The Effects of Short-Term PM 2.5 Exposure on Pulmonary Function among Children with Asthma-A Panel Study in Shanghai, China.

Fine particulate matter (PM 2.5 ) has been reported to be an important risk factor for asthma. This study was designed to evaluate the relationship between PM 2.5 and lung function among children with asthma in Shanghai, China. From 2016 to 2019, a total of 70 Chinese children aged 4 to 14 in Shanghai were recruited for this panel study. The questionnaire was used to collect baseline information, and the lung function covering forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF) were carried out for each child more than twice during follow-up. Meanwhile, the simultaneous daily air atmospheric pollutants and meteorological data were collected. The linear mixed effect (LME) model was used to assess the relationship between air pollutants and lung function. A significantly negative association was found between PM 2.5 and lung function in children with asthma. In the single-pollutant model, the largest effects of PM 2.5 on lung function were found for lag 0-2, with FVC and FEV1 decreasing by 0.91% [95% confidence interval (CI): -1.75, -0.07] and 1.05% (95% CI: -2.09, 0.00), respectively, for each 10 μg/m 3 increase in PM 2.5 . In the multi-pollution model (adjusted PM 2.5 + SO 2 + O 3 ), the maximum effects of PM 2.5 on FVC and FEV1 also appeared for lag 0-2, with FVC and FEV1 decreasing by 1.57% (95% CI: -2.69, -0.44) and 1.67% (95% CI: -3.05, -0.26), respectively, for each 10 μg/m 3 increase in PM 2.5 . In the subgroup analysis, boys, preschoolers (<6 years old) and hot seasons (May to September) were more sensitive to changes. Our findings may contribute to a better understanding of the short-term exposure effects of PM 2.5 on lung function in children with asthma.