Contaminants in the arctic marine environment: Priorities for protection

We assess evidence for significant adverse effects on the arctic marine environment associated with global and regional releases of chemical and radioactive contaminants from human activities. The sources, mode of transport, and biological effects of persistent organic compounds, lead, cadmium, mercury, artificial radionuclides, and oil are reviewed. An outline of the physical and biogeochemical processes occurring within the Arctic Ocean is used as a basis for identifying contaminant transport, accumulation, and exposure pathways. Where significant anthropogenic impacts can be inferred or suspected, we evaluate opportunities for human intervention through the introduction of new source controls, or other restrictions, to reduce impacts. We conclude that additional controls are justified only in the cases of persistent artificial organic compounds and petroleum exploitation and transport. Artificial radionuclides pose threats that are largely nominal. Protection of the arctic environment and human health can be achieved through universal compliance with existing international standards. Threats posed by cadmium and lead from anthropogenic sources are relatively minor. Trends in the anthropogenic mobilization of mercury are not currently defined with sufficient confidence to assess the associated dangers posed to animal and human health in the Arctic. Nevertheless, the properties of mercury and its current environmental levels suggest that the Arctic is sensitive to increased anthropogenic mobilization of this metal. There is also evidence that mercury levels in the Arctic are increasing due to anthropogenic activities. Accordingly, priority should be given to determining temporal trends of mercury within the Arctic. (C) 1996 International Council for the Exploration of the Sea.