Recovery from Severe Oligospermia After Exposure to Dibromochloropropane

Abstract

Screening studies of 71 petrochemical workers indicated that 15 men employed between January 1975 and July 1977 in the production of a widely used nematocide, 1,2-dibromo-3-chloropropane (DBCP), were oligospermic. Fourteen oligospermic men underwent extensive evaluation of their reproductive systems. Seven men had extratesticular abnormalities (epididymal obstruction, varicoceles, previous herniorrhaphies) which may have impaired their reproductive potential (group I); the remaining seven men (group II) had no other explanation for impaired testicular function. In neither group could the degree of impairment of semen quality be correlated with the calculated hours of exposure to DBCP. Chemical markers of accessory sex gland function revealed minimal deficiencies in patients with no extratesticular abnormalities (group II). Thirteen of the 14 men had normal basal serum luteinizing hormone (LH) levels and a normal LH response following the administration of LH-releasing hormone. However, basal and stimulated concentrations of follicle-stimulating hormone were elevated in two patients in group I and in one worker in group II. Serum concentrations of testosterone in all men studied were within the normal range, but mean concentrations were reduced in group I ( P < 0.001) and group II ( P < 0.02) as compared with levels in normal control subjects. Testicular histology revealed a spectrum of changes. Patchy tubular hyalinization with some continuing degree of spermatozoa formation were the predominant findings. Evaluation 18 to 21 months following the last DBCP contact demonstrated improvement of sperm count ( P < 0.02). This trend in improved semen quality suggests that recovery of spermatogenesis is possible if impairment in semen quality following a toxic chemical insult is recognized before irreversible changes occur.