多环芳香烃的特性及其对藻类的毒性_英文_

  • 格式:pdf
  • 大小:183.37 KB
  • 文档页数:7

© 1994-2010 China Academic Journal Electronic Publishing House. All rights reserved. http://www.cnki.net文章编号:100022618(2004)0320217207

收稿日期:2004206207

基金项目:国家重点基础研究发展计划项目(2002CB412309)作者简介:雷安平(19682),女(汉族),湖北省罗田县人,深圳大学博士.E2mail:bioaplei@szu1edu1cn

Propertiesofpolycyclicaromatichydrocarbonsandtheirtoxicityonalgae

LEIAn2pingCollegeofLifeScienceShenzhenUniversityShenzhen518060P.R.China

Abstract:Contaminationofpolycyclicaromatichydrocarbons(PAHs)intheenvironmentisaseriouspublichealthprob2lemandtheimpactofPAHsonhumanbeingsandecosystemshasattractedincreasingpublicandacademicconcern.How2ever,informationrelatedtothepropertiesofPAHsandtheirtoxicityonalgaeseemstobemeagerandwidelyscatteredinspitethatalgaeserveasmajorprimaryproducersandplayanimportantroleinaquaticecosystems,andanychangesinal2galcommunityarelikelytoleadtomajorecologicalconsequencesinaquaticecosystems.ThepresentreviewfirstdescribesthechemicalstructuresandgeneralpropertiesofPAHs,thenbrieflyintroducesthesourcesandfateofPAHsintheenvi2ronmentandfinallyencompassesthetoxicityofPAHsonalgae,withemphasisontheactivationofthetoxicityofPAHsandalgalspecies2specificdifferencesinsensitivitytoPAHs.Keywords:polycyclicaromatichydrocarbons(PAHs);properties;toxicity;algae

1 Chemicalstructuresandgeneralproper2tiesofPAHs

111 ChemicalstructuresPolycyclicaromatichydrocarbons(PAHs)areagroupofaromaticcompoundscontainingtwoormorefusedbenzeneringsinlinear,angular,orclusterstructure.Someofthemcanbeconsideredheterocyclicmoleculeswiththesubstitutionofanaromaticringcarbonbynitro2gen,oxygen,orsulphur[1].Thelipophili2city,environ2mentalpersistenceandgenotoxicityincreaseasthemolecu2larsizesofPAHsincreaseupto4or5fusedbenzeneringswhiletoxicologicalconcernshiftstowardsfromacutetochronictoxicity,primarilycarcinogenesisasthenumberofbenzeneringsincreasedfrom2to5[2,3].PAHswithfourormorefusedringsarelesssoluble,morestable,andmorerecalcitrant.112 Generalproperties2ubiquitous,bioaccumulativeandpersistentpollutantsPAHsareubiquitousintheenvironmentandarefoundinhighconcentrationsinmanyindustrialsites,par2ticularlythoseassociatedwithpetroleum,gas2productionandwood2preservingindustries[4].MostPAHsarepracti2callyinsolubleinwater.PAHs,likemanyotherlipophilicorganicenvironmentalpollutants,havelowvaporpressureandhighoctanol2waterpartitioncoefficients[3].PAHsarerapidlyabsorbedbyparticulatematterandbylivingorgan2isms.Inwater,PAHsmaybepresentinthevaporphase,dissolvedphase,micelleform,sorbedto“dissolved”orcolloidalorganicmatter,sorbedtoparticles,orincorporat2edintobiota[5].Duetotheirlipophilicandaccumulative

第21卷,第3期深圳大学学报理工版Vol121,No13

2004年7月JOURNALOFSHENZHENUNIVERSITYSCIENCEANDENGINEERINGJuly2004© 1994-2010 China Academic Journal Electronic Publishing House. All rights reserved. http://www.cnki.netnature,PAHπsbioavailabilityislowandtheyarepersistentwithinecosystems.Theyarerelativelystable,recalcitrant,moredifficulttodegradethanmanyotherorganiccom2pounds,andhavelonghalf2lifetimeinnature,especiallythosePAHswithupto4or5fusedbenzenerings[2].SomePAHsaremutagensandcarcinogens,and16PAHsaredesignatedbyUSEPAas“Prioritypollutants”[6].2 SourcesandfateofPAHsintheenvi2ronment211 SourcesofPAHsintheenvironmentSourcesofPAHsintheenvironmentincludebothnat2uralandanthropogenicinputs[4].NaturallyoccurringPAHswhichareintheterrestrialenvironmentfromforestfires,volcanicactivity,andsynthesisbyplantsandmi2croorganismsmakeaminorcontributiontothePAHcon2tentintheenvironment.TheanthropogenicPAHsemittedfromburningoffossilfuels,refusecombustion,andagri2culturalburningaremajorcontributorstothePAHpool(>90%ofemissionsfromthesesources)[4].ThePAHsemittedfromautomobileexhaustsarelocalizedalongroad2wayswhilethoseemittedfromjetaircraftandpowerplantsmaybespreadoverlongdistances.Neitherautomobilenorjetengineexhaustsaremajorcontributorstotheenviron2mentalburdenofPAHsonaglobalscale.Wasteproductsfromindustriesandmunicipalitiesaresignificantcontribu2torstosoilPAHsinisolatedareas.Anthropogeniccombus2tionactivitiesareprincipalsourcesofPAHstosoilsinin2dustrializedcountriesviaatmosphericdeposition.Asare2sult,soilconcentrationstendedtoincreaseoverthelast100~150years,particularlyinurbanareas[7].TheconcentrationsofPAHsintheenvironmentvarysignificantly,dependingonthelevelofindustrialdevelop2mentandcontaminationwithpetroleumproducts.Forex2ample,insoilitcouldrangefrom5μg・kg-1inanunde2velopedareato1179×106μg・kg-1atanoilrefinery[8].InHongKongSAR,totalPAHsarewidelydistributedinsediments,withbackgroundconcentrationoftotalPAHataround40to60μg・kg-1wetweight,butincreasedto116μg・kg-1wetweightinVictoriaHarbourandseveralothercontaminatedareas,andtheconcentrationswereupto1159μg・kg-1wetweightintyphoonshelterswithsubstan2tialcontamination[9].212 FateofPAHsintheenvironmentThepossiblefateofPAHsintheenvironmentincludeabioticandbioticprocesses,ofwhichvolatilization,pho2tooxidation,chemicaloxidation,bioaccumulation,adsorp2tiontosoilparticles,leachingandmicrobialdegradationarethemainprocesses[3].Inthecaseofphotochemicalactivation,PAHsabsorbultra2violetlightenergyandaresubjecttophotolyticacti2vationorbreakdown[10].Parketal.foundthatvolatiliza2tionwasnegligible,exceptfornaphthaleneandsubstitutednaphthalenes[11].PAHswiththreeandmoreringstendtobestronglyadsorbedtosoilparticles.Strongsorptioncou2pledwithlowwatersolubilityandverylowvaporpressuresmakesleachingandvolatilizationinsignificantpathwaysofPAHdissipation.ThemicrobialmetabolismisthemajorbioticprocessthatresultsinthedecontaminationofPAHsinnature[12].Awidevarietyofbacteria,fungiandalgaehavetheabilitytometabolizePAHs.Bioconcentrationisalsoanimportantprocesswhichaffectsthefateofhy2drophobiccompounds.Certainenvironmentalfactorssuchastemperature,pH,nutrients,oxygenandwateravail2ability,salinityandsoiltype,etc.wouldaffectthefateofPAHsintheenvironment[2,13].