Occurrence of heavy metal residues in fish and fishery products exported from India

Abstract

Several species of fish and shellfish from marine and freshwater sources are exported to foreign countries. These products are to be monitored for the toxic heavy metal residues such as mercury, cadmium and lead. Some species like cephalopods have a tendency to concentrate these metal residues, particularly cadmium, in their tissues. Heavy metal residues in samples of fish and fishery products processed for export from India were monitored for one year. out of sixty different samples, only five specimens showed high values of Pb (>3 ppm). All other specimen showed lead content much below the tolerance limit. The values for cadmium was in the range 0-4.39 ppm. Out of 60 samples, only in one sample Cd was above the tolerance limit of 3 ppm. The levels of mercury in all the samples were either nil or much below the tolerance limit of 0.5ppm. Heavy metals in the edible parts of the fish samples were in the safe permissible levels for human consumption.