Air Pollution | National Geographic Society

Air pollution consists of chemicals or particles in the air that can harm the health of humans, animals, and plants. It also damages buildings. ResourceLibraryENCYCLOPEDICENTRYResourceLibraryENCYCLOPEDICENTRYAirPollutionAirPollutionAirpollutionconsistsofchemicalsorparticlesintheairthatcanharmthehealthofhumans,animals,andplants.Italsodamagesbuildings.Grades4-12+SubjectsBiology,EarthScience,Ecology,GeographyPoweredbyEncyclopedicEntryVocabularyAirpollutionconsistsofchemicalsorparticlesintheairthatcanharmthehealthofhumans,animals,andplants.Italsodamagesbuildings.Pollutantsintheairtakemanyforms.Theycanbegases,solidparticles,orliquiddroplets.SourcesofAirPollutionPollutionenterstheEarth'satmosphereinmanydifferentways.Mostairpollutioniscreatedbypeople,takingtheformofemissionsfromfactories,cars,planes,oraerosolcans.Second-handcigarettesmokeisalsoconsideredairpollution.Theseman-madesourcesofpollutionarecalledanthropogenicsources.Sometypesofairpollution,suchassmokefromwildfiresorashfromvolcanoes,occurnaturally.Thesearecallednaturalsources.Airpollutionismostcommoninlargecitieswhereemissionsfrommanydifferentsourcesareconcentrated.Sometimes,mountainsortallbuildingspreventairpollutionfromspreadingout.Thisairpollutionoftenappearsasacloudmakingtheairmurky.Itiscalledsmog.Theword"smog"comesfromcombiningthewords"smoke"and"fog."Largecitiesinpooranddevelopingnationstendtohavemoreairpollutionthancitiesindevelopednations.AccordingtotheWorldHealthOrganization(WHO),someoftheworldsmostpollutedcitiesareKarachi,Pakistan;NewDelhi,India;Beijing,China;Lima,Peru;andCairo,Egypt.However,manydevelopednationsalsohaveairpollutionproblems.LosAngeles,California,isnicknamedSmogCity.IndoorAirPollutionAirpollutionisusuallythoughtofassmokefromlargefactoriesorexhaustfromvehicles.Buttherearemanytypesofindoorairpollutionaswell.Heatingahousebyburningsubstancessuchaskerosene,wood,andcoalcancontaminatetheairinsidethehouse.Ashandsmokemakebreathingdifficult,andtheycansticktowalls,food,andclothing.Naturally-occurringradongas,acancer-causingmaterial,canalsobuildupinhomes.RadonisreleasedthroughthesurfaceoftheEarth.Inexpensivesystemsinstalledbyprofessionalscanreduceradonlevels.Someconstructionmaterials,includinginsulation,arealsodangeroustopeople'shealth.Inaddition,ventilation,orairmovement,inhomesandroomscanleadtothespreadoftoxicmold.Asinglecolonyofmoldmayexistinadamp,coolplaceinahouse,suchasbetweenwalls.Themold'ssporesentertheairandspreadthroughoutthehouse.Peoplecanbecomesickfrombreathinginthespores.EffectsOnHumansPeopleexperienceawiderangeofhealtheffectsfrombeingexposedtoairpollution.Effectscanbebrokendownintoshort-termeffectsandlong-termeffects.Short-termeffects,whicharetemporary,includeillnessessuchaspneumoniaorbronchitis.Theyalsoincludediscomfortsuchasirritationtothenose,throat,eyes,orskin.Airpollutioncanalsocauseheadaches,dizziness,andnausea.Badsmellsmadebyfactories,garbage,orsewersystemsareconsideredairpollution,too.Theseodorsarelessseriousbutstillunpleasant.Long-termeffectsofairpollutioncanlastforyearsorforanentirelifetime.Theycanevenleadtoaperson'sdeath.Long-termhealtheffectsfromairpollutionincludeheartdisease,lungcancer,andrespiratorydiseasessuchasemphysema.Airpollutioncanalsocauselong-termdamagetopeople'snerves,brain,kidneys,liver,andotherorgans.Somescientistssuspectairpollutantscausebirthdefects.Nearly2.5millionpeopledieworldwideeachyearfromtheeffectsofoutdoororindoorairpollution.Peoplereactdifferentlytodifferenttypesofairpollution.Youngchildrenandolderadults,whoseimmunesystemstendtobeweaker,areoftenmoresensitivetopollution.Conditionssuchasasthma,heartdisease,andlungdiseasecanbemadeworsebyexposuretoairpollution.Thelengthofexposureandamountandtypeofpollutantsarealsofactors.EffectsOnTheEnvironmentLikepeople,animals,andplants,entireecosystemscansuffereffectsfromairpollution.Haze,likesmog,isavisibletypeofairpollutionthatobscuresshapesandcolors.Hazyairpollutioncanevenmufflesounds.AirpollutionparticleseventuallyfallbacktoEarth.Airpollutioncandirectlycontaminatethesurfaceofbodiesofwaterandsoil.Thiscankillcropsorreducetheiryield.Itcankillyoungtreesandotherplants.Sulfurdioxideandnitrogenoxideparticlesintheair,cancreateacidrainwhentheymixwithwaterandoxygenintheatmosphere.Theseairpollutantscomemostlyfromcoal-firedpowerplantsandmotorvehicles.WhenacidrainfallstoEarth,itdamagesplantsbychangingsoilcomposition;degradeswaterqualityinrivers,lakesandstreams;damagescrops;andcancausebuildingsandmonumentstodecay.Likehumans,animalscansufferhealtheffectsfromexposuretoairpollution.Birthdefects,diseases,andlowerreproductiverateshaveallbeenattributedtoairpollution.GlobalWarmingGlobalwarmingisanenvironmentalphenomenoncausedbynaturalandanthropogenicairpollution.Itreferstorisingairandoceantemperaturesaroundtheworld.Thistemperatureriseisatleastpartiallycausedbyanincreaseintheamountofgreenhousegasesintheatmosphere.GreenhousegasestrapheatenergyintheEarthsatmosphere.(Usually,moreofEarthsheatescapesintospace.)Carbondioxideisagreenhousegasthathashadthebiggesteffectonglobalwarming.Carbondioxideisemittedintotheatmospherebyburningfossilfuels(coal,gasoline,andnaturalgas).Humanshavecometorelyonfossilfuelstopowercarsandplanes,heathomes,andrunfactories.Doingthesethingspollutestheairwithcarbondioxide.Othergreenhousegasesemittedbynaturalandartificialsourcesalsoincludemethane,nitrousoxide,andfluorinatedgases.Methaneisamajoremissionfromcoalplantsandagriculturalprocesses.Nitrousoxideisacommonemissionfromindustrialfactories,agriculture,andtheburningoffossilfuelsincars.Fluorinatedgases,suchashydrofluorocarbons,areemittedbyindustry.Fluorinatedgasesareoftenusedinsteadofgasessuchaschlorofluorocarbons(CFCs).CFCshavebeenoutlawedinmanyplacesbecausetheydepletetheozonelayer.Worldwide,manycountrieshavetakenstepstoreduceorlimitgreenhousegasemissionstocombatglobalwarming.TheKyotoProtocol,firstadoptedinKyoto,Japan,in1997,isanagreementbetween183countriesthattheywillworktoreducetheircarbondioxideemissions.TheUnitedStateshasnotsignedthattreaty.RegulationInadditiontotheinternationalKyotoProtocol,mostdevelopednationshaveadoptedlawstoregulateemissionsandreduceairpollution.IntheUnitedStates,debateisunderwayaboutasystemcalledcapandtradetolimitemissions.Thissystemwouldcap,orplacealimit,ontheamountofpollutionacompanyisallowed.Companiesthatexceededtheircapwouldhavetopay.Companiesthatpollutedlessthantheircapcouldtradeorselltheirremainingpollutionallowancetoothercompanies.Capandtradewouldessentiallypaycompaniestolimitpollution.In2006theWorldHealthOrganizationissuednewAirQualityGuidelines.TheWHOsguidelinesaretougherthanmostindividualcountriesexistingguidelines.TheWHOguidelinesaimtoreduceairpollution-relateddeathsby15percentayear.ReductionAnybodycantakestepstoreduceairpollution.Millionsofpeopleeverydaymakesimplechangesintheirlivestodothis.Takingpublictransportationinsteadofdrivingacar,orridingabikeinsteadoftravelingincarbondioxide-emittingvehiclesareacoupleofwaystoreduceairpollution.Avoidingaerosolcans,recyclingyardtrimmingsinsteadofburningthem,andnotsmokingcigarettesareothers.FastFactDownwindersTheUnitedStatesconductedtestsofnuclearweaponsattheNevadaTestSiteinsouthernNevadainthe1950s.Thesetestssentinvisibleradioactiveparticlesintotheatmosphere.Theseairpollutionparticlestraveledwithwindcurrents,eventuallyfallingtoEarth,sometimeshundredsofmilesawayinstatesincludingIdaho,Utah,Arizona,andWashington.Theseareaswereconsideredtobe"downwind"fromtheNevadaTestSite.Decadeslater,peoplelivinginthosedownwindareascalled"downwinders"begandevelopingcanceratabove-normalrates.In1990,theU.S.governmentpassedtheRadiationExposureCompensationAct.Thislawentitlessomedownwinderstopaymentsof$50,000.FastFactGreenhouseGasesTherearefivemajorgreenhousegasesinEarth'satmosphere.watervaporcarbondioxidemethanenitrousoxideozoneFastFactLondonSmogWhathascometobeknownastheLondonSmogof1952,ortheGreatSmogof1952,wasafour-dayincidentthatsickened100,000peopleandcausedasmanyas12,000deaths.VerycoldweatherinDecember1952ledresidentsofLondon,England,toburnmorecoaltokeepwarm.Smokeandotherpollutantsbecametrappedbyathickfogthatsettledoverthecity.Thepollutedfogbecamesothickthatpeoplecouldonlyseeafewmetersinfrontofthem.MapsAIRNow:TrackingOzoneandParticlePollutionArticleEnvironmentalProtectionAgency:IndoorAirPollution—VolatileOrganicCompoundsNationalGeographicEnvironment:AirPollutionNationalGeographicEnvironment:GlobalWarmingEPA:AirandRadiationCreditsMediaCreditsTheaudio,illustrations,photos,andvideosarecreditedbeneaththemediaasset,exceptforpromotionalimages,whichgenerallylinktoanotherpagethatcontainsthemediacredit.TheRightsHolderformediaisthepersonorgroupcredited.WritersKimRutledgeMelissaMcDanielSantaniTengHilaryHallTaraRamroopErinSproutJeffHuntDianeBoudreauHilaryCostaIllustratorsMaryCrooks,NationalGeographicSocietyTimGuntherEditorsJeannieEvers,EmdashEditing,EmdashEditingKaraWestEducatorReviewerNancyWynneProducerNationalGeographicSocietyotherLastUpdatedJuly1,2022UserPermissionsForinformationonuserpermissions,pleasereadourTermsofService.Ifyouhavequestionsaboutlicensingcontentonthispage,pleasecontactngimagecollection@natgeo.comformoreinformationandtoobtainalicense.Ifyouhavequestionsabouthowtociteanythingonourwebsiteinyourprojectorclassroompresentation,pleasecontactyourteacher.Sheorhewillbestknowthepreferredformat.Whenyoureachouttohimorher,youwillneedthepagetitle,URL,andthedateyouaccessedtheresource.MediaIfamediaassetisdownloadable,adownloadbuttonappearsinthecornerofthemediaviewer.Ifnobuttonappears,youcannotdownloadorsavethemedia.TextTextonthispageisprintableandcanbeusedaccordingtoourTermsofService.InteractivesAnyinteractivesonthispagecanonlybeplayedwhileyouarevisitingourwebsite.Youcannotdownloadinteractives.RelatedResources