Manchester-Neesvig, JB, K Valters and WC Sonzogni. 2001. Comparison of Polybrominated Diphenyl Ethers (PBDEs) and Polychlorinated Biphenyls (PCBs) in Lake Michigan Salmonids. Environmental Science and Technology 35:1072-1077.
Manchester-Neesvig et al. report that PBDE (polybrominated diphenyl ether) contamination is widespread in salmon from Lake Michigan. Their findings add to growing evidence that these persistent and bioaccumulative chemicals have become a global toxic hazard.
What
did they do?
The authors collected 21 salmon of two distinct species (Coho and
Chinook) from two separate tributaries of Lake Michigan. They then assayed
PCB and PBDE levels using gas chromatography.
What
did they find?
All salmon had detectable levels of PBDEs. Total PBDE levels (the sum
of all congeners) averaged 80.1 ng/g of wet weight (1 ng/g is equivalent
to 1 part per billion. Measuring only the lipid portion of the sample,
they found 2440 ng/g. The concentration of PBDEs was correlated with the
size of the fish: the bigger the fish, the more PBDEs per unit weight.
Because salmon age one of the main determinants of salmon size, this indicates
(1) that the fish accumulate PBDEs over a long time period, not in acute
bouts, and (2) that PBDEs have been in Lake Michigan for many years.
The relative abundance of different PBDE congeners resembled the pattern of PBDE congeners in Bromkal 70-5DE, a commercial PBDE flame retardant. This suggests that Bromkal 70-5DE is an important source of the PBDEs in Lake Michigan.