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1、硕士学位论文AbstractDongtingLake,thesecondlargestlakeinChina,isawetlandofinternationalimportance.Ithasanimportantecologicalfunctionandeconomicvalue,whichisahabitatformanyfish,birdsandotherwildlife.Recently,ithasbeenexperiencedaseriouspollutionofheavymetalsinDongtingLakeduetoh
2、umanactivities.Heavymetalsaretoxic,persistentandnon-biodegradable.Theymayaccumulatethroughfoodchainintheecosystemandhaveapotentialeffectonorganisms.Therefore,ecologicalriskassessmentandsourceapportionmentarehelpfulforheavymetalcontrolinDongtingLake.Inaddition,exposureri
3、skassessmentofheavymetaltowaterfowlismeaningfulforwaterfowlconservationandriskmanagement.Firstly,surfacesedimentsofDongtingLakewetlandwerecollectedfromtensitestoinvestigatevariationtrend,riskandsourcesofheavymetaldistributionindryseasonsof2011~2013.Thethree-yearmeanconc
4、entrations(mg/kg)ofCr,Cu,Pb,Cd,HgandAswere91.33,36.27,54.82,4.39,0.19and25.67,respectively,whichwereallhigherthanthecorrespondingbackgroundvalues.Sedimentqualityguidelines(SQGs),Geo-accumulationindex(Igeo)andpotentialecologicalriskindex(RI)wereusedfortheassessmentofpoll
5、utionlevelofheavymetals.ThepollutionriskofCd,HgandAsweregreatandthatofCrneededurgentattentionbecauseofitsobviousincrease.Pollutionloadindex(PLI)andgeographicinformationsystem(GIS)methodswereconductedtoassessspatialandtemporalvariationofheavymetalcontamination.Resultscon
6、firmedanincreasedcontaminationcontributioninflowfromXiangRiver.Multivariatestatisticalanalyseswereappliedtoidentifycontributionsourcesofheavymetal,whichshowedanthropogenicoriginmainlyfrommining,smelting,chemicalindustryandagriculturalactivity.Secondly,anexposuremodelwas
7、integratedforassessingheavymetalexposurerisktomigratorybirdsinDongtingLakeWetland.TheconcentrationsofCr,Cu,Pb,Cd,HgandAsinwater,plant,soilandfishwereinvestigatedfrom9migratorybirdhabitats.Theresultsshowedthatexposuredosesfromdrinkingwaterpathwayswereverylow.Therewasasen
8、sitiveareathatCdandAsexposuredosesexceededthemostconservativetolerabledailyintake,whichislocatedattheestuaryof
