Long-term effects on male reproduction of early exposure to common chemical contaminants in drinking water

Abstract

We evaluated sequelae to early exposure of male rabbits to drinking water containing chemicals typical of ground water near hazardous waste sites. The mixture (p.p.m. at 1x) was 7.75 arsenic, 1.75 chromium, 9.25 lead, 12.5 benzene, 3.75 chloroform, 8.5 phenol and 9.5 trichloroethylene. Dutch-Belted does received mixture at 0x (deionized water; control), 1x or 3x as drinking water from day 20 pregnancy through weaning. Exposure of individual males (7-9/treatment) continued until 15 weeks (adolescence); then, all males received deionized water. At 57-61 weeks of age, ejaculatory capability and seminal, testicular, epididymal and endocrine characteristics were evaluated. At 10 opportunities with a female teaser, all seven control males ejaculated every time, but 12 of the 17 treated males failed to express interest, achieve erection and/or ejaculate on one to five occasions; four of the 12 accomplished ejaculation with a second male teaser. Total spermatozoa/ejaculate and daily sperm production were unaffected. However, treatment caused (P < 0.03) acrosomal dysgenesis and nuclear malformations. Baseline serum concentrations of LH were lower, but with borderline significance (P = 0.05). Testosterone secretion after exogenous human chorionic gonadotrophin (P < 0.04) was low. Thus, even at 45 weeks after last exposure to drinking water pollutants, mating desire/ability, sperm quality, and Leydig cell function were subnormal.