Abstract
BACKGROUND: Air pollution has been found to adversely affect children's lung function. Forced expiratory volume in 1 s and forced vital capacity from spirometry have been studied most frequently, but measurements of airway resistance may provide additional information. We assessed associations of long-term air pollution exposure with airway resistance. METHODS: We measured airway resistance at age 8 with the interrupter resistance technique (R(int)) in participants of the Dutch PIAMA birth cohort study. We linked R(int) with estimated annual average air pollution concentrations [nitrogen oxides (NO(2), NO(x)), PM(2.5) absorbance ("soot"), and particulate matter < 2.5 μm (PM(2.5)), < 10 μm (PM(10)) and 2.5-10 μm (PM(coarse))] at the birth address and current home address (n = 983). Associations between air pollution exposure and interrupter resistance (R(int)) were assessed using multiple linear regression adjusting for potential confounders. RESULTS: We found that higher levels of NO(2) at the current address were associated with higher R(int) [adj. mean difference (95% confidence interval) per interquartile range increase in NO(2): 0.018 (0.001, 0.035) kPa·s·L(- 1)]. Similar trends were observed for the other pollutants, except, PM(10). No association was found between R(int) and exposure at the birth address. CONCLUSIONS: Our results support the hypothesis that air pollution exposure is associated with a lower lung function in schoolchildren.