The update of World Health Organization air quality guidelines and its implications on health risk management in low- and middle-income countries

摘要

1.Introduction As one of the milestone documents on global air quality management,the World Health Organization(WHO)health guidelines have been periodically adopted and published air quality guidelines(AQGs)following systematic reviews on evidence from medical and public health studies,and through extensive expert panel discussion and consultation.Since 1987,WHO has periodically issued health-based air quality guidelines—Air Quality Guidelines for Europe(hereafter referred to as“AQGs(1987)”)to assist governments and civil society to reduce human exposure to air pollution and its adverse effects.1 In 2006,a global edition of the updated AQGs—WHO Air Quality Guidelines Global Update 2005(hereafter referred to as“AQGs(2005)”)was released.2 With increasing evidence on air pollution attributed heath risk and adverse effects,the global air quality guidelines were further updated and accomplished in 2021.2-3 AQGs(1987)provided health-based guideline levels for the major air pollutants,including carbon monoxide(CO),lead,nitrogen dioxide(NO2),ozone(O3),sulfur dioxide(SO2)and total suspended particulate(TSP)matter.However,in AQGs(2005),TSP was then replaced by particulate matter(PM)with aerodynamic dimeter less than 2.5µm(PM2.5)and PM with aerodynamic dimeter equal or less than 10µm,albeit without the provision of numerical guideline values.2 In each edition of the guidelines,air quality criteria values have been derived for recommendations protecting human populations from the adverse impacts of air pollution exposure,and guidelines are of significant importance for low-and middle-income countries(LMICs)in reducing air pollution exposure and resulting in beneficial impacts on health.