A new report from the U.S. Department of Commerce says levels of some persistent organic pollutants (POPs), including DDT ad polychlorinated biphenyls (PCBs) regulated by the Stockholm Convention are decreasing in the Arctic.
The report is of particular interest to residents of Alaska’s Arctic. Since indigenous peoples living in northern coastal areas, including Alaska, often consume more fish and other animals than come from higher on the food chain than the average American, these people are potentially exposed to larger amounts of these pollutants.
According to the National Institute of Standards and Technology, a physical sciences laboratory and non-regulatory agency of the Commerce Department, the work of an international team of researchers found that when POP use was curtailed, the change was reflected in declining concentrations in the Arctic environment.
Back in 2001, 152 countries signed a United Nations treaty in Stockholm, Sweden aimed at eliminating, restricting or minimizing unintentional production of 12 of the most widely used POPs. More chemicals were later added to the initial list, and today more than 33 POP chemicals or groups are covered by what is commonly known as the “Stockholm Convention”, recognized by 182 countries.
The action called for in the Stockholm Convention was initiated because POPs were found to cause health problems for people and wildlife, including reproductive, developmental, neurological and immunological problems in mammals. DDT was also linked to eggshell-thinning in fish-eating birds, including eagles, in the late 20th century and caused catastrophic population declines for some animals.
POPs are particularly problematic in the Arctic because the ecosystem there is fragile, and pollution can come from sources both local and from thousands of miles away due to air and water currents. Researchers noted that POPs bioaccumulate, that is they build up faster in animals and humans than they can be excreted, and that exposure can increase up the food chain. Plankton exposed to POPs in water are eaten by schools of fish, which in turn are eaten by seals or whales, and with each jump up the food chain amounts of POPs increase, researchers said.
Most of the research conducted for this paper was a direct result of the 2001 treaty stipulations, which included a requirement that sponsors participate in ongoing, long-term biological monitoring, the NIST said in its report.
The report was circulated on Aug. 27 by EurekAlert, the online science news publication of the American Association for the Advancement of Science.
