电子垃圾的健康负担：电子垃圾倾倒场对儿童死亡率的影响

StefaniaLovoandSamanthaRawlings Abstract E-wasteisoneofthefastestgrowingglobalwastestreams,andisfrequentlyshippedtopoorernationsille-gally,leadingtocontaminationoflocalenvironments.Theimpactofe-wastedumpingsitesonneonatalandinfantmortalityisinvestigated,focusingontwomajordumpsitesinGhanaandNigeria.Usingadifference-in-differencesapproach,outcomesarecomparedforchildrenbornnearandfarfromdumpsitesbeforeandaftertheircreation.E-wastesitesincreaseneonatalandinfantmortalityforthoselivingclosertosites.Eventstudiessuggestthateffectsemergetwotothreeyearsaftersiteopenings,consistentwithgradualandsystematicaccumulationofcontaminantsintheenvironment.Thereissuggestiveevidencethatcontaminationofwaterandofurbanfarmingproduceareamongthedriversoftheobservedeffects. JELclassification:I10,Q53,Q56,O10 Keywords:e-waste,health,infantmortality,dumpingsites,WestAfrica 1.Introduction E-wastereferstowastemadeupofelectricalandelectronicequipment(EEE),andisclassifiedashazardouswaste,duetothepresenceoftoxicmaterialsinmanyelectricalcomponents(Bakhiyietal.2018).Itisoneofthefastestgrowingwastestreams,with62millionmetrictonsofe-wastegeneratedgloballyin2022,estimatedtoriseto82millionmetrictonsby2030(Baldéetal.2024).E-wasteindevelopingcountriesoriginatesbothfromdomesticandinternationalsources.Internation- ally,avastshareofe-wasteimportscomprisesworkingorrepairableelectronicequipmentthatcon-sumerssoondiscard,becausealthoughoftenusable,importedsecondhandequipmenthasashortlifespan(Heacocketal.2016;Davis,Akese,andGarb2019).Indeed,many e-wastedumpingsitesorigi-natefromorareintheproximityofsecondhandmarkets(Manhartetal.2011).Evidencealsoindicatestheexistenceofanon-negligibleinternationalflowofe-wastethatentersdevelopingcountriesillegally(Kellenberg2010).Asignificantshareoftheinternationalflowisalsogeneratedwithinregionsratherthan StefaniaLovoisanassociateprofessorattheDepartmentofEconomics,UniversityofReading,Whiteknights,ReadingRG66AA.Heremailaddressiss.lovo@reading.ac.uk.SamanthaRawlings(correspondingauthor)isanassociatepro-fessorattheDepartmentofEconomics,UniversityofReading,Whiteknights,ReadingRG66AA.Heremailaddressiss.b.rawlings@reading.ac.uk.Theauthorsthanktheeditor,EricEdmonds,forhishelpfulcommentsonthepaper,andSoniaBhalotraandJorgeGarciaHombradosforvaluablediscussionandfeedback.TheauthorsalsothankseminarparticipantsattheUniversityofReading,theUniversityofBristol,the2021RESConference,the2021BREADconferenceontheeconomicsofAfricaandthe2021CREBAppliedDevelopmentEconomicsConference.AsupplementaryonlineappendixforthisarticlecanbefoundatTheWorldBankEconomicReviewwebsite. transferredbetweenregions(LepawskyandMcNabb2010).WithinWestAfrica,GhanaandNigeriaserveasthemaintradehubsforbothregionalandinternationaltradeinused-EEEande-waste(Schluepetal.2011),whichprimarilycomefromEurope(Baldéetal.2022). E-wasteisfrequentlyinappropriatelytransported,stored,ordisposedof(MaphosaandMaphosa2020).Itcontainssignificantamountsofpreciousmetalsandothervaluablematerials,resultinginamarketforsalvage,whichinmanycountriesisperformedbyinformalsectorworkers.Thestrippingofcomponentsisdonemanually,andunwantedcomponentsareburnedordiscardedinopendumpsites(Kellenberg2010).Themismanagedtreatmentanddisposalofe-wastecanleadtothereleaseofupto1,000differentchemicalcompoundsintotheenvironment,whicharenotbiodegradableandposesig-nificanthealthrisks(Widmeretal.2005).Theseincludepersistentorganicpollutants(POPs)withlonghalf-lives,brominatedflameretardants,andheavymetalsthatareknowntohavedevelopmentaleffectsonchildren,suchaslead,cadmium,arsenic,andmercury(Chenetal.2010;Grantetal.2013). Thispaperinvestigateshowexposuretothetwomajore-wastesitesinGhanaandNigeriahaveim-pactedinfantandneonatalmortality,employingadifference-in-differencesapproach.Childrenareespe-ciallyvulnerabletopollutantsduetophysiologicaldifferencesfromadults,includinghigherintakesofair,water,andfoodperbodyweight,andalessenedabilitytoeliminatetoxins,particularlyamongstinfants(Pronczuk-Garbinoetal.2007).Theyarealsosubjecttoadditionalexposurerouteslikebreastfeedingandthroughtheplacenta,aswellasbehaviorssuchasfrequenthand-to-mouthactivities(Grantetal.2013).1 Thispaperexploitshouseholds’distancetothedumpingsitetodefineintensityofexposuretopollutionatbirthorinthewomb.Theidentificationstrategyreliesonthecomparisonofchildrenbornbeforeandaftertheexistenceofthedumpsite,anddistancefromthedumpsite.Tomitigateconcernsaboutpotentialdump-inducedin-migration,thepaperfocusesonnon-migranthouseholdsandcomparessiblingsbornbeforeandafterthecreationofthedump.Thisanalysis,however,islimitedtoGhanaonlyduetolimitedmigrationinformationforNigeria,andmightleadtoanunderestimationofthetreatmenteffectsife-wasteaffectstheprobabilityofsuccessfulpregnancies.Theanalysiscannotruleoutthepotentialbiasinducedbyout-migration,andthedirectionofthisbiasremainsambiguous.Nonetheless,thelimitedevidenceofchangesinparentalcharacteristicsbeforeandafterthecreationofthesitesprovidessomereassurance,thoughthisconcerncannotbeentirelydismissed.Thestudyfindslargeandstatis