地下水污染外文翻译文献

1、 地下水污染外文翻译文献（文档含中英文对照即英文原文和中文翻译）外文：Arsenicintheenvironment:BiologyandChemistryAbstract：Arsenic(As)distributionandtoxicologyintheenvironmentisaseriousissue,withmillionsofindividualsworldwidebeingaffectedbyAstoxicosis.SourcesofAscontaminationarebothnaturalandanthropogenicandthescaleofcontaminationrang

2、esfromlocaltoregional.TherearemanyareasofresearchthatarebeingactivelypursuedtoaddresstheAscontaminationproblem.TheseincludenewmethodsofscreeningforAsinthefield,determiningtheepidemiologyofAsinhumans,andidentifyingtheriskofAsuptakeinagriculture.RemediationofAs-affectedwatersuppliesisimportantandresea

3、rchincludesassessingnaturalremediationpotentialaswellasphytoremediation.AnotherareaofactiveresearchisonthemicrobiallymediatedbiogeochemicalinteractionsofAsintheenvironment.In2005,aconferencewasconvenedtobringtogetherscientistsinvolvedinmanyofthedifferentareasofAsresearch.Inthispaper,wepresentasynthe

4、sisoftheAsissuesinthelightoflong-standingresearchandwithregardstothenewfindingspresentedatthisconference.ThiscontributionprovidesabackdroptotheissuesraisedattheconferencetogetherwithanoverviewofcontemporaryandhistoricalissuesofAscontaminationandhealthimpacts.CrownCopyright.2007PublishedbyElsevierB.V

5、.Allrightsreserved.1.IntroductionLocationandscaleofproblemArsenic(As)hasbeendetectedingroundwaterinseveralcountriesoftheworld,withconcentrationlevelsexceedingtheWHOdrinkingwaterguidelinevalueof10yg/L(WHO,2001)aswellasthenationalregulatorystandards(e.g.50yg/LinIndiaandBangladesh,Ahmedetal.,2004;Mukhe

6、rjeeetal.,2006).Arsenicingroundwaterisoftenassociatedwithgeologicsources,butinsomelocationsanthropogenicinputscanbeextremelyimportant.IngestionofgeogenicAsfromgroundwatersourcesismanifestedaschronichealthdisordersinmostoftheaffectedregionsoftheworld(BGS&DPHE,2001;Bhattacharyaetal.,2002a,b;Smedleyand

7、Kinniburgh,2002;WelchandStollenwerk,2003;Bundschuhetal.,2005;Naiduetal.,2006).InAsia,theimpactofAstoxicityisparticularlyalarming.Forexample,intheBengalBasinofBangladeshandWestBengal,India(Bhattacharyaetal.,1997,2002a,b,2004,2006a;MukherjeeandBhattacharya,2001),Asingroundwaterhasemergedasthelargesten

8、vironmentalhealthdisasterputtingatleast100millionpeopleatriskofcancerandotherAs-relateddiseases.RecentstudiesindicatetheoccurrenceofgeogenicAsintheCentralGangeticPlainsofUttarPradesh,Bihar,JharkhandandtheBrahmaputravalleyinAssam,andseveralregionsofMadhyaPradeshandChattisgarh,India(Chakrabortietal.,2

9、004;Mukherjeeetal.,2006).Duringthepastfewyears,AshasalsobeendetectedingroundwatersofthesedimentaryaquifersoftheTeraiBeltinSouthernNepal(Bhattacharyaetal.,2003;Tandukaretal.,2006),Pakistan(Nicksonetal.,2005),theRedRiverDeltaandMekongBasinofVietnamandCambodia(Bergetal.,2001,2007),raisingsevereconstrai

10、ntsonitsuseasadrinkingwaterresource.However,fewreportsareavailableontheepidemiologyandprevalenceofAsrelateddiseasesintheseareas.ArsenicisalsoreportedingroundwatersofAustralia(Smith,2005;OShea,2006;Smithetal.,2003,2006),wheretheconcentrationslevelsarewellabovethedrinkingwaterstandardof7yg/Lrecommende

11、dbytheNationalHealthandMedicalResearchCouncilandtheNaturalResourceManagementMinisterialCouncilofAustralia(NHMRC/NRMMC,2004).Inaddition,AsfromanthropogenicsourcesisalsoreportedingroundwatersofGuam(ATSDR,2002;Vukietal.,2007-thisvolume),asmallislandinWesternPacificOcean.Arsenicisalsofoundinwidelyscatte

12、redgeographicalareasintheUnitedStatesandCanadaaswellasinmanyothercountriesofLatinAmericasuchasMexico,Argentina,Bolivia,BrazilandNicaragua,wherethesourcesofAsaregeogenicaswellasanthropogenicsources(Matschullat,2000;Nordstrom,2002;Smedleyetal.,2002;2005;Barragner-Bigot,2004;Bundschuhetal.,2005;Bhattac

13、haryaetal.,2006b;Nriaguetal.,2007).FieldscreeningforarsenicFollowingthediscoveryofAsintheBengalBasin,thereisnowanurgentneedtoaddressthepublichealthimplicationsduetoexposurefromdrinkingwatersources.Inordertodothisandinitiateappropriatemitigationmeasures,thereisanurgentneedtoidentifytheAs-contaminated

14、tubewells(TW)thatsupplymostofthisdrinkingwater(ChowdhuryandJakariya,1999).ThisinvolvesscreeningofwaterinmillionsofTW,andraisingcommunityawarenessaboutthehealthproblemsrelatedtochronicAsexposurefromdrinkingwater.AnoverallriskassessmentincludingacomponentofmitigationforAscontaminationshouldbebasedonac

15、curatedeterminationofAslevelsinTWwaterusingeconomicallyviablemethodsforAsscreening.FieldtestkitsofferamorepracticaltoolthanlaboratorymeasurementswithinthetimeframeandfinancialresourcesavailableforscreeningandassessmentoftheAs-contaminatedwellsaswellastheirmonitoring.Simple,low-costmethodsforAsdeterm

16、ination,suchasthefieldtestkitshaveprovedtobemostsuitableforperformingtheTWscreeningquickly.SeveralcommercialfieldtestkitsareavailablefordeterminationofAsinTWwater(Rahmanetal.,2002;Khandaker,2004;DeshpandeandPande,2005;vanGeenetal.,2005;Steinmausetal.,2006).Fieldkitsprovidesemiquantitativeresultsandt

17、hereliabilityofseveralfieldkitsarequestionedbecauseofpooraccuracy(Rahmanetal.,2002).Thus,thereisaneedforfurtherevaluationofthescreeningresultsbythefieldkit,priortoitsrecommendationforwidescaleuseinBangladeshandelsewhereintheworld.EpidemiologyIngestionofgroundwaterwithelevatedAsconcentrationsandtheas

18、sociatedhumanhealtheffectsareprevalentinseveralregionsacrosstheworld.ArsenictoxicityandchronicarsenicosisisofanalarmingmagnitudeparticularlyinSouthAsiaandisamajorenvironmentalhealthdisaster(Chakrabortietal.,2004;Kapajetal.,2006).Arsenicisperhapstheonlyhumancarcinogenforwhichthereisadequateevidenceof

19、carcinogenicriskbybothinhalationandingestion(Centenoetal.,2002;ChenandAhsan,2004).MostoftheingestedAsisrapidlyexcretedviathekidneywithinafewdays(Tametal.,1979;Buchetetal.,1981;Vahter,1994).However,highlevelsofAsareretainedforlongerperiodsoftimeinthebone,skin,hair,andnailsofexposedhumans(Karagasetal.

20、,2000;Mandaletal.,2003).StudiesofAsspeciationintheurineofexposedhumansindicatethatthemetabolitescomprise1015%inorganicAs(iAs)andmonomethylarsonicacid(MMAV)andamajorproportion(60-80%)ofdimethylarsenicacid(DMAV)(Tametal.,1979;Vahteretal.,1995;Hopenhayn-Richetal.,1996).Recentstudieshavefoundmonomethyla

21、rsonousacid(MMAIII)anddimethylarsinousacid(DMAIII)intracequantitiesinhumanurine(Aposhianetal.,2000;DelRazoetal.,2001;Mandaletal.,2001).Ingeneral,MMAIIIismoretoxicthanAs(III)andAs(V)(viz.Petricketal.,2000,2001).AgricultureTheadverseeffectsofAsingroundwaterusedforirrigationwateroncropsandaquaticecosys

22、temsisalsoofmajorconcern.InadditiontopotentialhumanhealthimpactscausedbyingestionoffoodcontainingAs,thepotentialforreducedcropyieldduetoitsbuild-upinthesoilisanactiveareaofresearch.ThefateofAsinagriculturalsoilsisoftenlesswellstudiedcomparedtogroundwater,andingeneralhasbeenstudiedinthecontextofAsupt

23、akebydifferentplants(Huqetal.,2001,2006;Dasetal.,2004;AlRmallietal.,2005;Correlletal.,2006;Naiduetal.,2006).CropqualityandtheeffectofAsoncropqualityandyieldisbecomingamajorworldwideconcern,particularlyforricewhichformsthestapleformanySouth-Asiancountrieswheregroundwateriswidelyusedforirrigation(Meha

24、rgandRahman,2003).InarecentstudyitwasreportedthatirrigationhasincreasedinBangladeshsince1970,whilesince1980,theareaundergroundwaterirrigationforthecultivationofBororicehasincreasedbyalmostanorderofmagnitude(Harveyetal.,2005).BasedonavailableinformationonthedistributionofAsconcentrationingroundwater(

25、BGSandDPHE,2001)andtheareaundershallowtubewellirrigation(BADC,2005),Saha(2006)nestimatedthatapproximately1000metrictonsofAsiscycledwithirrigationwaterduringthedryseasonofeachyear.Riceyieldhasbeenreportedtodecreaseby10%ataconcentrationof25mg/kgAsinsoil(Xiongetal.,1987).AgreenhousestudybyAbedinetal.(2

26、002)revealedreducedyieldofalocalvarietyofrice(BR-11)irrigatedwithwaterhavingAsconcentrationsintherangeof0.2to8mg/L.TheaccumulationofAsinricefieldsoilsanditsintroductionintothefoodchainthroughuptakebythericeplantisofmajorconcern(Duxburyetal.,2003).AnthropogenicarsenicLargequantitiesofAsarereleasedint

27、otheenvironmentthroughindustrialactivities,whichcanbedispersedwidelyandassuchplayanimportantroleinthecontaminationofsoils,waters,andair(Nriagu,1989;JacksandBhattacharya,1998;Juillotetal.,1999;Matschullat,2000;PacynaandPacyna,2001).ElevatedconcentrationsofAsinsoilsoccuronlylocally,butinareasofformeri

28、ndustrialareasitmaycauseenvironmentalconcern(Nriagu,1994;Smithetal.,1998;Kabata-PendiasandPendias,2001).AlthoughmanymineralscontainAscompounds,theanthropogeniccontributiontotheenvironmentinthepastaccountedfor82,000metrictons/yearworldwide(NriaguandPacyna,1988).InorganicAscompoundssuchascalciumarsena

29、te,leadarsenate,sodiumarsenateandmanyotherswereusedbyfarmersasinsecticidespesticidesfordebarkingtrees,incattleandsheepdipstocontrolticks,fleas,liceandalsoinaquaticweedcontrol.Watersolublepreparatives,suchaschromatedcopperarsenate(CCA)andotherAs-basedchemicalsusedaswoodpreservativesduringthepasthavel

30、eadtowidespreadmetalcontaminationinsoilsaroundthewoodpreservationfacilities(Bhattacharyaetal.,2002c).However,theuseofinorganicAscompoundsinagriculturehasgraduallydisappearedsincethe1960sduetogreaterunderstandingofAstoxicityandawarenessregardingfoodsafetyandenvironmentalcontamination(Vaughan,1993;San

31、oketal.,1995;Smithetal.,1998).Inaddition,duringmanufacturingofAs-containingpesticidesandherbicides,releaseofwasteandAs-ladenliquidsnearthemanufacturingareasmaycontaminatesoilandwaterbodies(Mahimairajaetal.,2005).Thereareseveral“hotspots”aroundtheswOrlhavhveryhighconcentrationsofAscausedbynaturalgeoc

32、hemicalenrichmentandlong-lastingoreminingandprocessing.Forexample,inPoland,minespoils,slagdumpsandtailings,thatremainedintheareasofAsmanufacturingandindustrialprocesses,alsocontainextremelyhighconcentrationsofAs(Karczewskametal.,2004,2005).ThereisawidespreadconcernregardingbioavailabilityofAsinthete

33、rrestrialenvironmentinindustrializedregionsoftheworld.ThemajorityofincidencesofsoilAspollutioncouldbetracedbacktoaperiodpriortoextensivestatutorycontrolsoverAsemissions(Mehargetal.,1994).Forexample,Englandwasoneofthecradlesoftheindustrialrevolutioninthe19thcenturythathasleftbehindanextensivelegacyof

34、As-contaminatedsites.AspartoftheLandOceanInteractionStudy(LOIS)theAsconcentrationsintheriversofnortheasternEnglandrevealAsenrichmentwithintheurbanandindustriallyaffectedrivers(NealandRobson,2000;NealandDavies,2003).ThestudyrevealedthattheconcentrationofdissolvedAsintheruralareasaveragedbetween0.6and

35、0.9mg/L,whilefortheriversinfluencedbyindustrialdischargestheaveragebetween3.2and5.6mg/L,whilesuspendedparticulateAsismuchlower(average0.1to0.2mg/Lfortheruraland0.2to0.8mg/Lfortheindustrialrivers).However,fortheindustrializedriversdissolvedAsconcentrationscanbeashighas25.6mg/L.Thepossiblemobilization

36、ofAsinthesoils,andsubsequentleachingintogroundorsurfacewaterorentryintothehumanfoodchain,shouldalwaysbeconsideredasaserioushazard.DetailedinvestigationsarethereforenecessarytoestimatethetotalconcentrationsofAsinsoilsinsuchareas,itschemicalfractionation,andpotentialsolubilitytoevaluatethepotentialris

37、ksfromAsmobilization.MicrobialtransformationsofarsenicMobilizationofAsinnaturalecosystemsispredominantlydrivenbymicrobiallymediatedbiogeochemicalinteractions.MicrobialreductionofAs(V)tothemoretoxicandmobileAs(III)speciesoccursviadetoxification(Cervantesetal.,1994)orrespirationprocesses(Ahmannetal.,1

38、994).ThegenesthatencodetheproteinsinvolvedinAsresistanceareeitherplasmidorchromosomallyborne,andhavebeenbeststudiedinEscherichiacoli.PlasmidR773comprisesoffivegenesarsRDABCorganizedinanoperon(Chenetal.,1986).ThearsCgeneencodestheAs(V)-reductase;arsAandarsBactastheAs(III)effluxpumps;arsRandarsDregula

39、tethearsoperon.OnlyahandfulofmicroorganismscapableofrespiringAs(V)havebeenisolated(OremlandandStolz,2003).TheAs(V)-reductasegenes(arrAandarrB)involvedinAs(V)reductionhavebeenidentifiedinanumberofbacteria,andtheysharehighsequenceidentities(SantiniandStolz,2004).TheAs(V)-respiringmicroorganismscanused

40、ifferentelectrondonors(e.g.acetate,hydrogen),andrangefrommesophilestoextremophiles(OremlandandStolz,2003).TheselaboratorystudiesindicatethatmicrobialprocessesinvolvedinAs(V)reductionandmobilizationismanytimesfasterthaninorganicchemicaltransformations(Ahmannetal.,1997;Jonesetal.,2000).Thishasledresea

41、rcherstoconcludethatthesemicroorganismsplayanimportantroleinAscyclinginthesub-surface(Ahmannetal.,1997;Jonesetal.,2000;Islametal.,2004).RemediationSeveraltechnologiesarecurrentlyavailableforAsremoval,rangingfromsimpleandeffectivecoagulation-flocculation,tosophisticatedtechnologiessuchasionexchangean

42、dreverseosmosis(NaiduandBhattacharya,2006).Inaddition,low-costremediationmethods,suchasauto-attenuationandtheuseofgeologicalmaterialasnaturalsorbentsforAs(e.g.laterite,bauxsols,naturalredearthorFe-richoxisols)haveemergedaspossiblealternativesfortheremovalofAsfromgroundwaterinthedevelopingworld(Gen?F

43、uhrmanetal.,2004,2005;NaiduandBhattacharya,2006;Vithanageetal.,2006),butthereisapressingneedtodevelopthesemethodsfurtherandinacost-effectiveway.TheconceptofphytoremediationofAs-contaminatedsiteswasproposedovertwentyyearsago(Chaney,1983).PhytoremediationhasanadvantageoverconventionalremediationofAs-c

44、ontaminatedsoilsthatincludeburialandchemicalstabilization,whichmayposelong-termhealththreatsduetoleakageorchemicalinstability(Allen,2001;FostnerandHaase,1998).Thusphytoremediationhasthepotentialtobecomeanenvironmentallyfriendlyandlow-costalternativeremediationtechnique.Itiswelldocumentedthatsometrop

45、icalandsub-tropicalplantspeciescantolerateanduptakevariousinorganicandorganicformsofAs(MehargandHartley-Whitaker,2002).MesquiteisamplantthatgrowswellinhumidanddesertenvironmentsthathasbeenshowntoabsorbCr(VI)andothermetalssuchasPb(Aldrichetal.,2004).X-rayabsorptionspectroscopic(XAS)studiesrevealedtha

46、tmesquitecanbioreduceCr(VI)tothelesstoxicCr(III)(Aldrichetal.,2003).However,asignificantgapofinformationexistsontheabilityofdesertplantspeciestouptakeAsorothertoxicelements.CurrentresearchResearchonAsiscurrentlyveryactiveandincludesassessmentofinteractionsatscalesrangingfrommolecularbondingtosub-con

47、tinental,Asspeciationininorganicandorganicmaterialsthroughawidevarietyofchemicalandspectroscopicapproaches,andanemergingunderstandingoftheroleofmicrobesandotherbiotainAscycling.ArecentreviewonhealthimpactsofAsresultedindrinkingwaterstandardsof10yg/Lorevenlowerinsomecountries(Kapajetal.,2006).Theselo

48、weredstandardsareprojectedtogreatlyincreasewatersupplycostsinmanyregions.Theincreasedpressureonsocietytoprotecthumanhealthandtheecosystemhasstimulatedresearchusingawidemultitudeofapproachesandtechniques(Naiduetal.,2006;Bhattacharyaetal.,2007).ConsideringtheseriousnessofthisglobalAsproblem,atwo-daysy

49、mposiumwasorganizedtofacilitateathoroughdiscussiononabroadrangeofinter-disciplinaryissuesthatarerelatedtotheresearchonAsintheenvironment.TheseincludeunderstandingthenaturalandanthropogenicprocesseswhichaccelerateorcontrolhumanexposuretoAsanddifferentaspectsofremediation.Theoutlineofthesymposiumandth

50、esubsequentpublicationsaredescribedbelow.ThemeoftheSpecialSymposiumTheSpecialSymposium(SYP-4)“ArsenicintheEnvironment:BiologyandChemistry”wasorganizedaspartofthe8thInternationalConferenceonBiogeochemistryofTraceElements(ICOBTE)inAdelaide,AustraliaduringApril2005.ThisSpecialSymposiumattractedawideran

51、geofcontributionsfromalargenumberofmultidisciplinaryAsresearchers,thatcoveredmajorthemes,suchas:1)sourcesandcharacterizationofAsingroundwaterenvironment;2)processesthatcontrolmobilityandspeciationofAsinsoil,waterandbiota;3)predictionofthefateofAsinnaturalenvironmentsinresponsetogeochemical,hydrologi

52、c,andbiologicchanges;4)analyticaltechniquesandspeciationstudies;5)remediationandmanagementofAs-contaminatedsoilsandgroundwater;and6)impactofAsonagricultureandwatersupplymanagement.Thearticlesincludedinthisspecialissueaddressmanyoftheseissuesandpavethewaythroughrecentfindingsontheenvironmentalbehavio

53、urofAsintermsofitsoccurrence,sources,healthimpacts,andremediation.BesidesunderstandingthefundamentalprocessesofAsmobilization,thearticlesdiscussawidevarietyofchemicalandspectroscopicapproaches,andincreasedunderstandingoftheimportanceofmicrobesandotherbiotainAscycling.AlthoughmuchhasbeenlearnedaboutA

54、sintheenvironmenttheabilitytopredicttheimpactofintentionalandunintentionalchangestohydrologicandgeochemicalregimesoftenremainselusive.KeyresearchcontributionsfromseveralinternationalteamsofscientistsworkingonAsintheenvironment,groundwaterintheBengalDeltaPlainandelsewhereintheworldwerepresentedanddis

55、cussedduringthesymposiumandareamalgamatedinthisSpecialIssueofTheScienceoftheTotalEnvironment.LayoutandsummaryofthearticlesThisspecialissuecomprises14articlesand1shortcommunication,groupedintofoursections.1)Arsenicinthegroundwaterenvironment;2)arsenicinagriculturalsoilsandminingenvironment;3)biogeoch

56、emistryofAsandtoxicity,and4)remediationofAscontaminatedsoilsandsediments.ArsenicinthegroundwaterenvironmentThissectionhasfivearticles.ThefirsttwocontributionsdealwiththespecificissuesrelatedtotheoccurrenceofgeogenicAsinthealluvialaquifersofBangladesh.Thefirstpaper(vonBromssenetal.,2007-thisvolume)ta

57、rgetslow-arsenicaquifersinareaswithhighconcentrationsofgeogenicAsingroundwaterwithacasestudyfromMatlabUpazilainSoutheasternBangladesh.Thelocaldrillersareconstructingdeepertubewellsthanintherecentpast(60minsteadof30m),primarilybecauseoflowconcentrationsofdissolvedFeandAs(vonBromssenetal.,2005;Jakariy

58、aetal.,2007).Thepaperdiscussestherelationbetweenthecolourofthesedimentsandgroundwaterredoxconditions.ThisstudyrevealedthatthesedimentcolourisareliableindicatorofhighandlowAsconcentrationsthatcanbeusedbylocaldrillerstotargetlow-Asgroundwater.ThepresenceofAscontaminationofshallowfluvio-deltaicaquifers

59、intheBengalBasinhasalsoresultedinincreasingexploitationofgroundwaterfromdeeperaquifersthatgenerallycontainlowconcentrationsofdissolvedAs(Stollenwerk,2003).However,infiltrationofhigh-AsgroundwaterinducedbyincreasedpumpingoftheseaquifersclearlyindicatethepossiblerisksforanincreaseinAsconcentrations.Th

60、efollowingpaper(Stollenwerketal.,2007-thisvolume)presentsastudyontheinvestigationoftheadsorptioncapacityforAsofsedimentfromalow-AsaquifernearDhaka,Bangladesh.Atthissiteashallow,chemicallyreducedaquiferwith900yg/LAsoverliesamoreoxidizedaquiferwithb5yg/LAs.Sincenothicklayerofclaywaspresentatthesitetoi