AWWA JAW6790

In a review of research results available since a previous review in alternative means of disinfecting drinking water. These hazards can be associated with the disinfectants themselves, as well as with the products formed when disinfectants react with organic material present in the water. The effects of chlorine dioxide and monochloramine, and their by-products, such as chlorite, chlorate, trihalomethanes, and haloacetonitriles, are considered. The following experimental findings are reported: by-products of chlorination, that have been clearly identified, possess carcinogenic properties; chlorine dioxide, or some reaction product produced in vivo, possesses anti-thyroid activity; a substantial by-product of the use of chlorine dioxide in high demand waters produces hemolytic anemia; monochloramine possesses mutagenic properties in bacteria and produces changes in the livers of mice; there is little information available to begin evaluating hazards associated with the formation of toxic by-products; and pilot experiments using model substrates, including humic and fulvic acids, indicate that the formation of mutagenic and toxic by-products is substantively affected by water conditions. Includes 52 references, tables.