Effect of smoking on blood lead levels in workers and role of reactive oxygen species in lead-induced sperm chromatin DNA damage

Objective

To investigate whether cigarette smoking affects the blood lead levels (BLL) and whether exposure to lead introduces sperm chromatin DNA damage in factory workers.

Design

Cross-sectional study.

Setting

A battery plant in Taiwan.

Patient(s)

Eighty male workers employed within a battery plant.

Intervention(s)

Standard semen analysis was performed according to the World Health Organization guidelines.

Main Outcome Measure(s)

Assessment of BLL, sperm chromatin DNA structure, reactive oxygen species generation and other conventional parameters of semen quality.

Result(s)

As compared with nonsmoking workers, the BLL were found to be considerably higher among smokers. Statistically significant differences were found in the sperm DNA denaturation (αT) induction and the percentage of sperm with increased DNA denaturation (COMP αT) in workers with moderate BLL (≥25 μg/dL). After adjustment for smoking propensity, a positive correlation was discernible between BLL and αT, COMP αT, and morphologic abnormality. Furthermore, αT and COMP αT were also found to have positive correlations with sperm superoxide anion production.

Conclusion(s)

Workers with higher BLL were found to be at a higher risk of sperm morphologic abnormality and chromatin DNA integrity. These data are significant because they can facilitate the estimation of lead exposure in reproductive toxicology.

Key Words: Lead exposure, smoking, blood lead levels, sperm chromatin DNA