title: Ground and surface water for drinking: a laboratory study on genotoxicity using plant tests.
abstract: Surface waters are increasingly utilized for drinking water because groundwater sources are often polluted. Several monitoring studies have detected the presence of mutagenicity in drinking water, especially from surface sources due to the reaction of natural organic matter with disinfectant. The study aimed to investigate the genotoxic potential of the products of reaction between humic substances, which are naturally present in surface water, and three disinfectants: chlorine dioxide, sodium hypochlorite and peracetic acid. Commercial humic acids dissolved in distilled water at different total organic carbon (TOC) concentrations were studied in order to simulate natural conditions of both ground water (TOC=2.5 mg/L) and surface water (TOC=7.5 mg/L). These solutions were treated with the biocides at a 1:1 molar ratio of C:disinfectant and tested for genotoxicity using the anaphase chromosomal aberration and micronucleus tests in Allium cepa, and the Vicia faba and Tradescantia micronucleus tests. The tests were carried out after different times and with different modes of exposure, and at 1:1 and 1:10 dilutions of disinfected and undisinfected humic acid solutions. A genotoxic effect was found for sodium hypochlorite in all plant tests, at both TOCs considered, while chlorine dioxide gave positive results only with the A.cepa tests. Some positive effects were also detected for PAA (A.cepa and Tradescantia). No relevant differences were found in samples with different TOC values. The significant increase in all genotoxicity end-points induced by all tested disinfectants indicates that a genotoxic potential is exerted even in the presence of organic substances at similar concentrations to those frequently present in drinking water.
authors.affiliation: Department of Experimental and Applied Medicine, Institute of Hygiene, Epidemiology and Public Health, University of Brescia ;
authors.forename: Donatella
authors.initials: D
authors.lastname: Feretti
authors.affiliation: Department of Experimental and Applied Medicine, Institute of Hygiene, Epidemiology and Public Health, University of Brescia ;
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Ceretti
authors.affiliation: Department of Biology, Tor Vergata University , Rome ;
authors.forename: Bianca
authors.initials: B
authors.lastname: Gustavino
authors.affiliation: Department of Experimental and Applied Medicine, Institute of Hygiene, Epidemiology and Public Health, University of Brescia ;
authors.forename: Llaria
authors.initials: L
authors.lastname: Zerbini
authors.affiliation: Department of Experimental and Applied Medicine, Institute of Hygiene, Epidemiology and Public Health, University of Brescia ;
authors.forename: Claudia
authors.initials: C
authors.lastname: Zani
authors.affiliation: Department of Medical-Surgical Specialities and Public Health, University of Perugia , Italy.
authors.forename: Silvano
authors.initials: S
authors.lastname: Monarca
authors.affiliation: Department of Biology, Tor Vergata University , Rome ;
authors.forename: Marco
authors.initials: M
authors.lastname: Rizzoni
keywords: disinfection by-products; humic acids; mutagenicity; plant assays