Mutagenic activity of disinfection by-products.

Abstract

Data on raw water quality, disinfection treatment practices, and the resulting mutagenic properties of the treated water were compiled from pilot-and full-scale treatment experiments to evaluate that parameter which might produce variability in the results of a mutagenic study.Analysis of the data and comparison of treatment practices indicated that the measured mutagenic activity is strongly related to the characteristics of the organic matter in the raw water, the methodology used to sample and detect mutagens, the scale of the study both in terms of treatment flow and period of study, and the point at which and the conditions under which oxidants are added during treatment.Conclusions regarding disinfection systems in full-scale water treatment plants include the following: When raw water is pretreated and high concentrations of organics are present in the raw water, both ozonation and chlorination increased mutagenic activity. However, no significant difference in mutagenicity was found between the two oxidants.Both in the case of a nitrified groundwater and a clarified surface water, the mutagenic activity of the water after ozonation was related to its mutagenic activity before ozonation.With ozonation, mutagenic activity decreased after granular activated carbon (GAC) filtration. Thus, when GAC filtration follows ozone disinfection, early addition of oxidants may not be deleterious to the finished water quality. When chlorine or chlorine dioxide is added after GAC filtration, chlorine dioxide was found to produce a less mutagenic water than chlorine.Although these conclusions suggest means of controlling mutagenic activity during treatment, it must be stressed that the measurement of mutagenicity is a presumptive index of contamination level.

Determination of the Efficacy of Ozone Treatment Systems Using a Gap Junction Intercellular Communication Bioassay

“…Ames test results are often conflicting. For example, the treatment of water by ozone showed both an increase (28) and a decrease (27) in mutagenicity. Tumor-initiating properties determined in vivo also showed no effect (27).…”

“…Thus, the effects of pollutants on mammalian gap junction can give invaluable toxicological information. Previous toxicological evaluation of ozone byproducts has focused primarily on genotoxic events (e.g., see refs [27][28][29]. The objective of this research was to use a benchscale, completely, mixed, semicontinuous reactor to assess the efficacy of the ozonation of aqueous organic compounds to products that are not inhibitory to GJIC, which is a nongenotoxic bioassay.…”

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.…”

Subchronic toxicity study of ozonated and ozonated/chlorinated humic acids in Sprague-Dawley rats: a model system for drinking water disinfection

“…However, while chlorination has been invariably shown to increase the mutagenic activity of a variety of humic and fulvic acid solutions as well as drinking water concentrates, ozonation has been varied in its response, showing both enhancement (16)(17)(18)(19) and reduction (3,(20)(21)(22) of the mutagenic activity of humic acids and drinking water concentrates. Likewise, the ability of ozone to destroy the precursors to chlorination-derived mutagens has been varied and often dependent on the ozone to TOC ratio and the quality of the source water (25,26).…”