[Pollution of confined air in non-industrial environments]

Indoor atmospheric pollution includes a lot of pollutants coming partly from outdoors and produced partly by internal sources. Concerns about potential public health problems are based on evidence that urban residents typically spend more than 90 percent of their time indoors and concentrations of some contaminants are higher indoors than outdoors. Adverse effects of indoor air pollution are obviously dependent on the type of pollutant; among the more important indoor contaminants are passive tobacco smoke, radon decay products, carbon monoxide, nitrogen dioxide, formaldehyde, asbestos fibers, microorganisms and allergens. Efforts to assess health risks associated with indoor air pollution are limited by insufficient information about the number of people exposed, the pattern and severity of exposures and the health consequences of exposures. An overall strategy should be developed to control sources, dilute indoor contaminants and promulgate specific regulations.