Trace Metals in Edible Tissues of Livestock and Poultry

Abstract

Abstract Data from a random-sampling study are presented for trace metals in edible tissues of livestock (bovine including bull, steer, cow, heifer, calf; ovine including mature sheep and lambs; porcine including market hogs, boar/stag, and sow) and poultry (including young and mature chicken, young turkey, and duck). Tissue homogenates were ashed, and residual materials were dissolved in hydrochloric acid for analysis by atomic absorption spectroscopy. Statistical summaries of data are provided for the trace metals lead, cadmium, cobalt, copper, iron, manganese, nickel, and zinc. The heavy metals of toxicological concern, lead and cadmium, are emphasized in this study. Lead and cadmium were rarely detected in muscle (0.2-0.5% positive among 2314 animals sampled). Lead was also infrequently detected in liver (1.8% positive) and kidney (2.4% positive). Nearly 46% of livers analyzed were positive for cadmium, and approximately 78% of kidney samples were positive for cadmium. No regulatory limits are established in the United States for the trace metals reported in this study, although restrictions on the use of kidneys from mature poultry as human food have been established because of concern about potential cadmium levels. Kidneys from this study, more frequently than livers, bore cadmium levels that exceeded the regulatory limits of other countries or organizations. Regulatory implications of the data are discussed.