Exposure of man to metal trace elements and alteration of sperm parameters: study conducted in the mining areas of Haut-Katanga in the Democratic Republic of Congo

Arsenic and cadmium exposures cause significant adverse effects. This study aims to determine the urinary arsenic and cadmium concentrations in men in order to analyze their profile in relation to sperm count test values. We conducted an exposed-non-exposed analytical study of men exposed to arsenic and cadmium in a mining area in Upper Katanga, DRC and of non-exposed men living far from any mining area. Study results show that 48% of exposed subjects had semen pH below the threshold value of 7.2 versus 16% of non-exposed subjects. The risk of a lowering of pH below the standards was more than 4 times higher (OR=4.85[1.9-12.39]) among exposed men. The difference between the averages of the total number of spermatozoa was statistically significant to the advantage of non-exposed subjects. Abnormal number of spermatozoa was much higher in exposed subjects. It was recorded a more rapid spermatozoa mobility degradation in exposed subjects. In addition, 44% of exposed men had urinary arsenic concentration > 20 µg/L versus 8% of non-exposed subjects, the risk of excessive arsenic accumulation was nine times higher in exposed men than in non-exposed men (OR=9.04 [2.82-28.96]). Sixty percent of exposed men had urinary cadmium concentration ≥0.5µg/ml versus 38% of non-exposed subjects, with an Odd Ratio of 2.45 [1.1-5.47], reflecting a risk of excessive cadmium accumulation in exposed men. On the other hand, it was recorded that, among exposed men, high urinary arsenic and cadmium concentrations resulted in a proportional degradation of sperm count test values. This study shows, on one hand, high urinary arsenic and cadmium concentrations and, on the other hand, more rapid and more severe alterations of sperm count test values in men living in mining area. This suggests a decline in male fertility which deserves to be further documented in future studies.