title: Population-based case-control study of occupational exposure to electromagnetic fields and breast cancer.
abstract: OBJECTIVE
  This population-based case-control study examined occupational exposure to electromagnetic fields in relation to female breast cancer incidence among 843 breast cancer cases and 773 controls.
  
  
  METHODS
  Exposure was classified based on work in the two longest-held jobs, and indices of cumulative exposure to magnetic fields based on a measurement survey.
  
  
  RESULTS
  Female breast cancer was not associated with employment as an office or industrial worker. For the total study population, cumulative exposure over the entire career, and in the past 0-10 and 10-20 years generally showed odds ratios (ORs) close to the null. Moderately elevated risks were found for intermediate but not high levels of cumulative exposure accumulated 20 or more years ago (OR = 1.5; 95% CI = 1.1-2.0). Associations were stronger for premenopausal women (OR = 1.7; 95% CI = 1.1-2.7) in the past 10-20 years, and those with estrogen-receptor positive (ER+) breast tumors (OR = 2.06; 95% CI = 1.1-4.0). No consistent dose-response patterns were observed.
  
  
  CONCLUSIONS
  These findings give little support to the hypothesis that electromagnetic fields cause cancer of the female breast.
authors.affiliation: Departments of Epidemiology, School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: E
authors.initials: E
authors.lastname: Van Wijngaarden
authors.forename: L A
authors.initials: LA
authors.lastname: Nylander-French
authors.forename: R C
authors.initials: RC
authors.lastname: Millikan
authors.forename: D A
authors.initials: DA
authors.lastname: Savitz
authors.forename: D
authors.initials: D
authors.lastname: Loomis
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D016022:Case-Control Studies; D002979:Climacteric; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009657:North Carolina / Q000453:epidemiology; D016273:Occupational Exposure / Q000009:adverse effects*; D009790:Occupations; D016017:Odds Ratio; D012306:Risk; D013997:Time Factors