The influence of large-scale airborne particle decline and traffic-related exposure on children's lung function

Between 1991 and 2000, ambient air pollution in East Germany changed to resemble West German pollution levels: The concentration of total suspended particles (TSPs) decreased on a broad scale while traffic increased. During that time, we analyzed total lung capacity (TLC) and airway resistance (R-aw) of East and West German children. We tested children 5-7 years of age (n = 2,574) with cooperation-independent body plethysmography in repeated cross sections. We used random-effect models to determine the mutually adjusted association between lung function and short-term and chronic particle exposure and its interaction with living near a busy road. Annual averages of TSPs declined from 77 to 44 mu g/m(3); averages on the day of investigation declined from 133 to 30 mu g/m(3). Differences in lung function between East and West German children vanished during the investigation time. The association of TSPs with P, and TLC was stronger in children living > 50 m away from busy roads. East German children from this group had an R-aw 2.5% higher [95% confidence interval (CI), 0.0-5.1%] per 40-mu g/m(3) increase of daily TSP averages. TLC decreased by 6.2% (95% CI, 0.04-11.6%) per 40-mu g/m(3) increase in annual mean TSPs, and this effect was equally pronounced in East and West Germany. TSP exposure decreased on a broad scale between 1991 and 2000. Lower concentrations of TSPs were associated with better measures of lung function in 6-year-old children. For children living near busy roads, this effect was diminished.