Air pollution.

Despite progress in improving ambient air quality and reducing personal exposures to air pollutants in indoor settings, population exposures to air pollutants remain widespread and are an important public health concern. Many air pollutants are associated with adverse health effects; the most serious include development and exacerbation of asthma, loss of lung function, impaired neurobehavioral development, and death. These outcomes are the focus of current health effects research on environmental tobacco smoke and radon in indoor settings, and lead, ozone, and particulate matter outdoors. Advances in methods to measure exposures to specific pollutants and the identification of markers of individual susceptibility are providing improved data on the relation of exposure and disease, and, in turn, will improve efforts to protect public health.