Concentrations of cadmium, lead, selenium, and zinc in human blood and seminal plasma.

The concentrations of cadmium, lead, selenium, and zinc in blood and seminal plasma were determined in 76 Singapore males. Except for zinc, the concentrations were generally higher in blood than in seminal plasma (cadmium, 1.31 micrograms/L vs 0.61 micrograms/L; lead, 82.6 micrograms/L vs 12.4 micrograms/L, and selenium, 163.6 micrograms/L vs 71.5 micrograms/L). The mean concentration of zinc in seminal plasma was more than 30 times higher than in blood (202 mg/L vs 6.2 mg/L). Significant positive correlations were found between the concentrations in blood and seminal plasma for the two essential trace elements: selenium (r = 0.45, p < 0.001) and zinc (r = 0.25, p < 0.05). However, no relationships were found between the concentrations in blood and seminal plasma for two toxic metals (cadmium and lead). Significant inverse correlations were observed between Cd and Zn (r = -0.40, p < 0.01), and Pb and Se (r = -0.32, p < 0.05) in blood, whereas significant positive correlations were noted between Cd and Se (r = 0.45, p < 0.01), Cd and Zn (r = 0.35, p < 0.05), and Se and Zn (r = 0.57, p < 0.001) in seminal plasma. The physiological significance of these relationships are also discussed in this paper.