Increased asthma medication use in association with ambient fine and ultrafine particles

Abstract

The association between particulate air pollution and asthma medication use and symptoms was assessed in a panel study of 53 adult asthmatics in Erfurt, Germany in winter 1996/1997. Number concentrations of ultrafine particles, 0.01-0.1 μm in diameter (NC0.01-0.1), mean 17,300.cm-3, and mass concentrations of fine particles 0.01-2.5 μm in diameter (MC0.01-2.5), mean 30.3 μg.m-3, were measured concurrently. They were not highly correlated (r=0.45). The associations between ambient particle concentrations and the prevalence of inhaled β2-agonist, corticosteroid use and asthma symptoms, were analysed separately with logistic regression models, adjusting for trend, temperature, weekend, holidays, and first order autocorrelation of the error. Cumulative exposures over 14 days of ultrafine and fine particles were associated with corticosteroid use. β2-agonist use was associated with 5-day mean NC0.01-0.1 and MC0.01-2.5. The prevalence of asthma symptoms was associated with ambient particle concentrations. The results suggest that reported asthma medication use and symptoms increase in association with particulate air pollution and gaseous pollutants such as nitrogen dioxide.