Indoor air pollution and the respiratory health of children.

Children spend much of their time indoors, yet relatively little attention is paid to the effects of indoor air pollution owing to the difficulties of obtaining information about it. The most important single element is probably environmental tobacco smoke (passive smoking), which causes respiratory illness and impairment of lung function. Oxides of nitrogen, mostly derived from gas cookers, may cause symptoms in some children. House dust mites affect children with allergic asthma, but are very difficult to remove from the indoor environment. Indoor mould growth seems to be associated with ill-health, but it is not entirely clear whether this is attributable to exposure to the spores. Formaldehyde is emitted by some materials in buildings and furniture; it may affect children's respiratory health, but the information is rather sparse. VOCs are produced by a range of human activities; their significance for health is not known. More work is needed to ascertain the short-term and long-term effects of exposure to indoor air pollutants.