Chemicals Accumulating in Polar Bears Raise Concerns
January 20, 2006 -- Carried to the Arctic via wind and ocean currents, the toxic chemicals used in flame retardants may be threatening polar bears, one of the planet’s most contaminated organisms, according to Canada's National Water Institute. These toxic chemicals, known as polybrominated diphenyls, accumulate in the fatty tissue of animals and become more concentrated in the top predators of food chains as bigger animals eat smaller contaminated ones. Scientists are unsure of exactly what effects these flame retardant compounds have in polar bears.
Similar industrial chemicals have been shown to weaken immune systems, alter bone structure, disrupt sex hormones, and possibly cause hermaphroditism in bears. Some scientists also believe that many cubs are contaminated by their mothers’ milk and die. Bears in Canada's western Hudson Bay, the most well-researched population, declined from 1,100 in 1995 to fewer than 950 in 2004. Only 20,000 to 25,000 of these creatures remain throughout the world.
Several National Research Council reports discuss the effects of chemicals in the environment. The Environment: Challenges for the Chemical Sciences in the 21st Century discusses the effects that some chemicals have had on the environment, how industry and scientists have tried to deal with that, and what still has to be done. Hormonally Active Agents in the Environment examines how synthetic hormonally active chemicals get into the environment and their effects on fish, wildlife, and humans.
In addition, the Research Council's Polar Research Board explores matters of scientific research, environmental quality, natural resources, and other issues in the Arctic, Antarctic, and cold regions in general. A Vision for the International Polar Year 2007-2008 sets a framework for an internationally coordinated polar research campaign, recommending what could be explored, how new programs can be accomplished, and ways to excite the public and scientific communities in the polar regions' global importance.