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meaningthe

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?2023InternationalBankforReconstructionandDevelopment/TheWorldBank

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Pleasecitetheworkasfollows:“TheWorldBank.2023.AirQualityManagementinTajikistan.?World

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3

Contents

Acknowledgments 4

ExecutiveSummary 5

SummaryReport 6

AirQualityContextinTajikistan 6

AirQualityMonitoringandPopulationExposureintheAirshedofDushanbe 7

EmissionSourcesandSourceAttribution 8

PrioritizingandFinancingEmissionReductionInterventions 11

ComprehensiveAQMPolicies:GapsandRecommendations 12

FIGURES

Figure1:AnnualAverageSurfacePM2.5ConcentrationinTajikistanfor2021 7

Figure2:SourceApportionmentofPM2.5ConcentrationinDushanbe 9

Figure3:MainStationaryPollutionSourcesandMonitoringStationsinDushanbe 10

4

Acknowledgments

ThisstudywaspreparedbyaWorldBankcoreteamledbyElenaStrukovaGolub(SeniorEnvironmentalEconomist),SusannaDedring(EnvironmentalAnalyst),KirtanChandraSahoo(SeniorClimateChangeSpecialist),SayedMujtabaShobair(EnvironmentalSpecialist),YelenaYakovleva(EnvironmentalAnalyst),VasilZlatev(Consultant),andSarathGuttikunda(Consultant).

ThereportbenefittedagreatdealfromcontributionsbyotherWorldBankstaff:FaridaMamadaslamova,AbdulBaesAkhundzada,ChrisTrimble,Chyi-YunHuang,FaridunSanginov,MarcusLee,IlyasSarsenov,BakhromZiyaev,SanaZia,andGauravJoshi,aswellasbydevelopmentpartners:UNEP(KatherineHall),WHO(VictorOlsavszkyandKalandarovSafo),andWashingtonUniversityofSt.Louis(JayTurner).TheteamisgratefultotheWorldBankpeerreviewers:HelenaNaber(SeniorEnvironmentalSpecialist),JosephAkpokodje(SeniorEnvironmentalSpecialist),andAntonioNunez(SeniorTransportSpecialist,ProgramLeader),aswellasAndreaLiverani(ActingPracticeManager)fortheirreviewandfeedback.TheteamisalsogratefulfortheextensiveguidanceandsupportfromSamehWahba(RegionalDirectorforSustainableDevelopment,EuropeandCentralAsiaRegion)OzanSevimli(CountryManagerforTajikistan)andJuliaKomagaeva(SeniorOperationsOfficer).

TheteamthanksLinhVanNguyen,GraceAguilar,FatkhiyaKhamidova,andSukhrobjonTemirov,forprojectmanagementsupport,andNigaraAbateforeditingandpublicationsupport.

TheteamextendsitsdeepgratitudetothemanygovernmentofficialsofthegovernmentoftheRepublicofTajikistanwhosupportedthisworkwiththeirknowledgeandinsightsaswellasthroughdataprovidedtotheteam.TheteamthanksthemanagementandstaffoftheCommitteeforEnvironmentalProtection,theAgencyforHydrometeorology,theMinistryofEnergyandWater,MinistryofTransport,andMinistryofHealthandSanitaryProtectionoftheGovernmentoftheRepublicofTajikistan.Theteamalsothanksthemanystakeholderswhosharedtheirknowledgeandhelpedshapethecontentsandfinalpolicyrecommendationsofthisreport.

5

ExecutiveSummary

TheAirQualityManagement(AQM)systeminTajikistanneedsstrengtheninginitskeypolicyandinstitutionalaswellastechnicalaspectstoreducehealthimpactsofairpollutioninthemostpollutedairsheds(Dushanbeandotherurbancenters).TheWorldBank'sfirstengagementtostrengthenTajikistan'sAQMaimstodevelopabetterunderstandingoftheprioritiesandneedsinaddressingairpollutionandtosupportthegovernmentofTajikistaninidentifyingkeyairpollutionreductionmeasures.ThissummaryreportandtheattachedpresentationdetailtheoutcomesofTajikistan'sfirstAQMstudy,whichisenvisionedtocontinue.

ThestudyprovidesrecommendationsforallcomponentsoftheAQMframeworkbasedonananalysisofthecurrentstatusandgaps.Itprovides:1)airquality(AQ)monitoringandpopulationexposureassessment,2)sourceattribution,3)emissions-reductioninterventions,and4)recommendationstostrengthenAQMPolicies.Thestudyprioritizesfinedustparticles(PM2.5)duetotheirsignificanthealthimpacts.

AirpollutioncausessignificanthealthandeconomiclossesinTajikistan.Inarecentassessment,theannualaveragepopulation-weightedPM2.5concentrationinTajikistanwasestimatedtobe35.93μg/m31—thehighestamongCentralAsiacountries—andabovetheEuropeanUnion(EU)limitof25μg/m3,andmuchhigherthantheWHOtargetof5μg/m3.TheattributedmortalityrateduetoPM2.5pollutionisestimatedat78deathsper100,000inhabitants,whichisthesecondhighestinCentralAsiaafterUzbekistan.2

InthecityofDushanbein2021,datacollectedfromPM2.5monitoringrepresentedannualPM2.5concentrationbetween13.8and58.1μg/m3,withpeakconcentrationsoccurringinautumnandwintermonths.Thereisalackofreliabledatatoverifytherange.PreliminaryPM2.5sourceapportionmentshowedthatthehighestcontributionscomefromwindblowndust(33percent)andresidentialheating(31percent,individualhouseholds),followedbycontributionsfromelectricpowergeneration(9percent,includingcentralheatingplants),waste(7percent),industry(4percent),andtransport(3percent).

Basedonapreliminaryassessment,investmentneedsfortheimplementationofpriorityemissionreductioninterventionsinDushanbeareestimatedat$111million.TheAQMinterventionscouldresultina13-percentreductionofPM2.5levels(averagecostestimatesarebasedonrecentstudiesperformedinKazakhstan).TheinterventionsimplementedwithinkeypollutingsectorscouldreduceattributedPM2.5levelsby20to30percentandareprioritizedbyanaverageinterventioncosttoreducetheannualaverageconcentrationofPM2.5by1μg/m3.Thelargestpollutionreduction—2μg/m3ofPM2.5concentration—couldbeachievedintheresidentialsector(throughimprovedheatinginhouseholds).Thisinterventionhastheunitcostofabout$20millionper1μg/m3ofPM2.5concentration.Itcouldreducepollutionby13percentandwouldcost$111million,reducingannualmortalityby70to100cases.SimilarassessmentscouldbeusedtoformulateasetofinterventionsforanAQimprovementroadmapinthemostpollutedairshedsofTajikistan,includingDushanbe.

Theroadmaptoestablishabaselinefordevelopingastrong,effective,andefficientAQMsystemwillbedevelopedasthenextphaseoftechnicalassistance.Itwillcompriseasetofstepstocreateasolidregulatoryandgovernancebase,aplanningsystemonthenationalandlocallevel,horizontalandverticalcoordinationprocedures,andstrongtechnicalcapacityformonitoringandevaluation.Additionally,procedureswillbedefinedfordevelopmentoflocal-levelAQactionplanstostrengthenAQM.Theactionplansshouldprioritizeemissionreductioninterventionsforthesourceswiththehighestcontributiontopollution,shoulddefineimplementationmodalitiesfortheinterventionsandensuremonitoringandevaluation,andshouldincludeappropriatefinancemechanisms.

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6

SummaryReport

Tajikistan'sAirQualityManagement(AQM)systemneedsstrengtheninginitskeypolicyandinstitutionalaswellastechnicalaspectstoreducehealthimpactsofairpollutioninthemostpollutedairsheds(Dushanbeandotherurbancenters).RecognizingtheimportanceofarobustAQM,thegovernmentofTajikistanaimstoimproveandconsolidaterelevantnationalstrategies.Thisreportprovidesapreliminaryanalysisofairqualityandidentifiesdatagaps,options,andprioritiestoimproveit.TheobjectiveoftheAQMworkistodevelopabetterunderstandingoftheprioritiesandneedsinaddressingairpollutionandtosupportthegovernmentinidentifyingkeyairpollutionreductionmeasures.ThissummaryreportandtheattachedpresentationdetailtheoutcomesofthefirstAQMengagementoftheWorldBankinTajikistan,whichisenvisionedtocontinue.

Aspartofitstechnicalassistance,theWorldBankhasprovidedrecommendationsforallcomponentsoftheAQMframeworkbasedonananalysisofthecurrentstatusandgaps.Thecomponentsare:1)AQmonitoringandpopulationexposure,2)sourceattribution,3)emissions-reductioninterventions,and4)recommendationstostrengthenAQMPolicies.Prioritypollutantsarefinedustparticles(PM2.5),coarsedustparticles(PM10),3carbonmonoxide(CO),nitrogenoxides(NOx),andsulfurdioxide(SO2).ThisstudyprioritizesPM2.5duetotheirsignificanthumanhealthimpacts.PM2.5concentrationiscomprisedofdirectlyemittedparticlesandsecondaryparticlesformedthroughatmosphericchemistryprocesses.NOxandSO2areimportantprecursorsforthesereactionsandananalysisofthetrendsofthesepollutantscanindicatepriorityemissionsources.

Toanalyzethecurrentstateofairquality,datafrommonitoringstationsinDushanbewereusedandcomplementedbyglobalmodels.AllpubliclyavailabledatafrommonitoringstationsandemissionsourceswereprovidedbytheStateCommitteeofEnvironmentalProtection(CEP).Duetolimitedavailabilityoflocaldata,globaldatasetswithafocusonDushanbecompiledthroughsatellitemeasurementswereanalyzedthroughmodelingassessmentstodeterminePM2.5concentrations,sourceattributions,andseasonaltrends.Whileglobaldatahavetheirlimitations,4theycanrevealtrendsandhelptoidentifygapsforfurtherresearchontheground.ThisstudyrepresentedthefirstcomprehensiveapplicationoftheseglobalmodelsforDushanbe.Theresultswerediscussedinstakeholderconsultations,includingCEPandthelineministries.

AirQualityContextinTajikistan

Tajikistan’srecenteconomicgrowth,whileimpressive,isnotdecoupledfromgrowingpressureonnaturalresourcesandpollution.Tajikistan’sGDPhasbeengrowingatarateof7.6percentannuallysince2000,withrentscomingfromextractionofmetalssuchasaluminum,preciousmetals,lead,andzincoresdominatingitsexportandfuelinghighgrowthratestogetherwithremittancesfromabroad.Thelivelihoodsofthepopulationaredependentonagriculture,whichisvulnerabletoenvironmentalandclimaterisks.Since2000,naturalcapitalpercapita(croplandandpastureland)hasbeendecliningpartiallyduetosoilerosion,whilecarbonintensityofenergyproductionhasincreasedsince2013duetohighenergyintensityofmanufacturing,growthofconstruction(cementproduction),andcommissioningofnewcoal-firedcentralheatingandpowerplants(CHP).Theseprocessesincreasepressureonairqualityinmajorcities.Decouplingofeconomicdevelopmentfromincreasedpressureonnaturalresourcesandintensifiedpollutionrequirestransitiontoamoreproductiveandgreenergrowthpathway,includingimprovedAQM.

Population-weightedPM2.5concentrationinTajikistanisthehighestamongCentralAsiacountriesandwellabovetheWHOguidelines,asassessedintheglobalmodels.Inarecentassessment,the

3Particulatematterwithadiameterbelow2.5μm(PM2.5)and10μm(PM10),respectively.

4Limitationsincludethecoarseresolutionoftheglobalmodel,uncertaintyininputparameters(emissionsources,meteorology)duetoalackofdata,andrepresentationofatmosphericprocessesinvolved.

7

annualaveragepopulation-weightedPM2.5concentrationinTajikistanwasestimatedat35.93μg/m3—thehighestamongCentralAsiacountries—andabovetheEUlimitof25μg/m3,5andmuchhigherthantheWHOtargetof5μg/m3.6SurfacePM2.5concentrationsaresimilarlyelevatedinthemoredenselypopulatedwestofthecountrywhileinthemountainouseasternpartofTajikistantheyarelower(seeFigure1).

AirpollutioncausessignificanthealthandeconomiclossesinTajikistan.TheattributedmortalityrateduetoPM2.5pollutionisestimatedat78deathsper100,000inhabitants—thesecondhighestrateinCentralAsiaafterUzbekistan.Overall,4,800deaths7areattributabletoambientairpollutioninTajikistan,mostlyduetoischemicheartdisease(51percent)andstroke(27percent).8Anotherairpollutantwithconsiderablehealthimpactsisozone,towhich60to230deathscanbeattributed.Thecorrespondinghealthcostsareestimatedtobe4percentofGDP.Otherimpactsofairpollutionarelossofcropyields(duetoozone)andacceleratedmeltingofglaciers(duetoblackcarbon).

Figure1:AnnualAverageSurfacePM2.5ConcentrationinTajikistanfor2021

Source:MapcreatedbyJayTurner,datafromAaronvanDonkelaar,etal.2021(surfacePM2.5globalmodelV5.GL.03)colorcodedusingWHOannualaveragePM2.5AirQualityGuideline(AQG)andInterimTargets(IT)9

AirQualityMonitoringandPopulationExposureintheAirshedof

Dushanbe

WhileTajikistan'sallmajorcitiesshowhighpollutionlevels,Dushanbewaschosenforfurtheranalysisasanairpollutionhotspotandthecitywiththelargestpopulationinthecountry(12percentoftotalnationalpopulation).Thecity'sbuiltareahasnotincreasedsignificantlyinthepast30years,yetitspopulationdensityhasdoubled,increasingthenumberofpeopleexposedtoairpollution.Themodeledairsheddomainhasanareaof1,740km2,ofwhich200km2representsthemetropolitanareawithhighpopulationdensity.10

SomegeographicalandmeteorologicalcharacteristicsofDushanbeprovideconditionsfortrappingairpollutioninthecity.DushanbeislocatedintheWestofTajikistan,surroundedbymountainsranges

5

https://environment.ec.europa.eu/topics/air/air-quality/eu-air-quality-standards_en.

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/publications/i/item/9789240034228.

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/handle/10986/36501.

8

/data-visualization/gbd-results.

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/acag/datasets/surface-pm2-5/.

10Inthisstudy,theWorldBankdefinedandanalyzedAQintheDushanbeairshed.

8

intheGissarvalley.TheriversVarzobandKofarnihonconfluenceinthecity.TheclimatezoneisMediterraneanwithhumidcontinentalinfluences.Annualaverageprecipitationis654mm,mostlyduringwinter,springandautumnmonthswithalmostnoprecipitationinsummer.Overtheyear,themostprevalentwinddirectionisfromNorth-EastandSouth-East,butwindcancomefromalldirectionsandisgenerallycharacterizedbylowwindspeeds.

Thereisnocomprehensiveairquality(AQ)monitoringsysteminTajikistananddataavailabilityisachallenge.Dataareavailableonlyfortheyears2019-2021fromoneautomaticstationlocatedatthepremisesofandoperatedbyTajikistan'sAgencyforHydrometeorology(TajikistanHydromet)undertheCommitteeofEnvironmentalProtection(CEP).Dushanbe'sfiveadditionalstationsareoperatedmanually.TheonlyotherautomaticmonitoringstationinTajikistanislocatedattheU.S.EmbassyinDushanbe.Stationsarenotdistributedcomprehensivelyacrossthecitytocapturedifferentsources(background,traffic,industry).Thisstudy'sanalysisisthefirstattempttoproduceanassessmentofairqualitylevels,emissions,andsourcesintheairshedofDushanbeusingdifferentavailableglobalmodels.Thestudy'sresultsarepreliminaryandneedtobeconfirmedwithlocaldataonpollutionlevels,emissionsources,andmeteorologicaldata,whichdidnotfallwithinthescopeforthisstudy.

TheanalysisofconcentrationsfromglobalmodelsshowsasteadyincreaseofPM2.5concentrationsfrom17.8μg/m3in1998toanannualaverageof32.7μg/m3in2021.AnnualaveragePM2.5concentrationsarehighthroughouttheairshedofDushanbewiththehighestconcentrationsestimatedintheurbancenter.Themodeledconcentrationlevelscannotbeverifiedwiththecurrentlyavailablemonitoringdata–theU.S.Embassystationshowsalmostdouble(58.1μg/m3)theconcentrationthantheglobalmodels,theHydrometstationsshowalowerannualaverageconcentration(13.8μg/m3).Thedifferencesbetweentheglobalmodelandlocalmeasurementswillbefurtherinvestigated.

Nevertheless,theU.S.EmbassyandHydrometstationsshowsimilarpatternswithregardtoseasonaldifferencesinthePM2.5concentrationswiththehighestconcentrationsoccurringintheautumnandwintermonths.StartingfromJuly,concentrationsincreaseandpeakinNovember(91.0μg/m3/28.4μg/m3).OtherpollutantshavepeaksfromJulytoOctober(PM10,NO2,NO)andduringwintermonths(SO2)orshownoseasonaltrend(CO).Whiletherearenomeasurementsavailableforozone,modeledconcentrationsofozonepeakinsummerwithconcentrations130-140μg/m3fromMaytoAugust.

Withnocomprehensiveemissioninventoryavailable,emissionsofairpollutantswereestimatedfromglobalmodelsasapartofapreliminaryassessment.Emissionsoftheairpollutants:SO2,NOX,andCO(precursorsofPM2.5)areestimatedtobehigherduringwintermonthscorrespondingtohigherPM2.5levels.Thisislikelyduetoemissionsfromcoalcombustion,especiallyforheatinginthewinter.

EmissionSourcesandSourceAttribution

PreliminarysourceapportionmentofPM2.5hasidentifiedthatthehighestcontributionscomefromwindblowndust(33percent)andresidentialheating(31percent,individualhouseholds),followedbycontributionsfromelectricpowergeneration(9percent,includingcentralheatingplants),waste(7percent),industry(4percent)andtransport(3percent).11Accordingtotheassessment,40percentofthePM2.5concentrationscanbedirectlyattributedtothecombustionoffossilfuels.Sincesourceapportionmentdataarefromamodelthatusessatellite-basedmeasurementsoftheglobaldatasetwithacoarsegridresolution,theyneedtobevalidatedbyfurtherground-levelmeasurementsandlocalanalysis.YettheyareinlinewithothersourceapportionmentanalysesinCentralAsia,forexampleinAlmatyand

11McDuffie,E.E.,Martin,R.V.,Spadaro,J.V.,Burnett,R.,Smith,S.J.,O’Rourke,P.,Hammer,M.S.,vanDonkelaar,A.,Bindle,L.,Shah,V.andJaeglé,L.2021.'SourcesectorandfuelcontributionstoambientPM2.5andattributablemortalityacrossmultiplespatialscales.'Naturecommunications,12(1),p.3594.DataanalyzedinthegridoverlappingwiththeDushanbeairshed.

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Astana,whereasmallnumberofsingle-familyhomesgeneratesasignificantshareofexposuretoPM2.5pollution.12

Figure2:SourceApportionmentofPM2.5ConcentrationinDushanbe

Source:GBD-MAPS-Global(McDuffie,etal.,2021)[GlobalModel]./record/4739100#.YbhkLb1Bw2w.

ResidentialheatinginindividualhouseholdswasfoundasthelargestsourceofPM2.5pollution.Thehighsharecontributedbyresidentialheatingwasconfirmedthroughemissionandconcentrationassessmentsshowinghigherlevelsduringwintermonths.Thisfindingissurprising,becausethemajorityofindividualhouseholdsuseelectricityforheating(91percent),andonlyfivepercentusecoal-basedstovesorindividualboilers.13Whileadditionalresearchisneeded,thisdisproportionallyhighsharecontributedbyindividualhouseholdscanbeexplainedbytheuseofinefficientstovesandpotentiallysub-optimalfuelgeneratinghighprimaryandsecondaryaerosolemissions,whichtransformquicklyintoPM2.5duetonon-linearatmosphericchemistryprocesses.Similarly,inmosturbancentersinCentralandEasternEurope,EasternandWesternBalkans,andCentralAsia,seasonalpeaksinairpollutionarecausedbyresidentialheatinginthewintermonths.14

Thelargeststationarysourceofairpollutionislikelythecombinedheatingandpowerplant(CHP)combustingcoal,producingelectricityandheatingforthecentralheatingnetwork.TheCHPusescoalasamainfuel(80percent).Increaseddemandfromindustry,aswellasforcentralheatingfromtheresidentialsectorhasledtoadrasticincreaseincoalconsumptioninrecentyears.Connectiontothecentralheatingismandatoryfornewbuildings,andplansforanotherCHPexist.

12Forexample:WorldBank2022.CleanAirandCoolPlanet,VolumeII:IntegratedAirQualityManagementandGreenhouseGasReductionforAlmatyandNur-Sultan.?Washington,DC./10986/37938

13WorldBank2015.KeepingWarm:UrbanHeatingOptionsinTajikistan.SummaryReport.?Washington,DC.

/curated/en/353391467986295623/pdf/97495-WP-P133058-PUBLIC-Box391480B-Heating-

Assessment-for-Tajikistan-P133058-Final.pdf.

14Peszko.G.2023.PresentationattheCentralAsiaClimateChangeConference:'ClimateChangeandDevelopmentinCentralAsia,'May16-17,2023;Dushanbe,Tajikistan.

10

ThewastemanagementsectorisaconsiderablecontributorofthePM2.5concentrationinDushanbe(7percent).ThisisduetoalackofsolidwastemanagementattheonlylandfillinDushanbe.Wasteisdepositedbytrucksatvariouspointsalongtheperimeterroad,formingheapsthatareburnedatvariouspointsacrossthelandfill,withtheresultingsmokepollutingtheair.Otherwaste-sectorrelatedcontributiontoairpollutioncouldbelinkedtoinefficienciesintheexistingwastecollectionpracticesinthecity,whichrequirefurtheranalysis.15

AlthoughtransportwasassessedasaminorcontributorthePM2.5concentrationintheglobalstudy(3percent),inarecentlocalstudy,itwasestimatedtocontributeabout13percent.16WhileatthetimeofstudynodatawereavailableforDushanbe,thetransportsectorinTajikistanhasgrownrapidlywithconsumptionofoilproductsmorethandoublingsince2010,whichismostlydrivenbygrowing.Thus,transportemissionsareexpectedtoincreaseand–incontrasttoheating–areconsideredayear-roundenvironmentalchallenge.

PM2.5concentrationsareemittedbylargestationarysourcesthroughouttheairshedofDushanbe,includingindustryandcoal-firedCHP,quarriesandbrickkilns(seeFigure3).Thecoal-poweredcementplantandtheCHParelocatedinthenorth.TherearethreeotherCHPsmostlyoperatedbynaturalgasandhencecontributinglesstoPM2.5.Quarriesarelocatedalongthemostlydryriverbed.Brickkilnsareinthesouthandwestandareconsideredasareasourcesofairpollution.

Figure3:MainStationaryPollutionSourcesandMonitoringStationsinDushanbe

Source:Originalelaborationforthispublication.

15WorldBank.2023.CN.DushanbeSustainableUrbanDevelopmentProject(P179630).

16Almeida,S.M.,etal.2020.'AmbientparticulatemattersourceapportionmentusingreceptormodellinginEuropeanandCentralAsiaurbanareas.'EnvironmentalPollution266(2020):115199.

11

NaturalwindblowndustplaysanimportantroleinPM2.5concentrationinDushanbeandneedstobeconsideredinpolicyactions.Severalstrongandextremedusteventsoccureachyear.TheshareofwindblowndustintotalPM2.5concentrationsishigherduringthesummermonths,asopposedtoanthropogenicemissionsthatpeakinwinter.DustparticlesfoundinTajikistancomefromlong-rangetransportsourcesoutsidetheregion,asfarastheSaharaandtheMiddleEast,andregionalsources,likethedryAralSeabedandotherlocationsinCentralAsia.Whilethereisnodirectmeasuretocontrolwindblowndust,itisimportanttoassessitscontributiontoPM2.5concentrationasthefirststep.Additionally,whensettingairqualitystandards,exceptionalevents,likeduststorms,shouldbeconsidered.

Althoughtheuncertaintyofanalysisinthisfirstpreliminaryassessmentissignificant,itiswithintheacceptablerangeofuncertaintiesidentifiedfortheglobalsourceapportionmentstudy.ThesensitivityanalysisallowstoquantifyfractionalsourcecontributionstothetotalPM2.5concentrationundercompleteeliminationofemissionsfromindividualsources.ThisapproachisconsistentwithGlobalBurdenofDisease201917estimationofhealthburdenfromPM2.5pollutiongloballyandinTajikistan.Furtheranalysisofeachindividualpollutionsourcewithclarificationofmajordrivingfactors,includingairdispersionmodelingfortheairshed,willreduceuncertaintyandbetterinforminterventionstoreduceairpollutionlevels.

PrioritizingandFinancingEmissionReductionInterventions

Investmentneedsfortheimplementationofemission-reductionmeasuresthatprovideabouta13-percentreductionofPM2.5levelsinDushanbeareestimatedatabout$111million,usingaveragecostestimatesfromrecentstudiesinKazakhstan.18TheinterventionsinkeysectorswiththegreatestattributedPM2.5areprioritizedbyanaverageinterventioncosttoreducetheannualaveragePM2.5concentrationby1μg/m3orby20–30percent.Thelargestpollutionreduction–by2μg/m3ofPM2.5concentrationcouldbeachievedintheresidentialsector(improved