Commonly Used Chemicals Found in Polar Bears’ Brains

It has been too well documented that polar bears‘ survival is threatened as their habitat, the sea ice, melts. The disappearance of the ice has been linked to a possible decline in the number of polar bear births as well as to an increase in companies drilling for oil in the Arctic.

Another threat they face is from industrial chemicals that are resistant to thermal, biological and chemical degradation. A recent study has found that these are present in the brain tissue of polar bears in East Greenland.

The chemicals, PerFluoroAlkyl Substances (PFASs) and precursor compounds, are resistant to thermal, biological and chemical degradation. Over the past six decades, they have widely been used in a number of commercial and industrial products as coatings for textiles, paper products, carpets, upholstery and food packaging that are water, oil and soil repellent. They are also found in pharmaceuticals, cleaning products and fire-fighting foams.

As scientists from Carleton University in Canada and Aarhus University in Denmark underscore, these compounds can be carcinogenic and neurotoxic to wildlife and humans. That is, while PFASs and related substances do not directly cause the deaths of polar bears, the accumulation of them in their systems is dangerous, especially as they damage their bones, organs and reproductive systems. The new study says that that PFASs can also damage polar bears’ brains as the chemicals have been shown to cross the blood-brain barrier.

In fact, one particular type of PFAS, perfluorooctane sulfonate (PFOS), has been found at concentrations in polar bears’ livers that are 100 times higher than those in harp seals, which the bears feed on.

The use of PFASs and related compounds has risen dramatically in the past four decades. Due to concerns about safety, PFOS has not been produced in the western world since 2002 as these chemicals are exceptionally persistent (meaning that they only break down in the environment over a very long period of time) and can “bioaccumulate” in an animal’s system. Currently, the only known source of these chemicals is China. Even though there are replacements for these substances, the production of  PFOS has actually  ”increased by roughly a factor of 10, since it was phased out in the USA,” the scientists note.

Industrial chemicals are entering the Arctic via air and sea currents and their presence is likely to increase. The melting of the sea ice has meant that the Arctic is far more accessible to humans, via tourism and industry. Some companies are already planning to use Arctic waters as a regular shipping route. The result can only be an increase in contaminants entering the Arctic ecosystem.

The use of PFASs in everyday products is, the scientists underscore, “widespread.” As the presence of these chemicals is only rarely declared on many products, the least we can do is to seek out environmentally-labeled products. Even if we can slow down the rate at which temperatures around the world are rising and slow down the speed at which sea ice is melting, polar bears are still threatened by our activities.

Photo from Thinkstock

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Waheeda S.
Waheeda S.2 years ago

As if the polar bears needed one more barrier to their recovery and survival... :(

Biby C.
Biby C.2 years ago

I honestly think we're reaching the point of no return, if we have not already.....

June J.
June J.2 years ago

Thank you for you thought provoking and insightful article. Thanks for bringing to our attention these awful facts. Scientific studies are only confirming the worst fears of people who care about the impact of human activity (in this case pollution of toxic industrial chemicals) on the environment and wildlife in particular. What can you do when the people who own and run the companies producing these toxins don't care about the environmental damage that they are causing to polar bears and other wildlife and the environment? Do some homeowork and find out just what chemicals are used, their toxic effects, and how they dispose of the waste. The other thing is to not buy their products, I guess. There are environmental and animal rights/welfare groups who are fighting for change in our business mentality which is wholly lineal thing and totally selfish. These animals and their natural habitats are an intrinsic part of the Earth and we need to take an holistic approach to how we conduct business and the way we live. We humans must seriously include the negative (environmentally harmful) effects of our industrial scale activities on wildlife, their habitats and the environment. Mostly we don't and we're creating a rod for our own backs.

Vivianne Mosca-Clark

We live in a closed system. Until we really understands this ...we will have these issues.

Peggy A.
Peggy A.2 years ago

Interesting Thanks for sharing!

B Lewenza
B Lewenza2 years ago

I don't know how much these poor bears can take. It is bad enough that their habitats are subject to global warming and that is a threat, but now these poisons that are destroying their ability to reproduce and the suffering that they are enduring. These governments need to wake up quick, instead of worrying about how they are going to tax us to death or screw us in some other way, they need to take a good long look at the future and the environment.

Jeanne Rogers
Jeanne Rogers2 years ago

It makes me sick that there are so many that are working to destroy this planet and everything in it------all for greed.

David V.
David V.2 years ago

Melania P. - I could not have said it better myself. Humans are the cause, mother nature will get even sooner or later....just let's hope it is sooner.

Ruhee B.
Ruhee B.2 years ago

Horrible but what is as horrible is the thought that they must be getting this "brain tissue" from dead bears. Where do these dead bears come from? I don't understand why the killing of these bears is still going on. They are being killed in every way possible - it's completely wrong.

Ana Marija R.
Ana R2 years ago