Early life exposure to traffic-related air pollution and lung function in adolescence assessed with impulse oscillometry

To the Editor: Most studies linking air pollution exposure and lung function have focused on spirometry measurements, a method that mostly reflects total airway resistance and large airway function, rather than peripheral airway obstruction.1 It has been reported in animal studies that small aerosol particles in the size range typical of traffic-related air pollution are deposited in the peripheral airways.2 Indices related to peripheral airway function correlate with health status and asthma symptoms in children and adults.3,4 However, it is unknown whether exposure to traffic-related air pollution affects peripheral airway function. Exposure characteristics as well as lung function and anthropometry data for the present study population are presented in Tables E3 and E4, respectively (see this article's Online Repository at www.jacionline.org).\n4 -8.4 to 7.5 R20 (Pa·L-1·s) 2415 -0.5 -3.3 to 2.3 2297 1.6 -5.7 to 9.0 R5-R20 (Pa·L-1·s) 2415 2.0 0.3 to 3.6 2297 -0.4 -4.4 to 3.7 AX0.5 (Pa·L-1)0.5 2415 0.17 0.01 to 0.34 2297 0.12 -0.30 to 0.53 PM10 (per 5 μg/m3) R5 (Pa·L-1·s) 2415 4.3 -5.9 to 14.5 2297 4.1 -3.3 to 11 R20 (Pa·L-1·s) 2415 6.3 -2.2 to 14.8 2297 4.9 -2.0 to 11.8 R5-R20 (Pa·L-1·s) 2415 3.0 -2.1 to 8.0 2297 -1.5 -5.5 to 2.5 AX0.5 (Pa·L-1)0.5 2415 0.40 -0.08 to 0.89 2297 0.04 -0.35 to 0.43 Table E2 Associations of NOx and PM10 exposure during the first year of life and year 15-16 and IOS measurements at age 16 years Covariates[low *] Full cohort(N = 4089) Study population at 16 y(n = 2415[dagger]) n % n % 95% CI  Mean ± SD Mean ± SD 95% CI Sex: male 2065 50.5 1176 48.7 47.4-50.0 Socioeconomic status of parents White collar worker 3323 82.7 2013 84.5 83.5-85.4 Heredity Parents with allergy and/or asthma 1191 29.5 748 31.4 30.2-32.6 Ethnicity Any parents born outside of Scandinavia 543 16.0 372 16.1 15.3-17.0 Mother smoking during pregnancy or at 2 mo of child 563 13.8 294 12.2 11.4-13.0 Environmental tobacco smoke exposure at 16 y 413[double dagger] 13.6 287 12.6 11.9-13.2 Adolescence smoking at 16 y 373[double dagger] 12.0 298 12.4 11.8-13.1 Asthma at 0-2 y 334 10.9 208 10.0 9.3-10.7 Asthma at 16 y 199[double dagger] 6.4 160 6.8 6.3-7.3 Sensitized at 16 y 1170[double dagger] 45.9 1094 46.3 45.8-46.9 Birth weight (g) 3530 ± 558 3525 ± 556 3510-3539 Birth length (cm) 50.2 ± 2.6 50.2 ± 2.5 50.2-50.2 Gestational age (wk) 39.5 ± 1.8 39.5 ± 1.8 39.4-39.6 Exposure concentration during year 0-1 NOx (μg/m3) 20.9 ± 16.5 21.6 ± 17.0 21