School of Public & Environmental Affairs Podcast Series
Early in the classic coming-of-age movie The Graduate, during a college graduation party for the young Hero, Benjamin Braddock, an older man pulls Ben aside to impart some sage business advice. “I want to say one to you, just one word,” the man says. “Plastics.”
The Graduate has proven prophetic. Today we live in a world of not only plastics but also thousands of other kinds of synthetic materials. Virtually everything in our lives--clothes, furniture, computers, cell phones, toothbrushes, toothpaste--is made from a dizzying blend of exotic chemicals. Some of the most common are polybrominated diphenyl ethers, or PBDEs (otherwise known as flame retardants) -- handy chemicals that keep our possessions from easily catching fire.
But the problem with PBDEs is that, like many chemicals, they don’t always stay put. “One of the bigger sources of flame retardants to people is in fact household dust,” says SPEA professor Ronald Hites. “And it’s well documented that Lots of houses with foam filled furniture have higher levels of flame retardants.”
Hites has done several recent studies on PBDE’s in the environment. To test the level of flame retardant chemicals people may be inhaling and ingesting, Hites and SPEA graduate student Marta Venier looked at levels of PBDEs in our closest household non-human companions: dogs and cats.
“Lots of dogs spend as much time indoors as people,” Hites says. “We tested cats first because cats spend time licking themselves so they’re going to be picking up chemicals from dust and particles from the house that get one their fur. So cats are good representatives of what indoor contamination level is in a home.”
Hites and Venier found that PBDEs in cats are 20 to 100 times higher than in humans, and up to 10 times higher in dogs than in humans. But are these chemicals harming our beloved pets? More importantly, are PBDEs doing us harm? So far there’s no overwhelming body of evidence that PBDEs pose a significant environment or health risk. But the lack of evidence does not mean that flame retardants are necessarily safe. There’s a long history of useful, supposedly safe chemicals that turn out to cause all sorts of problems. Like, for example, the once widely used industrial chemicals known as PCBs. And there’s reason to believe that flame retardants may pose a similar risk.
“Flame retardants are structurally quite similar to PCBs, so there’s been a lot of toxicological reasoning by analogy,” Hites says. “PCBs have a long list of problems, and flame retardants are likely to have them too.”
Problems including cancer, low birth weight in animals and humans, and lower IQ. What Hites and other scientists know for certain is the flame retardants have spread far and wide around the world. Alarmingly high levels of PBDEs have been found in polar bears and even in bald eagles. Again, it’s not clear that the chemicals are doing harm. But their ubiquitous presence in our lives and ability to leach out into the environment have caught the attention of Hites and other scientists and given them pause.
“There’s enough reason to be concerned that the scientific community is largely come together and suggested these are compounds we should not have floating around in the environment,” Hites says.
Some PBDEs have already been taken off the market; more will be phased out within the next few years. But plenty of flame retardant chemicals remain among us, requiring continued, vigilant monitoring of their possible harmful effects.
Learn more about Ron Hites’ study on PBDEs in the environment.