Persistent organic pollutants (POPs)—organic compounds produced by human activities that are resistant to environmental degradation—include industrial chemicals such as polychlorinated biphenyls, and pesticides, such as DDT (dichlorodiphenyltrichloroethane).

POPs can be transported long distances in the atmosphere, and accumulate in regions such as the Arctic where low temperatures induce their deposition (and where the compounds accumulate in wildlife and humans, putting their health at risk).

The concentrations of many POPs have decreased in Arctic air over the past few decades owing to restrictions on their production and use. As the climate warms, however, POPs deposited in sinks such as water and ice are expected to revolatilize into the atmosphere, and there is evidence that this process may have already begun for volatile compounds.

Here we show that many POPs, including those with lower volatilities, are being remobilized into the air from repositories in the Arctic region as a result of sea-ice retreat and rising temperatures. We analyzed records of the concentrations of POPs in Arctic air since the early 1990s and compared the results with model simulations of the effect of climate change on their atmospheric abundances. Our results indicate that a wide range of POPs have been remobilized into the Arctic atmosphere over the past two decades as a result of climate change, confirming that Arctic warming could undermine global efforts to reduce environmental and human exposure to these toxic chemicals.

—Ma et al.

Resources

• Jianmin Ma, Hayley Hung, Chongguo Tian & Roland Kallenborn (2011) Revolatilization of persistent organic pollutants in the Arctic induced by climate change. Nature Climate Change doi: 10.1038/nclimate1167