地下水污染外文翻译文献.docx

地下水污染外文翻译文献.docx

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地下水污染外文翻译文献

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:

BiologyandChemistry

Abstract：

Arsenic（As）distributionandtoxicologyintheenvironmentisaseriousissue,withmillionsofindividualsworldwidebeingaffectedbyAstoxicosis.SourcesofAscontaminationarebothnaturalandanthropogenicandthescaleofcontaminationrangesfromlocaltoregional.TherearemanyareasofresearchthatarebeingactivelypursuedtoaddresstheAscontaminationproblem.TheseincludenewmethodsofscreeningforAsinthefield,determiningtheepidemiologyofAsinhumans,andidentifyingtheriskofAsuptakeinagriculture.RemediationofAs-affectedwatersuppliesisimportantandresearchincludesassessingnaturalremediationpotentialaswellasphytoremediation.AnotherareaofactiveresearchisonthemicrobiallymediatedbiogeochemicalinteractionsofAsintheenvironment.

In2005,aconferencewasconvenedtobringtogetherscientistsinvolvedinmanyofthedifferentareasofAsresearch.Inthispaper,wepresentasynthesisoftheAsissuesinthelightoflong-standingresearchandwithregardstothenewfindingspresentedatthisconference.ThiscontributionprovidesabackdroptotheissuesraisedattheconferencetogetherwithanoverviewofcontemporaryandhistoricalissuesofAscontaminationandhealthimpacts.CrownCopyright.2007PublishedbyElsevierB.V.Allrightsreserved.

1.Introduction

1.1.Locationandscaleofproblem

Arsenic（As）hasbeendetectedingroundwaterinseveralcountriesoftheworld,withconcentrationlevelsexceedingtheWHOdrinkingwaterguidelinevalueof10μg/L（WHO,2001）aswellasthenationalregulatorystandards（e.g.50μg/LinIndiaandBangladesh,Ahmedetal.,2004;Mukherjeeetal.,2006）.Arsenicingroundwaterisoftenassociatedwithgeologicsources,butinsomelocationsanthropogenicinputscanbeextremelyimportant.IngestionofgeogenicAsfromgroundwatersourcesismanifestedaschronichealthdisordersinmostoftheaffectedregionsoftheworld（BGS&DPHE,2001;Bhattacharyaetal.,2002a,b;SmedleyandKinniburgh,2002;WelchandStollenwerk,2003;Bundschuhetal.,2005;Naiduetal.,2006）.InAsia,theimpactofAstoxicityisparticularlyalarming.Forexample,intheBengalBasinofBangladeshandWestBengal,India（Bhattacharyaetal.,1997,2002a,b,2004,2006a;MukherjeeandBhattacharya,2001）,Asingroundwaterhasemergedasthelargestenvironmentalhealthdisasterputtingatleast100millionpeopleatriskofcancerandotherAs-relateddiseases.RecentstudiesindicatetheoccurrenceofgeogenicAsintheCentralGangeticPlainsofUttarPradesh,Bihar,JharkhandandtheBrahmaputravalleyinAssam,andseveralregionsofMadhyaPradeshandChattisgarh,India（Chakrabortietal.,2004;Mukherjeeetal.,2006）.Duringthepastfewyears,AshasalsobeendetectedingroundwatersofthesedimentaryaquifersoftheTeraiBeltinSouthernNepal（Bhattacharyaetal.,2003;Tandukaretal.,2006）,Pakistan（Nicksonetal.,2005）,theRedRiverDeltaandMekongBasinofVietnamandCambodia（Bergetal.,2001,2007）,raisingsevereconstraintsonitsuseasadrinkingwaterresource.However,fewreportsareavailableontheepidemiologyandprevalenceofAsrelateddiseasesintheseareas.ArsenicisalsoreportedingroundwatersofAustralia（Smith,2005;O'Shea,2006;Smithetal.,2003,2006）,wheretheconcentrationslevelsarewellabovethedrinkingwaterstandardof7μg/LrecommendedbytheNationalHealthandMedicalResearchCouncilandtheNaturalResourceManagementMinisterialCouncilofAustralia（NHMRC/NRMMC,2004）.Inaddition,AsfromanthropogenicsourcesisalsoreportedingroundwatersofGuam（ATSDR,2002;Vukietal.,2007-thisvolume）,asmallislandinWesternPacificOcean.ArsenicisalsofoundinwidelyscatteredgeographicalareasintheUnitedStatesandCanadaaswellasinmanyothercountriesofLatinAmericasuchasMexico,Argentina,Bolivia,BrazilandNicaragua,wherethesourcesofAsaregeogenicaswellasanthropogenicsources（Matschullat,2000;Nordstrom,2002;Smedleyetal.,2002;2005;Barragner-Bigot,2004;Bundschuhetal.,2005;Bhattacharyaetal.,2006b;Nriaguetal.,2007）.

1.2.Fieldscreeningforarsenic

FollowingthediscoveryofAsintheBengalBasin,thereisnowanurgentneedtoaddressthepublichealthimplicationsduetoexposurefromdrinkingwatersources.Inordertodothisandinitiateappropriatemitigationmeasures,thereisanurgentneedtoidentifytheAs-contaminatedtubewells（TW）thatsupplymostofthisdrinkingwater（ChowdhuryandJakariya,1999）.ThisinvolvesscreeningofwaterinmillionsofTW,andraisingcommunityawarenessaboutthehealthproblemsrelatedtochronicAsexposurefromdrinkingwater.AnoverallriskassessmentincludingacomponentofmitigationforAscontaminationshouldbebasedonaccuratedeterminationofAslevelsinTWwaterusingeconomicallyviablemethodsforAsscreening.FieldtestkitsofferamorepracticaltoolthanlaboratorymeasurementswithinthetimeframeandfinancialresourcesavailableforscreeningandassessmentoftheAs-contaminatedwellsaswellastheirmonitoring.Simple,low-costmethodsforAsdetermination,suchasthefieldtestkitshaveprovedtobemostsuitableforperformingtheTWscreeningquickly.SeveralcommercialfieldtestkitsareavailablefordeterminationofAsinTWwater（Rahmanetal.,2002;Khandaker,2004;DeshpandeandPande,2005;vanGeenetal.,2005;Steinmausetal.,2006）.Fieldkitsprovidesemiquantitativeresultsandthereliabilityofseveralfieldkitsarequestionedbecauseofpooraccuracy（Rahmanetal.,2002）.Thus,thereisaneedforfurtherevaluationofthescreeningresultsbythefieldkit,priortoitsrecommendationforwidescaleuseinBangladeshandelsewhereintheworld.

1.3.Epidemiology

IngestionofgroundwaterwithelevatedAsconcentrationsandtheassociatedhumanhealtheffectsareprevalentinseveralregionsacrosstheworld.ArsenictoxicityandchronicarsenicosisisofanalarmingmagnitudeparticularlyinSouthAsiaandisamajorenvironmentalhealthdisaster（Chakrabortietal.,2004;

Kapajetal.,2006）.Arsenicisperhapstheonlyhumancarcinogenforwhichthereisadequateevidenceofcarcinogenicriskbybothinhalationandingestion（Centenoetal.,2002;ChenandAhsan,2004）.MostoftheingestedAsisrapidlyexcretedviathekidneywithinafewdays（Tametal.,1979;Buchetetal.,1981;Vahter,1994）.However,highlevelsofAsareretainedforlongerperiodsoftimeinthebone,skin,hair,andnailsofexposedhumans（Karagasetal.,2000;Mandaletal.,2003）.StudiesofAsspeciationintheurineofexposedhumansindicatethatthemetabolitescomprise10–15%inorganicAs（iAs）andmonomethylarsonicacid（MMAV）andamajorproportion（60–80%）ofdimethylarsenicacid（DMAV）（Tametal.,1979;Vahteretal.,1995;Hopenhayn-Richetal.,1996）.Recentstudieshavefoundmonomethylarsonousacid（MMAIII）anddimethylarsinousacid（DMAIII）intracequantitiesinhumanurine（Aposhianetal.,2000;DelRazoetal.,2001;Mandaletal.,2001）.Ingeneral,MMAIIIismoretoxicthanAs（III）andAs（V）（viz.Petricketal.,2000,2001）.

1.4.Agriculture

TheadverseeffectsofAsingroundwaterusedforirrigationwateroncropsandaquaticecosystemsisalsoofmajorconcern.InadditiontopotentialhumanhealthimpactscausedbyingestionoffoodcontainingAs,thepotentialforreducedcropyieldduetoitsbuild-upinthesoilisanactiveareaofresearch.ThefateofAsinagriculturalsoilsisoftenlesswellstudiedcomparedtogroundwater,andingeneralhasbeenstudiedinthecontextofAsuptakebydifferentplants（Huqetal.,2001,2006;Dasetal.,2004;AlRmallietal.,2005;Correlletal.,2006;Naiduetal.,2006）.CropqualityandtheeffectofAsoncropqualityandyieldisbecomingamajorworldwideconcern,particularlyforricewhichformsthestapleformanySouth-Asiancountrieswheregroundwateriswidelyusedforirrigation（MehargandRahman,2003）.InarecentstudyitwasreportedthatirrigationhasincreasedinBangladeshsince1970,whilesince1980,theareaundergroundwaterirrigationforthecultivationofBororicehasincreasedbyalmostanorderofmagnitude（Harveyetal.,2005）.BasedonavailableinformationonthedistributionofAsconcentrationingroundwater（BGSandDPHE,2001）andtheareaundershallowtubewellirrigation（BADC,2005）,Saha（2006）nestimatedthatapproximately1000metrictonsofAsiscycledwithirrigationwaterduringthedryseasonofeachyear.Riceyieldhasbeenreportedtodecreaseby10%ataconcentrationof25mg/kgAsinsoil（Xiongetal.,1987）.AgreenhousestudybyAbedinetal.（2002）revealedreducedyieldofalocalvarietyofrice（BR-11）irrigatedwithwaterhavingAsconcentrationsintherangeof0.2to8mg/L.TheaccumulationofAsinricefieldsoilsanditsintroductionintothefoodchainthroughuptakebythericeplantisofmajorconcern（Duxburyetal.,2003）.

1.5.Anthropogenicarsenic

LargequantitiesofAsarereleasedintotheenvironmentthroughindustrialactivities,whichcanbedispersedwidelyandassuchplayanimportantroleinthecontaminationofsoils,waters,andair（Nriagu,

1989;JacksandBhattacharya,1998;Juillotetal.,1999;Matschullat,2000;PacynaandPacyna,2001）.ElevatedconcentrationsofAsinsoilsoccuronlylocally,butinareasofformerindustrialareasitmaycauseenvironmentalconcern（Nriagu,1994;Smithetal.,1998;Kabata-PendiasandPendias,2001）.AlthoughmanymineralscontainAscompounds,theanthropogeniccontributiontotheenvironmentinthepastaccountedfor82,000metrictons/yearworldwide（NriaguandPacyna,1988）.Inorgan