The Effects of Short-term Pm 2.5 Exposure on Pulmonary Function Among Children With Asthma——A Panel Study in Shanghai, China

Background: Fine particulate matter with aerodynamic diameter ≤ 2.5 mm (PM 2.5 ) has been reported to be an important risk factor for asthma. Our study was designed to evaluate the relationship between air PM 2.5 and lung function among children with asthma in Shanghai, China. MethodsFrom 2016 to 2019, a total of 70 Chinese children aged 4 to 14 in Pudong, Shanghai were recruited for this panel study. Upon entry to the group, questionnaire was used to collect basic information, and the lung function covering forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and peak expiratory flow (PEF) were carried out for each child more than two times 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 adjusting other covariates like sex, age, season and so on. ResultsA significantly negative association was found between PM 2.5 level and lung function in children with asthma. In the single-pollutant model, the largest effect of PM 2.5 on lung function were found on lag 0-2, FVC and FEV1 decreased by 0.91% [95% confidence interval (CI): -1.75, -0.07] and 1.05% (95% CI: -2.09, 0.00) for every 10 mg/m 3 increase of PM 2.5 . In the multi-pollution model (adjusted PM 2.5 +SO 2 +O 3 ), the maximum effect of PM 2.5 on FVC and FEV1 also appeared on lag 0-2, FVC and FEV1 decreased by 1.57% (95% CI: -2.69, -0.44) and 1.67% (95% CI: -3.05, -0.26) for every 10 mg/m 3 increase of PM 2.5 , respectively. In the subgroup analysis, boys, children and hot season more were sensitive. ConclusionThe short-term exposure of ambient PM 2.5 is a risk factor for the lung function of children with asthma, particularly in boys, preschoolers (<6 years old) and in the hot season.