biostudies-literatureWei SBeijing Science and Technology ProjectNational Natural Science Foundation of ChinaPeking University Clinical Research ProjectNational Key Research and Development Plan of ChinaCapital Health Research and Development of Special FundBeijing Natural Science Foundation139https://www.ebi.ac.uk/biostudies/studies/S-EPMC10214547biostudies-literatureUnknown24(1)<h4>Background</h4>The associations between short- and long-term exposure to ambient fine particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM_2.5) and allergic symptoms in middle-aged and elderly populations remain unclear, particularly in China, where most cities have severe air pollution.<h4>Methods</h4>Participants (n = 10,142; age = 40-75 years) were recruited from ten regions in China from 2018 to 2021 for the Predictive Value of Inflammatory Biomarkers and Forced Expiratory Volume in 1 s (FEV₁) for Chronic Obstructive Pulmonary Disease (PIFCOPD) study. Short-term (lag0 and lag0-7 day) and long-term (1-, 3- and 5-year) PM_2.5 concentrations at residences were extracted from the air pollutant database known as Tracking Air Pollution (TAP) in ChinRespiratory researchAmbient fine particulate matter and allergic symptoms in the middle-aged and elderly population: results from the PIFCOPD study.PMC102145472017YFC1309500813701067161013PUCRP2013032016-1-4071Z121100005512026Zhang GLiu HCao HFu XDong LJiang SWang GZhang LYu KDong SLiao JNing QXue TZhao LWang RMiao BWei SZhou BJia WZhang CDang XChen RSun JQiao HLi JSong BXie LHe LYan XLi WGao PXiao JYin MYin JfalseAmbient fine particulate matter and allergic symptoms in the middle-aged and elderly population: results from the PIFCOPD study.<h4>Background</h4>The associations between short- and long-term exposure to ambient fine particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM_2.5) and allergic symptoms in middle-aged and elderly populations remain unclear, particularly in China, where most cities have severe air pollution.<h4>Methods</h4>Participants (n = 10,142; age = 40-75 years) were recruited from ten regions in China from 2018 to 2021 for the Predictive Value of Inflammatory Biomarkers and Forced Expiratory Volume in 1 s (FEV₁) for Chronic Obstructive Pulmonary Disease (PIFCOPD) study. Short-term (lag0 and lag0-7 day) and long-term (1-, 3- and 5-year) PM_2.5 concentrations at residences were extracted from the air pollutant database known as Tracking Air Pollution (TAP) in Chin2023-01-01T00:00:00Z2023 May2026-07-14T22:22:09.564Z2025-04-19T15:06:57.456ZS-EPMC102145473723144510.1186/s12931-023-02433-2