Metal contents of four commercial fish species of NW Mexico.

The metal contents in tissues of fish species: M. cephalus, Diapterus sp., Scomberomorus sierra and Oreochromis aureus, were determined in order to evaluate if their consumption might become a health risk. The liver and gills of M. cephalus and Diapterus sp. had the highest values of Cu, Fe and Pb. In the muscle, there were no interspecific differences in the Cd, Cu and Pb contents (0.27-0.32, 0.96-1.30 and 2.12-2.80 microg/g dw, respectively). Cd and Pb may be of concern, since their mean contents in the edible muscle of the four species are higher than the limits of the European Community.