Short-Term Variation in Air Pollution and in Average Lung Function Among Never-Smokers

Abstract The present analysis was directed at investigating associations between short-term variations in air pollutant levels (NO2, total suspended particulates TSP, O3) and cross-sectional lung function (FVC, FEV1, and forced expiratory flow at 25% to 75% of FVC FEF25–75) within a random sample of 3,912 adult never-smokers from eight areas of Switzerland (i.e., participants in the Swiss Study on Air Pollution and Lung Diseases in Adults SAPALDIA cross-sectional study, 1991). Within each local data set, the logarithms of FVC, FEV1, and FEF25–75 were regressed against the 24-h-means of NO2 and TSP and the 8-h mean of O3 (10:00 a.m. to 6:00 p.m.) on the examination day, with control for subjects' sex, age, height and weight, seasonal fluctuations and weekly cycles and meteorologic factors. On average, a 10- μ g/m3 increment in the daily level of NO2, TSP, and O3 was associated with decrements in FEV1 of 0.67% (95% confidence interval CI: 0.13% to 1.21%), 0.46% (95% CI: 0.14% to 0.78%), and 0.51% (95% CI: 0.13% to 0.88%), respectively. Moreover, 10- μ g/m3 increments in NO2 and TSP were associated with decrements in FVC of 0.73% (95% CI: 0.22% to 1.23%) and 0.36% (95% CI: 0.06% to 0.66%), respectively, and a 10- μ g/m3 increment in O3 was associated with a decrement in FEF25–75 of 1.04% (95% CI: 0.22% to 1.85%). Our results suggest that FVC, FEV1, and FEF25–75 vary with the daily level of NO2, TSP, and O3, but that these measures of lung function do not allow separation of the effects of particulates from those of NO2.