1.1. The health burden from household fuel combustion

Well into the 21st century, 2.8 billion people (Figure 1.1) still rely on solid fuels (wood, dung, crop wastes, charcoal, coal, etc.) and simple stoves for cooking and heating (Figure 1.2), and 1.2 billion light their homes with simple kerosene lamps (Figure 1.3) (1). Many studies show that these household energy practices result in very high levels of household air pollution (HAP). Global burden of disease estimates have found that exposure to HAP from cooking results in around 4 million premature deaths (2,3), with the most recent estimates from WHO reporting 4.3 million deaths for 2012. (4). HAP is responsible for nearly 5% of the global disease burden (expressed as disability-adjusted life-years (DALYs)), making it globally the single most important environmental risk factor (3).

Figure 1.1

Percentage of population relying on solid fuels as the primary cooking fuel in 2012, by country. Source: WHO (5)

Figure 1.2

Exposure of family members to household air pollution (HAP) from cooking and heating.

Figure 1.3

Exposure from lighting and other household activities involving fuel combustion.

HAP is also a substantial contributor to outdoor air pollution-related deaths due to emissions into the ambient environment, responsible for around 0.4 million deaths (12% of the total from ambient air pollution (AAP)) (3).

These household energy practices are also linked to a high risk of burns (e.g. from children falling into fires, spilled fuel, etc.) and poisoning (mainly from children ingesting kerosene) (Figure 1.4). Women and children may also be at risk for injury and violence during fuel collection. Fuel gathering may take many hours per week, limiting other productive activities and taking children away from school (Figure 1.5). Figure 1.1, developed from WHO's household energy database (5), shows the global extent of reliance on solid fuels for cooking and how this is concentrated in low and middle-income countries (LMICs) across Asia, Africa and Latin America. More than 95% of the population uses solid fuels for cooking in a significant number of countries, most of which are in sub-Saharan Africa.

Figure 1.4

Safety risks.

Figure 1.5

Other impacts on health, development and environment.

Data for heating and lighting fuels are currently less complete and are not included in Figure 1.1. Further information on the distribution of fuels and technologies for these other household energy requirements, including the use of other sources of combustion pollution such as insect repellent coils, is provided in Review 1, available at: http://www.who.int/indoorair/guidelines/hhfc.

While HAP from household fuel combustion presents less risk to health in high-income countries, it remains an issue in some settings where solid fuel (mainly wood and other biomass) and kerosene are used for heating (Figures 1.6, 1.7, 1.8).

Figure 1.6

Solid fuel use in high-income countries.

Figure 1.7

Hazards with gas and kerosene.

Figure 1.8

Contributions from solid fuel use to ambient (outdoor) air pollution.

Action to address this problem has historically been slow, under-funded, and marked by many ineffective and/or unsustainable interventions. Efforts to implement interventions to improve use of household energy have a history extending back for at least 30–40 years. However, much of the emphasis was on reducing biomass fuel consumption, fostering local economic development and supporting the role of women, rather than on measures to directly improve health. Projects and programmes on use of solid fuel stoves range from small scale-local initiatives of nongovernmental organizations (NGOs) to very large national programmes, including those in India and China (6). This experience has been partially documented, in for example, resources such as Energypedia¹ and ad hoc evaluation studies in India (7) and China (8).

During this period, many households made their own (often incomplete) transition from solid fuels to modern fuels including liquefied petroleum gas (LPG) natural gas and electricity as their socioeconomic circumstances improved. Although the percentage of homes relying primarily on solid fuels for cooking has gradually fallen from 60% in 1980 to 41% in 2010, population growth means the actual number of users has remained stable at 2.8 billion over the same period (1). Some large national programmes have been able to implement or support transition to clean fuels. For example, Indonesia has implemented a very large project enabling more than 40 million homes to convert from kerosene use to LPG (9), and Brazil used targeted financial assistance to support low-income families to access LPG (10).

In recent years, several initiatives including the Global Alliance for Clean Cookstoves (GACC); Sustainable Energy for All (SE4All) and the Climate and Clean Air Coalition (CCAC)² have been mobilizing international efforts to secure achievable health, poverty reduction and environmental (including climate) benefits. These guidelines have been developed to help ensure that health gains are achieved through efforts to increase access to clean and safe household energy.

Given the mixed results of past intervention projects and programmes, and the fact that reliance on traditional solid fuels is closely linked to poverty (11), securing a rapid transition to clean, efficient and modern household energy systems for cooking, heating, lighting and other household uses will present challenges, especially for lower-income households.

The overall objective of these guidelines is to inform and support governments and their implementing partners to bring about the transition to modern household energy as quickly and equitably as is feasible. The guidelines focus on the following three areas of policy:

• What can realistically be done? This includes the development of a practical tool for selecting the best options for stoves and fuels based on their emission rates of key health-damaging pollutants.
• How clean is clean enough? This is a question of the best approach for ensuring that, during the transition from solid-fuel to cleaner burning fuels, those who cannot make an immediate and complete transition to clean, modern fuels (e.g. gas, electricity) still obtain substantial health benefits in the interim.
• What fuels should be restricted or avoided?

1.2. Scoping questions

Based on the policy objectives described above, the following four main scoping questions setting out the issues to be addressed by the guideline recommendations were developed:

1. What device and fuel emission rates are required to meet the WHO (annual average) air quality guideline and intermediate target-1 for PM2.5, and the (24-hour average) air quality guideline for carbon monoxide (CO)?
2. In light of the acknowledged challenges in securing rapid adoption and sustained use of very low emission household energy devices and fuels, particularly in low-income settings, what approach should be taken during this transition?
3. Should coal be used as a household fuel?
4. Should kerosene be used as a household fuel?

1.3. WHO guidelines relating to this topic

Prior to 2009, WHO had not produced guidelines for indoor air quality outside of occupational settings, and no internationally agreed health-based guidance with recommendations for policy was available on how to effectively address the public health impacts of household fuel combustion.

In recent years, WHO has been addressing this need through the development of a series of guidelines for indoor air quality. (AQGs). In 2005, when the global update of ambient (outdoor) air quality guidelines was prepared, it became clear that there was a need for guidance on indoor air quality. A planning meeting held in Bonn in 2006 set out the path for this work, and included plans for three indoor AQG volumes:

1. dampness and mould (published in 2009) (12)
2. selected pollutants (published in 2010) (13)
3. household fuel combustion (these guidelines)

The 2005 global update and the AQGs for selected pollutants (13), set guideline values for specific pollutants, but were not intended to provide practical recommendations and guidance to assist countries and implementing agencies to put those standards into practice. Furthermore, those guidelines did not specifically address household fuel combustion, nor the particular needs of LMIC populations.

The current guidelines are designed to provide this guidance and support, and build on the published WHO guidelines for indoor air quality: specific pollutants.

1.4. Target audience

The primary audience for these guidelines is decision-makers developing, implementing and evaluating policy to secure health benefits in the area of household energy, with a primary (but not exclusive) focus on LMICs, as follows:

• national government departments responsible for addressing this issue. including political, management and technical personnel from a range of ministries in charge of health, energy, environment, development/planning, infrastructure, forestry, etc;
• testing, standards and certification agencies and providers;
• public and private energy production and supply utilities;
• health authorities and health practitioners engaged in planning and delivery of preventive services at national, regional and local levels;
• multisectoral groups working to develop and implement country action plans/investment strategies for improving access to cleaner, safer and more efficient household energy;
• development cooperations and international nongovernmental organizations (NGOs) working to improve access to cleaner, safer and more efficient household energy;
• international initiatives working on improving access to cleaner, safer and more efficient household energy, including the UN Foundation's Global Alliance for Clean Cookstoves (GACC), and the UN Secretary-General's Sustainable Energy for All initiative (SE4All);
• researchers whose work focuses on investigating the causes of disease and the effectiveness of preventive interventions.

The primary audience for the systematic evidence reviews are researchers and technical staff (working in the organizations and ministries noted above) in the fields covered, that is combustion science and emissions, air pollution, environmental health, safety (burns and poisoning risks), and policy for the adoption and sustained use of interventions.

The best practice recommendation addressing synergies between the health and climate impacts of household energy is intended for those formulating policy on climate change mitigation. This includes a wide range of partners engaged with climate change mitigation strategies, including the Climate and Clean Air Coalition (an initiative focused on the shorter-acting climate pollutants, which are the main concern in respect of incomplete combustion of household fuels).

Finally, it is intended that these guidelines should contribute to general raising of awareness of an issue that has not received the attention that the health burden and other impacts of current household fuel combustion practices would warrant.

Footnotes

1

See for example: https://energypedia​.info​/wiki/Portal:Improved_Cooking

2

See Glossary for further explanation and web links.