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外文文献ARSENICINTHEENVIRONMENTBIOLOGYANDCHEMISTRYABSTRACTARSENICASDISTRIBUTIONANDTOXICOLOGYINTHEENVIRONMENTISASERIOUSISSUE,WITHMILLIONSOFINDIVIDUALSWORLDWIDEBEINGAFFECTEDBYASTOXICOSISSOURCESOFASCONTAMINATIONAREBOTHNATURALANDANTHROPOGENICANDTHESCALEOFCONTAMINATIONRANGESFROMLOCALTOREGIONALTHEREAREMANYAREASOFRESEARCHTHATAREBEINGACTIVELYPURSUEDTOADDRESSTHEASCONTAMINATIONPROBLEMTHESEINCLUDENEWMETHODSOFSCREENINGFORASINTHEFIELD,DETERMININGTHEEPIDEMIOLOGYOFASINHUMANS,ANDIDENTIFYINGTHERISKOFASUPTAKEINAGRICULTUREREMEDIATIONOFASAFFECTEDWATERSUPPLIESISIMPORTANTANDRESEARCHINCLUDESASSESSINGNATURALREMEDIATIONPOTENTIALASWELLASPHYTOREMEDIATIONANOTHERAREAOFACTIVERESEARCHISONTHEMICROBIALLYMEDIATEDBIOGEOCHEMICALINTERACTIONSOFASINTHEENVIRONMENTIN2005,ACONFERENCEWASCONVENEDTOBRINGTOGETHERSCIENTISTSINVOLVEDINMANYOFTHEDIFFERENTAREASOFASRESEARCHINTHISPAPER,WEPRESENTASYNTHESISOFTHEASISSUESINTHELIGHTOFLONGSTANDINGRESEARCHANDWITHREGARDSTOTHENEWFINDINGSPRESENTEDATTHISCONFERENCETHISCONTRIBUTIONPROVIDESABACKDROPTOTHEISSUESRAISEDATTHECONFERENCETOGETHERWITHANOVERVIEWOFCONTEMPORARYANDHISTORICALISSUESOFASCONTAMINATIONANDHEALTHIMPACTSCROWNCOPYRIGHT2007PUBLISHEDBYELSEVIERBVALLRIGHTSRESERVED1INTRODUCTION11LOCATIONANDSCALEOFPROBLEMARSENICASHASBEENDETECTEDINGROUNDWATERINSEVERALCOUNTRIESOFTHEWORLD,WITHCONCENTRATIONLEVELSEXCEEDINGTHEWHODRINKINGWATERGUIDELINEVALUEOF10G/LWHO,2001ASWELLASTHENATIONALREGULATORYSTANDARDSEG50G/LININDIAANDBANGLADESH,AHMEDETAL,2004MUKHERJEEETAL,2006ARSENICINGROUNDWATERISOFTENASSOCIATEDWITHGEOLOGICSOURCES,BUTINSOMELOCATIONSANTHROPOGENICINPUTSCANBEEXTREMELYIMPORTANTINGESTIONOFGEOGENICASFROMGROUNDWATERSOURCESISMANIFESTEDASCHRONICHEALTHDISORDERSINMOSTOFTHEAFFECTEDREGIONSOFTHEWORLDBGSBHATTACHARYAETAL,2002A,BSMEDLEYANDKINNIBURGH,2002WELCHANDSTOLLENWERK,2003BUNDSCHUHETAL,2005NAIDUETAL,2006INASIA,THEIMPACTOFASTOXICITYISPARTICULARLYALARMINGFOREXAMPLE,INTHEBENGALBASINOFBANGLADESHANDWESTBENGAL,INDIABHATTACHARYAETAL,1997,2002A,B,2004,2006AMUKHERJEEANDBHATTACHARYA,2001,ASINGROUNDWATERHASEMERGEDASTHELARGESTENVIRONMENTALHEALTHDISASTERPUTTINGATLEAST100MILLIONPEOPLEATRISKOFCANCERANDOTHERASRELATEDDISEASESRECENTSTUDIESINDICATETHEOCCURRENCEOFGEOGENICASINTHECENTRALGANGETICPLAINSOFUTTARPRADESH,BIHAR,JHARKHANDANDTHEBRAHMAPUTRAVALLEYINASSAM,ANDSEVERALREGIONSOFMADHYAPRADESHANDCHATTISGARH,INDIACHAKRABORTIETAL,2004MUKHERJEEETAL,2006DURINGTHEPASTFEWYEARS,ASHASALSOBEENDETECTEDINGROUNDWATERSOFTHESEDIMENTARYAQUIFERSOFTHETERAIBELTINSOUTHERNNEPALBHATTACHARYAETAL,2003TANDUKARETAL,2006,PAKISTANNICKSONETAL,2005,THEREDRIVERDELTAANDMEKONGBASINOFVIETNAMANDCAMBODIABERGETAL,2001,2007,RAISINGSEVERECONSTRAINTSONITSUSEASADRINKINGWATERRESOURCEHOWEVER,FEWREPORTSAREAVAILABLEONTHEEPIDEMIOLOGYANDPREVALENCEOFASRELATEDDISEASESINTHESEAREASARSENICISALSOREPORTEDINGROUNDWATERSOFAUSTRALIASMITH,2005OSHEA,2006SMITHETAL,2003,2006,WHERETHECONCENTRATIONSLEVELSAREWELLABOVETHEDRINKINGWATERSTANDARDOF7G/LRECOMMENDEDBYTHENATIONALHEALTHANDMEDICALRESEARCHCOUNCILANDTHENATURALRESOURCEMANAGEMENTMINISTERIALCOUNCILOFAUSTRALIANHMRC/NRMMC,2004INADDITION,ASFROMANTHROPOGENICSOURCESISALSOREPORTEDINGROUNDWATERSOFGUAMATSDR,2002VUKIETAL,2007THISVOLUME,ASMALLISLANDINWESTERNPACIFICOCEANARSENICISALSOFOUNDINWIDELYSCATTEREDGEOGRAPHICALAREASINTHEUNITEDSTATESANDCANADAASWELLASINMANYOTHERCOUNTRIESOFLATINAMERICASUCHASMEXICO,ARGENTINA,BOLIVIA,BRAZILANDNICARAGUA,WHERETHESOURCESOFASAREGEOGENICASWELLASANTHROPOGENICSOURCESMATSCHULLAT,2000NORDSTROM,2002SMEDLEYETAL,20022005BARRAGNERBIGOT,2004BUNDSCHUHETAL,2005BHATTACHARYAETAL,2006BNRIAGUETAL,200712FIELDSCREENINGFORARSENICFOLLOWINGTHEDISCOVERYOFASINTHEBENGALBASIN,THEREISNOWANURGENTNEEDTOADDRESSTHEPUBLICHEALTHIMPLICATIONSDUETOEXPOSUREFROMDRINKINGWATERSOURCESINORDERTODOTHISANDINITIATEAPPROPRIATEMITIGATIONMEASURES,THEREISANURGENTNEEDTOIDENTIFYTHEASCONTAMINATEDTUBEWELLSTWTHATSUPPLYMOSTOFTHISDRINKINGWATERCHOWDHURYANDJAKARIYA,1999THISINVOLVESSCREENINGOFWATERINMILLIONSOFTW,ANDRAISINGCOMMUNITYAWARENESSABOUTTHEHEALTHPROBLEMSRELATEDTOCHRONICASEXPOSUREFROMDRINKINGWATERANOVERALLRISKASSESSMENTINCLUDINGACOMPONENTOFMITIGATIONFORASCONTAMINATIONSHOULDBEBASEDONACCURATEDETERMINATIONOFASLEVELSINTWWATERUSINGECONOMICALLYVIABLEMETHODSFORASSCREENINGFIELDTESTKITSOFFERAMOREPRACTICALTOOLTHANLABORATORYMEASUREMENTSWITHINTHETIMEFRAMEANDFINANCIALRESOURCESAVAILABLEFORSCREENINGANDASSESSMENTOFTHEASCONTAMINATEDWELLSASWELLASTHEIRMONITORINGSIMPLE,LOWCOSTMETHODSFORASDETERMINATION,SUCHASTHEFIELDTESTKITSHAVEPROVEDTOBEMOSTSUITABLEFORPERFORMINGTHETWSCREENINGQUICKLYSEVERALCOMMERCIALFIELDTESTKITSAREAVAILABLEFORDETERMINATIONOFASINTWWATERRAHMANETAL,2002KHANDAKER,2004DESHPANDEANDPANDE,2005VANGEENETAL,2005STEINMAUSETAL,2006FIELDKITSPROVIDESEMIQUANTITATIVERESULTSANDTHERELIABILITYOFSEVERALFIELDKITSAREQUESTIONEDBECAUSEOFPOORACCURACYRAHMANETAL,2002THUS,THEREISANEEDFORFURTHEREVALUATIONOFTHESCREENINGRESULTSBYTHEFIELDKIT,PRIORTOITSRECOMMENDATIONFORWIDESCALEUSEINBANGLADESHANDELSEWHEREINTHEWORLD13EPIDEMIOLOGYINGESTIONOFGROUNDWATERWITHELEVATEDASCONCENTRATIONSANDTHEASSOCIATEDHUMANHEALTHEFFECTSAREPREVALENTINSEVERALREGIONSACROSSTHEWO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