Exposure assessment for heavy metal ingestion from a sport fish in Puerto Rico: estimating risk for local fishermen.

Sport or subsistence fishermen sometimes underestimate the risks from eating local fish and distrust authorities regarding potential hazards from fish. We report on lead, cadmium, selenium, and mercury levels in snook, locally called robalo (Centropomus spp.), consumed by local fishermen in Puerto Rico, who ate up to 23 fish/wk. Median levels (in ppb, dry weight) for muscle, adipose, and liver ranged from 683 to 780 for lead, 37 to 600 for cadmium, 50 to 146 for mercury, and 361 to 3986 for selenium. Lead levels were similar in all tissues, and selenium and cadmium levels were highest in the liver. Mercury was higher in muscle than in liver. Computing exposure via ingestion for the average fisherman indicated that if one were to consume robalo throughout the year one would be exposed in excess of the EPA Reference Dose (RfD) for mercury. Using a widely accepted maximum consumption of 200 g/d for fishermen yielded hazard indices (daily consumption/RfD) below 1 for all four metals, with a value approaching 1 for mercury in adults, and over 1 for 16-kg children. The possibility that in certain localities and cultures sport or subsistence fishermen may consume fish at levels substantially above 200 g/d should be investigated in performing risk assessments, particularly outside the continental United States.