title: Ambient air pollution and risk of tuberculosis: a cohort study.
abstract: OBJECTIVE
  Several respirable hazards, including smoking and indoor air pollution from biomass, were suggested to increase the risk of tuberculosis. Few studies have been conducted on ambient air pollution and tuberculosis. We investigated the association between exposure to ambient air pollution and incidence of active tuberculosis.
  
  
  METHODS
  We conducted a cohort study using 106,678 participants of a community-based screening service in Taiwan, 2005-2012. We estimated individual exposure to air pollution using data from the nearest air quality monitoring station and the road intensity within a 500 m buffer zone. The incidence of tuberculosis was ascertained from the national tuberculosis registry.
  
  
  RESULTS
  After a median follow-up of 6.7 years, 418 cases of tuberculosis occurred. Exposure to fine particulate matter (PM2.5) was associated with increased risk of active tuberculosis (adjusted HR: 1.39/10 μg/m3 (95% CI 0.95 to 2.03)). In addition, traffic-related air pollution including nitrogen dioxide (adjusted HR: 1.33/10 ppb; 95% CI 1.04 to 1.70), nitrogen oxides (adjusted HR: 1.21/10 ppb; 95% CI 1.04 to 1.41) and carbon monoxide (adjusted HR: 1.89/ppm; 95% CI 0.78 to 4.58) was associated with tuberculosis risk. There was a non-significant trend between the length of major roads in the neighbourhood and culture-confirmed tuberculosis (adjusted HR: 1.04/km; 95% CI 0.995 to 1.09).
  
  
  CONCLUSIONS
  Our study revealed a possible link between ambient air pollution and risk of active tuberculosis. Since people from developing countries continue to be exposed to high levels of ambient air pollution and to experience high rates of tuberculosis, the impact of worsening air pollution on global tuberculosis control warrants further investigation.
authors.affiliation: Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan Department of Medical Research and Teaching, Mennonite Christian Hospital, Hualien, Taiwan.
authors.forename: Ting-Chun
authors.initials: TC
authors.lastname: Lai
authors.affiliation: International Union Against Tuberculosis and Lung Disease, Paris, France Division of Pulmonary Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
authors.forename: Chen-Yuan
authors.initials: CY
authors.lastname: Chiang
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University, Taipei, Taiwan.
authors.forename: Chang-Fu
authors.initials: CF
authors.lastname: Wu
authors.affiliation: Centers for Disease Control, Taipei, Taiwan.
authors.forename: Shiang-Lin
authors.initials: SL
authors.lastname: Yang
authors.affiliation: Centers for Disease Control, Taipei, Taiwan.
authors.forename: Ding-Ping
authors.initials: DP
authors.lastname: Liu
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University, Taipei, Taiwan Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Miaoli, Taiwan.
authors.forename: Chang-Chuan
authors.initials: CC
authors.lastname: Chan
authors.affiliation: Institute of Epidemiology and Preventive Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Hsien-Ho
authors.initials: HH
authors.lastname: Lin
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D002248:Carbon Monoxide / Q000009:adverse effects*; D015331:Cohort Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000009:adverse effects; D009589:Nitrogen Oxides / Q000009:adverse effects*; D052638:Particulate Matter / Q000009:adverse effects*; D012306:Risk; D013624:Taiwan / Q000453:epidemiology; D014376:Tuberculosis / Q000453:epidemiology / Q000209:etiology*; D001335:Vehicle Emissions
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D052638:Particulate Matter; D001335:Vehicle Emissions; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide