ASSOCIATIONS BETWEEN RESPIRATORY ILLNESS AND PM(10) AIR-POLLUTION

In this study, the association between daily morbidity and respirable particulate pollution (i.e., particles with a mass median aerodynamic diameter of less than or equal to 10 microns [PM(10)]) was evaluated i n the general population of Anchorage, Alaska. Using insurance claims data for state employees and their dependents who lived in Anchorage, Alaska, the authors determined the number of medical visits for asthma , bronchitis, and upper respiratory infections. The number of visits w ere related to the level of particulate pollution in ambient air measu red at air-monitoring sites. This study was conducted during a 3-y per iod, which included several weeks of higher-level particulate pollutio n that resulted from a volcanic eruption (i.e., August 1992). The part iculate pollution was measured by the Anderson head sampler (24-h accu mulation). The medical visits of the population at risk were also tall ied daily. To help confirm whether PM(10) exposure was a risk factor i n the exacerbation of asthma, we used a regression analysis to regress daily asthma visits on PM(10) pollution levels, controlling for seaso nal variability. A significant positive association between morbidity and PM(10) pollution was observed. The strongest association was with concurrent-day PM(10) levels. The relative risk of morbidity was highe r with respect to PM(10) pollution during warmer days.