Toxins from distant countries found in polar bears’ brains
Polar bears in East Greenland have toxins in their brains, which can impact the endangered animals’ fertility, Danish researchers have discovered. What’s worse is that the polar bears have not have ingested products containing the dangerous perfluoroalkyl substances (PFAS) accidentally.
“Other pollutants dissipate into the environment, but these don’t,” lead researcher Rune Dietz, professor of Wildlife Biology and Toxicology at Aarhus University in Denmark, tells Metro. “And they don’t exist in polar bears’ habitat either. A lot of the production of products with these substances now takes place in China. [Our findings] show how far these pollutants are able to travel.”
Dietz’s team has studied 500 polar bears in East Greenland for the past 30 years.
The products in question are everyday items like Teflon pans and textile coatings. Precisely because they don’t dissipate into the environment, they travel up the food chain once they’ve been ingested by a lowly fish species. They also travel far distances inside the bodies of the various fish species and marine mammals, which is how they arrive in polar bear habitats. “When you get to the top of the food chain, where the polar bear reside, you get the highest concentration of these toxins,” explains Dietz.
Though no conclusive evidence exists, PFAS are suspected of damaging the brain, liver and reproduction.
“There are higher levels of PFASs in the brains of Inuits (Greenlanders) as well,” explains Dietz.
Even more worryingly, people in industrialized countries who have never eaten marine mammals have PFASs in their brains, too. But, if they eat neither marine mammals nor fish, how do they ingest the toxins? Researchers at the Norwegian Institute for Air Research are the science world’s detectives, trying to establish how the poisonous substances enter our bodies.
“The increase in PFASs in humans and polar bears is very frightening,” notes Dietz. “The good news is that production of products using these pollutants peaked in 2006. But it’s worrying that there’s still very little regulation of PFASs in China.”