Background: Trihalomethanes (THMs) and haloacetic acids (HAAs) are regulated disinfection by-products (DBPs); their joint reproductive toxicity in drinking water is unknown.
Objective: We aimed to evaluate a drinking water mixture of the four regulated THMs and five regulated HAAs in a multigenerational reproductive toxicity bioassay.
Methods: Sprague-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).
Results: Maternal 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× had a small but significantly increased incidence of retained nipples and compromised sperm motility. Onset of puberty was delayed at 1,000× and 2,000×. F1 estrous cycles and fertility were unaffected, and F2 litters showed no effects on pup weight or survival. Histologically, P0 (parental) dams had nephropathy and adrenal cortical pathology at 2,000×.
Conclusions: A mixture of regulated DBPs at up to 2,000× the MCLs had no adverse effects on fertility, pregnancy maintenance, prenatal survival, postnatal survival, or birth weights. Delayed puberty at ≥ 1,000× may have been secondary to reduced water consumption. Male nipple retention and compromised sperm motility at 2,000× may have been secondary to reduced body weights.
National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
Recommended Citation:
Michael G. Narotsky,Gary R. Klinefelter,Jerome M. Goldman,et al. Reproductive Toxicity of a Mixture of Regulated Drinking-Water Disinfection By-Products in a Multigenerational Rat Bioassay[J]. Environmental Health Perspectives,2015-01-01,Volume 123(Issue 6):564