ABSTRACT
Background: Long-term exposure to air pollution is associated with lung function impairment. However, whether long-term improvements in air quality could improve lung function is unclear. Methods: : We conducted a prospective quasi-experiment cohort study with 1731 college students in Shandong, China from September 2019 to September 2020, covering COVID-19 lockdown period. Data on PM 2.5 , PM 10 , NO 2 and SO 2 concentrations were obtained from China Environmental Monitoring Station. The concentration of O3 was obtained from Tracking Air Pollution in China. Lung function indicators included forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and forced expiratory flow at 50% of FVC (FEF50%). Linear mixed-effects model was used to examine the associations between the change of air pollutants’ concentrations and the change of lung functions. We also conducted stratified analysis by sex. Results: : Compared with 2019, the mean FVC, FEV1 and FEF50% were elevated by 414.4ml, 321.5ml, and 28.4ml respectively in 2020. Every 5μg/m 3 decrease in annual average PM 2.5 concentrations was associated with 36.0ml [95% confidence interval (CI):6.0, 66.0ml], 46.1ml (95% CI:16.7, 75.5ml), and 124.2ml/s (95% CI:69.5, 178.9ml/s) increment in the FVC, FEV1, and FEF50%, respectively. Similar associations were found for PM 10 . There was no significant effect difference between male and female. Conclusions: : Long-term improvement of air quality can improve lung function among young adults. Stricter policies on improving air quality are needed to protect human health. Funding Taishan Scholar Program