title: Lung cancer in a U.S. population with low to moderate arsenic exposure.
abstract: BACKGROUND
  Little is known about the carcinogenic potential of arsenic in areas with low to moderate concentrations of arsenic (< 100 microg/L) in drinking water.
  
  
  OBJECTIVE
  We examined associations between arsenic and lung cancer.
  
  
  METHODS
  A population-based case-control study of primary incident lung cancer was conducted in 10 counties in two U.S. states, New Hampshire and Vermont. The study included 223 lung cancer cases and 238 controls, each of whom provided toenail clippings for arsenic exposure measurement by inductively coupled-plasma mass spectrometry. We estimated odds ratios (ORs) of the association between arsenic exposure and lung cancer using unconditional logistic regression with adjustment for potential confounders (age, sex, race/ethnicity, smoking pack-years, education, body mass index, fish servings per week, and toenail selenium level).
  
  
  RESULTS
  Arsenic exposure was associated with small-cell and squamous-cell carcinoma of the lung [OR = 2.75; 95% confidence interval (CI), 1.00-7.57] for toenail arsenic concentration > or = 0.114 microg/g, versus < 0.05 microg/g. A history of lung disease (bronchitis, chronic obstructive pulmonary disease, or fibrosis) was positively associated with lung cancer (OR = 2.86; 95% CI, 1.39-5.91). We also observed an elevated risk of lung cancer among participants with a history of lung disease and toenail arsenic > or = 0.05 microg/g (OR = 4.78; 95% CI, 1.87-12.2) than among individuals with low toenail arsenic and no history of lung disease.
  
  
  CONCLUSIONS
  Although this study supports the possibility of an increased risk of specific lung cancer histologic types at lower levels of arsenic exposure, we recommend large-scale population-based studies.
authors.affiliation: International Agency for Research on Cancer, Lyon, France.
authors.forename: Julia E
authors.initials: JE
authors.lastname: Heck
authors.forename: Angeline S
authors.initials: AS
authors.lastname: Andrew
authors.forename: Tracy
authors.initials: T
authors.lastname: Onega
authors.forename: James R
authors.initials: JR
authors.lastname: Rigas
authors.forename: Brian P
authors.initials: BP
authors.lastname: Jackson
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Karagas
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Duell
mesh_terms: D000328:Adult; D000368:Aged; D001151:Arsenic / Q000032:analysis / Q000633:toxicity*; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000453:epidemiology / Q000473:pathology; D016022:Case-Control Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008171:Lung Diseases / Q000150:complications; D008175:Lung Neoplasms / Q000139:chemically induced / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009262:Nails / Q000737:chemistry; D009513:New Hampshire / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D012643:Selenium / Q000378:metabolism; D055752:Small Cell Lung Carcinoma / Q000139:chemically induced / Q000453:epidemiology / Q000473:pathology; D013054:Spectrophotometry, Atomic; D014707:Vermont / Q000453:epidemiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D012643:Selenium; D001151:Arsenic