Reproductive toxicity of a mixture of regulated drinking-water disinfection by-products in a multigenerational rat bioassay.

BackgroundTrihalomethanes (THMs) and haloacetic acids (HAAs) are regulated disinfection by-products (DBPs); their joint reproductive toxicity in drinking water is unknown.ObjectiveWe aimed to evaluate a drinking water mixture of the four regulated THMs and five regulated HAAs in a multigenerational reproductive toxicity bioassay.MethodsSprague-Dawley rats were exposed (parental, F1, and F2 generations) from gestation day 0 of the parental generation to postnatal day (PND) 6 of the F2 generation to a realistically proportioned mixture of THMs and HAAs at 0, 500×, 1,000×, or 2,000× of the U.S. Environmental Protection Agency’s maximum contaminant levels (MCLs).ResultsMaternal water consumption was reduced at ≥ 1,000×; body weights were reduced at 2,000×. Prenatal and postnatal survival were unaffected. F1 pup weights were unaffected at birth but reduced at 2,000× on PND6 and at ≥ 1,000× on PND21. Postweaning F1 body weights were reduced at 2,000×, and water consumption was reduced at ≥ 500×. Males at 2,000×...