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

Abstract

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 microg/m2; averages on the day of investigation declined from 133 to 30 microg/m2. Differences in lung function between East and West German children vanished during the investigation time. The association of TSPs with R(aw) 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-microg/m2 increase of daily TSP averages. TLC decreased by 6.2% (95% CI, 0.04-11.6%) per 40-microg/m2 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.

Figure 1

TLC of German children living > 50 m (A) and ≤ 50 m (B) away from a street with heavy traffic, living at least 2 years at their place of residence and without asthma: place- and year-specific geometric mean values and regression line adjusted for education, bedroom sharing, sex, age, height, BMI, birth weight, heating with fossil fuels, cooking with gas, passive smoking and/or maternal smoking during pregnancy, and outdoor temperature on the day of investigation. Data points indicate place and year of investigation: B, Borken; DN, Duisburg north; DS, Duisburg south; EK, Essen and Cologne; H, Halle; L, Leipzig; M, Magdeburg; O, Osterburg; S, Salzwedel.