Abstract: Objective To exlpore the short-term effect of ambient fine particle matter （PM_2.5） on the incidence of acute cough. Methods A questionnaire survey on environment and health was conducted among residents in seven communities in three cities in the Pearl River Delta from November 2017 to February 2018, to investigate the occurrence of acute cough symptoms two weeks prior to the survey. Data of daily air pollution and weather of the communities were also collected simultaneously. Two-level logistic regression model was used to estimate the association between PM_2.5 and occurrence of acute cough. Results A total of 7 151 residents were surveyed, and 223（3.12%）of them had acute cough symptoms in the past two weeks. A significant short-term effect of exposure to PM_2.5 on acute cough was observed, with a delayed effect for seven days. The odds ratio （OR） was 1.21（95% CI：1.06,1.37） for each increment of 10 µg/m³ in PM_2.5 on lag day1, and the effect of PM_2.5 sliding average was the highest （OR=1.19; 95% CI：1.05,1.37）from lag day 0 to lag day 4. The stratified analyses revealed that a higher risk of onset was observed in females （OR=1.25, 95%CI： 1.04, 1.50） than that in males （OR=1.10, 95%CI： 0.92, 1.33）（P<0.05）. Conclusion PM_2.5 can increase the risk of acute cough in the short term, and women had higher risk of acute cough induced by PM_2.5 exposure.

Key words: PM_2.5, Acute cough, Short-term effect, Multi-level model