title: [Chlorination of drinking water--possible cancer risk from a by-product].
abstract: In a recent study, 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-furanone (MX; CAS no 77439-76-0) which is formed during chlorination of water containing organic substances, was found to be carcinogenic in the rat, at multiple sites in both sexes. MX is known as a potent bacterial mutagen. Epidemiological studies have suggested an association between chlorinated water consumption and a moderate increase in the risk of cancer. Although MX is a strong mutagen in prokaryotes, its genotoxic effects in mammalian cells are not so large, and more variable results are obtained. Very low concentrations of MX are found in drinking water (ng/L), whereas the genotoxic and carcinogenic effects in experimental animals of this compound are detectable at relatively high doses (mg/kg body weight). Relative to the risk for infectious diseases from the consumption of contaminated drinking water, the possible cancer risk associated with MX exposure appears to be low. Even so, efforts should be made to reduce disinfection byproduct formation by removing organic matter before chlorination.
authors.affiliation: Avdeling for miljømedisin Statens institutt for folkehelse, Oslo.
authors.forename: J A
authors.initials: JA
authors.lastname: Holme
authors.forename: I L
authors.initials: IL
authors.lastname: Steffensen
authors.forename: G
authors.initials: G
authors.lastname: Brunborg
authors.forename: G
authors.initials: G
authors.lastname: Becher
authors.forename: J
authors.initials: J
authors.lastname: Alexander
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000009:adverse effects* / Q000737:chemistry / Q000378:metabolism; D002713:Chlorine / Q000009:adverse effects* / Q000737:chemistry / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D005663:Furans / Q000009:adverse effects / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D051381:Rats; D012307:Risk Factors; D014881:Water Supply
chemical_list: D002273:Carcinogens; D005663:Furans; D002713:Chlorine
vernacular_title: Klorering av drikkevann--mulig kreftrisiko av et biprodukt.