Air quality guidelines for health

Clean air is considered to be a basic requirement of human health and well-being. However, air pollution continues to pose a significant threat to health worldwide. According to a WHO assess¬ment of the burden of disease due to air pollution, more than 2 million premature deaths each year can be attributed to the effects of urban outdoor air pollution and indoor air pollution (caused by the burning of solid fuels). More than half of this disease burden is borne by the populations of developing countries.

Air quality guidelines have been published by WHO in 1987 and they were revised in 1997. Given the wealth of new studies on the health effects of air pollution that have been published in the scientific literature since the completion of the second edi¬tion of the Air quality Guidelines for Europe, includ¬ing important new research from low-and middle-income countries where air pollution levels are at their highest, WHO has undertaken to review the accumulated scientific evidence and to consider its implications for its air quality guidelines. The result of this work is presented in this document in the form of revised guideline values for selected air pollutants, which are applicable across all WHO regions.