Formation and characterization of bacterial mutagens from reaction of the alternative disinfectant monochloramine with model aqueous solutions of fulvic acid
✍ Scribed by D. A. Cozzie; R. Kanniganti; M. J. Charles; J. D. Johnson; Dr. L. M. Ball
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 961 KB
- Volume
- 21
- Category
- Article
- ISSN
- 0893-6692
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✦ Synopsis
Monochloramine hcts been suggested as an 01ternative disinfectant to chlorine to reduce levels of trihalomethanes in treated drinking water, but little is known of the toxicological properties and potential health implications of by-products specific to the chloi-amination process. Model aqueous fulvic acid solutions (200-400 mg C/liter), serving as surrogates for humic surface waters, were chlorarninated over a range of molar CI:C ratios from, 1 :40 to 1 :2. The resulting by-products were extracted into diethyl ether at pH 2 and investigated with the Ames plate incorporation assay. Extractable mutagenicity increased with increasing chlorine and carbon dose up to about 30,000 revertants/liter at CI:C ratios of 1 :2. Mutagenicity was higher in Solmonella fyphimurium strain TAlOO than in strain ~ ~~~ TA98, and was decreased in the presence of S9,
indicating that the mutagens formed were direct-acting and induced predominantly basepair substitutions. Bovine serum albumin decreased slightly, and glutathione reduced greatly, the mutagenic activity detected in extracts. HPLC fractionation of the by-products indicated that most of the mutagenic activity was found in the earliest-eluting (most polar) fraction. The mutagenic by-products appeared to be qualitatively similar to 3-chloro-4-dichloromethyl-5-hydroxy-2-(5H)-furanone (MX) in their chromatographic behavior and responses to glutathione and bovine serum albumin, but were less readily detoxified by S9 than was MX.