Reproductive hazards in the workplace. Development of epidemiologic research

Application of the techniques of epidemiology and clinical toxicology has accelerated study of the reproductive effects of toxic chemical and physical exposures in the workplace. Three examples of work in progress are included in the present communication. The first concerns 1,2-dibromo-3-chloropropane, a known cause of male sterility, which continues to be used as a nematocide in Hawaii. Occupational exposures of Hawaiian agricultural workers to airborne 1,2-dibromo-3-chloropropane are mainly in the range of parts per billion. A prospective study of pineapple field workers has been undertaken to evaluate sperm counts and morphology before, during, and after 1,2-dibromo-3-chloropropane application. To date, no sperm count depression is evident at this level of exposure. The second example involves a cluster of seven spontaneous abortions in female office workers exposed to video display terminals. The cluster has been analyzed with the use of fetal life tables. Excess incidence was confirmed (p = 0.0045), but no etiology was determined. The findings may have been due to chance. The third example pertains to male chemical workers manufacturing diaminostilbene, an optical brightener, and the workers' reported sexual impotence. Impotence was confirmed in 7 of 29 workers by questionnaire and suggested for another 7. Serum testosterone analyses found depressed values (less than 300 mg/ml) in 8 of 28 exposed workers. The luteinizing hormone and follicular stimulating hormone levels were generally normal.