Some penguins for Ruth...
A disturbing New Scientist Environment newsflash came today about work done by Heidi Geisz, a marine biologist at Virginia Institute of Marine Science in Gloucester in the US. (As you probably know) DDT was widely used as a pesticide from the late 1940s onwards, but was banned in many countries since the 1970s and these days its usually only used to control disease-bearing mosquitos However DDT has been showing up in tissue samples from Adélie penguins. If this was DDT that had been around in the foodchain for 30-40 years, then the scientists would expect to find DDE (a DDT breakdown product). Turns out, there were large deposits of ice in Antarctic glaciers in the 1950s and 60s and the DDT has been sequestered there for the last 50-odd years, only trickling out now as the glaciers melt. Fortunately, the levels aren't high enough to harm the penguins, but they're worried that other toxins (eg dioxins, PCBs from refrigeration) may also be being released. It really makes you realise how even relatively short periods of pollution can have long-lasting, far-reaching effects (cos I'm guessing DTT was never sprayed in Antarctica!).
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