Mutagenicity studies in salmonella: Residues of ozonated and/or chlorinated water fulvic acids

Abstract

Aqueous residues of ozonated, chlorinated, and ozonated/chlorinated water fulvic acids (WFA) were tested for induction of His+ reversion in Salmonella typhimurium strain TA100 in fluctuation tests for mutagenicity. The data suggest that ozonation of natural organics present in sources of drinking water can prevent subsequent formation of by-products of chlorination that are mutagenic in bacteria. Ozonation of the WFA at different pH and at varying dose levels produced residues that were not or were only weakly mutagenic. Chlorination of WFA or of previously ozonated WFA led to residues that were highly mutagenic. However, mutagen formation in the ozonated/chlorinated residues could be prevented, depending upon the pH of the WFA solutions during ozonation-mutagenicity decreased as pH increased. This decrease in mutagenicity is associated with previous observations of enhanced ozone decomposition into its highly reactive oxidant species at higher pH. Since ozonation seems to be more effective at alkaline pH, alkaline raw water sources seem to be the best candidates for water treatment that involves ozonation.

Evaluation of mutagenic activity of ozonated and ozonated‐chlorinated humic substances by sos chromotest

“…Some researchers were reported that mutagenic activity appeared by ozonation of humic substances [13][14][15], drinking water [12] and polluted ground water [11], while the others reported that mutagenicity disappeared by ozonation of humic substances [20] and drinking water [16,17,19]. In the previous paper [21], we could not observed mutagenicty on ozonated humic substances by Ames assay.…”

“…Some reports indicated that mutagenicity appeared or increased by ozonation of some organic compounds [11][12][13][14][15]. While, other reports indicated contrary results [16][17][18][19][20].…”

3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and mutagenic activity in Massachusetts drinking water.

“…The choice of disinfectant greatly influences the type and amount of byproducts that are formed. Chloramination (40), ozonation (41), and a combination of the two (39,42) have been shown to result in reduced mutagenic activity. Alternative disinfectants result in fewer trihalomethanes (43) but produce additional by-products.…”

The Effects of Subacute Exposure of Peracetic Acid on Lipid Peroxidation and Hepatic Enzymes in Wistar Rats

“…However, the use of chemical disinfectants in water treatment usually results in the formation of by-products that can be toxic and/or mutagenic. [23][24][25][26][27][28][29][30][31] Although drinking water has certainly a greater potential to impact human health, wastewater contamination may also pose health risks. The aim of this study was to evaluate the effect of peracetic acid on lipid peroxidation and hepatic enzymes in Wistar rats.…”