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Researchers at Indiana University have found flame retardants in the blood of pet dogs at levels five to ten times higher than typically found in humans. Could dogs be the canary in the coal mine for how accumulating polybrominated flame retardants will affect humans?
We already know that polybrominated diphenyl ethers (PDBEs for short) are found everywhere -- they are used in everything from computers to carpeting, and can be measured even in the dust bunnies that gather in the corners of our living spaces. What PBDEs do to us is scary enough that these persistant, bioaccumulating chemicals are being phased out*. This is where the two most interesting aspects of the Indiana University study arise.
First, the scientists found that the level of PBDEs building up in dog's blood serum is lower than found in cats, where PBDE exposure has even been linked to cat death. This probably reflects better metabolization of PBDEs by dogs, eliminating some PBDEs from their system so that the rate of accumulation slows. Humans metabolize PBDEs more like dogs than like cats, which might make dogs useful biosentinels, or early warning indicators of effects that could impact humans.
Second, the study detected newer flame retardants, that have come on the market to replace the PBDEs, in the dogs tested. These substitutes -- which include Dechlorane Plus, decabromodiphenylethane, and hexabromocyclododecane -- are not regulated because they are too new to have built up a body of evidence that can be used to force regulatory agencies into action. The Safe Chemicals Act of 2011 recently introduced by Senator Lautenberg addresses the need to restrict chemical uses before large quantities of a chemical are in our environment.
The study Flame Retardants in the Serum of Pet Dogs and in their Food, published in Environmental Science & Technology, was authored by Marta Venier and Ronald Hites. Seventeen dogs, with mainly indoor lifestyles, were tested. Dog food was also found to contain higher levels of PBDEs than the foods humans eat, suggesting that dogs may have higher exposures than humans.
* PBDEs with fewer bromine moieties are banned in the EU (Directive 2003/11/EC) and were voluntarily phased out by industry in the USA in 2004.
More on PBDEs and Chemical Control:
Pediatricians Say U.S. Policy Fails Children on Chemical Safety
Did the State of California Kill This Woman's Cat?
PDBEs: Where Do They Come From And What Are They Doing To Us?