What are the WHO Air quality guidelines? - WHO | World ...

The WHO Air quality guidelines are a set of evidence-based recommendations of limit values for specific air pollutants developed to help ... Home/ Newsroom/ Featurestories/ Detail/ WhataretheWHOAirqualityguidelines? francovolpato/AdobeStock © Credits WhataretheWHOAirqualityguidelines? Improvinghealthbyreducingairpollution. 22September2021 WhataretheWHOAirqualityguidelines?TheWorldHealthOrganization’sAirqualityguidelines(AQG)serveasaglobaltargetfornational,regionalandcitygovernmentstoworktowardsimprovingtheircitizen’shealthbyreducingairpollution.WhydoesWHOpublishAirqualityguidelines?Cleanairisabasichumanright.Yet,airpollutioncontinuestoposeasignificantthreattopeopleworldwide–itisthegreatestenvironmentalthreattohealthandaleadingcauseofnon-communicablediseases(NCDs)suchasheartattacksorstroke.AccordingtotheWorldHealthOrganization,thereare7millionprematuredeathseveryyearduetothecombinedeffectsofoutdoorandhouseholdairpollution–withmillionsmorepeoplefallingillfrombreathingpollutedair.Morethanhalfofthesedeathsarerecordedindevelopingcountries.WHOregularlyintegratesscientificevidenceonairpollution’shealthimpactsaswellasmonitorscountriesairqualityprogress.TherecommendationsincludedintheWHOAirqualityguidelinesarebasedonsystematicliteraturereviewsandsubsequentrigorousevaluationmethodsaswellasextensiveconsultationwithexpertsandend-usersoftheguidelinesfromallregionsoftheworld.Aheadofthepublicationofthe2021WHOAirQualityguidelines,hereisabreakdownofwhattheyareandhowgovernmentscan usethem.Whatisairpollution?Airpollutionisacomplexmixtureofsolidparticles,liquiddroplets,aswellasgases.Itcancomefrommanysourcesforexample:householdfuelburning,industrialchimneys,trafficexhausts,powergeneration,openburningofwaste,agriculturalpractices,desertdustandmanyothersources.Differentsourcescanleadtodifferentmixturesofairpollution.Forexample,anurbancityneartotheseacanhaveparticulatematterconsistingofseasalt,roaddustandsmokefromdieselengines.Incontrast,aruralareaneartoaforestmayhaveparticulatematterconsistingofsoil,smokefromcookstovesandforestfires.AirpollutantsmeasuredincludePM2.5 andPM10 (particleswithanaerodynamicdiameterofequalorlessthan2.5,alsocalledfine,and10micrometrerespectively),ozone(O3),nitrogendioxide(NO2),carbonmonoxide(CO)andsulfurdioxide(SO2).Whatistheeffectsofairpollutiononhumanhealth?Fineparticulatematter(PM2.5)canpenetratethroughthelungsandfurtherenterthebodythroughthebloodstream,affectingallmajororgans.ExposuretoPM2.5cancausediseasesbothtoourcardiovascularandrespiratorysystem,provoking,forexamplestroke,lungcancerandchronicobstructivepulmonarydisease(COPD). Newresearchhasalsoshownanassociationbetweenprenatalexposuretohighlevelsofairpollutionanddevelopmentaldelayatagethree,aswellaspsychologicalandbehaviouralproblemslateron,includingsymptomsofattentiondeficithyperactivitydisorder(ADHD),anxietyanddepression.Howaretheguidelinesdeveloped?TheWHOAirqualityguidelinesareasetofevidence-basedrecommendationsoflimitvaluesforspecificairpollutantsdevelopedtohelpcountriesachieveairqualitythatprotectspublichealth.Thefirstreleaseoftheguidelineswasin1987.Sincethen,severalupdatedversionshaveappearedandthelatestglobalversionwaspublishedin2005.WHOupdatestheAirQualityGuidelinesonaregularbasissoastoassuretheircontinuedrelevanceandtosupportabroadrangeofpolicyoptionsforair-qualitymanagementinvariouspartsoftheworld,especiallytakingintoaccountthebreadthofnewhealthstudiesthathavebeenpublishedinthemeanwhile.The2021updateoftheWHOairqualityguidelinesisinresponsetotherealandcontinuedthreatofairpollutiontopublichealth.AccordingtoWHOrulesandproceduresforguidelinesdevelopment,severalexpertgroupsareestablished,eachonewithaveryspecificfunction.Theselectionofwhichpollutantstoupdateisagreeduponbyonegroup,inthiscase,particulatematter,ozone,nitrogendioxideandsulfurdioxide.Otherteamsofexpertsdraftthebackgroundmaterial—theliteraturereviewsanditsassessment—whichisreviewedandcommentedbythemaingroupofexperts.Basedonthebackgroundmaterialsandthecomments,anotherExpertGroupagreesontheformatandcontentsoftheupdatedguidelinesandrecommendedchangesinthetextsupportingtheguidelines. Whatdotheguidelinesrecommend?TheWHOAirqualityguidelinesrecommendlevelsandinterimtargetsforcommonairpollutants:PM,O3,NO2,andSO2.Recommended2021AQGlevelscomparedto2005airqualityguidelinesμg=micrograma99thpercentile(i.e.3–4exceedancedaysperyear).bAverageofdailymaximum8-hourmeanO3concentrationinthesixconsecutivemonthswiththehighestsix-monthrunning-averageO3concentration.Note:Annualandpeakseasonislong-termexposure,while24hourand8hourisshort-termexposure.Howcangovernmentsusethem? Governmentsacrosstheworldusetheguidelinesindifferentwaysdependingontheirtechnicalcapabilities,economiccapacity,airqualitymanagementpoliciesandotherpoliticalandsocialfactors.BeforeadoptingtheWHOguidelinevaluesaslegallybasedstandards,governmentsshouldconsidertheirunique,localconditions. Whatdotheguidelinesaimtoachieve?Althoughtheguidelinesareneitherstandardsnorlegallybindingcriteria,theyaredesignedtoofferguidanceinreducingthehealthimpactsofairpollutionbasedonexpertevaluationofcurrentscientificevidence.Theseguidelinesincorporatescientificevidencefrommultiplecountries,whichmakesthemrelevanttothediverseconditionsaroundtheworldandcapableofsupportingabroadrangeofpolicyoptionsforairqualitymanagement.TheyareintendedtobeusedindiverseconditionsinallWHO’sregionsandtosupportabroadrangeofpolicyoptionsforairqualitymanagement.Knowledgeaboutthehazardouspropertiesofthepollutantsandindicationoftheriskrelatedtoexposure,provideanessentialscientificcontributionforairqualitymanagement.Significanthealthbenefitscanbeachievedbyreducingapopulation’sexposuretoairpollution.Addressingairpollutionthroughpolicyactionsinenergy,transport,wastemanagement,agricultureandurbanplanningcanalsouncoveradditionalco-benefitsforhealth,climatemitigationandsustainableeconomicdevelopment.Additionalresources:Airqualityguidelinesglobalupdate2021Airqualityguidelinesglobalupdate2005WHOFactsheet:Ambient(outdoor)airpollutionWHOFactsheet:HouseholdairpollutionandhealthWHOAirpollutiondataportalWHO:BreatheLife-Howairpollutionimpactsyourbody 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