Does heavy metals pollution affects semen quality in men? A case of study in the metropolitan area of Naples (Italy)

In recent years, a significant increase in the incidence of male infertility has been observed and described in the international literature, raising questions about its causes. Several authors have suggested that exposure to environmental pollution may contribute to a perceived decline in semen quality worldwide. Although several studies have been conducted about the effects on male fertility caused by exposure to heavy metals in the workplace, research on the effects caused by continued exposure to low doses of heavy metals pollution in urban areas is still scarce. The aim of this study is to identify the relationships between high concentrations of heavy metals and male semen quality in the metropolitan area of Naples. We considered only those elements (Al, As, Cd, Cr, Cu, Hg, Mn, Mo, Pb, Sb, Tl, Zn) that previous studies have indicated as possible candidates to have some influence on human semen quality. We measured semen quality among 600 subjects selected from a sample of 1237 men regularly examined at the Andrology Laboratory of the University of Naples "Federico II" for problems related to male fertility. Using statistical methods the semen data (semen volume, sperm concentration, sperm total count, sperm motility, pH) were compared with the geochemical distribution of heavy metals in soils of the Napoli metropolitan area. Results show a strong correlation between anomalous Pb and Sb concentrations and men with poor semen quality. A weaker correlation was also observed with Hg and Zn while the anomalous concentration values of the other elements (Al, As, Cd, Cr, Cu, Mn, Mo and Tl) appear to have no correlation with poor quality of the human semen. (C) 2011 Elsevier B.V. All rights reserved.