Trace metal levels in eels grown in power station cooling water

Measurements have been made of heavy metal concentrations in eels grown in condenser discharge water and cooling-tower pond water to ascertain if abnormal metal accumulation occurs under these conditions. Eels from other locations were also analysed to provide comparative data. Cadmium, copper, iron, nickel and zinc concentrations were measured in liver and muscle tissue. Comparison of the metal concentrations in the eels maintained in the three experimental regimes with those from other sites does not indicate any abnormal accumulation in those fish kept at an elevated temperature. The fastest growing eels in condenser water appear to develop new tissues more rapidly than they accumulate metals, thus reducing the specific metal concentration.There is considerable variation in metal concentrations in eels, with particularly high liver cadmium concentrations being observed in eels collected from polluted areas of the Bristol Channel. Muscle cadmium levels, however, are generally low and constant and would not appear to constitute a human health risk from food consumption.