title: Effect of Short-Term Exposure to High Particulate Levels on Cough Reflex Sensitivity in Healthy Tourists: A Pilot Study.
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 PM2.5and PM10concentrations 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 (FEV1), forced vital capacity (FVC), and FEV1/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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Seiryo-machi 1-1, Aoba-ku, Sendai 980-8574, Japan; Department of Rehabilitation Medicine, Toho University Graduate School of Medicine, Omori-nishi 6-11-1, Ota-ku, Tokyo 143-8541, Japan; 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.
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Sato
authors.affiliation: Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Seiryo-machi 1-1, Aoba-ku, Sendai 980-8574, Japan.
authors.forename: Peijun
authors.initials: P
authors.lastname: Gui
authors.affiliation: Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Seiryo-machi 1-1, Aoba-ku, Sendai 980-8574, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Ito
authors.affiliation: Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Seiryo-machi 1-1, Aoba-ku, Sendai 980-8574, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kohzuki
authors.affiliation: Department of Internal Medicine and Rehabilitation Science, Tohoku University Graduate School of Medicine, Seiryo-machi 1-1, Aoba-ku, Sendai 980-8574, Japan; Department of Rehabilitation Medicine, Toho University Graduate School of Medicine, Omori-nishi 6-11-1, Ota-ku, Tokyo 143-8541, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Ebihara
keywords: Cough reflex; Leicester cough questionnaire-acute; Particulate matter; Pulmonary function; Short-term exposure; Urge-to-cough