Indoor and outdoor air pollution: tobacco smoke, moulds and diseases in infants and children.

Although outdoor air pollution first brought the issue of air pollution health effects to public attention, it is now indoor air pollution that likely has the greatest impact on children's health. The World Health Organization estimates that the global burden of disease from indoor air pollution is far greater than the burden from outdoor air pollution. This review focuses on two indoor pollutants, one that has been well studied, and another that deserves additional study. There is very strong evidence about the harmful effects of tobacco. Policy to decrease children's tobacco exposure and use should be implemented without delay. The emerging findings linking household inhalation of mould spores and infant pulmonary hemorrhage merit follow-up in other countries, because they may provide clues to some deaths from the sudden infant death syndrome.