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

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 (Rint) in participants of the Dutch PIAMA birth cohort study. We linked Rint with estimated annual average air pollution concentrations [nitrogen oxides (NO2, NOx), PM2.5 absorbance ("soot"), and particulate matter < 2.5 μm (PM2.5), < 10 μm (PM10) and 2.5-10 μm (PMcoarse)] at the birth address and current home address (n = 983). Associations between air pollution exposure and interrupter resistance (Rint) were assessed using multiple linear regression adjusting for potential confounders.

RESULTS

We found that higher levels of NO2 at the current address were associated with higher Rint [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 Rint 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.