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Polar bears' greasy fur could hold the secret to ditching harmful forever chemicals, says researcher

Julian Carolan says researchers are looking at polar bear grease because it repels ice. That property could help replace the harmful forever chemicals currently used in non-stick cookware.

Experiments found fur oil keeps them the bears from sticking to ice

Polar bear standing in bush of twigs looks toward camera
Polar hair hair oil has natural non-stick qualities that help these animals from getting stuck on ice, says PhD candidate Julian Carolan. (© Kieran McIver / Polar Bears International)

Polar bears' greasy fur oil helps them repel ice, researchers say — and it may hold the key to helping humanity ditch harmful forever chemicals.

So-called forever chemicals, or PFAs, can be found in common household items like non-stick cookware. They take thousands of years to break down by conventional methods and build up in the environment and in bodies.

Polar hair oil has non-stick qualities that come without the harmful environmental impacts. Essentially, it's Mother Nature's Teflon.

"We found that when you had unwashed, greasy polar bear fur, it didn't stick that strongly at all," said Julian Carolan, a PhD student at Trinity College Dublin, who worked on the project.

While other animals and human hair secretes oils, he said polar bears hair oil is different and fattier.

"It's a little more specialized for their cold, icy environment," Carolan said.

LISTEN | PhD candidate Julian Carolan chats about the unique properties of polar bear fur: 
Polar bears spend so much time going in and out of the water that they are considered marine mammals. So when they do this in the frozen Arctic, why are they not covered in ice? A new study reveals the secret turns out to lie in the unique oils they produce that covers their white fur. Julian Carolan, a PhD candidate at Trinity College Dublin, worked with scientists in Norway, Denmark and the U.K. on this paper published in the journal Science Advances.

The research team used computational models to look at how the polar bear grease components interacted with ice.

"We found that some of the components that are really abundant in polar bear oils, like the long fatty acids and the cholesterols, stick very weakly to ice — at least in the simulated model," he said.

In fact, Carolan said they had a similar weakness to forever chemicals that are used to reduce ice adhesion.

"A really impressive performance, to see this natural example do as well as the ... synthetic and environmentally unfriendly standard," said Carolan.

Man in beige sweater next to man in grey shirt next to some equipment.
PhD candidate Julian Carolan, next to his supervisor Richard Hobbs, worked on recent experiments into the non-adhesive qualities of polar bear fur oil. (Submitted by Julian Carolan/Richard Hobbs)

It could take time, though, before polar bear grease — or a comparable man-made analog — replaces forever chemicals.

"It'll be kind of dependent on the application. We'd want to really avoid [it] in places where maybe these waxes and fluorinated waxes get into the environment," he said.

"But it will be sort of one step at a time. How best to use these? Do they need to be waxed onto a surface? Do they need to be chemically bonded to the surface?" he said.

For science

Carolan said the team carried out experiments on how well ice stuck to polar bear fur by measuring the strength it took to remove it from the ice.

"It was clear from this experiment that the polar bear hair oils have an important influence on stopping ice from sticking to the polar bear, allowed it to stay ice-free in the Arctic," he said.

Carolan added that as part of the experiment, he refrained from washing his hair for a week so the researchers would have something to compare to polar bear fur.

"It sort of became long greasy strands and then shaved it all off and used that as comparison. And we found that human hair, washed and unwashed, stuck very strongly to the ice, similar to the washed polar bear."

He added it was an awkward time to shave his head, as it was in the cold month of January, "But needs must for science," he said.

The results made the team wonder what was so special about polar bear grease, said Carolan, so they brought in experts in oil and fat and got new samples of polar bear hair oil that were collected by the researchers on the team who worked for the Norwegian Polar Institute.

From there, he said they determined the oil's exact composition and found it was complex.

"We found that polar bear hair was very fatty, much faster than human and other mammals that have been studied. We found in particular an abundance of this cholesterol, cholest-5-en-3-beta-ol, as well as other fatty compounds."

That makes sense, he said, since polar bears have a fatty diet.

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ABOUT THE AUTHOR

Elizabeth Whitten is a journalist and editor based in St. John's.

With files from Newfoundland Morning