Effect of dibromochloropropane on human testicular function.

Severe impairment of spermatogenesis was found in 18 (78%) of 23 workers after exposure to 1,2-dibromo-3-chloropropane (DBCP). Azoospermia associated with elevated plasma follicle-stimulating hormone was diagnosed in 12 workers whose exposure time to DBCP varied from 100 to greater than 6,000 h. Oligospermia and normal plasma follicle-stimulating hormone were found in six employees with exposure times between 34 and 95 h. Plasma luteinizing hormone, testosterone and thyroxine were within the normal range. Testicular biopsy showed selective atrophy of the germinal epithelium, intact Sertoli cells and normal appearance of Leydig cells. The mechanism and potential reversibility of these testicular changes are still to be evaluated.