PM2.5 Exposure | State of Global Air

Figure B. Population-weighted annual average PM2.5 concentrations in 2019. Hot Spots. PM2.5 exposures are highest in Asia, Africa, and the Middle East. Skiptomaincontent PM2.5Exposure Fine-particleoutdoorairpollutionremainshighacrossmuchoftheworld. FigureB.Population-weightedannualaveragePM2.5concentrationsin2019.Hoverortaptoexplorethedata. PM2.5Exposure AmbientPM2.5comesfromvehicleemissions,coal-burningpowerplants,industrialemissions,andmanyotherhumanandnaturalsources. HotSpots PM2.5exposuresarehighestinAsia,Africa,andtheMiddleEast. LearnMore UnevenProgress Someregionshaveseenmodestimprovements,butprogressisstalledinothers. LearnMore DisparitiesContinue Less-developedcountriestendtohavehigherPM2.5concentrations. LearnMore HealthImpactsofPM2.5 SeethetollofPM2.5pollutiononhealtharoundtheglobe. LearnMore HowWeEstimatePollutionExposure Finddetailsondatasources,modelingmethods,andhowwetracktrendsovertime. LearnMore HotSpots PM2.5 exposuresarehighestinAsia,Africa,andtheMiddleEast. MostpeopleonEarthareexposedtoharmfullevelsofPM2.5pollution,withthehighestexposuresoccurringinAsia,Africa,andtheMiddleEast.The10countrieswiththehighestPM2.5levelsareIndia,Nepal,Niger,Qatar,Nigeria,Egypt,Mauritania,Cameroon,Bangladesh,andPakistan.The10countrieswiththelowestPM2.5levelsareAustralia,BruneiDarussalam,Canada,Estonia,Finland,Iceland,NewZealand,Norway,Sweden,andtheUnitedStates. SourcesofPM2.5pollutionvarywithinandbetweencountriesandregions,andthemixofsourceschangesovertime.Someplacesarerestrictingactivitiesoremissions,whileothersareincreasingtheuseofcoalandothermajordriversofPM2.5pollution.​ 92% oftheworld'spopulationlivesinareasthatexceedtheWHOAirQualityGuideline 81% oftheworld'spopulationlivesinareasthatexceedInterimTarget3(15µg/m3) 65% oftheworld'spopulationlivesinareasthatexceedInterimTarget2(25µg/m3) 51% oftheworld'spopulationlivesinareasthatexceedInterimTarget1(35µg/m3) Unevenprogress Someregionshaveseenmodestimprovements,butprogressisstalledinothers. Onaverage,globalPM2.5exposuresdeclinedslightlyfrom2010to2019.ThemostnotableimprovementsoccurredintheGBDSuperRegionofSoutheastAsia,EastAsia,andOceania,drivenlargelybyairqualitycontrolsinChina.Otherregions,particularlyinAfricaandtheMiddleEast,haveseenincreasesinPM2.5exposures.ExposureshaveremainedpersistentlyhighinSouthAsia. FigureC.TrendsinaverageannualPM2.5concentrationsgloballyandintheGBDSuperRegions. Fourteenoftheworld’s20mostpopulouscountrieshaveseenmodestdeclinesinPM2.5levelssince2010.Evencountrieswithsomeofthehighestexposuresintheworld—India,Pakistan,andBangladesh—havebeguntoseemodestimprovements,muchofitcominginthelastfewyearsofthedecade.However,populouscountriesinsub-SaharanAfricasawsubstantialincreasesinPM2.5overthesametimeperiod. FigureD.Changeinpopulation-weightedannualaveragePM2.5exposureinthe20mostpopulouscountries,2010–2019. Toggletoswitchestimates. disparitiescontinue Less-developed countriestendtohavehigherPM2.5. Disparitiesinsocioeconomicdevelopmentcontributetodisparitiesinexposureandhealth.Tocapturedifferentfacetsofdevelopmentthatarerelevanttohealthoutcomes,theGBDproject usesametriccalledthe sociodemographicindex(SDI). LowerSDItendstobeassociatedwithhigherexposurestoPM2.5.Countriesinsub-SaharanAfricagenerallyhavethelowestSDIandthehighestPM2.5levels,whilehigh-incomecountriesexperiencethelowestPM2.5exposure.However,thecorrelationbetweenSDIandPM2.5isonlymoderate.ThisislikelybecausePM2.5isaregionalpollutantthatcanbecarriedlongdistances,affectingneighboringcountriesregardlessoftheirlevelsofdevelopment.HigherPM2.5exposuresinsomemore-developedcountriesinNorthAfricaandtheMiddleEastmayalsoreflectimpactsfromlocaldustsourcesaswellaswind-blowndustfromtheSahara,whichwouldnotbeexpectedtobeassociatedwithSDI. FigureE.PM2.5exposuresincountrieswithdifferentlevelsofsociodemographicdevelopment.Dotsrepresentindividualcountries,color-codedaccordingtoGBDSuperRegion.Dotsizereflectspopulationsize.