title: Ambient particulate matter and lung cancer incidence and mortality: a meta-analysis of prospective studies.
abstract: BACKGROUND
  Chronic exposure to ambient particulate matter (PM) has been suggested to be associated with an increased risk of lung cancer, but the results were inconsistent. We performed a systematic review and meta-analysis of prospective studies to assess the association between exposure to PM and the incidence and mortality of lung cancer in adults.
  
  
  METHODS
  We searched PUBMED and EMBASE databases for prospective cohort studies that evaluated the association between PM2.5 (diameter < 2.5 μm), PM10 (diameter < 10 μm) and lung cancer incidence and mortality. Relative risks (RRs) and 95% confidence interval (CI) were calculated using fixed-effect or random-effects models when appropriate.
  
  
  RESULTS
  We initially identified 1987 citations, and 19 prospective cohort studies were finally included in our meta-analysis. The pooled adjusted RRs for lung cancer mortality were 1.09 (95% CI: 1.06-1.11; I(2) = 18.3%, P = 0.26) for 10 µg/m(3) increase in the concentration of PM2.5 (12 studies), and 1.05 (95% CI: 1.03-1.07; I(2) = 41.9%, P = 0.11) for 10 µg/m(3) increase in the concentration of PM10 (seven studies). The increased risk of lung cancer mortality associated with PM2.5 and PM10 was consistent across most subgroups. PM10 (three studies) and PM2.5 (two studies) were not found to be significantly associated with lung cancer incidence.
  
  
  CONCLUSIONS
  Ambient PM2.5 and PM10 pollutions are prospectively associated with a significantly increased risk of lung cancer mortality. More studies addressing the association between PM and lung cancer incidence are required.
authors.affiliation: 1 Department of Epidemiology and Biostatistics, Key Laboratory of Cancer Prevention and Therapy, Tianjin, National Clinical Research Centre of Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, P. R. China.
authors.forename: Ping
authors.initials: P
authors.lastname: Cui
authors.affiliation: 1 Department of Epidemiology and Biostatistics, Key Laboratory of Cancer Prevention and Therapy, Tianjin, National Clinical Research Centre of Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, P. R. China.
authors.forename: Yubei
authors.initials: Y
authors.lastname: Huang
authors.affiliation: 2 Department of Epidemiology, Fairbanks School of Public Health, Simon Cancer Center, Indiana University, Indianapolis, Indiana.
authors.forename: Jiali
authors.initials: J
authors.lastname: Han
authors.affiliation: 1 Department of Epidemiology and Biostatistics, Key Laboratory of Cancer Prevention and Therapy, Tianjin, National Clinical Research Centre of Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, P. R. China.
authors.forename: Fengju
authors.initials: F
authors.lastname: Song
authors.affiliation: 1 Department of Epidemiology and Biostatistics, Key Laboratory of Cancer Prevention and Therapy, Tianjin, National Clinical Research Centre of Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, P. R. China chenkexin1963@yahoo.com songfengju@163.com.
authors.forename: Kexin
authors.initials: K
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000032:analysis*; D011446:Prospective Studies; D015996:Survival Rate
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter