Occupation- and exposure-related studies on human sperm.

Many kinds of exposures and chemicals have been shown to affect human sperm quantity and quality. This review focuses first on the best known occupational testicular toxin, dibromochloropropane. Prolonged heat is clearly detrimental to spermatogenesis. Studies on occupational heat, radiation, and chemical exposures and their effects on sperm are reviewed. The evaluation of human sperm studies is hampered by inconsistencies in biological analytical methods, in control for confounders, and in weaknesses of study design. Still, there is reason to suggest that human semen parameters can serve as valuable indicators of toxic and, in future, even genotoxic effects of occupational and environmental factors.