Characteristic levels of heavy metals in canned tuna fish

Concentrations of metals (aluminium, cadmium, lead and mercury) were determined from canned tuna commercialized in Canada and India, by inductively coupled plasma - optical emission spectrometer (ICP-OES) and direct mercury analyzer (DMA 80). Higher concentration of Al (1.806 to 3.161 µg/g) and Hg (0.60 to 0.62 µg/g) were found in tuna processed from India. Cd and Pb ranged from 0.020 to 0.025 and 0.011 to 0.089 µg/g respectively in Canadian canned tuna. Among metals, Cd showed lower values in both samples. In conclusion, highest levels of metals were accumulated in Indian made product. This can be attributed to differences in the canning process and quality of food. It was concluded that heavy metals in canned tuna must be monitored comprehensively and periodically with respect to the consumer health.   Key words: Canned tuna, heavy metals, inductively coupled plasma - optical emission spectrometer (ICP-OES), seafood.