Although epidemiological research suggests that ambient PM2.5 hurts children’s lung function growth, it is unclear whether low-level PM2.5 exposure causes long-term lung function growth decrements in pre- to early adolescent schoolchildren. Repeated lung function tests investigate the long-term effects of PM2.5 within the 4-year concentration range of 10 to 19 μg/m3 on lung function growth. A multilevel linear regression model was used to analyze 6,233 lung function data in 1,466 participants aged 8 to 12 from 16 school communities in 10 cities across, covering a large country region to represent the PM2.5 concentration range. The effects of 10-μg/m3 increases in PM2.5 concentration on relative growth per 10-cm increase in height were studied using forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and maximal expiratory flow at 50% of FVC (V50) as lung function markers.
The annual mean PM2.5 concentration was 13.5 μg/m3 (range: 10.4 to 19.0 μg/m3), with a range of 10.4 to 19.0 μg/m3. Even after correcting for potential confounders, researchers found no link between any lung function growth indicators and increases in PM2.5 levels in children of both sexes. The null results were not changed using two-pollutant models with O3 or NO2. This countrywide longitudinal study reveals that pre-adolescent boys and pre- to early teenage girls have little effect on lung function growth when exposed to PM2.5 at concentrations ranging from 10.4 to 19.0 μg/m3.