Environmental Exposure and Biomarker Lab

Highlights

• Passive samplers directly measure the bioavailable fraction of contaminants in the sediment.
• Passive samplers in the sediment predicted [PAH] in clams within a factor of 2, on average.
• Contaminants on traditional Native American clamming grounds may lead to unacceptable risk.
• This model could be used to predict risk from eating traditionally harvested clams.

Abstract

Native Americans face disproportionate exposures to environmental pollution through traditional subsistence practices including shellfish harvesting. In this study, the collection of butter clams (Saxidomus giganteus) was spatially and temporally paired with deployment of sediment pore water passive samplers at 20 locations in the Puget Sound region of the Salish Sea in the Pacific Northwest, USA, within adjudicated usual and accustomed tribal fishing grounds and stations. Clams and passive samplers were analyzed for 62 individual PAHs. A linear regression model was constructed to predict PAH concentrations in the edible fraction of butter clams from the freely dissolved fraction (C_free) in porewater. PAH concentrations can be predicted within a factor of 1.9 ± 0.2 on average from the freely dissolved PAH concentration in porewater using the following equation: PAHClam=4.1±0.1×PAHporewater This model offers a simplified, cost effective, and low impact approach to assess contaminant levels in butter clams which are an important traditional food

Graphical abstract

Sediment pore water passive sampling devices (PSDs) were spatially and temporally paired with collection of 5 butter clams at each of 4 locations on adjudicated usual and accustomed tribal fishing grounds in the Salish Sea Region of the Pacific Northwest. Both sediment pore water and clams were analyzed for 62 individual PAHs.

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