Problematiche della sicurezza alimentare: contaminazione del suolo da metalli, biodisponibilità e trasferimento di elementi in traccia nel sistema suolo-pianta : il caso di studio del distretto conciario vicentino

Heavy metals (and other trace elements) can pose a potential hazard to human health if accumulated in the human body up to excessive levels. One of the main ways of exposure to this kind of substances is the consumption of food containing high quantities of heavy metals. Trace elements can enter the food chain through plant uptake via the root system or, to a lesser extent, through foliar uptake. In this study heavy metals distribution in agricultural soils of the tannery district of Arzignano-Chiampo was evaluated, together with the uptake of potentially toxic elements by two widespread and relevant to human diet foodcrops: wheat (Triticum aestivum L.) and maize (Zea mays L.). The soils of the area are moderately polluted by Cr, Ni, V, Cu, partially of anthropic and partially of geological origin. Nonetheless, the heavy metal contents in the grains of wheat and maize are generally low and there seems to be no health risk for the population of the area due to the consumption of cereal grains. Wheat and maize seem to behave as excluder species as regards the accumulation of potentially toxic elements in grains. Heavy metal contents in maize leaves are relatively high, still, metal levels are thought to be safe for cattle nutrition; according to these results, maize could be used to lower heavy metal contents in soil through phytoremediation processes.