家庭空气污染及其对健康的影响

Household air pollutionandrelated health impacts Technical brief Key messages More than a quarter of the global population still cook meals over open fires and/or on simplestovesfuelled by firewood, agricultural waste, dried dung, charcoal, and coal. This practiceresults in the emission of harmful and dangerously high levels of household air pollution.Exposure to this household air pollution has been estimated to cause around 3.2 million deathsannually in 2019; these emissions also worsen ambient air quality, alter the global climate,have gendered livelihood impacts, and degrade the local environment. Lower-emission andexposure-reducing alternatives – like gas and electricity – are widely used among middle- andupper-income households globally but have not yet been made available or affordable topoorer households at scale. It is also important to tackle household air pollution in refugeeand migrant communities, where people are often forced to burn harmful materials like trashand plastics for their basic needs. This exacerbates health risks for already vulnerable groups,especially given the growing conflicts and climate change. Transition to clean cooking is occurring globally, albeit at different rates; in many places,especially in Africa, too slowly to meet Sustainable Development Goal (SDG) 7, which callsfor “affordable, reliable, sustainable and modernenergy for all” by 2030. Some countries,including India and Indonesia, have had success increasing access to cleaner fuels like liquefiedpetroleum gas (LPG). Others, for example, Ecuador, are undergoing a second transition – fromLPG to electric cooking. In all cases, financial instruments have enabled poorer households toaccess and, in some cases, afford and adopt cleaner stoves and fuels. Clean household energytransitions are slowed primarily by issues of affordability and accessibility; addressing this dualchallenge can unlock health, economic, environmental, and climate benefits. The durability ofthese transitions relies on the stability of mechanisms to ensure consistent affordability untilclean fuels and technologies are viewed as indispensable to users and households. Key definitions Household air pollution:This arises from the combustion of polluting fuels,such as wood, dung, coal and crop residues, with inefficient technologies forcooking, heating and lighting. Clean household energy:Clean household energy refers to fuels andtechnologies which attain the fine particulate matter (PM2.5) and carbonmonoxide levels recommended in the WHO global air quality guidelinesand WHO guidelines for indoor air quality: household fuel combustion.Such energy includes solar, electric, biogas, LPG, alcohol (i.e. ethanol) andbiomass stoves classified as Tier 4 or 5 for PM2.5emissions and Tier 5 forcarbon monoxide emissions(1). Overview Current status Access to clean household energy has improved in recent decades yet still lags behindglobal goals.According to the latest Tracking SDG 7 report, as of 2023, approximately 74%of the global population has access to clean fuels and technologies for cooking, a 17%improvement since 2010(2).Despite this progress, 2.1 billion people still depend heavilyon polluting fuels and technologies for cooking. If the current trajectory continues, onlyan estimated 78% of the world’s population will have access to clean cooking fuels andtechnologies by 2030 (relative to 1990), failing to achieve the SDG 7 target of universal accessto clean cooking(3). Household air pollution exposures remain high in many parts of the world.Burningpolluting fuels such as wood, dung, charcoal, coal and kerosene in inefficient devicesfor cooking, heating and lighting in poorly ventilated homes releases dangerous levelsof air pollutants including PM2.5, black carbon, carbon monoxide, polycyclic aromatichydrocarbons, volatile organic compounds, and hundreds of other health-damagingcompounds (termed household air pollution) to which the inhabitants are highly exposed(4).Pollutant levels vary widely depending on fuel type, fuel moisture content, forms ofcombustion, etc. Measurements of household air pollution have focused on indoor concentrations andexposure monitoring (that is, pollution monitors worn by people that follow them throughspace and time). The WHO Global Database of Household Air Pollution Measurements,1witha focus on PM2.5and CO levels, contains 1,000+ measurements from 196 studies performedin 53 countries. Kitchen concentrations of and personal exposure to PM2.5in householdsusing solid fuels varied widely, ranging between approximately 150 and 1,200 μg/m3– 30to 240 times higher than the PM2.5guideline value of 5 μg/m3.(5)Recent measurements – inGuatemala, India, Peru and Rwanda, Peru, and Guatemala as part of a large multi-countrytrial(6)and in Ghana(7), Cameroon, and Kenya as part of the CLEAN-Air(Africa) study(8)–found lower exposures among biomass users than previously reported, but still substantiallyhigher than exposures among LPG us