Heading north. Persistent toxic compounds accumulate in the Russian Arctic; a new study finds elevated levels of an insecticide (HCH) in breast milk of indigenous people in the Chukotka region.

Toxins Persist in the Russian Arctic

The first comprehensive look at persistent toxic substances across the vast Russian Arctic reinforces what studies in other Arctic nations have revealed: that indigenous people in this northern swath of the world are inordinately exposed to pesticides, industrial compounds, and heavy metals, with uncertain health effects.

Conducted by the Arctic Monitoring and Assessment Program, the environmental research arm of the eight-nation Arctic Council, the 4-year, $2.8 million study sampled pollutant levels in the four major regions of the Russian Arctic. The researchers found that samples of breast milk and maternal and umbilical cord blood contained moderate to extremely high levels of DDT, PCBs, mercury, lead, and brominated flame retardants, among other chemicals. Due to northward flows in rivers, oceans, and atmospheric currents, persistent toxins released elsewhere, along with some local contaminants, have accumulated heavily in many areas of the Arctic, where frigid temperatures retard their dispersal and degradation.

In people, the highest toxin levels were found in the Chukotka region on the eastern coast of the Russian Arctic, where the indigenous population eats large quantities of marine mammals and fish, which can be heavily contaminated both with local and long-range pollutants. Researchers found that about 5% of the population, mostly males, have some of the highest PCB contamination levels--10,000 nanograms per gram of blood lipid—ever seen, says Éric Dewailly of the Centre for Inuit Health and Changing Environments at the National Institute of Public Health of Québec. The Chukotka region, Valerie Chashchin of the Northwest Public Health Centre in St. Petersburg notes, "is a wasteland where millions of tons of chemicals were imported during the Soviet era and never cleaned up."

Preliminary evidence, from comparisons of these contamination data with information reported in health interviews with Arctic inhabitants, suggests that exposure to some persistent toxics may be linked to reproductive effects such as stillbirths, birth defects, low birth weight, and spontaneous abortions. The study also noted an apparent association between reduced numbers of male births and increases in Arctic maternal blood concentrations of both lead and some types of PCBs. "We are surprised and a little worried," says a member of the study's Steering Committee, Jon Øyvind Odland of the Institute of Community Medicine at the University of Tromsø in Norway.

Related site
Arctic Monitoring and Assessment Program, with a link to the report

Posted in Environment