Air quality, energy and health
The unit provides technical support to WHO’s Member States in the development of normative guidance, tools and provision of authoritative advice on health issues related to air pollution and its sources. The unit leads monitoring and reporting on global trends and changes in health outcomes associated with actions taken to address air pollution at the national, regional and global scales.
About us

Strategies

Strategies for reducing exposure household air pollution include clean fuels and stoves, supportive policies and awareness-raising campaigns

Strategies for reducing exposure household air pollution include clean fuels and stoves, supportive policies and awareness-raising campaigns

There are multiple strategies for reducing exposure to household air pollution and accelerating the transition to clean household energy. These include: 1) the introduction of cleaner technologies and fuels for cooking, heating and lighting, 2) improved housing and ventilation design; 3) supportive government policies and economic incentives, and 4) education and awareness-raising to support necessary changes in cultural habits related to cooking and household energy management.  

Cleaner stoves and fuels for cooking, heating and lighting

The WHO defines technologies as clean for health following the recommendations in the WHO Guidelines for indoor air quality: household fuel combustion. If the emission rates of PM2.5 and CO for the device meet the recommendations in the Guidelines it is classified as clean – this is equivalent to maintaining indoor levels of fine particulate matter at or below the annual average WHO guideline level of 5 µg/m3 or the interim target 1 level of 35 µg/m3 (WHO 2014; WHO 2021).  

Technologies fueled by solar, electric, biogas, liquefied petroleum gas, and alcohol (e.g., ethanol) are considered clean for health at the point of use. Biomass stoves with an emission rate meeting tier 4 or 5 standards for PM2.5 and tier 5 standards for CO are also considered clean (measured using the ISO Harmonized Laboratory Test Protocol and classified using the ISO Voluntary performance targets for cookstoves, which are based on the WHO Guidelines for indoor air quality: household fuel combustion). Biomass stoves with an emission rate meeting tier 3 standards for PM2.5 and tier 3 or 4 standards for CO are defined as transitional technologies (they provide some health benefit, but do not enable achievement of the air quality guideline).  

Unprocessed coal and kerosene are major sources of health-damaging pollutants and pose risks for burns and poisoning. The WHO Guidelines recommend that unprocessed coal should not be used as household fuel, and kerosene use is discouraged.  

The WHO Guidelines recommend that countries prioritize increasing access to clean technologies, and promote the highest performing transitional technologies if cleaner options are inaccessible.  

Cleaner household energy options include:  

Cleaner fuels: Use of cleaner fuels, such as biogas, ethanol and liquefied petroleum gas minimize the health risk from household air pollution. Improved distribution networks and subsidies are making these cleaner fuels more widely available in emerging economies. 

Electric, wind and solar energy: At point of use, electric stoves (including lower-cost induction cookers) are the cleanest option for health; however, they require an adequate, reliable, and affordable electricity supply. The source of the electricity supply must also be clean for electric stoves to be truly clean for the environment and climate. In communities lacking reliable grid access but with ample wind or sunlight, solar stoves can be used for cooking and micro-grids or home systems using photovoltaic solar or wind energy can power a household’s electrical lights or small appliances. Rooftop thermal solar panels can be used to heat water for bathing, personal hygiene and kitchen sanitation, or for filling hot water radiators for heat.  

Low-emission biomass stoves: Stoves with special features, such as secondary combustion, insulated combustion chambers and/or fans can improve combustion efficiency and significantly lower emissions. While not all "improved" biomass stoves meet WHO guidelines, low-emission stoves can serve as an important transitional technology. 

Improved ventilation and housing design to reduce household pollution exposures

Installing ventilation in households, such as chimneys or hoods, can reduce exposure to smoke indoors. However, smoke vented to the outdoors can re-enter the home and contributes to outdoor air pollution. Therefore, ventilation is most effective when paired with cleaner fuels and low-emission stoves. Also, strategic placement of windows, insulated walls, and reflective roofs can reduce demand for space heating in cool climates.  

Policies for increasing access to cleaner technologies

Effective policies can facilitate the ability of households to obtain and use cleaner technologies for their cooking, heating, and lighting needs. Policies can provide financial support to enable the household purchase of improved household energy devices or clean fuels or encourage the manufacture and distribution of clean household energy to increase supply and availability. Some examples of household energy policies include:  

Shifting fuel subsidies: Fuel subsidies can be shifted to cleaner household energy fuels and technologies. For example: 

Subsidies for improved technologies: Governments can institute subsidies for clean household fuels and technologies to enable under-resourced families to purchase and use clean household energy. For example: 

Tax incentives: Tax exemptions, rebates or other forms of tax incentives can support sales of clean household energy fuels and technologies. For example, tax policies can waive duties for the import of clean technologies, or offer VAT exemption for sales of clean stoves or fuels. For example:

Microfinance: Microfinance schemes can help entrepreneurs and small businesses obtain loans to set up kiosks for selling or servicing cleaner technologies. The money earned from sales can then be used to pay back the loan. For example: 

Consumer credit/lease arrangements for stove purchases: Cookstove sales-offers that include a rent-to-own option and allow payments to be made over time can also increase the accessibility of clean energy for poor households. For example: 

Pay-As-You-Go (PAYG): The large upfront costs of cleaner energy, such as solar panels or LPG tanks, often deters clean energy use. Pay-as-you-go schemes use smart meters installed in households to monitor energy use and enable consumers to pay in smaller increments using mobile banking platforms. For example: 

Conditional cash-transfers: Conditional cash transfers are performance-based payments that can be provided to households contingent on their use of clean energy sources. For example: 

Behaviour changes for clean energy adoption

Reducing household air pollution requires that individuals use clean household energy and stop using polluting fuels and devices. Clean energy devices can be designed in ways that will facilitate household use (e.g., ensuring the clean device has an adequate number of burners of the appropriate size). However, even if stoves are designed with user needs in mind, people often continue to use polluting fuels and devices after obtaining a cleaner technology. 

Behaviour changes related to social and cultural practices are often necessary when transitioning to clean energy devices. Additionally, behaviour changes such as opening windows and doors while cooking or cooking outside can help reduce personal exposures to harmful air pollutants. Achieving necessary shifts in behaviour requires understanding household preferences and priorities.  

Several strategies have been used to promote the behavioural changes needed for clean energy adoption: 

Rewards and threats: Provision of incentives for clean energy adoption or threats for failure to adopt can increase clean energy use. Communities could come together to support the transition to clean household energy and be rewarded for becoming “smoke-free”.  

Shaping knowledge: Education and awareness-raising can help stimulate and sustain clean energy-related behaviour changes. Educational campaigns, radio ads, flyers, billboards, posters, or other mediums could be used to highlight the benefits of clean fuel use and the negative impacts of polluting fuels.  

Social support: Establishing clean energy use as a social norm can encourage adoption. People may also be more likely to adopt clean fuels and technologies if they are promoted by trusted community members, such as community health workers or religious leaders.  

Comparisons: Highlighting how clean options compare to polluting ones can enable people to observe the relative advantages of clean technologies and fuels. For example, cooking demonstrations in which the same dish is cooked side by side on a polluting stove and on a clean stove, to demonstrate how the clean stove is easier to use, releases less smoke, cooks faster, or other advantages. Other strategies involve comparing the blackened walls that result from polluting fuels to blackened lungs, to help people understand how household air pollution affects their bodies and motivate them to reduce exposures.  

Identity and self-belief: Strategies that promote clean household energy as an essential part of a modern identity and empower women to purchase and use clean energy can impart the desire and self-efficacy to transition to cleaner energy options.