Can biotransformation of BDE-209 in lake trout cause bioaccumulation of more toxic, lower-brominated PBDEs (BDE-47, -99) over the long term?
Much debate exists on the future direction of policy related to the deca-brominated diphenyl ethers (deca-BDE) mixture. This debate, in part, results from the fact that BDE-209 can debrominate to more toxic lower-polybrominated diphenyl ethers (PBDEs). However, such debromination is difficult to study using measured concentrations alone because of the short-term nature of laboratory experiments and the presence of lower-brominated congeners in the environment. Here, a rigorously calibrated, multichemical, dynamic fish model (Bhavsar et al. 2008, Environ. Sci. Technol., 42, 3724-3731) is used to predict the debromination of BDE-209 to more toxic lower-brominated PBDEs over a 15-year life period of piscivorous- and non-piscivorous lake trout (pLT, npLT; Salvelinus namaycush). A sensitivity analysis was performed by changing BDE-209 dietary dose, gut absorption efficiency and half-life for generally conservative scenarios. Estimated BDE-209, -99 and -47 concentrations were compared with human fish consumption guidelines developed using the draft U.S.EPA tolerable daily intakes. The model predicted that bioaccumulation of BDE-209 as well as BDE-47 and -99 due to dietary exposure to deca-BDE over the 15-year period would not be appreciable in pLT (generally unrestricted consumption advisory) and would be moderate in npLT (unrestricted to 2 meals/month advisory) even for worst-case scenarios.
Gandhi
Nilima
N
University of Toronto, Toronto, ON, Canada.
Bhavsar
Satyendra P
SP
Gewurtz
Sarah B
SB
Tomy
Gregg T
GT
D000818:Animals; D001711:Biotransformation; D004784:Environmental Monitoring; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism* / Q000633:toxicity; D008954:Models, Biological; D008956:Models, Chemical; D011075:Polybrominated Biphenyls / Q000378:metabolism* / Q000633:toxicity; D014337:Trout / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
D055768:Halogenated Diphenyl Ethers; D011075:Polybrominated Biphenyls; D014874:Water Pollutants, Chemical; C511295:2,2',4,4'-tetrabromodiphenyl ether; C010902:decabromobiphenyl ether