Exposure to coal mine fire smoke emissions impairs lung function in young children
01 Feb 2020
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.