Indoor pollution or tobacco smoke exposure and lung function at 3 years in an African birth cohort

Abstract

<b>Introduction:</b> Postnatal exposure to indoor air pollution(IAP) and environmental tobacco smoke(ETS) in early childhood has been associated with reduced lung function in childhood <b>Aim:</b> To assess the impact of postnatal IAP and ETS on lung function and bronchodilator response(BDR)at 3 years <b>Methods:</b> Children enrolled in the Drakenstein Child Health Study, had lung function tested at 6 weeks and 3 years using standard and intra-breath measures of oscillometry. BDR was measured at 3 years. Indoor air pollutants(PM10, benzene) were measured in homes at 4-6 months postnatally. ETS was assessed by highest infant urine cotinine during 2 years <b>Results:</b> 347 children were tested at 6 weeks and 3 years; BDR was successful in 224(65%): 114(50.7%)male,110(48.9%)Black African, mean(SD)BMI z-score 0.39(1.2). The mean(SD) resistance(R10)and reactance at 10 Hz(X10) was 12.9(3.4) hPa.L.s^-1and-3.7(2.1)hPa.L.s^-1 respectively and post BD administration,R₁₀post 11.0(2.7)hPa.L.s^-1 and X₁₀post-2.8(1.5)hPa.L.s^-1. Children exposed to high levels of ETS had higher R₁₀(R₁₀post:3.0hPa.L.s^-1;p&lt;0.01;CI1.4,4.5) and lower X₁₀(X₁₀:-1.6hPa.L.s^-1;p=0.04;CI-3.0,-0.1 and X₁₀post:-1.3hPa.L.s^-1;p=0.03;CI-2.4,-0.15)compared to unexposed children;adjusted for 6 week lung function. After BD, children exposed to high levels of PM10 had higher R₁₀(R₁₀ at end inspiration:1.6hPa.L.s^-1;p=0.048;CI 0.2,3.1)and lower X10(X10:-1.4 hPa.L.s^-1;p=0.01;CI-2.4,-0.3 and X10 at end inspiratory:-2.1hPa.L.s^-1;p&lt;0.01;CI-3.4,-0.8) <b>Conclusions:</b> High exposure to ETS or IAP in early life is associated with impaired lung function at 3 years, adjusted for 6-week lung function. The effect of IAP was most notable after bronchodilator, highlighting lung development restriction