Impact of prenatal and postnatal household air pollution exposure on lung function of 2-year old Nigerian children by oscillometry.

Abstract Rationale Lung function is adversely affected by exposure to household air pollution (HAP). Studies investigating the impact of prenatal and postnatal HAP exposure on early childhood lung development are limited, especially from Sub-Saharan Africa. Objective We used oscillometry to investigate the impact on lung function of prenatal and postnatal HAP exposure of children born to Nigerian women who participated in a randomized controlled cookstove intervention trial. Methods We performed oscillometric measurements (R: airway resistance; X: airway reactance; Fres: resonant frequency; AX: reactance area) in 223 children starting at age of 2 years (ethanol stove, n=113; firewood/kerosene, n=110). Personal exposure monitoring assessed mothers’ prenatal exposure to particulate matter less than 2.5μm in aerodynamic diameter (PM2.5). Postnatal HAP exposure was measured by determining household PM2.5 levels. We employed linear regression analysis to examine the association of prenatal and postnatal HAP exposures with children’s lung function. Models were adjusted for age, gender, weight, height, group (intervention or control), birthweight and gestational age. Results Mean age of the children was 2.9 years (standard deviation = 0.3); 120 were boys (53.8%) and 103 were girls (46.2%). Higher postnatal PM2.5 exposures were significantly associated with higher airway reactance at 5 Hertz (X5 Hz; p=0.04) in adjusted models. There were no significant associations between prenatal or postnatal PM2.5 exposure levels and other oscillometry parameters in adjusted regression analysis. Conclusions This is the first study to use oscillometry to explore the relationship between HAP exposure and lung function in children as young as 2 years. The findings provide some evidence that increased postnatal HAP exposure may result in poorer lung function in children, although larger studies are needed to confirm observed results. This study indicates that oscillometry is a low-cost and effective method to determine lung function in early childhood.