Send Orders for Reprints to reprints@benthamscience.ae 96 The Open Respiratory Medicine Journal, 2016, 10, 96-104 1874-3064/16 2016 Bentham Open The Open Respiratory Medicine Journal Content list available at: www.benthamopen.com/TORMJ/ DOI: 10.2174/1874306401610010096 RESEARCH ARTICLE Effect of Short-Term Exposure to High Particulate Levels on Cough Reflex Sensitivity in Healthy Tourists: A Pilot Study Ryuhei Sato 1,2,3 , Peijun Gui 1 , Kumiko Ito 1 , Masahiro Kohzuki 1 and Satoru Ebihara 1,2,* 1 Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Seiryo- machi 1-1, Aoba-ku, Sendai 980-8574, Japan 2 Department of Rehabilitation Medicine, Toho University Graduate School of Medicine, Omori-nishi 6-11-1, Ota-ku, Tokyo 143-8541, Japan 3 Department of Critical Care Nursing, School of Human Health Science, Kyoto University Graduate School of Medicine, Shogoin Kawahara-cho 53, Sakyo-ku, Kyoto 606-8507, Japan Received: June 14, 2016 Revised: December 05, 2016 Accepted: December 05, 2016 Abstract: Background: Previous studies have reported a relationship between particulate air pollution and respiratory symptoms or decline in lung function, but information about acute effects of short-term exposure to airborne particulate matter (PM) on cough and pulmonary function is scarce. Objective: To investigate the effect of short-term exposure to high concentrations of PM on the cough reflex threshold, urge-to-cough, pulmonary function, and cough-related quality of life in a group of healthy non-resident volunteers visiting Beijing, China. Methods: Seventeen healthy residents of Sendai, Japan, who planned to attend a meeting in Beijing, were recruited. We checked local air quality and measured cough reflex thresholds, urge-to-cough, pulmonary function, and Leicester Cough Questionnaire-acute (LCQ- acute) scores in the volunteers before, during, and after their trip to Beijing. Results: The PM 2.5 and PM 10 concentrations in Beijing were significantly higher than those in Japan on the measurement days. Cough reflex thresholds, expressed as nebulized citric acid concentrations required to induce ≥ 2 and ≥ 5 coughs, were significantly lower during the stay in Beijing than before or after the visit. Vital capacity, forced expiratory volume in one second (FEV 1 ), forced vital capacity (FVC), and FEV 1 /FVC were significantly lower during the stay in Beijing than before the trip. Similarly, the urge-to-cough threshold was significantly lower during the stay in Beijing than after the trip, as was the total LCQ-acute score. Conclusion: We tentatively concluded that short-term exposure to high PM concentrations may have adverse effects on cough reflex and urge-to- cough thresholds, pulmonary function, and cough-related quality of life. Keywords: Cough reflex, Particulate matter, Leicester cough questionnaire-acute, Pulmonary function, Short-term exposure, Urge- to-cough. * Address correspondence to this author at the Department of Rehabilitation Medicine, Toho University Graduate School of Medicine, Omori-nishi 6-11-1, Ota-ku, Tokyo 143-8541, Japan; Tel: +81-3-3762-4151; Fax: +81-3-3768-6125; E-mail: satoru.ebihara@med.toho-u.ac.jp