By Janet Raloff
A common Arctic fish can suffer subtle immunological impairments from polychlorinated biphenyls (PCBs) at concentrations found in some remote polar waters, new research indicates.
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Alec G. Maule of the U.S. Geological Survey in Cook, Wash., and his colleagues fed various doses of PCBs to Arctic char (Salvelinus alpinus) living in laboratory tanks. Then, for 4 months, the researchers fed some fish and starved others. The latter regimen replicates the fast that char endure each year during a fresh water phase of their life cycle. At the end of the period, the scientists measured the activity of disease-fighting proteins and enzymes in the fish.