title: Influence of environmental exposures on patients with chronic obstructive pulmonary disease in Korea.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation and results from environmental factors and genetic factors. Although cigarette smoking is a major risk factor, other environmental exposures can influence COPD. The purpose of this study is to investigate the clinical characteristics of COPD according to the history of environmental exposure.
  
  
  METHODS
  The study population comprised of 347 subjects with COPD who were recruited from the pulmonary clinics of 14 hospitals within the Korean Obstructive Lung Disease Study Group. We classified environmental exposures according to history of living near factory, and direct exposure history to firewood or briquette. According to living environmental exposures, we compared the frequency of respiratory symptoms, pulmonary function, quality of life, exercise capacity, and computed tomography phenotypes.
  
  
  RESULTS
  Thirty-one subjects (8.9%) had history of living near factory, 271 (78.3%) had exposure history to briquette, and 184 (53.3%) had exposure history to firewood. Patients with history of living near a factory had a significantly longer duration of sputum, while patients with exposure to firewood tended to have lower forced expiratory volume in one second, and patients with exposure to briquette tended to have lower six minute walk distance.
  
  
  CONCLUSIONS
  COPD subjects with the history of living near factory had more frequent respiratory symptoms such as sputum. Our data suggest that environmental exposure may influence clinical phenotype of COPD.
authors.affiliation: Department of Internal Medicine and Environmental Health Center, Kangwon National University Hospital, Chuncheon, Korea.
authors.forename: Yoonki
authors.initials: Y
authors.lastname: Hong
authors.affiliation: Department of Respiratory Center, Kangwon National University Hospital, Kangwon National University School of Medicine, Chuncheon, Korea.
authors.forename: Myoung Nam
authors.initials: MN
authors.lastname: Lim
authors.affiliation: Department of Internal Medicine and Environmental Health Center, Kangwon National University Hospital, Chuncheon, Korea.
authors.forename: Woo Jin
authors.initials: WJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
authors.forename: Chin Kook
authors.initials: CK
authors.lastname: Rhee
authors.affiliation: Department of Internal Medicine, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Kwang Ha
authors.initials: KH
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
authors.forename: Ji-Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
authors.forename: Ho Il
authors.initials: HI
authors.lastname: Yoon
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
authors.forename: Tae-Hyung
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Ewha Womans University Mokdong Hospital, Ewha Womans University College of Medicine, Seoul, Korea.
authors.forename: Jin Hwa
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seong Yong
authors.initials: SY
authors.lastname: Lim
authors.affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Lee
authors.affiliation: Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Yeon-Mok
authors.initials: YM
authors.lastname: Oh
keywords: Air Pollutants; Environmental Exposure; Fossil Fuels; Occupational Exposure; Pulmonary Disease, Chronic Obstructive