Potentially harmful elements and human health

Abstract

Potentially harmful elements, or more generally trace elements, are now considered to be among the most effective environmental contaminants, and their release into the environment is increasing since the last decades. Metals released by different sources, both natural and anthropic, can be dispersed in the environment and accumulated in plants and, ultimately, in human body, causing serious health problems as intoxication, neurological disturbances and also cancer. Widespread interest in trace elements has risen as major scientific topic only over the last 50 years, when it was realized that some elements were essential to human health (e.g. Fe, Cu, Zn), whereas some others were toxic (e.g. As, Hg, Pb), and likely responsible for serious human diseases, with frequent lethal consequences. Since that time, great progresses in knowledge of links between environmental geochemistry and human health have been achieved, in combination with epidemiology. The effects of most trace metals on human health are not yet fully understood, partly because of the interactions between them, and partly because of the complex metabolic reactions in the human body. Despite the copious research addressed to this topic, there is still a paucity of quantitative information on the relations between elements in soils and human health. Much is known about the functions of most elements in human body, but there is increasing evidence that the interactions among them are more complex than originally thought. Uncertainty is still prevailing, particularly with non essential elements that are “suspected” to be harmful to humans. The nonessential elements As, Cd, Hg, Pb have attracted most attention worldwide, due to their toxicity towards living organisms. Other elements (Al, B, Be, Bi, Co, Cr, Mn, Mo, Ni, Sb, Sn, Tl, V, W, Zn) are likely harmful, but may play some beneficial functions not yet well known, and should be more investigated.