Exposure measurement for air pollution epidemiology.
Ferris-BG Jr.; Ware-JH; Spengler-JD
NIOSH 1985 May; :1-17
Measuring exposures in air pollution epidemiologic studies was discussed. Long term effects of exposure to air pollutants have traditionally been studied by comparing health status of people living in different communities with different air quality. These studies seldom measured concentrations of air pollutants; when they did, measurements were usually obtained at sites chosen for regulatory purposes. Later studies measured concentrations of sulfur-dioxide (7446095), nitrogen-dioxide (10102440), ozone (10028156), respirable particulates, and other substances, but these have been of little value in estimating personal exposures. Recent studies of human activity patterns have indicated that most people spend at least 70 percent of their time indoors. Personal exposure to air pollutants is strongly influenced by indoor air quality. Indoor air quality can differ markedly from outdoor air quality and between homes. Recent studies using data from indoor and outdoor sites have shown that sulfur-dioxide concentrations are generally lower indoors than outdoors but undergo variation depending on air exchange rates and presence or absence of sinks indoors. For pollutants with indoor sources such as nitrogen-dioxide, indoor concentrations can exceed outdoor concentrations, especially in homes that use gas for cooking. Outdoor air pollutant measurements have been of little value in predicting personal exposures to pollutants from indoor sources. Alternatives to outdoor pollutant measurement procedures were discussed. Air pollutant measurements intended to provide estimates of indoor exposure should take into account indoor environments and personal activity patterns. A study of indoor exposures to nitrogen-dioxide in Portage, Wisconsin, based on concentrations measured in bedrooms explained 67 percent of variation in week long integrated personal exposures of adults and children and 80 percent of variation in children. Only 1 percent of variation could be explained by measurements made of ambient outdoor air.
Epidemiology; Environmental-pollution; Air-contamination; Air-quality-monitoring; Environmental-factors; Environmental-exposure; Nitrogen-oxides; Sulfur-oxides
7446-09-5; 10102-44-0; 10028-15-6
Proceedings of a Symposium on Epidemiology and Health Risk Assessment, Columbia, Maryland, May 14-16, 1985, Centers for Disease Control/NIOSH, 17 pages, 8 references