Cold POPs

Although often called “pristine,” researchers know that the Arctic hasn’t been spared from pollution. Air and water currents have imported plenty of smutz from far off smokestacks and sewer pipes, imperiling sensitive species. A new effort to track Arctic pollution over the last 25 years, however, finds that efforts to control some of these pollutants have helped – even as the burning of fossil fuels has helped create new threats.

“Protecting the health of Arctic ecosystems is a global concern,” an international research team writes in Environmental Science & Technology. But “an often overlooked potential source of stress for these ecosystems is the exposure to persistent organic pollutants (POPs)” – chemicals that don’t break down quickly and can accumulate in the tissues of plants and animals. Although an international effort known as the Arctic Monitoring and Assessment Programme (AMAP) has been measuring POPs in the Arctic for about 25 years, the data is often fragmentary and short-term, making it hard to assess how Arctic pollution is changing.

To get a bigger picture, the researchers pooled data from more than 20,000 tissue samples of Arctic organisms and then used a statistical model to evaluate how pollution levels changed between 1985 and 2010 in the Barents and Norwegian seas. The good news, they report, is that tissue levels of “legacy POPS” appear to have “decreased tenfold… which reflects regulatory efforts to restrict these substances.”

In contrast, however, concentrations of 29 POPs produced by the burning of fossil fuels are on the rise in fish and invertebrates near the bottom of the Arctic food chain. These 29 polycyclic aromatic hydrocarbons (PAHs) have “increased 10 to 30 fold over the past 25 years and now dominate” Arctic POP pollution. Before 2000, they note, chemicals called polychlorinated biphenyl (PCBs), once widely used in electrical equipment, “dominated the summed POP burden in top 32 predators.”

Although PAH levels “seem to be stabilizing during the last 5 years, which may be explained by the search for and use of alternative energy sources that are independent of fossil fuels,” their presence suggest that climate change isn’t the Arctic’s only problem. “Our findings indicate that the debate on the environmental impacts of fossil fuel burning should move beyond the expected sea water temperature increase,” they conclude, “and examine the possible environmental impact of fossil fuel derived PAHs.” – David Malalkoff | September 11, 2011

Source: F. De Laender, J. Hammer, A.J. Hendriks, K. Soetaert and C.R. Janssen. Combining monitoring data and modelling identifies PAHs as emerging contaminants in the Arctic. Environmental Science & Technology doi: 10.1021/es202423f.

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