A study found flame retardants in the blood of pet dogs at concentrations five to 10 times concentrations in humans, but lower than concentrations in cats.
The journal Environmental Science & Technology published the study online in late April.
Researchers at Indiana University measured concentrations of polybrominated diphenyl ethers, common flame retardants in furniture and electronics, in the blood of 17 pet dogs and in the dry food that made up the dogs' diet.
The mean serum concentration of PBDEs was about 1.8 nanograms per gram, five to 10 times concentrations reported in the few studies of human exposure in North America.
The mean concentration of PBDEs in the dry dog food samples was about 1.1 nanograms per gram. Concentrations of PBDEs are much lower in meat and poultry consumed by humans, suggesting that PBDEs detected in dry dog food could have resulted from processing rather than being derived from the food sources.
Also in the dog serum samples, the study detected newer flame retardants that have come onto the market as manufacturers have phased out the use of PBDEs.
A 2007 study by the same researchers and several co-authors found concentrations of PBDEs in house cats that were 20 to 100 times the concentrations in humans.