title: Ambient air pollution and primary liver cancer incidence in four European cohorts within the ESCAPE project.
abstract: Tobacco smoke exposure increases the risk of cancer in the liver, but little is known about the possible risk associated with exposure to ambient air pollution.
  
  
  
  We evaluated the association between residential exposure to air pollution and primary liver cancer incidence.
  
  
  
  We obtained data from four cohorts with enrolment during 1985-2005 in Denmark, Austria and Italy. Exposure to nitrogen oxides (NO2and NOX), particulate matter (PM) with diameter of less than 10µm (PM10), less than 2.5µm (PM2.5), between 2.5 and 10µm (PM2.5-10) and PM2.5 absorbance(soot) at baseline home addresses were estimated using land-use regression models from the ESCAPE project. We also investigated traffic density on the nearest road. We used Cox proportional-hazards models with adjustment for potential confounders for cohort-specific analyses and random-effects meta-analyses to estimate summary hazard ratios (HRs) and 95% confidence intervals (CIs).
  
  
  
  Out of 174,770 included participants, 279 liver cancer cases were diagnosed during a mean follow-up of 17 years. In each cohort, HRs above one were observed for all exposures with exception of PM2.5 absorbanceand traffic density. In the meta-analysis, all exposures were associated with elevated HRs, but none of the associations reached statistical significance. The summary HR associated with a 10-μg/m3increase in NO2was 1.10 (95% confidence interval (CI): 0.93, 1.30) and 1.34 (95% CI: 0.76, 2.35) for a 5-μg/m3increase in PM2.5.
  
  
  
  The results provide suggestive evidence that ambient air pollution may increase the risk of liver cancer. Confidence intervals for associations with NO2and NOXwere narrower than for the other exposures.
authors.affiliation: The Danish Cancer Society Research Center, Copenhagen, Denmark; Centre for Epidemiology and Screening, Department of Public Health, University of Copenhagen, Copenhagen, Denmark. Electronic address: mp@sund.ku.dk.
authors.forename: Marie
authors.initials: M
authors.lastname: Pedersen
authors.affiliation: Centre for Epidemiology and Screening, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Zorana J
authors.initials: ZJ
authors.lastname: Andersen
authors.affiliation: Department of Epidemiology, Lazio Regional Health Service, Local Health Unit ASL RM1, Rome, Italy; Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Massimo
authors.initials: M
authors.lastname: Stafoggia
authors.affiliation: Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany.
authors.forename: Gudrun
authors.initials: G
authors.lastname: Weinmayr
authors.affiliation: Unit of Cancer Epidemiology, Città della Salute e della Scienza University-Hospital and Center for Cancer Prevention (CPO), Turin, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Galassi
authors.affiliation: The Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Mette
authors.initials: M
authors.lastname: Sørensen
authors.affiliation: The Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Kirsten T
authors.initials: KT
authors.lastname: Eriksen
authors.affiliation: The Danish Cancer Society Research Center, Copenhagen, Denmark.
authors.forename: Anne
authors.initials: A
authors.lastname: Tjønneland
authors.affiliation: Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Steffen
authors.initials: S
authors.lastname: Loft
authors.affiliation: Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Jaensch
authors.affiliation: Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany; Agency for Preventive and Social Medicine, Bregenz, Austria.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Nagel
authors.affiliation: Agency for Preventive and Social Medicine, Bregenz, Austria.
authors.forename: Hans
authors.initials: H
authors.lastname: Concin
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA.
authors.forename: Ming-Yi
authors.initials: MY
authors.lastname: Tsai
authors.affiliation: Epidemiology and Prevention Unit, Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Grioni
authors.affiliation: Unit of Epidemiology & Medical Statistics, Department of Diagnostics and Public Health, University of Verona, Verona, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marcon
authors.affiliation: Epidemiology and Prevention Unit, Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Krogh
authors.affiliation: Unit of Epidemiology, Regional Health Service ASL TO3, Grugliasco, Italy; Unit of Cancer Epidemiology, Città della Salute e della Scienza University-Hospital and Center for Cancer Prevention (CPO), Turin, Italy.
authors.forename: Fulvio
authors.initials: F
authors.lastname: Ricceri
authors.affiliation: Unit of Cancer Epidemiology, Città della Salute e della Scienza University-Hospital and Center for Cancer Prevention (CPO), Turin, Italy.
authors.forename: Carlotta
authors.initials: C
authors.lastname: Sacerdote
authors.affiliation: Environmental Health Reference Centre, Regional Agency for Prevention, Environment and Energy of Emilia-Romagna, Modena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ranzi
authors.affiliation: Centre for Atmospheric and Instrumentation Research, University of Hertfordshire, College Lane, Hatfield, United Kingdom.
authors.forename: Ranjeet
authors.initials: R
authors.lastname: Sokhi
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands; Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands; School of Public Health, Imperial College, London, United Kingdom.
authors.forename: Roel
authors.initials: R
authors.lastname: Vermeulen
authors.affiliation: Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland.
authors.forename: Kees de
authors.initials: K
authors.lastname: Hoogh
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA.
authors.forename: Meng
authors.initials: M
authors.lastname: Wang
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands; National Institute for Public Health (RIVM), Bilthoven, The Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Beelen
authors.affiliation: School of Public Health, Imperial College, London, United Kingdom; Molecular end Epidemiology Unit, HuGeF, Human Genetics Foundation, Torino, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Vineis
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands; Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Bert
authors.initials: B
authors.lastname: Brunekreef
authors.affiliation: Institute for Risk Assessment Sciences, Utrecht University, Utrecht, The Netherlands.
authors.forename: Gerard
authors.initials: G
authors.lastname: Hoek
authors.affiliation: The Danish Cancer Society Research Center, Copenhagen, Denmark; Department of Environmental Science, Aarhus University, Roskilde, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Raaschou-Nielsen
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects* / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000032:analysis; D001317:Austria / Q000453:epidemiology; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D007558:Italy / Q000453:epidemiology; D008113:Liver Neoplasms / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D009589:Nitrogen Oxides / Q000009:adverse effects* / Q000032:analysis; D052638:Particulate Matter / Q000009:adverse effects* / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis / Q000633:toxicity*
chemical_list: D000393:Air Pollutants; D009589:Nitrogen Oxides; D052638:Particulate Matter; D001335:Vehicle Emissions
keywords: Ambient air pollution; Cohort; Environment; Liver cancer; Motorized vehicle traffic