Indoor air pollution in developing countries: a major environmental and public health challenge
Around 50% of people, almost all in developing countries, rely on coal and biomass in the form of wood, dung and
crop residues for domestic energy. These materials are typically burnt in simple stoves with very incomplete
combustion. Consequently, women and young children are exposed to high levels of indoor air pollution every day.
There is consistent evidence that indoor air pollution increases the risk of chronic obstructive pulmonary
disease and of acute respiratory infections in childhood, the most important cause of death among children under
5 years of age in developing countries. Evidence also exists of associations with low birth weight, increased infant
and perinatal mortality, pulmonary tuberculosis, nasopharyngeal and laryngeal cancer, cataract, and, specifically in
respect of the use of coal, with lung cancer. Conflicting evidence exists with regard to asthma. All studies are
observational and very few have measured exposure directly, while a substantial proportion have not dealt with
confounding. As a result, risk estimates are poorly quantified and may be biased. Exposure to indoor air pollution
may be responsible for nearly 2 million excess deaths in developing countries and for some 4% of the global burden
of disease.
Indoor air pollution is a major global public health threat requiring greatly increased efforts in the areas of
research and policy-making. Research on its health effects should be strengthened, particularly in relation to
tuberculosis and acute lower respiratory infections. A more systematic approach to the development and evaluation
of interventions is desirable, with clearer recognition of the interrelationships between poverty and dependence on
polluting fuels.
