title: A case-control study of asphalt and tar exposure and lung cancer in minorities.
abstract: OBJECTIVE
  Considerable controversy surrounds the carcinogenic potential of asphalt and tar. Since minority individuals may have had relatively high historical exposures, we investigated asphalt and tar exposure and lung cancer risk among African Americans and Latino Americans.
  
  
  METHODS
  We conducted a case-control study of lung cancer among African Americans and Latino Americans in the San Francisco Bay area (422 cases, 894 controls). A questionnaire was used to obtain detailed work histories and exposure information. Self-reported exposure to asphalt and tar as well as other factors (e.g., smoking, automobile exhaust, and asbestos) were evaluated as predictors of lung cancer risk. Potential effect modification by cytochrome P450 (CYP) 1A1 was also explored.
  
  
  RESULTS
  Self-reported duration of exposure to asphalt and tar was associated with a statistically significant excess risk of lung cancer in the overall population (OR: 1.11, 95% CI: 1.01-1.22), evaluating risk per year of exposure. Years of exposure to automobile exhaust (OR: 1.02, 95% CI: 1.00-1.05) and asbestos (OR: 1.04, 95% CI: 1.02-1.06) were also associated with statistically significant elevations in risk. In Latino Americans, the lung cancer risks associated with polycyclic aromatic hydrocarbon-related exposures were consistently higher in the CYP1A1 wild-type subjects as compared to the variant genotype subjects, and the interaction was statistically significant for smoking and the CYP1A1 M2 polymorphism (P-value(interaction) = 0.02).
  
  
  CONCLUSIONS
  These data are consistent with the literature suggesting that exposure to asphalt and tar may increase risk of lung cancer. However, it was not possible to separate the effects and asphalt and tar in this study.
authors: Department of Environmental Health, Boston University School of Public Health, Massachusetts, USA. mmcclean@bu.edu
authors: Michael D
authors: MD
authors: McClean
authors: Karl T
authors: KT
authors: Kelsey
authors: Jennette D
authors: JD
authors: Sison
authors: Charles P
authors: CP
authors: Quesenberry
authors: Margaret R
authors: MR
authors: Wrensch
authors: John K
authors: JK
authors: Wiencke
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D006630:Hispanic or Latino / Q000706:statistics & numerical data; D006801:Humans; D006838:Hydrocarbons / Q000633:toxicity*; D016015:Logistic Models; D008175:Lung Neoplasms / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D008913:Minority Groups / Q000706:statistics & numerical data*; D016273:Occupational Exposure / Q000009:adverse effects*; D016017:Odds Ratio; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D012307:Risk Factors; D012495:San Francisco / Q000453:epidemiology; D011795:Surveys and Questionnaires
chemical_list: D006838:Hydrocarbons; D011084:Polycyclic Aromatic Hydrocarbons; C006647:asphalt