold King Mine, Colorado, which was closed in 1920, more than 3m gallons were accidentally spilled into the Animas River. The polluted plume turned the entire river a deep mustard yellow. Water <a href="http://www.wildlife.state.nm.us/download/fishing/hatcheries-fisheries/san-juan-river-fishery/Gold-King-Mine-White-Paper-Report-08_15_2015-NMDGF.pdf">acidity levels increased 100-fold</a>, and in some places a thousand times over levels considered safe for wildlife. </p>
<p>The spill only posed no threat to fish in the Animas because ongoing pollution had already killed them. But the plume drained into the San Juan, a larger and cleaner river that flows into the spectacular Glen Canyon and, eventually, the Grand Canyon. There, the pollution threatened rare birds and endangered fish like the Colorado pikeminnow and razorback sucker.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/184715/original/file-20170905-32271-1cg95ex.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/184715/original/file-20170905-32271-1cg95ex.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/184715/original/file-20170905-32271-1cg95ex.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=340&fit=crop&dpr=1 600w, https://images.theconversation.com/files/184715/original/file-20170905-32271-1cg95ex.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=340&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/184715/original/file-20170905-32271-1cg95ex.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=340&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/184715/original/file-20170905-32271-1cg95ex.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=427&fit=crop&dpr=1 754w, https://images.theconversation.com/files/184715/original/file-20170905-32271-1cg95ex.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=427&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/184715/original/file-20170905-32271-1cg95ex.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=427&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Animas River as normal, on the day of the Gold King Mine spill (L), and a day later (R).</span>
<span class="attribution"><span class="source">Barbara K Powers / shutterstock</span></span>
</figcaption>
</figure>
<p>EPA chief Scott Pruitt returned to the site at the beginning of August this year vowing to complete the clean-up after the agency had “<a href="http://www.denverpost.com/2017/08/04/scott-pruitt-epa-walked-away-from-colorado-gold-king-spill/">walked away</a>” from the problem. At a water treatment plant installed on the site, <a href="http://www.npr.org/2016/08/04/488579040/one-year-after-a-toxic-river-spill-no-clear-plan-to-clean-up-western-mines">500 gallons of mercury and arsenic-laced water a minute</a> flow from the Gold King Mine. The clean-up could take a decade and has already cost the EPA <a href="http://www.npr.org/sections/thetwo-way/2016/09/08/493061675/more-than-a-year-after-spill-colorados-gold-king-mine-named-superfund-site">US$29m</a>. The EPA has estimated that the cost of cleaning up just 156 mines in the US could be between <a href="https://www.earthworksaction.org/issues/detail/financial_assurance_bonding_and_cercla_108b">US$7billion and US$24 billion</a>. Clean-up on most sites will take decades – those with acid drainage will require water treatment in perpetuity.</p>
<h2>A global crisis</h2>
<p>Acid drainage is a little-known global crisis. The UN has even labelled it the second biggest problem facing the world after global warming. In the US, an <a href="https://uwaterloo.ca/wat-on-earth/news/acid-mine-drainage-past-presentfuture">estimated</a> 22,000km of streams and 180,000 acres of freshwater reservoirs are affected by acid mine drainage. Rivers and lakes in Arizona, Patagonia, Guangdong (China), Ontario, Papua New Guinea, and at Rio Tinto in Spain, to name just a few, have all been polluted by acid mine drainage. In South Africa, <a href="https://www.theguardian.com/world/gallery/2015/dec/25/south-africa-acid-rivers-pollution-in-pictures">the problem is chronic</a>.</p>
<p>These threats are prescient. Brazil recently announced a <a href="https://theconversation.com/only-local-amazonians-can-bring-true-sustainable-development-to-their-forest-83326">huge reserve in the Amazon rainforest</a> has been earmarked for mining, including gold. In New Zealand, local activists fear the Karangahake Gorge is now <a href="https://www.theguardian.com/world/2017/jul/18/new-zealand-fight-for-sacred-mountain-after-discovery-of-significant-gold-seam">under threat</a> after a large, high-quality gold seam was found in the region. Around the Yellowstone National Park, mining companies are positively salivating at the possibility that Obama-era restrictions will be lifted, granting access to <a href="https://www.theguardian.com/environment/2017/jul/16/yellowstone-mining-montana-public-lands">3,000 tonnes of proven in-ground gold reserves</a>. In Peru, <a href="https://www.nytimes.com/2016/07/26/world/americas/peru-illegal-gold-mining-latin-america.html">marines</a> have been dispatched to wage war against illegal mining on the River Santiago in the northern Amazon, which has done enormous damage to the region’s bio-diversity and placed the livelihoods of 70,000 indigenous Awajúns and Wampís at risk.</p>
<p>Multinationals hold out the promise of sustainable development through mining. But without careful forethought we’ll find ourselves dealing with chronic pollution for centuries.</p><img src="https://counter.theconversation.com/content/83515/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Tuffnell does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A gold rush brings in lots of money in the short-term, but leaves a toxic legacy.Stephen Tuffnell, Associate Professor of Modern US History, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/678362016-10-28T01:15:17Z2016-10-28T01:15:17ZJessica Wongso found guilty in cyanide coffee case, but she may not yet have had a fair trial<figure><img src="https://images.theconversation.com/files/143605/original/image-20161027-11268-kg9k3w.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Jessica Wongso during her sentence hearing at the Central Jakarta District Court in Jakarta.</span> <span class="attribution"><span class="source">AAp/Oscar Siagian</span></span></figcaption></figure><p>On Thursday in Central Jakarta District Court, a panel of three judges decided one of the most high-profile and controversial criminal cases in Indonesian legal history. </p>
<p>The case highlights issues with Indonesia’s <a href="https://theconversation.com/bali-nine-hypocrisy-politics-and-courts-play-out-in-death-row-lottery-36205">widely</a> <a href="https://theconversation.com/jokowi-should-halt-executions-under-indonesias-corrupt-judicial-system-37463">criticised</a> judicial system.</p>
<p>After a four-month trial, broadcast live on two national television stations, Jessica Kumala Wongso, an Australian permanent resident, <a href="http://www.smh.com.au/world/cyanide-coffee-murder-australia-resident-jessica-wongso-jailed-for-20-years-20161027-gsc15t.html">was found guilty of premeditated murder</a>. The judges sentenced her to 20 years’ imprisonment for poisoning her friend Mirna Salihin at an upmarket cafe in Jakarta in January this year.</p>
<p>They accepted the prosecution claim that, after arranging to meet Salihin and a mutual friend, Hani, at the cafe, Wongso arrived early. She ordered drinks, and before her friends arrived, put a dose of cyanide into Salihin’s Vietnamese iced coffee. The prosecution said she placed three paper shopping bags on the table she was sitting at to hide what she was doing from CCTV cameras. </p>
<p>Salihin drank the coffee and then collapsed, dying before she reached hospital. For the judges, Wongso’s motives were jealousy and revenge. Wongso was jealous of Salihin’s happy marriage, and wanted revenge after Salihin had told her to break up with her Australian boyfriend, and because she had not been invited to Salihin’s wedding.</p>
<p>Wongso’s case was highly controversial from the start. Indonesia asked the Australian Federal Police to help them investigate Wongso for charges of premeditated murder, even though Indonesia’s Criminal Code allows judges to impose the death penalty for that crime. </p>
<p>Indonesian Law and Human Rights Minister Yasonna Laoly, reportedly gave a <a href="http://www.smh.com.au/world/coffee-murder-indonesian-minister-signed-guarantee-jessica-wongso-wouldnt-be-executed-20160602-gp9vff.html">guarantee</a> she would not face the death penalty. However, the minister <a href="http://www.smh.com.au/world/coffee-murder-indonesian-minister-signed-guarantee-jessica-wongso-wouldnt-be-executed-20160602-gp9vff.html">cannot give such a guarantee</a>, because prosecutors decide what penalty to pursue, and the courts can impose any penalty they like.</p>
<p>Adding to the controversy were allegations that senior Indonesian police refused to allow her lawyer to accompany her during questioning, <a href="http://www.hukumonline.com/berita/baca/lt56a32b5298883/mengusir-pengacara-saat-dampingi-klien--polisi-langgar-aturan-ini">thereby breaching police procedures and perhaps even the Code of Criminal Procedure</a>. <a href="http://www.hukumonline.com/berita/baca/lt56ab8befc8e4f/diberitakan-mengusir-advokat--ini-jawaban-kombes-krishna-murti">Police deny that they forced her lawyer from the room</a>, but admitted that they “asked” the lawyer to leave the room to prevent him influencing her statement. </p>
<p>In court, and in the media, Wongso was portrayed as crazed, malicious and capable of murder. However, the evidence against Wongso has always been circumstantial and threadbare. Even prosecutors appeared reluctant to proceed to trial in her case, asking the police for more evidence on four occasions.</p>
<p>Because no direct evidence of her guilt exists, the trial consisted largely of expert witnesses, for both the prosecution and defence, opining about Wongso’s mental state and post-mortem tests on Salihin’s body. There was limited CCTV footage available. Almost none of the prosecution-led evidence was convincing, at least when compared with the defence evidence.</p>
<p>The prosecution called several psychologists as expert witnesses to testify about Wongso’s mental state in general, and after Salihin collapsed. However, none of them examined Wongso themselves, and their testimony appeared to be crude and lay rather than expert. For example, one described Wongso’s reaction to Salihin’s collapse as <a href="http://www.hukumonline.com/berita/baca/lt57b165b3856ad/psikolog-nilai-janggalnya-ketenangan-jessica-saat-mirna-kejang">“strange”</a> because the CCTV footage did not show that Wongso tried to help Salihin.</p>
<p>Another testified that it was unusual for someone to place their bags on a table when the seat beside them was vacant. Yet another raised questions about Wongso’s mental state, based on a police statement made by her former boss in Australia, who said she heard Wongso say: </p>
<p>“If I wanted to kill anyone, I know how to do it. I could use a gun. And I know the right dosage.”</p>
<p>Wongso’s former boss did not appear at trial to confirm this statement.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/143610/original/image-20161028-11275-1nkgmo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143610/original/image-20161028-11275-1nkgmo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143610/original/image-20161028-11275-1nkgmo8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143610/original/image-20161028-11275-1nkgmo8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143610/original/image-20161028-11275-1nkgmo8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143610/original/image-20161028-11275-1nkgmo8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143610/original/image-20161028-11275-1nkgmo8.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">Supporters hold Justice for Mirna pins outside the sentencing hearing for Jessica Kumala Wongso at Central Jakarta District Court in Jakarta.</span>
<span class="attribution"><span class="source">AAP/Oscar Siagian</span></span>
</figcaption>
</figure>
<p>Prosecutors alleged that Wongso knew that the café had CCTV cameras and where they were located, so that, as mentioned, she used shopping bags to block the view of her putting the cyanide in Salihin’s coffee. One expert testified that the CCTV footage showed Jessica making “suspicious movements” when she opened her handbag, and that perhaps she had <a href="http://www.hukumonline.com/berita/baca/lt5761c89ed3579/jaksa-beberkan-motif-jessica-lakukan-pembunuhan-berencana">put something on the table</a>.</p>
<p>However, none of the footage played during the trial showed that she took anything from her handbag, much less that she pulled out cyanide and then stirred it into Salihin’s drink. In fact, Wongso’s lawyer demonstrated that she had sent a text message on her phone at the time her hands were obscured by the bags. This could account for the so-called “suspicious” movements.</p>
<p>Worse, the prosecution did not convincingly prove that Salihin died from ingesting poison, let alone cyanide. The coffee that Salihin drank was neither tested nor produced at trial. It was likely discarded at the cafe soon after Salihin collapsed. One expert from the National Police Hospital testified that Salihin’s intestines were corroded and her mouth was blackened, which was consistent with cyanide poisoning. The Court appears to have accepted this testimony over the mountain of expert testimony called by the defence, <a href="http://www.hukumonline.com/berita/baca/lt57c6e450158f4/ahli--mirna-meninggal-belum-tentu-karena-sianida">serious doubts about whether the cause of Salihin’s death was cyanide</a>.</p>
<p>Critically, <a href="http://www.smh.com.au/world/alleged-cyanide-coffee-murder-jessica-wongso-faces-20-years-jail-20161004-grv410.html">no autopsy was conducted</a>, and toxicology tests conducted 70 minutes after her death revealed no cyanide in her gastric fluid, bile, liver and urine. Only small traces of cyanide were found in her stomach fluid several days after her death, but, as University of Indonesia forensic pathologist Jaya Surya Atmaja testified, this was probably from embalming chemicals. </p>
<p>The possibility remains, then, that Salihin died from <a href="http://www.hukumonline.com/berita/baca/lt57d08aa5df259/ahli-forensik-sebut-efek-samping-pengawetan-mayat">natural causes</a> such as a heart attack. An Australian pathologist supported these conclusions, testifying that he would expect much higher levels of cyanide in the stomach of a person fatally poisoned, there would also be cyanide in the bowels and liver. He explained that the onset of cyanide poisoning typically occurred up to <a href="http://www.smh.com.au/world/australian-expert-questions-cyanide-poisoning-in-alleged-coffee-murder-in-indonesia-20160906-gra5cm.html">30 minutes after ingestion, not two minutes</a> as the prosecution claimed. <a href="http://www.hukumonline.com/berita/baca/lt57d08aa5df259/ahli-forensik-sebut-efek-samping-pengawetan-mayat">Other typical indications of cyanide</a> mentioned by defence experts, including red skin, the smell of cyanide, and poison in the stomach, were not present.</p>
<p>Other important issues were ignored by the judges. After Salihin apparently complained about the taste of the coffee, both Hani and the cafe owner tasted it, but suffered no ill effects. Does this add support to the defence argument that Salihin might not have been poisoned after all? </p>
<p>The claim that Wongso “arrived early” at the cafe as part of a plan to put the cyanide in the coffee also does not withstand scrutiny: text messages produced by the defence suggest that Wongso arrived at the time the three women had agreed, but Salihin and Hani arrived late. If they had arrived on time, as planned, Jessica would not have had an opportunity to lace the drink.</p>
<p>With not much evidence to go on, the prosecution, and even the judges, asked numerous seemingly random questions to witnesses and the defendant during the trial that had no clear progression or direction, apparently to “trip up” the defendant.</p>
<p>The judges wrote in their judgement that Wongso’s crying during the trial had been a “stage show” because it had not “come from deep within her heart”; she had sobbed, but could produce no tears and did not need to hold a tissue to wipe tears from her face, <a href="http://m.detik.com/news/berita/d-3330513/jessica-menanti-nasib-di-ujung-palu-hakim#key1">they observed</a>.</p>
<p>Immediately after the judges finished reading their decision, Wongso’s lawyer, Otto Hasibuan, declared that she would appeal, calling the decision a “death knell” for justice. The judges, he suggested, had ganged up again the defence, acting as though it were the prosecution and ignoring the defence’s evidence.</p>
<p>Whether she poisoned her friend or not, Jessica Wongso is entitled to a fair trial under Indonesian law. She does not seem to have had one yet. </p>
<p><em>CORRECTION: This article was corrected on October 28 to replace the line “She was deported” with “Indonesia asked the Australian Federal Police to help them investigate Wongso…” and the line “the Australian police relied…” with “Indonesian Law and Human Rights Minister Yasonna Laoly, reportedly gave a guarantee that she would not face the death penalty.” The Conversation apologises for the error.</em></p><img src="https://counter.theconversation.com/content/67836/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Butt receives funding from the Australian Research Council </span></em></p>A young Australian has been sentenced to 20 years in prison for murdering her friend, but the evidence against her was circumstantial and threadbare.Simon Butt, Professor of Indonesian Law, University of SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/560892016-04-12T10:26:37Z2016-04-12T10:26:37ZHandle with care – the world’s five deadliest poisons<figure><img src="https://images.theconversation.com/files/118322/original/image-20160412-15871-l2cy2y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Terrible by name ... Phyllobates terribilis</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/lwpkommunikacio/22591477950/in/photolist-8MCNG1-ek4cuf-dRs6nF-dRxDBA-dbaPBD-4gS8Rq-6zgDtX-aaXPpU-aaUZea-6wvJGh-6wgLdn-dRs6kD-8yBW8N-nutDN2-dSjE7C-8yyQYg-8yBUyu-dSe5a6-dSe5ir-dSe5cp-6LyZad-dSjErh-dSjEjJ-dSjEaq-6KBXyQ-6KBWbE-nNKav6-Aqkejw">Lwp Kommunikáció/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>When asked to name a poison, people may well think of cyanide, arsenic or strychnine. But these are not the most toxic substances known. More poisonous than these, but still not near the top of the tree, is <a href="http://www.chm.bris.ac.uk/motm/ttx/ttx.htm">tetrodotoxin</a>, the pufferfish toxin that poisons around 50 Japanese people every year. The fish is a delicacy in Japan, but can be lethal if prepared incorrectly. Incidentally, this was the poison favoured by evil assassin Rosa Klebb in James Bond film <a href="http://www.007james.com/articles/james_bonds_top_10_close_shaves_part_2.php">From Russia With Love</a>. It also crops up in the <a href="http://www.thecephalopodpage.org/bluering2.php">blue-ringed octopus</a> and was more recently discovered in <a href="https://theconversation.com/the-deadly-poison-lurking-in-a-frog-the-size-of-your-fingernail-43020">tiny frogs in Brazil</a>. </p>
<p>The LD50 (Lethal Dose, 50%) – the amount needed to kill 50% of the test population – is how toxicity is most often assessed, and is usually quoted per kilogram of body weight. On this scale, for example, sodium cyanide comes out at around 6 milligrams per kg. The LD50 of tetrodoxotin, by comparison, is around 300 micrograms per kg if orally ingested, and as little as 10 micrograms per kg if injected.</p>
<p>Assessing toxicity is not easy. The chemical state of a substance is important, as is how we ingest it. If we swallowed liquid mercury metal (as distinct from inhaling the vapour), it would very likely <a href="http://berkeleysciencereview.com/toxic-mercury/">pass straight through us harmlessly</a>. And yet when in 1996 an American professor got just a drop or two of the compound dimethyl mercury on her rubber gloves, it penetrated the gloves and her skin, sending her into a <a href="http://www.chm.bris.ac.uk/motm/dimethylmercury/dmmh.htm">fatal coma some months later</a>. </p>
<p>Nevertheless, here is a representative selection, in ascending order, of five truly deadly poisons, all at least a hundred times more toxic than cyanide, arsenic or strychnine.</p>
<h2>5. Ricin</h2>
<p>This extremely toxic plant poison was famously used to kill the Bulgarian dissident <a href="http://news.bbc.co.uk/onthisday/hi/dates/stories/september/11/newsid_2514000/2514187.stm">Georgi Markov</a>, exiled in London. On September 7 1978, he was waiting for a bus near Waterloo Bridge, when he felt an impact on the back of his right thigh. Looking round he saw a man bending down to pick up an umbrella. Markov was soon taken to hospital with a high fever – and died three days later. An autopsy revealed a tiny sphere made of a platinum-iridium alloy in Markov’s thigh. The sphere had been drilled to take a small amount of ricin and may have been fired from an air gun hidden in the umbrella.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/118323/original/image-20160412-15864-fcnv98.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/118323/original/image-20160412-15864-fcnv98.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=449&fit=crop&dpr=1 600w, https://images.theconversation.com/files/118323/original/image-20160412-15864-fcnv98.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=449&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/118323/original/image-20160412-15864-fcnv98.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=449&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/118323/original/image-20160412-15864-fcnv98.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=564&fit=crop&dpr=1 754w, https://images.theconversation.com/files/118323/original/image-20160412-15864-fcnv98.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=564&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/118323/original/image-20160412-15864-fcnv98.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=564&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ricinus communis: find ricin here.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/museumdetoulouse/10588323154/in/photolist-h8DVzL-dqAhE9-9Dfv5P-bWD4Jw-bWD9NY-8h7tRs-bD38ou-5ssdke-bd67WP-f31ZbY-szRqK-j2HUb4-74Jh44-5jiZz5-ymioDY-dj18gF-diVJSG-CWX9Yu-5jj58u-kyCiVB-9Dfvfg-ARAMzn-dqAbVX-Enchj7-fbmtHY-5jj691-dDshz3-D1xW6k-DgN3KT-az9JsH-CrykKU-j2HR92-6y9ksw-D11NWo-DstHhA-DtKvry-DAeZ9y-CFf9ej-8TgGzn-DXXg1v-oRipi2-DsKapJ-DMwJzf-h9a2Vo-9LJpKH-9ByA7o-DXfQn6-Eistwk-nwxwRz-netN1Y">Muséum de Toulouse/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p><a href="http://www.newyorker.com/tech/elements/the-science-of-ricin">Ricin</a> is obtained from the beans of the castor oil plant (Ricinus communis), which is cultivated to extract the oil – the ricin remains in the solid fibre. It is a glycoprotein that interferes with protein synthesis in the cell, <a href="http://www.rsc.org/chemistryworld/podcast/CIIEcompounds/transcripts/ricin.asp">causing cell death</a>. It has an LD50 of 1-20 milligrams per kg if orally ingested, but far less is required to kill if inhaled or injected (as in Markov’s case).</p>
<h2>4. VX</h2>
<p>The only synthetic compound in our top five, VX is a nerve agent with the consistency of engine oil. It emerged from ICI’s research into new insecticides in the early 1950s but proved too toxic to use in agriculture. VX kills by interfering with the transmission of nerve messages between cells; this requires a molecule called acetylcholine. After acetylcholine has passed on its message, it needs to be broken down (otherwise it will keep sending the message) by an enzyme catalyst called acetylcholinesterase. VX and other nerve agents stop this enzyme from working, so muscle contractions go out of control and you die of asphyxiation. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/seZmxDSrieM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Nerve agents explained.</span></figcaption>
</figure>
<p><a href="http://www.rsc.org/chemistryworld/2013/06/vx-sarin-tabun-nerve-weapon-podcast">Nerve agents</a> were made by both sides during the <a href="http://www.compoundchem.com/2015/02/19/nerveagentspart2/">Cold War</a>, but VX became particularly well-known after featuring in Hollywood blockbuster film <a href="http://youtube-downloader-mp3.com/watch-the-rock-sarin-gas-chamber-id-gMVnCL50SgQ.html?similar">The Rock</a>. Only one person is known to have been killed by VX, a former member of the <a href="https://en.wikipedia.org/wiki/Aum_Shinrikyo">Aum Shinrikyo cult</a>, though some 4,000 sheep were killed by it in an accident in Skull Valley, Utah in 1968. It has an LD50 of as little as 3 micrograms per kg (although some reports suggest the figure is a little higher).</p>
<h2>3. Batrachotoxin</h2>
<p>We’ve all heard of South American Indians using venom-tipped blowpipes to hunt their prey. Curare is the best known, and comes <a href="http://ethnobotany09.providence.wikispaces.net/Curare">from a plant</a>. The most toxic, however, come from the skins of tiny frogs – and the deadliest of all is <a href="http://www.chm.bris.ac.uk/motm/batrachotoxin/batrah.htm">Batrachotoxin</a>.</p>
<p>Native Indians in Western Colombia collect these frogs – golden <em>Phyllobates terribilis</em> and multicoloured <em>Phyllobates bicolor</em> – and sweat out the poison over a fire before putting it on their darts. The LD50 is around 2 micrograms per kg, meaning that an amount the size of two grains of table salt will kill you. </p>
<p>Batrachotoxin kills by interfering with sodium ion channels in the cells of muscles and nerves, jamming them open so that they do not close. The continued migration of Na+ ions results ultimately in <a href="http://www.rsc.org/chemistryworld/2014/02/batrachotoxin-poison-dart-frog-podcast">heart failure</a>. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/TjTOJ6zIbys?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A very poisonous bird.</span></figcaption>
</figure>
<p>Interestingly, captive-born frogs of these species are not poisonous, suggesting that the poison is derived from their diet. Indeed, nearly 30 years ago, <a href="http://www.jackdumbacher.com/blog">Jack Dumbacher</a>, an American ornithologist, was working in Papua New Guinea when he was scratched on the hand by one of the local Pitohui birds. He instinctively put his hand to his mouth, which started to go numb. Eventually, it was found that these birds – on the opposite side of the world to Colombia – have plumage containing the same poisonous molecule as the frogs. It is thought that both the birds and frogs obtain the toxin from the beetles they eat – although the poison is far less potent in the birds</p>
<h2>2. Maitotoxin</h2>
<p>There are a number of potent <a href="http://www.mdpi.com/1660-3397/6/2/349/htm">marine toxins</a>, such as Saxitoxin, which are often the cause of poisoning after <a href="http://www.cdc.gov/ncidod/dbmd/diseaseinfo/marinetoxins_g.htm">eating contaminated shellfish</a>. These are often associated with harmful <a href="http://onlinelibrary.wiley.com/doi/10.2310/7060.2003.30550/pdf">algal blooms in the sea</a>.</p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/118324/original/image-20160412-15853-100y5s8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/118324/original/image-20160412-15853-100y5s8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=413&fit=crop&dpr=1 600w, https://images.theconversation.com/files/118324/original/image-20160412-15853-100y5s8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=413&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/118324/original/image-20160412-15853-100y5s8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=413&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/118324/original/image-20160412-15853-100y5s8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=518&fit=crop&dpr=1 754w, https://images.theconversation.com/files/118324/original/image-20160412-15853-100y5s8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=518&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/118324/original/image-20160412-15853-100y5s8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=518&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Dinoflagellate.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/fickleandfreckled/6939384773/in/photolist-bzdak4-5q1gF3-mxwfYA-5pVNDz-mxpLBX-dmM7bt-8Nreaj-c6uHfL-rddRJJ-qxZRgB-rdcRWC-ruFLrG-rdd6Tq-qxZGFa-rbsZee-aFcoi3-qwAB1L-rde7ru-ruM1TR-qxN7UL-qxMVXA-ragJUk-rdd6FS-rc2yDj-ruFoKp-ruMn1e-ruFRRE-rsuERG-ruF5Nc-8ZASTe-fKxgky-qxN71S-ragM4k-ruMC8Z-rsuie3-qy1cxZ-rdkA7r-ruG7vj-ruF5pM-rdkKvX-bsB5BB-bsB5V8-bsB5S6-nHHCGJ-nttowW-nGw5XN-nG7viP-nep7ne-nf3Uow-newPgL">fickleandfreckled/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Maitotoxin is the most lethal of these substances, reckoned to have a LD50 about an order of magnitude less than batrachotoxin. Formed by a dinoflagellate, a kind of marine plankton, it has a very complicated structure, which presents a massive challenge to synthetic chemists. Maitotoxin is a cardiotoxin, it exerts its effects by increasing the flow of calcium ions through the <a href="http://www.rsc.org/chemistryworld/2015/01/chemistry-grandest-total-synthesis-challenge-maitotoxin-put-hold-lack-funds">cardiac muscle membrane</a>, causing heart failure.</p>
<h2>1. Botulinum toxin</h2>
<p>Scientists differ about the relative toxicities of substances, but they seem to agree that <a href="https://theconversation.com/explainer-the-good-the-bad-and-the-ugly-of-botulinum-toxin-16728">botulinum toxin</a>, produced by anaerobic bacteria, is the <a href="http://www.chm.bris.ac.uk/motm/botulism/both.htm">most toxic substance known</a>. Its LD50 is tiny – at most 1 nanogram per kilogram can kill a human. Extrapolating from its effect on mice, an intravenous dose of just 10<sup>-7</sup>g would be fatal to a 70kg person.</p>
<p>It was first identified as a cause of food poisoning due to incorrectly prepared sausage (Latin, <em>botulus</em>) in late-18th century Germany. There are several botulinum toxins, with type A being the most potent. These are polypeptides, consisting of over 1,000 amino acid molecules joined together. They cause muscle paralysis by preventing the release of the signalling molecule (neurotransmitter) acetylcholine.</p>
<p>This same paralysing property is fundamental to the clinical use of the botulinum toxin in cosmetic <a href="https://www.nlm.nih.gov/medlineplus/botox.html">Botox</a>. Targeted injections of tiny amounts of the toxin stop particular muscles from working, relaxing muscles that would otherwise cause wrinkly skin. But it has also been applied to a range of clinical conditions, such as paralysing muscles that, if untreated, would cause crossed eyes (strabismus).</p>
<p>There is increasing interest in using the properties of toxic substances medicinally. The venom of the lethal Brazilian pit viper, <em>Bothrops jararaca</em>, for example, contains blood-pressure reducing molecules that have led to pioneering treatments for <a href="http://blogs.discovermagazine.com/loom/2011/03/11/how-a-pit-viper-saved-millions-of-lives-snakes-as-drug-factories/#.VwZEgPkrLcs">high blood pressure</a>.</p>
<p>As Paracelsus is reported to have said 500 years ago: “All things are poison, and nothing is without poison: the dose alone makes a thing not poison.” And he had a point. Ultimately, we are surrounded by potentially dangerous substances – it’s the dose that makes it deadly.</p><img src="https://counter.theconversation.com/content/56089/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Simon Cotton does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Don’t forget to wash your hands.Simon Cotton, Senior Lecturer in Chemistry, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.