Bioaccumulation and oxidative damage in juvenile scallop Chlamys farreri exposed to benzo[a]pyrene, benzo[b]fluoranthene and chrysene.

The study is aimed at investigating the bioaccumulation and oxidative damage of juvenile scallops (Chlamys farreri) exposed to three selected PAHs: benzo[a]pyrene (BaP), benzo[b]fluoranthene (BbF) and chrysene (CHR). For this purpose, a study was performed on juvenile scallops exposed to BaP (0.01, 0.2 and 4μg/L), BbF (0.02, 0.2 and 2μg/L) and CHR (0.2, 0.8 and 3.2μg/L) for 21 days. Accumulations of these three PAHs in soft parts of scallops, except the 0.01μg/L BaP group and the 0.02μg/L BbF group, showed obvious time and dose dependence, and CHR accumulation was higher when compared to BaP and BbF. Oxidative damage indicators, including lipid peroxidation (LPO), protein carbonyl (PC) and DNA strand breaks, were also measured in soft parts to assess effects of the selected PAHs. The results showed that the LPO levels, PC contents and DNA damage were induced significantly (P<0.05 or P<0.01), except in the low level groups of BaP and BbF, and different trends were detected with time of exposure. According to the correlation analysis results, PC content in soft parts showed a good correlation with the target contaminant and seemed to be proposed as a potential early indicator of BaP, BbF and CHR. In addition the sequence of toxicity is BaP>BbF>CHR, judging by the level of induction of oxidative damage at 0.2μg/L levels. The results of this research are expected to contribute to the establishment of a good biochemical index of exposure to PAHs in laboratory experiments, which can be further useful in field studies.