Exposure to coal mine fire smoke emissions impairs lung function in young children
Infants who have been exposed to coal mine fire emissions are at increased risk of long-term impairment of lung reactance, suggest the results of a prospective cohort study.
The authors assessed the association between exposure to a 6‐week episode of air pollution from a coal mine fire in children aged <2 years and their lung function 3 years after the fire. They used dispersion and chemical transport modelling to estimate individual exposure to 24-h average and peak concentrations of particulate matter with an aerodynamic diameter <2.5 μm (PM2.5) during the fire.
Forced oscillation technique (FOT) was carried out to measure lung function, generating standardized Z-scores for resistance and reactance at a frequency of 5 Hz (Rrs5 and Xrs5), and area under the reactance curve (AX). Finally, the associations between PM2.5 exposure and lung function were examined using linear regression models, adjusted for potential confounders.
Eighty-four (aged 4.3±0.5 years) of the 203 infants recruited completed FOT testing. Average and peak PM2.5 had median values of 7.9 (interquartile range [IQR], 6.8–16.8) and 103.4 (IQR, 60.6–150.7) μg/m3, respectively. Mean Z-scores for Rrs5, Xrs5 and AX were 0.56±0.80, –0.76±0.88 and 0.72±0.92, respectively.
A 10-μg/m3 increase in average PM2.5 resulted in worsening AX (β‐coefficient, 0.260; 95 percent confidence interval [CI], 0.019–0.502), while a borderline association was observed between a 100‐μg/m3 increase in peak PM2.5 and AX (β‐coefficient, 0.166; 95 percent CI, −0.002 to 0.334), after adjusting for potential confounders including maternal smoking during pregnancy.