Daily Mortality and PM10 Pollution in Utah Valley

Abstract

The association between daily mortality and respirable particulate pollution (PM₁₀) in Utah County was assessed from April 1985 through December 1989. Poisson regression analysis was used to regress daily death counts on PM₁₀ pollution levels, controlling for variability in the weather. A significant positive association between nonaccidental mortality and PM₁₀ pollution was observed. The strongest association was with 5-d moving average PM₁₀ levels, including the concurrent day and the preceding 4 d. An increase in 5-d moving average PM₁₀ levels, equal to 100 μg/m², was associated with an estimated increase in deaths per day equal to 16%. The association with mortality and PM₁₀ was largest for respiratory disease deaths, next largest for cardiovascular deaths, and smallest for all other deaths. Mean PM₁₀ concentrations during the study period equaled 47 μg/m². The maximum 24-h and 5-d moving average PM₁₀ levels equaled 365 and 297 μg/m³, respectively. Relatively low levels of sulfur dioxide, aerosol acidity, and ozone suggested an independent association between mortality and PM₁₀. The relative risk of death increased monotonically with PM₁₀, and the relationship was observed at PM₁₀ levels that were well below the current National Ambient Air Quality Standard of 150 μg/m³.