Toxic and essential metals in liver, kidney and muscle of pigs at slaughter in Galicia, north-west Spain

The aims of the study were to evaluate toxic and essential metal concentrations in meat and offal from pigs in north-west Spain to compare these with reported metal concentrations in pigs in other countries and in cattle in this region, and to relate the observed concentrations to maximum acceptable concentrations. Samples from 63 pigs aged 6 months were randomly collected at slaughter. After acid digestion, levels of metals were determined by ICP-OES and ICP-MS. As regards the toxic metals, mean concentrations in liver, kidney and muscle were 0.073, 0.308 and 0.009 mg kg-1 fresh weight for cadmium, 0.004, 0.008 and 0.003 mg kg-1 for lead, 0.013, 0.011 and 0.003 mg kg-1 for arsenic, and 0.001, 0.002 and 0.001 mg kg-1 for mercury. These concentrations can be considered low, and in general similar to those reported in similar studies in recent years. In addition, maximum admissible concentrations established by the European Union were not exceeded in any sample. As regards the essential metals, concentrations in liver, kidney and muscle were 14.9, 5.63 and 6.85 mg kg-1 for copper, 81.3, 28.9 and 42.5 mg kg-1 for zinc, 195, 51.6 and 26.5 mg kg-1 for iron; 1.17, 2.51 and 0.656 mg kg-1 for selenium, 3.32, 1.56 and 1.01 mg kg-1 for manganese, 0.023, 0.027 and 0.003 mg kg-1 for cobalt, 0.120, 0.077 and 0.131 mg kg-1 for chromium, 0.009, 0.027 and 0.026 mg kg-1 for nickel, and 1.62, 0.683 and 0.140 mg kg-1 for molybdenum. These concentrations are all within the accepted adequate-safe ranges for this animal species, and in general are in line with those previously reported in the literature.