Lake sediments in Greenland show mercury concentrations are three times higher than in pre-industrial times. Globally, 5,000 tons of mercury are present in the air at any time.
In addition to known pollutants, newly-detected toxins were added to the list. Among those were flame retardants that affect brain development and weaken immunity, and perfluorooctane sulfonate (PFOS), a stain repellant. PFOS, which was recently found in the livers of northern Alaskan bears, is of particular concern because of its "extreme persistence." "It does not seem to break down under any circumstance," the authors said.
Many of these chemicals persist longer here than in other regions because of the frigid climate and the lack of soil and vegetation to absorb pollution. Even small amounts of toxins go a long way since northern animals accumulate them over a lifetime in the fat they store to survive the extreme cold.
Chemicals in Breast Milk
Inuit people are particularly at risk because the staples of their diet include animals that sit high on the food chain, like seal, whale, and fish, that have absorbed large quantities of contaminants. Chemicals have also been found in breast milk.
There was some good news. Since the introduction of non-leaded gasoline in North America in the 1970s, lead levels have dropped steadily in Greenland ice core samples. But tests on animals, from moose in the Yukon Territory to Swedish reindeer, show little change in the amount of lead stored in body tissues.
Steps are being taken to address the problem. In 2001, the United Nations Environment Programme identified the most dangerous pollutants and initiated global negotiations, a move that created the Stockholm Convention on Persistent Organic Pollutants, an international treaty to ban these chemicals. As of July, Canada, Iceland, Norway and Sweden had ratified the agreement.
WWF says that toxic chemicals are slowly poisoning some of Earth's most unique residents, and is urging the United States and Russia to act. "Without a global ban, we can't protect indigenous communities and wildlife in the Arctic," said Smith. "The U.S. and Russia need to stop ignoring the scientific evidence and ratify the Stockholm Convention."
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