title: Dietary factors, food contamination and lung cancer risk in Xuanwei, China.
abstract: BACKGROUND
  In rural Xuanwei County, China, the high incidence of lung cancer is attributable largely to burning smoky coal indoors for heating and cooking without adequate ventilation. Such burning generates very high levels of indoor air pollutants, including carcinogenic polycyclic aromatic hydrocarbons, which could contaminate foodstuffs in the home. Thus, residents could be exposed to carcinogenic coal emissions not only via inhalation but also via ingestion of these foodstuffs.
  
  
  METHODS
  A population-based case-control study of 498 lung cancer patients and 498 controls was conducted from 1985 through 1990 in Xuanwei. The interviewer-administered study questionnaire queried the frequency of food items commonly consumed in this region. Overall and sex-specific multiple logistic regression models were constructed to estimate Odds ratios (OR) and 95% confidence intervals (CI) for consumption of these foods.
  
  
  RESULTS
  Intake of rice, green vegetables, mushrooms and fresh meat was associated with an increased risk of lung cancer. In contrast, intake of corn, buckwheat, radishes, peppers, melons, pickled vegetables, and salt-preserved meats was associated with reduced risk. The detrimental effect of ingesting green vegetables (OR, 2.39; 95% CI, 1.28-4.48) is consistent with previous reports.
  
  
  CONCLUSIONS
  These findings suggest that in Xuanwei, food contamination by environmental polycyclic aromatic hydrocarbons may be an important risk factor for lung cancer, and that differential contamination of foods by polycyclic aromatic hydrocarbons possibly explained the different associations with lung cancer risk.
authors.affiliation: Division of Cancer Epidemiology and Genetics, NCI, NIH, DHHS, Bethesda, MD, United States. shenmi@mail.nih.gov
authors.forename: Min
authors.initials: M
authors.lastname: Shen
authors.forename: Robert S
authors.initials: RS
authors.lastname: Chapman
authors.forename: Xingzhou
authors.initials: X
authors.lastname: He
authors.forename: Larry Z
authors.initials: LZ
authors.lastname: Liu
authors.forename: Hong
authors.initials: H
authors.lastname: Lai
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Qing
authors.initials: Q
authors.lastname: Lan
mesh_terms: D016902:Air Pollution, Indoor / Q000009:adverse effects*; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D003031:Coal / Q000633:toxicity*; D004032:Diet; D005260:Female; D005506:Food Contamination; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008175:Lung Neoplasms / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D012307:Risk Factors; D012424:Rural Population; D011795:Surveys and Questionnaires
chemical_list: D003031:Coal; D011084:Polycyclic Aromatic Hydrocarbons