Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 46 11 2017 11 01 1486 1494 Guangxi LI Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China AND Division of Pulmonary and Critical Care Medicine, Mayo Epidemiology and Translational Research in Intensive Care, Rochester, United States Haitao LAN Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China AND Division of Pulmonary and Critical Care Medicine, Mayo Epidemiology and Translational Research in Intensive Care, Rochester, United States Zhiguo LIU Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Ting RUI Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Jiapeng LU Fu Wai Hospital, Chinese National Center for Cardiovascular Diseases, Beijing, 100037, China Lingjie BIAN Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Yinghui WANG Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Shihan WANG Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Hong ZHANG Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Yongjun BIAN Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Hui LI Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Yuyan GUO Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Shigang LIU Guang'anmen Hospital, Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China Liang LI Dept. of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100050, China 2017 11 01 2017 11 01 Background: We tried to investigate the effect of PM2.5 on daily counts of outpatient visits in the Guang’anmen Hospital to determine if short-term PM2.5 exposure with extremely high concentration affects cardiopulmonary function of Beijing residents. Methods: Outpatient visits and PM2.5 data from 01/11/2011 to 03/31/2013 were extracted from the Guang’anmen Hospital and the American Embassy in Beijing, respectively. Followed by using a semi-parametric generalized additive model (GAM) with time dependent covariates, we analyzed the association between PM2.5 concentrations and daily count of outpatient visits on Day 0, 1, 2, 3, 4 and 5 of PM2.5 exposure. Results: Overall, 284354 subjects were collected. There were significant associations of short-term PM2.5 exposures with outpatient visits for cardiopulmonary diseases (P<0.05). Specifically, a 10 µg/m3 increase in PM2.5 was positively associated with a 0.74% of increase in angina visit on the first day and 0.50% increased visit on the second day (P<0.05). With an increase in PM2.5, the cough and respiratory visits significantly decreased by 0.17% and 0.30% on the first day, respectively (P<0.05). However, there were significant positive associations of PM2.5 with increased cough and respiratory visits (increased by 0.17% and 0.10%, respectively) on the fifth day (P<0.05). Conclusion: Our association studies showed an instant effect of PM2.5 level on cardiovascular outpatient visit in the Guang’anmen Hospital in Beijing while a lag effect on respiratory outpatient visits.     https://ijph.tums.ac.ir/index.php/ijph/article/view/11476 https://ijph.tums.ac.ir/index.php/ijph/article/download/11476/5815