Persistant Organic Pollutans (POPs) are toxic, hang around for a long time, and tend to build up in the bodies of humans and animals, particularly in predators. POPs are moved by air so they can be generated in one place and travel easily to other areas. In particular they are focused in cold areas of the planet, like the Poles and the high mountains. These compounds were widely used in agricultura and industry after the II World War and currently, most of them are banned or monitored by international agreements.
According to a study published in December 2016 in Journal Environmental Toxicology and Chemistry and led by researchers from IMDEA Water Institute (Spain) and University of Milano Bicocca (Italy) looked at the effects of Persistent Organic Pollutants on high trofic chain level species in the Artic.
A new analysis of pollutants in the Arctic has found that polar bears are at a particularly high risk, compared to other animals like seals. Chemicals are accumulating in polar bear mother's milk, with a fat content of 35%, and getting passed onto bear cubs.
For the study, researchers collected data poduced over the last 4 decades over a large sector of Arctic and sub-Arctic regions, which considered food chains, diets of animals, concentration of POPs and the surrounding environment. The scientists estimated concentrations of 19 chemicals in Arctic cod, ringed seals, and polar bears.
“This work is the first attempt to quantify the overall risk of POPs for the Arctic ecosystem and to define a ranking in order to highlight the most dangerous chemicals in the mixture,” said Sara Villa co–lead author of the Environmental Toxicology and Chemistry study.
The study made it clear that since the 1980s, there had been a measurable decrease in the risk of POPs for bear cubs, mainly thanks to international control measures. But the composition of POPs changes constantly, and the recent addition of new POPs into the environment, particularly something called perfluorooctane sulfonate, which was used in fabric protector, increased since the 1970s until it was banned in the early 2009.
The work also contributes information that could be used to assess the effectiveness of control measures (in particular, the Stockholm Convention) in reducing the global risk of POPs, to estimate the time needed for a substantial reduction in the risk of legacy POPs, and to highlight future research priorities for emerging potential POPs
“The results demonstrate that international control measures are effective at reducing the risk to ecosystems. Nevertheless it is fundamental to continuously implement the control of new and emerging contaminants,” added co–lead author Marco Vighi and IMDEA water researcher at Aquatic Ecotoxicology and Ecological Risk Assessment area.
You can see the article here