Does the Genetic Toxicity of Water Chlorination Products Pose a Risk to Public Health

Abstract Several reports from epidemiological studies have indicated a weak but significant correlation between the consumption of chlorinated water and Cancers of the bladder and colon. Experimental studies have concentrated on the effects of various genotoxic components of chlorinated water (particularly the chloro-hydroxy-furanone, MX, which can be derived from humic substances). Despite evidence for the potential of MX to damage DNA and induce DNA repair in mammalian cells, the effects of this agent in vivo would appear to be very restricted because of the limited extent to which it appears to be absorbed as reactive MX, and because of the presence of effective cellular defence Systems. Even though the concentrations of MX in potable water are very low, the recent finding that MX is carcinogenic in animals highlights the need for a better mechanistic understanding.