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Thousands of tonnes of British shellfish currently eaten in Europe could be banned under new international safety limits for radioactivity in food, the UK Food Standards Agency (FSA) has warned.

Lobsters, cockles and scallops from the north west of England and the south west of Scotland are so contaminated with plutonium from the Sellafield nuclear complex in Cumbria that they will breach limits due to be introduced by the United Nations in 2005.

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Further down...

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Concentrations of plutonium and related isotopes in all the shellfish sampled by the FSA between the Ribble estuary at Preston and Kirkcudbright on the North Solway coast in 2002 exceeded 1Bq/kg. Winkles from St Bees, next to Sellafield, contained 66 Bq/kg.

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1 Becquerel per kilogram is the limit to be set in 2005.

This is actually an important debate, since it points up the continuing need (and which I plan to study, incidentally, next semester) for a good knowledge of the chemistry of radioactive heavy metals. Very little chemistry of the transuranic actinides is in the literature, for example. Even for the naturally-occurring actinides, the chemistry is still being studied with interest.

While the chemistry involved may have largely theoretical interest only (since radioactive compounds as a rule require special safety precautions, and in general can be used extensively only in closed-loop systems), there are practical effects mainly to do with understanding properly these metals' coordination chemistry with water, for example.

Insofar as this touches on food contamination, it is important to not overstate or understate the risk of ingesting potentially contaminated food. 66 Becquerels per kilogram is 66 disintegrations per second per kilogram. When one considers that macroscopic quantities of radioactive material are usually quoted in kiloBq or even megaBq^*, it may be more understandable why the shellfish industry is (reflexively, unfortunately as is the case with any industry that automatically resists government regulation) insisting that the 1 Bq per kilogram limit is too stringent.

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^* In point of fact, in my radiochemistry lab I routinely worked with kiloBq or megaBq beta emitters and those would register on a radiation detector (you can start to get an idea of the amount of radioactivity needed to really register as being potentially dangerous), but even these were not considered very harmful as long as proper safety guidelines were followed.

(Edited to change the thread title because of what I've added)

[ 13 October 2004: Message edited by: DrConway ]

Y'all may not realize it, but there's a tiny bit of radioactive potassium in all concrete, since the isotope is so long-lived. ⁴⁰K goes by either beta minus to ⁴⁰Ca or beta plus/electron capture to ⁴⁰Ar. One of those daughters then goes by gamma ray emission to the ground state. So always we are bathed with a few extra gamma rays near concrete.

The steel industry used recycled ships from the Bikini Atoll atom bomb tests, and what had happened was the iron in those ships underwent neutron capture to produce the long-lived ⁶⁰Fe, which goes by beta minus to ⁶⁰Co (Cobalt), which then goes by beta minus to ⁶⁰Ni (Nickel) which then goes by gamma ray emission. So all the world's steel is radioactively contaminated (thanks to extensive recycling and dilution) and will be for at least 1,500,000 more years (one half-life of the Iron-60). Cobalt-60 has a half-life of about 5 years, so it is negligible compared to the Iron-60. (the steel is not really dangerous, but it does increase one's gamma-ray exposure a little)

Just some food for thought.

[ 13 October 2004: Message edited by: DrConway ]

[ 13 October 2004: Message edited by: DrConway ]

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Originally posted by Gir Draxon:
Shellfish are contaminated with radioactive waste, but hey, at least the plant didn't release any carbon dioxide. w00t for the Kyoto protocol!

No I'm not a greenhouse effect denier, I'm just saying that we should be paying more attention to pollutants that we know are toxic rather than ones that we think are changine the climate. Granted, the theory makes sense, but there is doubt. There is no doubt as to the harmful effects of radioactive and/or heavy metals.

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Yes, there is some dispute about climate change and its causes. I'll leave that for another thread, and suppose for now that the anti-Kyoto crowd are not just cranks and vested interests, and that they might actually have a valid argument. Even so, if there is a reasonable doubt about which side is correct, I would prefer to err on the side of caution.

The most terrifying article I've ever read is the one linked to at the top of this thread, and I truly mean that. War, massacres, torture and the like are sickening and deplorable, but still leave room for hope that there could be some happiness in this world now, and a better future for all, no matter how much individuals may suffer. A runaway greenhouse effect could turn Canada and every other place on earth into a global version of the worst African famine you've ever seen... until we are extinct, that is.

I don't know that this will come to pass, but I think that the evidence should be assessed, and if there is doubt about which side is correct, I would rather do what it takes to reduce greenhouse gas emissions, and reduce the risk of ending up like Mars.

[ 15 October 2004: Message edited by: Albireo ]