Kelly McSweeney

Mar 4th 2020

Polar Bears at Risk From Toxic Chemical Exposure


A new study has illuminated the fact that there are polar bears at risk for health problems caused by exposure to toxic chemicals around Hudson Bay, Canada. These chemicals can disrupt biological functions in polar bears and damage their immune, digestive and reproductive systems, according to CBC News.

Even without the revelations about toxic chemicals, scientists have predicted that we could lose wild polar bears by 2100 due to climate change, according to Polar Bears International. After several decades of research, scientists are still learning more about how animals are affected by pollution.

New Study Reveals Chemicals in Polar Bears

Researcher Robert Letcher told CBC News that, “The new study complicates our understanding of the complex cocktail of chemicals the bears are exposed to as they try to adapt to changing climate … if a compound can migrate its way through the food web, all the way up to the polar bear, it must be pretty extensive.'”

According to WWF, bears with high levels of certain chemicals have “low levels of vitamin A, thyroid hormones and some antibodies. These are important for a wide range of biological functions, such as growth, reproduction and the ability to fight off diseases.”

Even worse, according to the National Center for Biotechnology Information, if mother polar bears are exposed to high levels of chemicals, their milk can even become poisonous to bear cubs, which are especially sensitive to environmental toxins in early development.

The 2001 Stockholm Convention

Although the new study reveals a new mix of chemicals in bears, scientists have been concerned about this class of chemicals — called persistent organic pollutants — for decades. POPs are toxicants that remain in the environment for long periods of time and can travel via wind and water, so they often accumulate thousands of miles from the source, according to the Stockholm Convention.

According to the United States Environmental Protection Agency, POPs have caused environmental and health problems for both wildlife and humans, which led to 91 countries signing an international treaty called the Stockholm Convention on Persistent Organic Pollutants — designed to address transboundary pollution. They “agreed to reduce or eliminate the production, use, and/or release of the 12 most dangerous POPs,” said the EPA. More chemicals have since been added to the list, such as substances used for everything from flame retardants to pesticides.

Unfortunately, POPs still put animals like polar bears at risk. Even though these chemicals are now banned, they still pose a threat to wildlife and human health for several reasons, according to the EPA. First, POPs last so long that even if production was completely eliminated, they would remain in our environment for many years. Secondly, they are difficult to contain and track; since they travel though wind and water, POPs can affect ecosystems far away from where they were originally produced. Additionally, many developing nations have only recently started to restrict POPs.

Keeping an Eye on Arctic Wildlife

The good news is that there is new technology to keep track of how animals are affected by pollution. New screening methods are better at detecting chemicals and researchers are keeping a close eye on Arctic wildlife. For example, a Northrop Grumman team recently developed a drone specifically designed to track polar bears.

Now that scientists have a better understanding of global warming, they are investigating what happens to these persistent chemicals when Earth’s temperatures rise. “‘If there’s any stressing factor to life in the Arctic, it is climate change,'” Letcher said. “‘It’s a major challenge for us to understand how climate change variables are affecting contaminant exposure.'”