title: Lung cancer risk among workers in the construction industry: results from two case-control studies in Montreal.
abstract: BACKGROUND
  Given the large number of workers in the construction industry, it is important to derive accurate and valid estimates of cancer risk, and in particular lung cancer risk. In most previous studies, risks among construction workers were compared with general populations including blue and white collar workers. The main objectives of this study were to assess whether construction workers experience excess lung cancer risk, and whether exposure to selected construction industry exposures carries excess risks. We wished to address these objectives within the sub-population of blue collar workers.
  
  
  METHODS
  Two case-control studies were conducted in Montreal. Combined, they included 1593 lung cancer cases and 1427 controls, of whom 1304 cases and 1081 controls had been blue collar workers. Detailed lifetime job histories were obtained and translated by experts into histories of exposure to chemical agents. The two key analyses were to estimate odds ratio (OR) estimates of lung cancer risk: a) for all blue-collar construction workers compared with other blue-collar workers, and b) for construction workers exposed to each of 20 exposure agents found in the construction industry compared with construction workers unexposed to those agents. All analyses were conducted using unconditional logistic regression adjusted for socio-demographic factors and smoking history.
  
  
  RESULTS
  The OR for all construction workers combined was 1.11 (95 % CI: 0.90-1.38), based on 381 blue collar construction workers. Analyses of specific exposures were hampered by small numbers and imprecise estimates. While none of 20 occupational agents examined was significantly associated with lung cancer, the following agents manifested non-significantly elevated ORs: asbestos, silica, Portland cement, soil dust, calcium oxide and calcium sulfate.
  
  
  CONCLUSIONS
  Compared with other blue collar workers, there was only a slight increased risk of lung cancer for subjects who ever held an occupation in the construction industry. The analyses of agents within the construction industry produced imprecise estimates of risk, but nevertheless pointed to some plausible associations. Excess risks for asbestos and silica were in line with previous knowledge. The possible excess risks with the other inorganic dusts require further corroboration.
authors.affiliation: University of Montreal Hospital Research Center (CRCHUM), 850 rue St-Denis, Montreal, Qc, H2X 0A9, Canada. aude.lacourt@isped.u-bordeaux2.fr.|Université de Bordeaux, ISPED, Centre INSERM U897-Epidemiologie-Biostatistique, F-33000, Bordeaux, France. aude.lacourt@isped.u-bordeaux2.fr.|INSERM, ISPED, Centre INSERM U897-Epidemiologie-Biostatistique, F-33000, Bordeaux, France. aude.lacourt@isped.u-bordeaux2.fr.
authors.forename: Aude
authors.initials: A
authors.lastname: Lacourt
authors.affiliation: University of Montreal Hospital Research Center (CRCHUM), 850 rue St-Denis, Montreal, Qc, H2X 0A9, Canada. javier.pintos@crchum.qc.ca.
authors.forename: Javier
authors.initials: J
authors.lastname: Pintos
authors.affiliation: University of Montreal Hospital Research Center (CRCHUM), 850 rue St-Denis, Montreal, Qc, H2X 0A9, Canada. jerome.lavoue@umontreal.ca.|Department of Environmental and Occupational Health, School of Public Health, University of Montreal, Montreal, QC, Canada. jerome.lavoue@umontreal.ca.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Lavoué
authors.affiliation: University of Montreal Hospital Research Center (CRCHUM), 850 rue St-Denis, Montreal, Qc, H2X 0A9, Canada. lesley.richardson@sympatico.ca.
authors.forename: Lesley
authors.initials: L
authors.lastname: Richardson
authors.affiliation: University of Montreal Hospital Research Center (CRCHUM), 850 rue St-Denis, Montreal, Qc, H2X 0A9, Canada. j.siemiatycki@umontreal.ca.|Department of Social and Preventive Medicine, School of Public Health, University of Montreal, Montreal, QC, Canada. j.siemiatycki@umontreal.ca.|Guzzo-Cancer Research Society Chair in Environment and Cancer, School of Public Health, University of Montreal, Montreal, QC, Canada. j.siemiatycki@umontreal.ca.
authors.forename: Jack
authors.initials: J
authors.lastname: Siemiatycki
mesh_terms: D000328:Adult; D000368:Aged; D001194:Asbestos; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D060389:Construction Industry / Q000706:statistics & numerical data*; D004391:Dust; D005260:Female; D006801:Humans; D016015:Logistic Models; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology*; D016273:Occupational Exposure / Q000706:statistics & numerical data; D016017:Odds Ratio
chemical_list: D004391:Dust; D001194:Asbestos