A four-year reassessment of workers with dibromochloropropane-induced testicular dysfunction.

The present study summarizes a four-year follow-up of 20 production workers with D.B.C.P.-induced testicular dysfunction. In 4 of the 13 initially azoospermic men, sperm density increased to 1.5 to 48.0 millions/ml. Five of the seven initially oligozoospermic workers showed a marked increase in sperm count. In all the men with improved spermatogenesis, plasma levels of FSH, LH and testosterone were within the normal range when first evaluated. Nine spontaneous pregnancies occurred in the spouses of seven of the recovered workers. All the pregnancies went to term and culminated in the spontaneous of normal healthy infants. There was not improvement in the sperm counts of all azoospermic and oligozoospermic men with prolonged exposure to the chemical. It is suggested that the gonadotoxic effect of D.B.C.P. in human males is reversible, this reversibility being inversely related to previous exposure time and being most likely to occur in the presence of normal FSH values. The further increase in plasma FSH and LH and the moderate decrease in the mean testosterone level in the non-recovered workers is of prime importance. It may suggest a delayed toxic effect of D.B.C.P. on Sertoli and Leydig cell function during the four-year follow-up period, explaining lack of spermatogenic recovery over a prolonged period of time.