PolycyclicaromatichydrocarbonsinriverinerunoffofthePearlRiverDelta,ChinaJi-ZhongWanga,c,Yun-FengNiea,c,Yu-Feng,Guana,c,Hong-GangNia,c,Feng-Hui-Lua,c,Xian-LinLuob,EddyY.Zenga,*aStateKeyLaboratoryofOrganicGeochemistry,GuangzhouInstituteofGeochemistry,ChineseAcademyofScience,Guangzhou510640,ChinabSchoolofGeographyandPlanning,SunYat-senUniversity,Guangzhou510275,ChinacGraduateSchool,ChineseAcademyofSciences,Beijing100049,ChinaAbstractAsystematicstudyonmeasureofPAHsinwaterfromeightoutletsofthePearlRiverDelta(PRD)basedonmonthlysamplingcollectedinaspanof1yearwascarriedout.TheresultsshowedthetotalconcentrationsofPAHsinwaterphaseplussuspendedparticlematter(SPM)rangedfrom55.5to521.9ng/L,whichwerecomparedwithotherriversandestuaries.FingerprintscharacterswerecalculatedtodiscussthesourcesofPAHs.NocleartemporalandspatialtrendsofPAHconcentrationswerefound.However,concentrationsofPAHsassociatedtoSPMhavearelationinagreementwiththemonthlyprecipitationofGuangzhou,whichimplicatedtheimportanceofbulkatmosphericdeposition,specialforwetdeposition.Normalizedpartitioncoefficient(Koc)betweenwaterandsuspendedparticlematter(SPM)wascalculatedcorrelatedwiththeiroctanol-waterpartitioncoefficient(Kow).Furtheranalysisbyhierarchicalclusteranalysiswascarriedouttogrouptheseeightoutlets.*Correspondingauthor.Tel:+86-20-85291421;fax:86-20-85290706.E-mail:eddyzeng@gig.ac.cn(E.Y.Zeng).1123456789101112131415161718192021123Keywords:Polycyclicaromatichydrocarbons;Source;Koc;hierarchicalclusteranalysis2222341.IntroductionPolycyclicaromatichydrocarbons(PAHs)areaclassoforganicchemicalscomposedofbenzenerings,andknowntobewidespreadintheenvironment,persistence,prevalenceandtheirtoxicitytotheecosystemandhumanbeing.Therefore,16PAHshavebeenlistedasprioritypollutantsbytheUnitedStatesEnvironmentalProtectionAgency(USEPA)andtheEuropeanCommunity.PAHshavesufferedtobeeninvestigatedinkindsofmediumsdetailedlyduringthepastseveraldecades(Lietal.,2006,Mackayetal.,2000).Moreandmoreattentionwasplayedtoglobalscaleduetotheirpotentialityoflong-distancetransportbyatmosphericandriverinvectors.Theglobaloceansareagiganticsinkfororganiccontaminantsderivedfromavarietyofsource.Howeveranunansweredquestionoftheimportancetoanunderstandingoftheriverinerunoffintotheoceansisthecriticalroleofpollutantsglobaldistributionandbudget,specially,totheriversofcoastalregions.ThePearlRiverDelta(PRD)isoneofthemostdevelopedandpopulatedregionsinChina,connectingthePearlRiverEstuary(PRE)andSouthChinaSea(SCS)viaeightmajorriverinerunoffoutlets(Figure1).Therefore,largeamountsoforganiccontaminantsarelikelyreleasedintothecoastaloceansthroughriverinerunoff.In2005,thePRDregionhadapproximately25millionpermanentresidentsandninemillionregisteredmotoredvehicles(GuangdongStatisticalYearbook,2005),whichwereconsideredthemostimportantanthropogenicsourceofPAHsinurbanareas(Hwangetal.,2006).ItisconceivablethatanthropogenicallyderivedPAHsisanimportantsourcetotheglobaloceansystem(Wangetal.,2007).CombustionofdifferentfuelsgeneratesdifferentPAHsemission“fingerprint”,thereforePAHsisomersratiosinfieldmeasuredcanprovidesomediagnosticinformationabouttheir324252627282930313233343536373839404142434445465sources(Luoetal.,2006,Maietal.,2001).Howeversomesignaturescanbealteredduringenvironmentalprocessessuchasdegradation,sorptionandvolatilization(McVeetyetal.,1988),somegivenPAHswiththesamemolecula...