title: Environmental tobacco smoke and risk of adult leukemia.
abstract: BACKGROUND
  The role of environmental tobacco smoke (ETS) in the causation of lung and breast cancer has been repeatedly evaluated over recent years. In contrast, its impact on the risk of adult leukemia has received little attention.
  
  
  METHODS
  We used the lifetime residential and occupational ETS exposure histories from a population-based sample of 1068 incident and histologically confirmed adult leukemia cases and 5039 population controls age 20 to 74 years to evaluate the relationship between ETS exposure and adult leukemia risk among nonsmokers in Canada. The duration of exposure and smoker-years index were used as indices of ETS exposure. We restricted our analysis to the 266 case and 1326 control subjects who reported being lifetime nonsmokers and provided residential ETS exposure history for at least 75% of their lifetime.
  
  
  RESULTS
  No association was found for most leukemia subtypes, and in particular for acute myeloid leukemia. In contrast, the risk for chronic lymphocytic leukemia was clearly associated with ETS exposure, with an adjusted odds ratio of 2.3 (95% confidence interval = 1.2-4.5) for more than 83 smoker-years of residential exposure and 2.4 (1.3-4.3) for more than 72 smoker-years of occupational exposure. There was a dose-response relationship for chronic lymphocytic leukemia with both indices of exposure. Risk was not higher with recent exposure, using time-window-exposure analyses.
  
  
  CONCLUSIONS
  Regular long-term ETS exposure may be a risk factor for chronic lymphocytic leukemia.
authors.affiliation: Département de médecine sociale et préventive, Faculté de Médecine, Université Laval, Sainte-Foy, Québec, Canada.
authors.forename: Khaled
authors.initials: K
authors.lastname: Kasim
authors.forename: Patrick
authors.initials: P
authors.lastname: Levallois
authors.forename: Belkacem
authors.initials: B
authors.lastname: Abdous
authors.forename: Pierre
authors.initials: P
authors.lastname: Auger
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000368:Aged; D002170:Canada / Q000453:epidemiology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D015994:Incidence; D007938:Leukemia / Q000453:epidemiology*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D011159:Population Surveillance; D012042:Registries; D012306:Risk; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution