[Effects of harmful trace elements on iron, zinc and copper: their interactions in animals and humans. II. Lead].

Toxic effect of lead is related, among others, to metabolic interactions with essential trace elements i.e. iron, zinc and copper. Lead stimulates urinary excretion of these elements interfering with their reabsorption in kidney as well as inhibits ceruloplasmin activity in plasma, ferrochelatase activity in reticulocytes and copper- and zinc-dependent superoxide dismutase activity in tissues--with all functional consequences for organism. Iron, zinc and copper deficiency results in increased lead toxicity through considerable enhancement of lead absorption from intestinal tract, producing greater degree of anemia as well as decreasing of metalloenzymes activity. Increasing dietary zinc and probably copper suppresses intestinal absorption of lead. The addition of iron, zinc and copper to the diet prevents lead accumulation within the tissues and subsequent toxicity of this element. It seems that increasing intake of food products containing a lot of essential trace elements can diminish risk of lead toxicity for human.