Effects of parental occupational exposure to lead and other metals on spontaneous abortion.

The aim of this article was to summarize the epidemiologic studies on the possible impact of parental occupational exposure to lead or other metals on spontaneous abortion. For paternal exposure, the total number of abortions in the studies with adequate exposure contrast were 340 for lead, 240 for mercury, and 90 for unspecified metals and, correspondingly, for maternal exposure, about 80 for lead, 80 for mercury, 70 for nickel, and 130 for exposure to unspecified metals. Epidemiologic studies indicate that paternal exposure to lead or mercury might be associated with the risk of spontaneous abortion. For maternal exposure, no clear conclusion could be reached. In particular, paternal occupational exposure levels to metals were substantial compared with population values. Even though there are shortcomings in the present knowledge, protective goals for paternal exposure to lead and mercury are warranted. More well-designed studies on metals are needed.