Drinking water treatment is not associated with an observed increase in neural tube defects in mice
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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.
KeywordsNeural tube defects (NTDs) Birth defects Teratogens Purge-trap gas chromatography-mass spectroscopy (PT GC-MS) Disinfection by-products (DBPs) Trihalomethanes (THMs)
We thank the NIH for grant 1R21 ES016886, Jerry Higgins (Blacksburg-Christiansburg-Virginia Tech Water Authority), Marc Edwards (Department of Civil and Environmental Engineering, Virginia Tech), and William Knocke (Department of Civil and Environmental Engineering, Virginia Tech) for helpful discussions.
Conflict of interest
None of the authors have conflicts of interest.
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