RichardsonetalDBPMutatRes2007final

See discussions, stats, and author profiles for this publication at: Genotoxicity, and Carcinogenicityof Regulated and Emerging Disinfection By-Products in Drinking Water: A Review...Article in Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis · November 2007DOI: 10.1016/j.mrrev.2007.09.001 · Source: PubMedCITATIONS901READS1,4095 authors, including:Rita SchoenyUnited States Environmental Protection Age…78 PUBLICATIONS 2,477 CITATIONS SEE PROFILEDavid DeMariniUnited States Environmental Protection Age…227 PUBLICATIONS 7,024 CITATIONS SEE PROFILEAll content following this page was uploaded by David DeMarini on 02 December 2014.The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original documentand are linked to publications on ResearchGate, letting you access and read them immediately.ReviewOccurrence,genotoxicity,andcarcinogenicityofregulatedandemergingdisinfectionby-productsindrinkingwater:AreviewandroadmapforresearchSusanD.Richardsona,*,MichaelJ.Plewab,ElizabethD.Wagnerb,RitaSchoenyc,DavidM.DeMarinidaNationalExposureResearchLaboratory,U.S.EnvironmentalProtectionAgency,Athens,GA30605,USAbDepartmentofCropSciences,CollegeofAgricultural,Consumer,andEnvironmentalSciences,UniversityofIllinoisatUrbana-Champaign,Urbana,IL61801,USAcOfficeofWater,U.S.EnvironmentalProtectionAgency,ML4301,1200PennsylvaniaAvenueNW,Washington,DC20460,USAdNationalHealthandEnvironmentalEffectsResearchLaboratory,U.S.EnvironmentalProtectionAgency,ResearchTrianglePark,NC27711,USAReceived7May2007;receivedinrevisedform5September2007;accepted6September2007Availableonline12September2007AbstractDisinfectionby-products(DBPs)areformedwhendisinfectants(chlorine,ozone,chlorinedioxide,orchloramines)reactwithnaturallyoccurringorganicmatter,anthropogeniccontaminants,bromide,andiodideduringtheproductionofdrinkingwater.Herewereview30yearsofresearchontheoccurrence,genotoxicity,andcarcinogenicityof85DBPs,11ofwhicharecurrentlyregulatedbytheU.S.,and74ofwhichareconsideredemergingDBPsduetotheirmoderateoccurrencelevelsand/ortoxicologicalproperties.These74includehalonitromethanes,iodo-acidsandotherunregulatedhalo-acids,iodo-trihalomethanes(THMs),andotherunregulatedhalomethanes,halofuranones(MX[3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone]andbrominatedMXDBPs),haloamides,haloacetonitriles,tribromopyrrole,aldehydes,andN-nitrosodimethylamine(NDMA)andothernitrosamines.Alternativedisinfectionpracticesresultindrinkingwaterfromwhichextractedorganicmaterialislessmutagenicthanextractsofchlorinatedwater.However,thelevelsofmanyemergingDBPsareincreasedbyalternativedisinfectants(primarilyozoneorchloramines)comparedtochlorination,andmanyemergingDBPsaremoregenotoxicthansomeoftheregulatedDBPs.OuranalysisidentifiedthreecategoriesofDBPsofparticularinterest.Category1containseightDBPswithsomeorallofthetoxicologiccharacteristicsofhumancarcinogens:fourregulated(bromodichloromethane,dichloroaceticacid,dibromoaceticacid,andbromate)andfourunregulatedDBPs(formaldehyde,acetaldehyde,MX,andNDMA).Categories2and3contain43emergingDBPsthatarepresentatmoderatelevels(sub-tolow-mg/L):category2contains29ofthesethataregenotoxic(includingchloralhydrateandchloroacetaldehyde,whicharealsoarodentcarcinogens);category3containstheremaining14forwhichlittleornotoxicologicaldataareavailable.Ingeneral,thebrominatedDBPsarebothmoregenotoxicandcarcinogenicthanarechlorinatedcompounds,andiodinatedDBPswerethemostgenotoxicofallbuthavenotbeentestedforcarcinogenicity.Thereweretoxicologicaldatagapsforevensomeofthe11regulatedDBPs,aswellasformostofthe74emergingDBPs.AsystematicassessmentofDBPsforgenotoxicityhasbeenperformedfor60DBPsforDNAdamageinmammaliancellsand16formutagenicityinSalmonella.Arecentepidemiologicstudyfoundthatmuchoftheriskforbladdercancerassociatedwithdrinkingwaterwasassociatedwiththreefactors:THMlevels,showering/bathing/swimming(i.e.,dermal/inhalationexposure),and:(2007)178–242*Correspondingauthor.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](S.D.Richardson).1383-5742/$–seefrontmatter#2007ElsevierB.V.Allrightsreserved.doi:10.1016/j.mrrev.2007.09.001genotype(havingtheGSTT1-1gene).Thisfinding,alongwithmechanisticstudies,highlightstheemergingimportanceofdermal/inhalationexposuretotheTHMs,orpossiblyotherDBPs,andtheroleofgenotypeforriskfordrinking-water-associatedbladdercancer.Morethan50%ofthetotalorganichalogen(TOX)formedbychlorinationandmorethan50%oftheassimilableorganiccarbon(AOC)formedbyozonationhasnotbeenidentifiedchemically.Thepotentialinteractionsamongthe600identifiedDBPsinthecomplexmixtureofdrinkingwatertowhichweareexposedbyvariousroutesisnotreflectedinanyofthetoxicologystudiesofindividualDBPs.ThecategoriesofDBPsdescribedhere,theidentifieddatagaps,andtheemergingroleofdermal/inhalationexpo