Distributions and Congener Patterns of PCBs in Fish from Major Aquaculture Areas in the Pearl River Delta, South China

ABSTRACT

The distribution and concentrations of polychlorinated biphenyls (PCBs) were determined in surface sediments and fish collected from freshwater fishponds in six major aquaculture areas of the Pearl River Delta. The concentrations of total PCBs ranged from 7.32 to 36.2 ng/g (dry weight) in sediments and 5.15 to 226 ng/g (lipid weight) in five species of fish, with higher concentrations in fishponds from two industrialized areas. Feeding habits of fishes played a significant role on the accumulation of PCBs and their homologue patterns in fish tissues, with higher concentrations in muscle and viscera of mandarin fish (Siniperca kneri), and tilapia (Tilapia mossambica) and lower in grass carp (Ctenopharyngodon idellus). In muscle, IUPAC No. 118, 138, 81/87, 153, 180, 52, 49, 99, and 44 congeners were the most dominant out of the 36 congeners measured in the present study. The contents of PCBs in fish cultivated in the Pearl River Delta were rather low when compared with the maximum concentration of total PCBs of 2.0 μg/g (wet weight), imposed by the U.S. Food and Drug Administration edible seafood. However, due to the bioaccumulation and biomagnification nature of PCBs through the food chain, continuous monitoring of PCBs as well as other Persistent Organic Pollutants in this rapidly developed region is encouraged.

Key Words:

• polychlorinated biphenyls
• freshwater fishponds
• pond sediment
• fish muscle
• fish viscera.

ACKNOWLEDGMENTS

The authors thank Mr. K. W. Chan and Mr. B. N. T. Boon for their technical assistance. Financial support from the Research Grants Council of University Grants committee (HKBU-2/00C), Hong Kong, and NSFC Grant (2003C34510; 40471118) is gratefully acknowledged.