Sub-chronic Exposure to Dibromoacetic Acid, a Water Disinfection By-product, Does Not Affect Gametogenic Potential in Mice

Abstract

Water disinfection by-products, such as dibromoacetic acid (DBA), are formed when drinking water is treated with chlorination, bromination, or ozonation. Epidemiological studies have linked these byproducts to adverse effects in humans such as cancer, developmental defects, and reproductive toxicities. DBA has been shown to produce reproductive toxicity in rodents at relatively high doses. The present study used a mouse model to determine the developmental and reproductive effects of sub-chronic, low-dose exposure to DBA. Pregnant mice (10/dose group) were exposed with DBA in drinking water at 0, 5, or 50 mg/kg/day from gestation day 15 though nursing. Upon weaning at 3 weeks, one group of pups (pre-pubertal group: 7-10 pups of each gender/treatment group) were euthanized and weights of liver, paired kidneys, testes, and ovaries were measured. In the 50 mg dose group, weights of testes and liver in males and weights of liver and kidneys in females were significantly higher (p < 0.05). The remaining pups (15-17 of each gender/dose group) continued to be dosed similarly through adulthood. At 7 weeks of age (neo-pubertal group), animals were euthanized and tissues weighed and processed for evaluation of reproductive organs and gametogenic potential. Except for decreased (p < 0.05) testes and kidney weights in 50 mg dose group males, there were no differences in organ weights. No significant differences were noted between control and dosed animals in daily sperm production, testicular sperm counts, epididymal sperm reserves, morphology of seminiferous epithelium, or ovarian follicle counts.