It has been getting ever harder to pretend that Antarctica is a pristine place. We like to think of it as being scoured clean by hostile winds and extreme cold. But more and more, Antarctica, like the Arctic, shows the lasting scars of human negligence.
The effects of climate change are being felt far more strongly at the poles than elsewhere on the planet. Some of the most persistent and dangerous chemicals ever created have accumulated there and remain there.
Take DDT, the long-banned pesticide. When it was still sprayed on crops and gardens across the globe, it moved through the atmosphere to the polar regions, where it was deposited in water, snow and ice, ultimately making its way into the food chain.
The residue of DDT found in many Arctic species has declined in the past 30 years. But recently, scientists in Antarctica reported that Adelie penguins have a constant and, in some cases, increasing level of DDT in their body fat. It appears that the birds are being newly exposed to remnants of DDT that was deposited long ago.
Scientists estimate that about 1 to 4 kilograms of DDT are being released annually. This is not a large amount, but it is troubling nonetheless, especially since the levels released are likely to rise as climate change intensifies.
As more ice melts, it will only add to the burden of so-called persistent organic pollutants that have made their way into the Antarctic’s life stream.
Nothing could seem farther removed from our ordinary lives than these isolated populations of Adelies. But they are frighteningly near to our pesticidal past and one more reminder of the longlasting consequences of human behavior.