Air pollution exposure and lung function until age 16 years: the PIAMA birth cohort study

Evidence for the effects of air pollution exposure on lung function growth into adolescence is scarce. We investigated associations of air pollution exposure with lung function and lung function growth until age 16.We conducted both longitudinal (n=915) and cross-sectional (n=721) analyses of associations of air pollution exposure with forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC) growth from ages eight to 16 and FEV₁ and FVC at age 16. We estimated residential concentrations of nitrogen dioxide (NO₂), "soot" and particulate matter (PM_x, where x is the 50% cut-off aerodynamic diameter in µm) with diameters of <2.5 µm (PM_2.5), <10 µm (PM₁₀) and 2.5-10 µm (PM_coarse) during the preschool, primary school and secondary school time windows by land use regression models. Associations with (growth in) FEV₁ and FVC were analysed by linear (mixed effects) regression.Higher air pollution exposure was associated with reduced FEV₁ growth (e.g. adjusted difference -0.26% (95% CI -0.49 to -0.03%) per interquartile range increase in secondary school PM_2.5) and lower FEV₁ (adjusted difference -2.36% (95% CI -3.76 to -0.94%)), but was not adversely associated with FVC. Associations with FEV₁ were stronger in boys than girls and were not modified by asthma status.Higher air pollution exposure may lead to increased airway obstruction, but not reduced lung volume in adolescence.