Trace elements in blood and seminal plasma and their relationship to sperm quality.

The concentrations of cadmium, lead, selenium, and zinc in blood and seminal plasma were determined in 221 Singapore men. The relationship of trace element concentration to sperm density, motility, morphology, and semen volume was also investigated. The concentrations of elements were in the following descending order: Zn > Se > Pb > Cd. Except for zinc, the concentrations were generally higher in blood than in seminal plasma. The mean concentration of zinc in seminal plasma (ZnSP) was about 30 times higher than in blood (ZnB). A significant inverse correlation was observed between blood cadmium levels (CdB) and sperm density (r = -0.24, P < 0.05) in oligozoospermic men (sperm density below 20 million/mL) but not in normospermic men. Cadmium in seminal plasma (CdSP) was also associated with low semen volume (r = -0.29, P < 0.05). These findings suggest that cadmium may have an effect on the male reproductive system. In contrast, positive correlations were observed between concentrations of selenium and zinc in seminal plasma (SeSP and ZnSP) and sperm density in normospermic men but not in oligozoospermic men. The correlation coefficients with sperm density for SeSP and ZnSP were 0.35 (P < 0.05) and 0.41 (P < 0.01), respectively. The concentrations of lead in blood (PbB) or seminal plasma (PbSP) did not appear to have any correlation with the sperm parameters studied.