Drinking water treatment is not associated with an observed increase in neural tube defects in mice

Abstract

Disinfection by-products (DBPs) arise when natural organic matter in source water reacts with disinfectants used in the water treatment process. Studies have suggested an association between DBPs and birth defects. Neural tube defects (NTDs) in embryos of untreated control mice were first observed in-house in May 2006 and have continued to date. The source of the NTD-inducing agent was previously determined to be a component of drinking water. Tap water samples from a variety of sources were analyzed for trihalomethanes (THMs) to determine if they were causing the malformations. NTDs were observed in CD-1 mice provided with treated and untreated surface water. Occurrence of NTDs varied by water source and treatment regimens. THMs were detected in tap water derived from surface water but not detected in tap water derived from a groundwater source. THMs were absent in untreated river water and laboratory purified waters, yet the percentage of NTDs in untreated river water were similar to the treated water counterpart. These findings indicate that THMs were not the primary cause of NTDs in the mice since the occurrence of NTDs was unrelated to drinking water disinfection.

Direct potable reuse and birth defects prevalence in Texas: An augmented synthetic control method analysis of data from a population-based birth defects registry

“…20 In addition, some animal studies of specific contaminants failed to produce deleterious effects. 25,26 Because of the lack of clarity regarding the relationship between drinking water quality and birth defects prevalence, and because DPR has been approved or is under consideration as a source of drinking water for additional population centers, we performed the first assessment of birth defects prevalence in relation to DPR. Our objective was to inform future policy decisions by determining whether the implementation of DPR was associated with a change in birth defects prevalence at the population level.…”

“… 20 In addition, some animal studies of specific contaminants failed to produce deleterious effects. 25 , 26 …”