Oral bioaccessibility and human risk assessment of organochlorine pesticides (OCPs) via fish consumption, using an in vitro gastrointestinal model

The oral bioaccessibility of dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexanes (HCHs) in twenty fish species were evaluated using an in vitro gastrointestinal model. Relatively high concentrations of ∑HCH (0.33–9.88 ng g−1, mean 1.57 ng g−1) and ∑DDT (0.74–131 ng g−1, mean 12.2 ng g−1) were observed in all market fish. The average bioaccessibilities for ∑HCHs were 3.35% and 8.73% in gastric and intestinal conditions, respectively, and for ∑DDTs were 5.48% and 17.6%, respectively. Significant (p < 0.05) correlations were observed between OCP congener digestible concentrations in fish muscle and their corresponding concentrations in human tissues of Hong Kong residents. The health risk assessments based on solvent and digestible concentrations were found to be contradictory due to the fact that only a limited proportion of OCP was bioaccessible. It was concluded that human health risk assessment based on solvent concentrations should be modified by taking bioaccessibility of the contaminant into account.