2004美国EPA饮用水标准

’sOfficeofWateronan“asneeded”basis.ThefollowinginformationshouldbekeptinmindwhenusingtheTables:Referencedose(RfD)valuesareupdatedtoreflectthevaluesintheIntegratedRiskInformationSystem(IRIS),andtheDrinkingWaterEquivalentLevel(DWEL)hasbeencalculatedaccordingly.Thus,boththeRfDandDWELintheTablesdifferfromthevaluesintheHealthAdvisorydocumentiftheIRISRfDismorerecentthantheHealthAdvisorydocumentvalue.RfDvaluesfromIRISthatdifferfromthevaluesintheHealthAdvisorydocumentsarepresentedinBOLDtype.ForunregulatedchemicalswithanewIRISRfD,thelifetimeHealthAdvisorywascalculatedfromtheDWELusingtherelativesourcecontributionvaluepublishedintheHealthAdvisory.Forregulatedchemicals,wheretherevisedlifetimevaluedifferedfromtheMaximumContaminantLevelGoal(MCLG),nolifetimevaluewasprovidedintheTable.Forregulatedchemicals,thecancergroupdesignationand10-4cancerriskreflectthestatusatthetimeofregulation.Forunregulatedchemicals,thecancergroupdesignationorcancerclassificationand10-4cancerriskreflectthevaluespresentlyonIRIS.NewIRIScancerdesignationsand10-4cancerriskvaluesarepresentedinBOLDtype.SeveralpesticideslistedinIRIShavebeenre-evaluatedbytheOfficeofPesticidePrograms(OPP)resultinginanRfDotherthanthatinIRIS.Forthesepesticides,theIRISvalueislistedintheTable,andthenewerOPPvalueisgiveninafootnote.InsomecasesthereisaHealthAdvisoryvalueforacontaminantbutthereisnoreferencetoaHealthAdvisorydocument.TheseHealthAdvisoryvaluescanbefoundintheDrinkingWaterCriteriaDocumentforthecontaminant.Withafewexceptions,theHealthAdvisoryvalueshavebeenroundedtoonesignificantfigure.TheDrinkingWaterStandardsandHealthAdvisoriestablesmaybereachedfromtheWaterSciencehomepageat(i):00AMto5:30PMESTCopiesofthesupportingtechnicaldocumentationforthehealthadvisoriescanbeorderedforafeeontheInternetat(ERIC)1929KennyRoadColumbus,OH43210-1080Telephonenumber614-292-6717;[e-mail]r/Check/VisaorMastercardForfurtherinformationregardingtheDrinkingWaterStandardsandHealthAdvisories,calltheSafeDrinkingWaterHotlineat1-800-426-4791or703-285-1093.(ii)“official”definitions.Theyareintendedtoassisttheuserinunderstandingtermsfoundonthefollowingpages.ActionLevel:Theconcentrationofacontaminantwhich,ifexceeded,triggerstreatmentorotherrequirementswhichawatersystemmustfollow.Itisthelevelofleadorcopperwhich,ifexceededinover10%ofthehomestested,triggerstreatment.CancerClassification:Adescriptiveweight-of-evidencejudgmentastothelikelihoodthatanagentisahumancarcinogenandtheconditionsunderwhichthecarcinogeniceffectsmaybeexpressed.Underthe1999EPAProposedGuidelinesforCarcinogenRiskAssessment,descriptivetermsforcarcinogenicityreplacetheearlieralphanumericCancerGroupdesignations(USEPA1986guidelines).Thesuggesteddescriptivetermsareasfollows:CarcinogenictohumansLikelytobecarcinogenictohumansSuggestiveevidenceofcarcinogenicpotentialInadequateinformationtoassesscarcinogenicpotentialNotlikelytobecarcinogenictohumansCancerGroup:Aqualitativeweight-of-evidencejudgementastothelikelihoodthatachemicalmaybeacarcinogenforhumans.Eachchemicalisplacedintooneofthefollowingfivecategories(USEPA1986guidelines):GroupCategoryAHumancarcinogenB Probablehumancarcinogen:B1indicateslimitedhumanevidenceB2indicatessufficientevidenceinanimalsandinadequateornoevidenceinhumansPossiblehumancarcinogenDNotclassifiableastohumancarcinogenicityEEvidenceofnoncarcinogenicityforhumansThiscategorizationisbasedonEPA’s1986GuidelinesforCarcinogenRiskAssessment.TheProposedGuidelinesforCarcinogenRiskAssessment,whichwerepublishedin1999,havereplacedthe1986cancerguidelinesonaninterimbasisfornewassessments.(iii)C:Anonregulatoryconcentrationofacontaminantinwaterthatislikelytobewithoutadverseeffectsonbothhealthandaesthetics.DWEL:DrinkingWaterEquivalentLevel.Alifetimeexposureconcentrationprotectiveofadverse,non-cancerhealtheffects,thatassumesalloftheexposuretoacontaminantisfromdrinkingwater.HA:HealthAdvisory.Anestimateofacceptabledrinkingwaterlevelsforachemicalsubstancebasedonhealtheffectsinformation;aHealthAdvisoryisnotalegallyenforceableFederalstandard,butservesastechnicalguidancetoassistFeder