Somebody call the Lorax: last week, a team of scientists at McGill University declared a Cooper’s hawk found in the Vancouver area was “the most polluted wild bird that has been found anywhere in the world.”
After analyzing its liver, the researchers found the hawk was stuffed with a class of chemical called polybrominated diphenyl ether, or PBDE. Once used to fireproof plastics used in computers, TVs and carpets, these chemicals have been banned in Canada and the United States since the 2000s because they tend to stick around and contaminate the environment. As Larry Pynn wrote for the Vancouver Sun, the chemical average for the other 15 Cooper’s hawks that were tested for PBDEs was about 18,730 parts per billion.
This hawk, in contrast, had PBDE levels of 197,000 parts per billion — more than 10 times the others. Higher even than any of the birds found in an electronic waste site in China.
In a press release, McGill University professor Kyle Elliot, one of the study's authors, suggested the hawks’ favored food source, starlings, had been contaminated by food they had found in a nearby landfill.
"Many animals, including coyotes, eagles and hawks benefit from the excess food in our cities,” Elliot said. “The levels of flame retardants in starlings, a favourite prey of hawks, which nested near the landfill site were fifteen times higher than levels in starlings found elsewhere in Vancouver.”
The super-contaminated hawk didn’t die from the chemical exposure, Pynn writes. However, it is likely the PBDEs in it’s system affected the hawk’s thyroid gland, which could have affected its size, behavior and metabolism.
Despite being banned in the last decade, the PBDEs don't seem to be going away. In fact, the EPA believes that levels in the environment could be rising, possibly due to the chemicals breaking down over time along with more products containing PBDEs being imported from other countries writes John Metcalfe for The Atlantic. And as people throw away their old things, the old chemicals are concentrating in landfills.
But like the Lorax's last Truffula seed, there might be a glint of bright side to this grimy story: Elliot noted that the study found PBDE levels in other local birds were starting to drop.
“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,” Elliot said in the press release.