title: Long-term exposure to fine particulate matter air pollution and the risk of lung cancer among participants of the Canadian National Breast Screening Study.
abstract: Recently, air pollution has been classified as a carcinogen largely on the evidence of epidemiological studies of lung cancer. However, there have been few prospective studies that have evaluated associations between fine particulate matter (PM2.5 ) and cancer at lower concentrations. We conducted a prospective analysis of 89,234 women enrolled in the Canadian National Breast Screening Study between 1980 and 1985, and for whom residential measures of PM2.5 could be assigned. The cohort was linked to the Canadian Cancer Registry to identify incident lung cancers through 2004. Surface PM2.5 concentrations were estimated using satellite data. Cox proportional hazards models were used to characterize associations between PM2.5 and lung cancer. Hazard ratios (HRs) and 95% confidence intervals (CIs) computed from these models were adjusted for several individual-level characteristics, including smoking. The cohort was composed predominantly of Canadian-born (82%), married (80%) women with a median PM2.5 exposure of 9.1 µg/m(3) . In total, 932 participants developed lung cancer. In fully adjusted models, a 10 µg/m(3) increase in PM2.5 was associated with an elevated risk of lung cancer (HR: 1.34; 95% CI = 1.10, 1.65). The strongest associations were observed with small cell carcinoma (HR: 1.53; 95% CI = 0.93, 2.53) and adenocarcinoma (HR: 1.44; 95% CI = 1.06, 1.97). Stratified analyses suggested increased PM2.5 risks were limited to those who smoked cigarettes. Our findings are consistent with previous epidemiological investigations of long-term exposure to PM2.5 and lung cancer. Importantly, they suggest associations persist at lower concentrations such as those currently found in Canadian cities.
authors.affiliation: Department of Health Sciences, Carleton University, Ottawa, ON, K1S5B6, Canada.
authors.forename: Anna
authors.initials: A
authors.lastname: Tomczak
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, Toronto, ON, M5T 3M7, Canada.
authors.forename: Anthony B
authors.initials: AB
authors.lastname: Miller
authors.affiliation: Department of Epidemiology, Biostatistics, and Occupational Health and Gerald Bronfman Department of Oncology, McGill University, Montreal, QC, H3A 1A2, Canada.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Weichenthal
authors.affiliation: Child Health Evaluative Sciences, The Hospital for Sick Children, Ottawa, ON, M5G1X8, Canada.
authors.forename: Teresa
authors.initials: T
authors.lastname: To
authors.affiliation: Dalla Lana School of Public Health, University of Toronto, Toronto, ON, M5T 3M7, Canada.
authors.forename: Claus
authors.initials: C
authors.lastname: Wall
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: van Donkelaar
authors.affiliation: Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
authors.forename: Randall V
authors.initials: RV
authors.lastname: Martin
authors.affiliation: NB Institute of Research, Data and Training, University of New Brunswick, Fredericton, NB, E3B 5A3, Canada.
authors.forename: Dan Lawson
authors.initials: DL
authors.lastname: Crouse
authors.affiliation: Department of Health Sciences, Carleton University, Ottawa, ON, K1S5B6, Canada.|Dalla Lana School of Public Health, University of Toronto, Toronto, ON, M5T 3M7, Canada.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Villeneuve
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced / Q000453:epidemiology*; D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D001943:Breast Neoplasms / Q000175:diagnosis; D002170:Canada; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D008403:Mass Screening; D008875:Middle Aged; D052638:Particulate Matter / Q000633:toxicity*; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012042:Registries; D055752:Small Cell Lung Carcinoma / Q000139:chemically induced / Q000453:epidemiology*; D012907:Smoking / Q000009:adverse effects
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter
keywords: cigarette smoking; cohort study; fine particulate matter air pollution; histological type; lung cancer