title: Lifetime environmental exposure to tobacco smoke and primary lung cancer of non-smoking Taiwanese women.
abstract: BACKGROUND
  For a female population with a high lung cancer mortality rate, such as Taiwanese women, who smoke relatively rarely, but live in an environment with high male smoking prevalence, the risk and population burden of lung cancer due to environmental tobacco smoke (ETS) are relatively important.
  
  
  METHODS
  An age-matched case-control study was designed to investigate the effects of cumulative environmental exposure to tobacco smoke during childhood and adult life on lung cancer risk among non-smoking women in Taiwan. Information on passive smoking from all possible sources and life periods were obtained from interviews with 268 and 445 lifetime non-smoking cases and controls. Conditional logistic regression and synergism 'S' index were applied to the data to assess the independent and joint effects of passive smoking in different life stages while controlling for possible confounding variables.
  
  
  RESULTS
  Risks of contracting lung cancer among women near-distantly exposed to the highest level of ETS in childhood (>20 smoker-years) and in adult life (>40 smoker-years) were 1.8-fold (95% CI: 1.2-2.9) and 2.2-fold (95% CI: 1.4-3.7) higher than that among women being never exposed to ETS, and the two variables accounted for about 37% of tumours in this non-smoking female population. Children were found to be more susceptible to ETS than adults and such early exposure was found to modify the effect of subsequent tobacco smoke exposure in adult life based on an additive interaction model.
  
  
  CONCLUSIONS
  Environmental tobacco smoke exposure occurring in childhood potentiates the effect of high doses of exposure in adult life in determining the development of lung cancer. Smoking prohibition would be expected to protect about 37% of non-smoking Taiwanese women against lung cancer.
authors.affiliation: Graduate Institute of Medicine, School of Public Health, Kaohsiung Medical University, Taiwan, ROC.
authors.forename: C H
authors.initials: CH
authors.lastname: Lee
authors.forename: Y C
authors.initials: YC
authors.lastname: Ko
authors.forename: W
authors.initials: W
authors.lastname: Goggins
authors.forename: J J
authors.initials: JJ
authors.lastname: Huang
authors.forename: M S
authors.initials: MS
authors.lastname: Huang
authors.forename: E L
authors.initials: EL
authors.lastname: Kao
authors.forename: H Z
authors.initials: HZ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D016902:Air Pollution, Indoor / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D015996:Survival Rate; D013624:Taiwan / Q000453:epidemiology; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D014028:Tobacco Smoke Pollution