HEAVY METAL CONTAMINATION IN CANNED TUNA FISH

Heavy metal contamination of food products, especially seafood is a major concern because of the bioaccumulation and biomagnification of metal contaminants. Their detection in fish is an indicator of marine pollution. In this study heavy metal concentrations were measured in a sample of commercially obtained canned tuna; after digestion and preparation of 21 such samples, levels of mercury and arsenic were determined by the hydride generation technique, while those of lead and cadmium were measured by the graphite furnace system. Tin levels were determined by flame atomic absorption spectrophotometery. The mean contents of heavy metals expressed in ug/g of wet weight were O.U3±0.027 (range 0.082-0.16) for mercury, 0.129±0.082 (0.037-0.262) for arsenic, 0.029±0.019 (0.006-0.088) for cadmium, and 0.33±0.12 (0.016-0.049) for lead. No tin was detected any of the samples. The concentrations of toxic metals in this study were below the WHO/FAO-recommended levels, but further studies are needed to assess the risk associated other types of food.