OCCURRENCE AND SAFETY ASSESSMENT OF HEAVY METALS IN MUSCLES AND LIVERS OF ITALIAN HEAVY PIGS

The specific breeding and feeding strategies adopted in the context of the Italian heavy pig production system have repercussions on the hygienic and safety aspects of the related meat and meat products, including the occurrence of metals of toxicological significance [1]. The aims of this study were to determine the levels of some toxic metals in pig muscles and livers and estimate the dietary exposure of the Italian population to these contaminants through meat and liver consumption. A total of 80 heavy pigs from 16 different farms were randomly selected for this study. For each animal, the diaphragm muscle and right lateral lobe of the liver were collected in a large slaughterhouse of northern Italy (Emilia-Romagna region), sub-portioned, and freeze-dried. Both tissues were analyzed via a singlepurpose atomic absorption spectroscopy (AAS) for total Hg and inductively coupled plasma-mass spectrometry (ICP-MS) for As, Al, Cd, Cr, Cu, Fe, Ni, Pb, Sn, U, and Zn quantification. The dietary intakes of these metals by different age groups of the Italian population (children, adolescents, adults) through the consumption of pig fresh meat and liver were estimated taking into account both mean and 95th percentile (P95) chronic consumption data [2], and then compared with the relative health-based guidance values set up by the European Food Safety Authority and the Joint FAO/WHO Expert Committee on Food Additives. Although all the samples were in line with the maximum limits for toxic heavy metals established by European Union [3], significant higher levels of Fe, Zn, Cd, Sn, Pb, U, Cu, and Hg were found in liver compared to muscles samples (p<0.001), especially concerning Cd concentrations which varied two orders of magnitude (43.3±19.6 vs. 0.77±0.42 μg/kg wet weight). When estimating the average dietary intake of heavy metals through meat and liver consumption, no severe risk for health was found, since heavy metals intakes were all below the toxicological health-based guidance values. Besides, the estimated levels of exposure to Cd through the consumption of mean liver amounts by children, adolescents, and adults were found to contribute to 24, 12, and 9% of the total tolerable weekly intake (TWI) of 2.5 μg/kg bw/week, respectively. In the calculation for P95 consumers (i.e., worst case scenario), the contribution of liver to TWI value of Cd was found to be higher (12%) only for adults. These results warn about the high probability for the younger population of exceeding the TWI of Cd though the whole diet, considering that many other foods may be contaminated by significant Cd levels and that the same pig liver can be used as ingredients for the preparation of other meat products. In conclusion, since pig liver can be also employed as the primary ingredient for the formulation of pet foods, our data may provide some insights about the potential negative impact of Cd exposure on both human and animal health, hence reminding of the importance of targeted intervention measures aimed to reduce its occurrence into the food chain.