Polar bears threatened by toxic chemicals in melting sea ice

Polar bears are being exposed to the toxic chemicals used in cosmetics and non-stick pans, and this exposure is directly related to global warming, according to a new study from Lancaster University.

The chemicals are being released into the air in high concentrations from manufacturing sites, and then carried by the wind to the Arctic, where they accumulate in sea ice. 

As temperatures rise throughout the Arctic, the chemicals are running off into the ocean from melting ice. The contaminants are then consumed by algae and zooplankton, before making their way up the food chain to polar bears. 

Poly and perfluoroalkyl substances (PFAS) are referred to as “forever chemicals” that do not fully break down in the environment. The Lancaster team has discovered the toxic chemicals in brine on the underside of the ice – a preferred habitat for algae and other organisms at the bottom of the marine food web. 

The experts tested samples from the Barents Sea, thousands of miles away from the densely populated areas of Europe. They found that the concentration of the toxic chemicals was up to double the concentration that has been observed in the North Sea. 

According to the researchers, there is evidence that PFAS are disrupting the hormone systems of polar bears. PFAS are also linked to a range of health issues in humans, including liver damage, birth defects, cancer, and impaired immunity. According to the CDC, PFAS have been found in the blood of nearly every American tested.

In the Arctic, sea ice used to remain frozen for years at a time but is now melting each summer as a result of global warming. 

‘This one-year ice contains a lot of mobile brine that interacts with the overlying snowpack and can serve to concentrate pollutants like PFAS, which are usually found at very low levels,’ said study co-author Professor Crispin Halsall.

“Unfortunately, with earlier and more erratic thaw events, this can lead to the rapid release of the stored chemicals resulting in high concentrations in the waters surrounding the ice floes.”

Professor Halsall said that it is only through this type of investigative science that we can understand the dynamics of pollutant behavior and identify key hazards, particularly those related to climate change.

“In turn this can drive international legislation so that chemicals that exhibit this type of behavior are banned.”

The study is published in the journal Environmental Science and Technology.

–—

By Chrissy Sexton, Earth.com Staff Writer