Bioaccumulation and primary risk assessment of persistent organic pollutants with various bivalves

Field surveys on persistent organic pollutant (POP) bioaccumulation were conducted with oysters, clams and scallops whose consumption amount accounted for large shares in the total consumption of shellfish in Japan. There was no numerical difference in bioaccumulation characteristics between oysters, clams, scallops, Corbicula and Mytilus galloprovincialis. Therefore, it was clear that the bioaccumulation characteristics in oysters, clams and scallops, which are important for food, could be ascertained by using the monitoring results with Corbicula and M. galloprovincialis which are easily sampled in various water areas in the world. Non-cancer risk (hazard quotient, HQ) and cancer risk (excess cancer risk, ΔR) via shellfish ranged from 10⁻⁸ to 10⁻⁴ and from 10⁻¹¹ to 10⁻⁷, respectively, at sampling points, which showed the risks of POP exposure via shellfish to be low enough. However, concerning the intake of other food, the importance of dieldrin monitoring should be suggested in Japan. Based on these results, the effectiveness of primary risk assessment could be suggested for screening chemicals whose preferential monitoring is needed.