'Flameproof' Falcons, Hawks Discovered in Vancouver

"Flameproof" is not usually a word that you would use to describe a bird, and yet that's exactly the type of falcons and hawks that Canadian researchers have discovered recently in Vancouver, new research shows.

That's the result of polybrominated diphenyl ethers, or PBDEs, which are a group of chemicals that act as flame retardants and were once used widely in computers, stereos, televisions, vehicles, carpets and furniture. Although many of the PBDEs have been banned since the 2000s in Canada, they continue to accumulate in landfill sites where people dispose of PBDE-rich items. In British Columbia's Fraser River delta, for example, the quantity of PBDEs has doubled every four years over the past four decades.

And these chemicals are already having a significant effect on bird populations living nearby, such as the Cooper's hawk in Greater Vancouver, which is reportedly the most polluted wild bird that has been found anywhere in the world. That was determined after researchers analyzed liver samples from birds of prey that were found either injured or dead in the Vancouver area.

"Many animals, including coyotes, eagles and hawks benefit from the excess food in our cities. A downside is the high levels of pollution," Professor Kyle Elliott of McGill University, one of the study authors, said in a statement. "The levels of flame retardants in starlings, a favorite prey of hawks, which nested near the landfill site were fifteen times higher than levels in starlings found elsewhere in Vancouver."

PBDEs are particularly long-lasting because of the way they are added to various plastic and foam products. Rather than being bound to these materials, the chemicals are merely mixed in, allowing PBDEs to leave the products that contain them and enter the environment, according to the Agency for Toxic Substances & Disease Registry (ATSDR). This way, they can enter the air, water and soil, and even accumulate in fish, potentially causing harm to local wildlife like birds.

"We were surprised to see such high levels of contaminants in what I think of as 'green' city," Elliott added. "We can only hope that because many forms of PBDEs have now been banned and the levels of these contaminants are rapidly disappearing from herons and cormorants in Vancouver, the same will be true for other bird species."

The results were published in the journal Science of The Total Environment.

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