title: Exposure to multiple sources of polycyclic aromatic hydrocarbons and breast cancer incidence.
abstract: BACKGROUND
  Despite studies having consistently linked exposure to single-source polycyclic aromatic hydrocarbons (PAHs) to breast cancer, it is unclear whether single sources or specific groups of PAH sources should be targeted for breast cancer risk reduction.
  
  
  OBJECTIVE
  This study considers the impact on breast cancer incidence from multiple PAH exposure sources in a single model, which better reflects exposure to these complex mixtures.
  
  
  METHODS
  In a population-based case-control study conducted on Long Island, New York (N=1508 breast cancer cases/1556 controls), a Bayesian hierarchical regression approach was used to estimate adjusted posterior means and credible intervals (CrI) for the adjusted odds ratios (ORs) for PAH exposure sources, considered singly and as groups: active smoking; residential environmental tobacco smoke (ETS); indoor and outdoor air pollution; and grilled/smoked meat intake.
  
  
  RESULTS
  Most women were exposed to PAHs from multiple sources, and the most common included active/passive smoking and grilled/smoked food intake. In multiple-PAH source models, breast cancer incidence was associated with residential ETS from a spouse (OR=1.20, 95%CrI=1.03, 1.40) and synthetic firelog burning (OR=1.29, 95%CrI=1.06, 1.57); these estimates are similar, but slightly attenuated, to those from single-source models. Additionally when we considered PAH exposure groups, the most pronounced significant associations included total indoor sources (active smoking, ETS from spouse, grilled/smoked meat intake, stove/fireplace use, OR=1.45, 95%CrI=1.02, 2.04).
  
  
  CONCLUSIONS
  Groups of PAH sources, particularly indoor sources, were associated with a 30-50% increase in breast cancer incidence. PAH exposure is ubiquitous and a potentially modifiable breast cancer risk factor.
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA. Electronic address: whitea@unc.edu.
authors.forename: Alexandra J
authors.initials: AJ
authors.lastname: White
authors.affiliation: Department of Nutrition, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Patrick T
authors.initials: PT
authors.lastname: Bradshaw
authors.affiliation: Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Amy H
authors.initials: AH
authors.lastname: Herring
authors.affiliation: Department of Preventive Medicine, Ichan School of Medicine at Mt. Sinai, New York, NY, USA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Teitelbaum
authors.affiliation: Consulting in the Public Interest (CIPI), Lambertville, NJ, USA.
authors.forename: Jan
authors.initials: J
authors.lastname: Beyea
authors.affiliation: Department of Epidemiology, Columbia University, USA.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Stellman
authors.affiliation: Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Steck
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Irina
authors.initials: I
authors.lastname: Mordukhovich
authors.affiliation: Department of Epidemiology, Columbia University, USA.
authors.forename: Sybil M
authors.initials: SM
authors.lastname: Eng
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Lawrence S
authors.initials: LS
authors.lastname: Engel
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Conway
authors.affiliation: Division of Cancer Epidemiology and Genetics, Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD, USA.
authors.forename: Maureen
authors.initials: M
authors.lastname: Hatch
authors.affiliation: Department of Epidemiology, Columbia University, USA; Department of Medicine, Columbia University, USA.
authors.forename: Alfred I
authors.initials: AI
authors.lastname: Neugut
authors.affiliation: Department of Environmental Health Sciences, Columbia University, USA.
authors.forename: Regina M
authors.initials: RM
authors.lastname: Santella
authors.affiliation: Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.
authors.forename: Marilie D
authors.initials: MD
authors.lastname: Gammon
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D001499:Bayes Theorem; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D003296:Cooking; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D005260:Female; D006798:Housing / Q000592:standards; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D016017:Odds Ratio; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis*; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014028:Tobacco Smoke Pollution / Q000032:analysis
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D014028:Tobacco Smoke Pollution
keywords: Breast cancer; Environmental tobacco smoke; Grilled meat; Indoor air; Outdoor air; Polycyclic aromatic hydrocarbons; Smoking