Air pollution is a major environment-related health threat to children and a risk factor for both acute and chronic respiratory disease. While second-hand tobacco smoke and certain outdoor pollutants are known risk factors for respiratory infections, indoor air pollution from solid fuels is one of the major contributors to the global burden of disease. In poorly ventilated dwellings, indoor smoke can be 100 times higher than acceptable levels for small particles. Exposure is particularly high among women and young children, who spend the most time near the domestic hearth.
WHO is providing technical support to countries in their own evaluations and scale up of promoting safer stove technologies, as well as air quality guidelines to offer global guidance on reducing the health impacts of air pollution.
Outdoor air pollution
Outdoor air pollution is large and increasing a consequence of the inefficient combustion of fuels for transport, power generation and other human activities like home heating and cooking. Combustion processes produce a complex mixture of pollutants that comprises of both primary emissions, such as diesel soot particles and lead, and the products of atmospheric transformation, such as ozone and sulfate particles.
In 2012, ambient air pollution was responsible for 3 million deaths worldwide, and 169 250 child deaths under five. Children are particularly at risk due to the immaturity of their respiratory organ systems. Exposure to air pollutants is largely beyond the control of individuals are requires action by public authorities at the national, regional and even international levels.
Indoor air pollution
Indoor cooking and heating with biomass fuels (agricultural residues, dung, straw, wood) or coal produces high levels of indoor smoke that contains a variety of health-damaging pollutants. There is consistent evidence that exposure to indoor air pollution can lead to acute lower respiratory infections in children under age five, and chronic obstructive pulmonary disease and lung cancer in adults.
In 2012, household air pollution was responsible for 4.3 million deaths worldwide, which includes 531 190 child deaths under five from lower respiratory infections. Acute lower respiratory infections, in particular pneumonia, continue to be the biggest killer of young children and this burden is experienced most by children in low- and middle-income countries.