The adverse effect of low levels of ambient air pollutants on lung function growth in preadolescent children

The main purpose of our study was to assess the effect of low concentration s of ambient air pollution on lung function growth in preadolescent childre n. We accounted for height velocity over the follow-up period and also for other possible confounders such as baseline anthropometric and physiologic characteristics of children. In addition to outdoor air pollution, we consi dered the possible effects of social class and exposure to indoor pollutant s such as gas stove fumes or environmental tobacco smoke. The cohort prospe ctive study was carried out in 1,001 preadolescent children from two areas of Krakow, Poland, that differed in ambient air pollutants. In the city cen ter (higher pollution area), the mean annual level [+/- standard deviation (SD)] of suspended particulate matter was 52.6 +/- 53.98 mu g/m(3) and that of SO2 was 43.87 +/- 32.69 mu g/m(3); the corresponding values in the cont rol area were 33.23 +/- 35.99 mu g/m(3) and 31.77 +/- 21.93 mu g/m(3). Mean lung function growth rate adjusted to height velocity and lung function le vel at the study entry was significantly lower in boys and girls living in the more polluted areas. Also, the proportion of children with the slower l ung function growth (SLFG) was higher in the children from the more pollute d area of the city. The analysis completed in the group of children after t he exclusion of asthmatic subjects and those with asthmalike symptoms confi rmed that, in boys, odds ratios (ORs) for SLFG [forced vital capacity (FVC) ] and air pollution after adjustment to baseline FVC, height, and growth ra te was significant [OR = 2.15; 95% confidence interval (CI), 1.25-3.69)]. T he analysis also confirmed that for SLFG(FEV1) the OR was 1.90 (CI, 1.12-3. 25). The corresponding OR values in girls were insignificant (OR = 1.50; CI , 0.84-2.68 and OR = 1.39; CI, 0.78-2.44). The association between ambient pollutants and poorer gain of pulmonary volumes in children living in more polluted areas suggests that air pollution in the residence area may be a p art of the causal chain of reactions leading to retardation in pulmonary fu nction growth during the preadolescent years.