Indoor air pollution and household energy

Indoor air pollution illustration
UNEP/Topham; Nigel Bruce/ITDG/Nepal

Directory of web-accessible resources

The directory provides links to web-accessible resources in categories of relevance to policymaking. Links to portals of the WHO (Programme on Indoor Air Pollution) and UNEP are in Section 9. Links to other organizations, e.g. development agencies, academic/research institutions and civil society, are in Section 10.

Policy Brief – Indoor air pollution: environment and health linkages

In many of the poorest areas of the developing world, one of the most insidious killers is indoor air pollution.

Indoor air pollution – generated largely by inefficient and poorly ventilated stoves burning biomass fuels such as wood, crop waste and dung, or coal – is responsible for the deaths of an estimated 1.6 million people annually. More than half of these deaths occur among children under five years of age. In developing countries with high mortality rates overall, indoor air pollution ranks fourth in terms of the risk factors that contribute to disease and death(1).

According to current World Health Organization estimates, more than half of the world's population (52%) cook and heat with solid fuels, including biomass fuels and coal (2). It has been estimated that more than 2.4 billion people, generally among the world's poorest, rely directly upon biomass, e.g. wood, crop residues, dung and other biomass fuels for their heating and cooking needs (3).

deaths from indoor smoke from solid fuels map

Health and environment impacts

Biomass smoke contains thousands of health-damaging substances. Small particles of less than 10 microns in diameter (PM10), are among the most dangerous. Such pollutants penetrate deep into the lungs and are an important factor in the development of acute lower respiratory disease, chronic obstructive pulmonary disease, cancers, and other illnesses. Average, or mean, 24-hour concentrations of PM10 in poor households using biomass stoves may exceed standards for ambient air pollution levels promulgated by developed countries (e.g. United States Environmental Protection Agency/European Union) by a factor of 2 to 60 (4, 5).

Solid fuel dependency exacerbates deforestation, a process that contributes to the build-up of greenhouse gasses, particularly carbon dioxide, in the earth's atmosphere, and thus to global climate change. Locally, deforestation, can generate soil erosion, pollution of streams with sediment and debris, loss of biodiversity, and changed patterns of vector-borne disease transmission – all of which impact health (6).

Strategies to reduce health and environment impacts

  • Shifting from solid fuels to cleaner energy technologies – for instance, liquid petroleum gas (lpg), biogas or solar power generation – can potentially yield the largest reduction in indoor air pollution levels while minimizing environmental impacts of energy production and consumption in general.
  • Improved design of stoves and ventilation systems can reduce indoor air pollution in many poor communities, where fuel distribution networks remain limited or alternative technologies are unavailable, providing the design is acceptable locally and systems for marketing/maintenance of the improved stove are developed.
  • Public awareness of the health risks of indoor air pollution is also an important factor in change. For instance, mothers can be encouraged to keep small children away from constant contact with fires.

  • WHO, ed. The World Health Report 2002 : Reducing Risks, Promoting Healthy Life. Geneva, World Health Organization, 2002.
  • World Health Organization, Air Pollution, percentage of population using biomass fuels, Millennium Indicators Database, United Nations, Department of Economic and Social Affairs, Economic and Social Development, Statistics Division. (
  • World energy outlook 2004. Paris, Organization for Economic Co-operation and Development/International Energy Agency, 2004.
  • Bruce, N, Perez-Padilla, R & Albalak, R. The health effects of indoor air pollution exposure in developing countries. Geneva, World Health Organization, 2002.
  • Gordon, B, Mackay, R & Rehfuess, E. Inheriting the world: the atlas of children's health and the environment. Geneva, World Health Organization, 2004.
  • Emerging challenges – new findings: emerging and re-emerging infectious diseases: links to environmental change. In: Harrison P, ed. GEO Yearbook 2004/5: An overview of our changing environment. Nairobi, United Nations Environment Programme, 2005.