Mercury contamination in the Newark Bay estuary

As a result of several decades of industrialization, heavy metals, including mercury, have become the focus of ecological and human health concerns in Newark Bay, New Jersey. In this study, concentrations of mercury were determined in 18 surficial sediment samples collected from throughout the estuary. Measured concentrations ranged from nondetectable (0.1 mg/kg) to 9.8 mg/kg (dry weight). These results were compared to data from previous investigations of sediment and biota in the estuary in an effort to characterize the extent of mercury contamination and the potential for toxic effects in humans and biota. Mean concentrations of total mercury were elevated above estimated background levels throughout the estuary. Areas with the highest sediment concentrations included the lower Passaic River and the Arthur Kill. Comparisons to various state and federal sediment quality criteria and guidelines suggest that the presence of mercury poses a toxic hazard to aquatic biota. These data suggest that further investigation of sources is needed to reduce or eliminate this contamination.