Distribution of polybrominated diphenyl ethers in fish tissues from the Pearl River Delta, China: Levels, compositions, and potential sources

Fish tissues from three different farming types (freshwater farmed, seawater farmed, and seawater wild fish collected from the Pearl River Delta of South China), including skin, gills, gastrointestinal tract (GIT), liver, and muscle, were analyzed for polybrominated diphenyl ethers (PBDEs). In general, the dry weight based concentrations of Sigma 10PBDE (sum of BDE-28, -47, -66 -85, -997 -100, -138, -153, -154, and -183) in fish tissues followed the sequence of liver > gill > skin > GIT and muscle. The BDE congener profiles varied with fish species. Decabrominated diphenyl ether was detected in 37.4% of the total 187 samples, and this ratio may actually have been underestimated because the reporting limit for BDE-209 was considerably higher than those for other congeners. Decabrominated diphenyl ether was the dominant BDE congener in skin and GIT, and less abundant in gills, muscle. and liver. Except for skin, no significant difference in BDE-209 lipid-normalized concentrations was observed among fish tissues. These results suggest that BDE-209 can occur abundantly in the fish species under investigation, somewhat inconsistent with the results from most previous studies that reported low bioaccumulative potential of BDE-209. Combined with the likelihood that BDE-209 can be debrominated into lower brorninated congeners that tend to be more toxic than BDE-209, the abundant occurrence of BDE-209 could continue to pose prolonged health risk to the ecological environment.