PCBs Now Genetically
Damaging Polar Bears
in Norwegian Islands
By Doug Mellgren
Associated Press Writer
OSLO, Norway (AP) -- Polar bears fear nothing they can see in their icy domain -- but they can't see polychlorinated biphenyls, and scientists worry the bears are succumbing to the invisible toxins.
Last year, researchers in Norway's remote Svalbard islands reported they found seven female polar bears with vestigial male organs. Research team leader Andrew Derocher says the anomaly may be caused by toxic chemicals.
Derocher, a Canadian affiliated with the Norwegian Polar Institute, will lead a team to the Svalbards to try to determine whether PCBs and other toxins have affected polar bears' immune systems.
"We are going to study the Svalbard bears, which is the most polluted population in the world, and compare them with a low-end population in Canada," he said.
The Svalbard archipelago, just 600 miles from the North Pole, might seem to be about as far as possible from man's pollution.
But the islands are at a crossroads of air and ocean currents bringing pollution from distant industrial sites in Europe, North America and even Asia.
The level of PCBs in the Svalbards is at least 2.5 times higher than in Canada's polar bear territory, Derocher said. Other scientists have reported levels of PCBs in Svalbard bears 10 times higher than in Alaska.
PCBs, chemical compounds once widely used in plastics and electrical insulation, were banned in the United States in the 1970s and are restricted under international agreements. But it takes years, even decades, for them to break down.
PCBs dissolve readily in animal fat, such as blubber, and stay there. A polar bear's favorite food is seal blubber.
Derocher and his team are headed to Svalbard for an Aug. 8-16 study in which they plan to mark attach radio-tracking devices to 30 adult bears and up to 20 cubs and give them vaccine designed to test their immune systems.
Then, four to six weeks later, they will track down the same bears to see how their immune system responded to the vaccine.
"We want to test the ability of the immune system in these high pollution bears," he said. The results will be compared with Canadian bears to be tested next year in Wapsuk National Park.
He said the level of PCBs found in Svalbard's bears are similar to those shown to have caused damage to seals, otters and mink, ranging from short-term memory loss to sterility and a reduced ability to withstand disease.
Derocher said the Svalbards and the ice-pack to the north probably sustain a population of 4,000-5,000 bears in a 100,000-square-mile area, where they have no natural enemies. The population of bears, which grow to 440- to 880-pounds, has appeared stable since Norway banned hunting them 25 years ago.
But if their immune systems are weakened or fail, that could quickly change, he said.
"If they were hit by a disease, there could be a great impact in decades, even in years," Derocher said. "It is certainly something to be concerned about," he said about the toxins.