Semen quality of workers occupationally exposed to hydrocarbons

Objective: To determine whether occupational exposure of men to hydrocarbons has adverse effects on the quality of their semen. Design: Comparative study. Setting: The rubber industry in Mexico City. Patient(s): Forty-eight workers who were exposed to hydrocarbons for 2-24 years and 42 unexposed workers. Intervention(s): None. Main Outcome Measure(s): Environmental hydrocarbon concentrations were determined by continuous air monitoring in all areas of the factory. Analyses of semen samples were performed in accordance with World Health Organization criteria. Result(s): Hydrocarbon concentrations were as follows: ethylbenzene, 220.7-234 mg/m(3); benzene, 31.9-47.8 mg/m(3); toluene, 189.7-212.5 mg/m(3); and xylene, 47-56.4 mg/m3. The number of subjects with ejaculates that had normal characteristics was greater in the unexposed group (76%) than in the exposed group (17%). More abnormal characteristics were found in the semen of exposed workers than unexposed workers, including alterations in viscosity, liquefaction capacity, sperm count, sperm motility, and the proportion of sperm with normal morphology. Some abnormal characteristics correlated with the number of years of exposure to the hydrocarbons. Conclusion(s): Damage to the spermatogenic process resulting from hydrocarbon exposure was demonstrated by an increased rate of abnormalities in the semen of exposed workers compared with unexposed workers. This information may be useful for conducting future analyses of reproductive risks related to exposure to high concentrations of hydrocarbons. (Feril Steril(R) 2000;73:221-8. (C) 2000 by American Society for Reproductive Medicine).