Methylsulfonyl polychlorinated biphenyls in fish from an electronic waste-recycling site in South China: Levels, congener profiles, and chiral signatures

Abstract

Great concerns have been raised about the fate and effects of polychlorinated biphenyls (PCBs) and other organic contaminants contained in electronic waste (e-waste) exported from industrialized countries at midlatitudes to subtropical and tropical regions. Information on the metabolites of these chemicals, for example, methylsulfonyl-PCBs (MeSO(2)-PCBs) in wildlife from the later regions is scarce. In the present study, 17 MeSO(2)-PCBs, including five chiral congeners, were detected in the muscle, liver, and brain tissues of two benthic fish species--northern snakehead and mud carp--from a small pond near an electronic waste recycling site in South China. The mean concentrations of the sum of the MeSO(2)-PCBs ranged from 80 to 340 ng/g lipid weight in the tissues, with relative higher levels in the liver than the muscle and brain tissues. These levels were one order of magnitude greater than the highest levels of MeSO(2)-PCBs previously reported in fish. The 3'-MeSO(2)-CB 87, 3'- and 4'-MeSO(2)-CB 101, 4-MeSO(2)-CB 110, and 4-MeSO(2)-CB 149 were dominant, collectively comprising more than 55% of the total MeSO(2)-PCBs. Except for 4-MeSO(2)-CB149, all of the investigated chiral MeSO(2)-PCBs displayed a clear, congener-specific enantiomeric enrichment in the tissues. No tissue-specific enantioselective retention of the enantiomers was observed in the investigated fish. This is the first report on chiral signatures of MeSO(2)-PCBs in fish tissues.