Background: Exposures to lead above the threshold value of 50–60 μg/dL have been linked to diminished semen quality parameters. Worldwide, the lead exposure has been diminished during the last years. Therefore, it has become of a great concern to examine the effects of lead exposures on semen quality at low levels of exposure.

Objective: To evaluate the effect of low level (<20 µg/dL) blood lead on semen quality and sperm chromatin structure.

Methods: A cross-sectional study was conducted on 29 men with primary infertility attending the outpatient clinic of infertility in Mansoura University Hospital, Egypt, from March to May 2010. Semen quality parameters and sperm flow-cytometry analysis were compared between two groups of infertile men with blood lead level (BLL) above, and below 20 µg/dL, respectively.

Results: The mean BLL in the studied subjects was 20.08 µg/dL. 45% of the studied men had BLL ≥20 µg/dL. Non-significant reduction in sperm count, impaired sperm motility and altered sperm morphology were observed in those with BLL ≥20 µg/dL compared to those with BLL <20 µg/dL. Concerning semen flow-cytometry analysis, percentage of haploid sperms was significantly lower among men with BLL ≥20 µg/dL (78%) compared to that among those with BLL <20 µg/dL (87%). A positive significant correlation was observed between BLL and percentage of diploid sperms. The chromatin condensation was however, negatively correlated with BLL (p<0.05).

Conclusion: Semen quality of men with primary infertility does not have any correlation with BLL at the cutoff value of 20 µg/dL. However, even at this low level, a significant decrease in haploid sperm counts and chromatin condensation was observed.