Combining Long-Range Transport and Bioaccumulation Considerations to Identify Potential Arctic Contaminants

摘要

The identification of potential Arctic contaminants requires an assessment of both the long-range transport and the bioaccumulation of the chemicals, most particularly in the indigenous inhabitants of the Arctic. Forthis purpose, a nonsteady state, zonally averaged global distribution model was linked to a nonsteady state bioaccumulation model describing Inuit exposure from a marine diet The potential of hypothetical, perfectly persistent chemicals with varying combinations of partitioning properties to enrich in the Arctic environment following emission in the lower latitudes and, additionally, to bioaccumulate in the Arctic food chains was evaluated using the Arctic contamination and bioaccumulation potential (AC-BAP). The AC-BAP is defined as the quotient of the human body burden of the chemical and the quantity of chemical cumulatively emitted to the global environment. The highest AC-BAP values (up to 3.7 × 10~(-11) person~(-1)) were obtained for hypothetical multimedia chemicals with intermediate volatility and hydrophobicity. Perfectly persistent chemicals with 3.5 < log K_(OW) < 8.5 and log K_(OA) > 6 had AC-BAP values of at least 10% of the maximum value, indicating that a broad range of chemicals are potential Arctic contaminants if they are persistent. Moreover, the simulation results suggest that a chemical's potential to bioaccumulate has a stronger impact on the overall potential to become an Arctic contaminant in humans than its potential for long-range transport. This modeling exercise demonstrates how linking nonsteady state models of chemical bioaccumulation and of global chemical fate can provide a valuable tool for assessing a chemical's potential to be a contaminant in remote regions.