Air pollution and airway resistance at age 8 years - the PIAMA birth cohort study

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.

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 (NO₂, NO_x), PM_2.5 absorbance ("soot"), and particulate matter < 2.5 μm (PM_2.5), < 10 μm (PM₁₀) 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.

We found that higher levels of NO₂ at the current address were associated with higher R_int [adj. mean difference (95% confidence interval) per interquartile range increase in NO₂: 0.018 (0.001, 0.035) kPa·s·L^- 1]. Similar trends were observed for the other pollutants, except, PM₁₀. No association was found between R_int and exposure at the birth address.

Our results support the hypothesis that air pollution exposure is associated with a lower lung function in schoolchildren.