The Canadian government is poised to ban two out of the three PBDE (polybrominated diphenyl ethers) formulations sold and used in Canada, as there is mounting evidence that PBDEs, like PCBs, are persistent, bioaccumulative, and toxic. PBDEs are flame retardant chemicals that are widely used in upholstery, textiles, plastics and electronics.
These two products (penta and octa formulations) have not been sold or manufactured since December 2004, when the sole manufacturer ceased making them in the United States.
Sales of a third product (decaBDE formulation) are increasing exponentially and, inexplicably, will not be banned unless Environment Canada revisits its draft decision. Canada, under the Canadian Environmental Protection Act, prohibits chemicals defined as persistent, bioaccumulative or toxic, yet decaBDE qualifies as all three. And decaBDE breaks down into penta and octaBDE forms. In terms of net effect in protecting Canadians and their wildlife, the draft decision to ban penta and octaBDE will be negated by the continued use of decaBDE.
Research by scientists at the Institute of Ocean Sciences (IOS) shows that PBDE concentrations are doubling every 3.5 – 4 years in harbour seals from Puget Sound, and they are found in the region’s endangered killer whales. IOS research shows that PBDEs are now the number two chemical in the Puget Sound food web, having surpassed even DDT, and PBDEs are the number three chemical in the Georgia Basin food web.
Scientists predict that PBDEs will be the number one chemical contaminant in killer whales within 15-20 years, and that by 2020 PBDEs will be the dominant persistent organic pollutant (POP) in the province of British Columbia’s marine environment, surpassing DDT and PCBs.
There is little question that this is a very serious concern for the Canadian environment, and a serious health threat to wildlife, including the endangered southern resident killer whale population.
British Columbia’s killer whales are already the world’s most PCB-contaminated marine mammals in the world. Without a ban on decaBDE by Canada (and the US), they are poised to become the world’s most PBDE-contaminated marine mammals. Is this what we want for future generations?
If marine predators like salmon-eating killer whales are at risk, what about terrestrial predators that feed on the marine food web? Could coastal grizzly bears be exposed to PBDEs as a consequence of their reliance on Pacific salmon?
To answer this question Raincoast Conservation Society teamed up with wildlife toxicologist Dr. Peter S. Ross at IOS and PhD student Jennie Christensen at the University of Victoria. By measuring contaminants in the tissue of the bears, and using stable isotopes in the hair to understand diet, our results clearly showed that salmon delivered contaminants to grizzly bears. The greater the consumption of salmon, the higher the contaminant levels. However, a notable finding was that decaBDE levels were higher in the non salmon-eating grizzlies in the interior of B.C., indicating that decaBDE does travel through the atmosphere, partition into terrestrial food webs, and get taken up by wildlife (contrary to industry statements).
PBDEs are of concern because they can act as hormone mimics in the body of mammals. They can disrupt thyroid hormones (hence alter normal growth and development), impact the immune system (thereby making wildlife and humans more vulnerable to disease), and impair neurological development. The concentrations in grizzlies exceeded those found in Swedish women’s breast milk, levels which led to the ban of two of the three commercial PBDE products in Europe in 1998. In addition, grizzly bear cubs may face additional health risks as they nurse during hibernation of the mother, thereby being exposed to those PBDEs which have been liberated from fatty tissues.
PBDEs are increasing exponentially in the British Columbia environment. There are safe, environmentally-friendly alternatives to PBDEs that can be used to protect Canadian lives and property. Without substantive regulation to ban decaBDE, Canadian wildlife, including grizzly bears and killer whales, face an increasing conservation threat from this chemical and its breakdown products.