Fine particulate air pollution, resuspended road dust and respiratory health among symptomatic children

The short-term association of particulate air pollution with peak expirator y how rate (PEF) and respiratory symptoms was examined. Forty-nine children with chronic respiratory symptoms aged 8-13 yrs were fo llowed daily for six weeks in spring, 1995, in Kuopio, Finland, Daily conce ntrations of particulate material with a 50% cut-off aerodynamic diameter l ess than or equal to 10 mu m and less than or equal to 2.5 mu m (PM10 and P M2.5, respectively), black carbon, and the number concentrations of particl es from 0.01-10 mu m diameter were measured, During the study period, PM10 were mainly resuspended soil and street dust, and the concentration was est imated using aluminum content of PM10 samples. No consistent effect of particles was found as the associations varied by l ag. Of the lags examined, only 1-day lagged PM2.5 was statistically signifi cantly associated with morning PEF (beta=-1.06, SE=0.52 (per interquartile increase in pollutant)). Evening PEF was significantly associated with the 1-day lagged number of particles in the size range 0.1-1.0 mu m(beta=-1.56, SE=0.72), One-day lagged PM10, PM2.5-10, PM2.5 and resuspended PM10, and 4 -day average of PM2.5 were significantly associated with increased risk of cough. Given the short duration of the study, separating the effects of dif ferent types of particles was difficult. The present study demonstrates the highly variable size and number distribu tion and chemical composition of particles in Finland, and underlines the i mportance of measuring the size and chemical composition of particles to de termine which types of particles are associated with health effects.