Human health risk assessment in relation to environmental pollution of twoartificial freshwater lakes in the Netherlands

A human health risk assessment has been performed in relation to recreation al activities on two artificial freshwater lakes along the river Meuse in T he Netherlands. Although the discharges of contaminants into the river Meus e have been reduced in the last decades, which is reflected in decreasing c oncentrations of pollutants in surface water and suspended matter, the leve ls in sediments are more persistent. Sediments of the two freshwater lakes appear highly polluted and may pose a health risk in relation to recreation al activities. To quantify health risks for carcinogenic (e.g., polycyclic aromatic hydrocarbons) as well as noncarcinogenic compounds (e.g., heavy me tals), an exposure assessment model was used. First, we used a standard mod el that solely uses data on sediment pollution as the input parameter, whic h is the standard procedure in sediment quality assessments in The Netherla nds. The highest intake appeared to be associated with the consumption of c ontaminated fish and resulted in a health risk for Pb and Zn (hazard index exceeded 1). For the other heavy metals and for benzo(a)pyrene, the total a veraged exposure levels were below levels of concern. Secondly, input data for a more location-specific calculation procedure were provided via analys es of samples from sediment, surface water, and suspended matter. When thes e data (concentrations in surface water) were taken into account, the risk due to consumption of contaminated fish decreased by more than two orders o f magnitude and appeared to be negligible. In both exposure assessments, ma ny assumptions were made that contribute to a major degree to the uncertain ty of this risk assessment. However, this health risk evaluation is useful as a screening methodology for assessing the urgency of sediment remediatio n actions.