Dietary intake and potential health risk of DDTs and PBDEs via seafood consumption in South China

A total of 602 seafood samples, including fish, shrimps, crabs and molluscs, were analyzed for a suite of persistent halogenated compounds. The residual levels of DDTs (sum of o,p′- and p,p′-DDT, DDD, and DDE) and polybrominated diphenyl ethers (PBDEs) varied significantly among different species, and ranged from non-detectable (nd) to 699 ng/g and nd to 5.93 ng/g, respectively. Comparison of the levels of DDTs and PBDEs in mussel samples worldwide suggested that South China is probably one of the most DDT-polluted areas, but is moderate at most in terms of PBDE contamination. Combined with a recent dietary survey at the same sampling locations, dietary intakes of DDTs and PBDEs by local residents via seafood consumption for all age groups were estimated to be 147–564 and 4.7–18.5 ng/day, or 8.5−12.9 and 0.27−0.46 ng/kg bw/day, respectively. Among the different seafood types, fish contributed the largest portion of the dietary intakes of DDTs (57%), followed by molluscs (38%). Similarly, the dietary intakes of PBDEs were also dominated by fish (45%) and molluscs (45%). Assessment based on several available guidelines suggested that though no significant human health risk associated with the dietary intake of PBDEs, a lifetime cancer risk from dietary exposure to DDTs remains a probability. Because dietary intake of DDTs was dominated by fish and molluscs, added concern should be paid to fish and molluscs.