Heavy metals, selenium and arsenic in nine species of Australian commercial fish

Abstract

Results of a survey of metal levels in nine species of important commercial fish from New South Wales waters are reported. Muscle samples from 20-30 individuals of each species were analysed for mercury, cadmium, lead, copper and zinc. Eight to 12 individuals of each species were analysed for selenium and arsenic.

Of the 232 fish analysed, 231 had concentrations of cadmium, lead, copper and zinc below the National Health and Medical Research Council (NHMRC) standards for these elements in foodstuffs.

Several specimens of bream, snapper, mulloway, kingfish, Australian salmon and yellowfin tuna had total mercury concentrations in excess of the NHMRC standard of 0.5 ppm. These fish accounted for approximately 7% of the total number sampled. None of the sea mullet, flathead and tailor sampled exceeded the standard for mercury. The mercury in all species sampled occurred almost entirely as methyl mercury.

Of the 95 fish analysed for arsenic and selenium, 20 fish (21 %) had arsenic concentrations equal to or greater than the NHMRC standard for selenium.

The health risks associated with the presence of mercury and arsenic in these species are discussed.