Lead-exposed workmen and fertility: a cohort study on 354 subjects.

A cohort study was conducted in a French battery factory in 1977-1982 to explore the relationship between occupational lead exposure and fertility. A total of 354 battery workers, divided into 229 lead-exposed subjects (corresponding with 886 person-years) and 125 non-lead-exposed subjects (corresponding with 598 person-years) were compared, in a person-year analysis, for the risk of infertility. Lead exposure, at any level of absorption, did not appear significantly associated with a reduction in fertility after controlling for potential confounders: age, French origin, educational level, number of children at start of the period, cigarette smoking and exposure to heat. The apparent inconsistency between our results and those of several studies involving biological data and semen analysis is partially explained by recent knowledge relating to predictive value on the pregnancy of semen abnormalities.