title: Case-control study on occupational exposure to extremely low-frequency electromagnetic fields and glioma risk.
abstract: BACKGROUND
  Exposure to extremely low-frequency electromagnetic fields (ELF-EMF) was in 2002 classified as a possible human carcinogen, Group 2B, by the International Agency for Research on Cancer at WHO.
  
  
  METHODS
  Life time occupations were assessed in case-control studies during 1997-2003 and 2007-2009. An ELF-EMF Job-Exposure Matrix was used for associating occupations with ELF exposure (μT). Cumulative exposure (μT-years), average exposure (μT), and maximum exposed job (μT) were calculated.
  
  
  RESULTS
  Cumulative exposure gave for astrocytoma grade IV (glioblastoma multiforme) in the time window 1-14 years odds ratio (OR) = 1.9, 95% confidence interval (CI) = 1.4-2.6, p linear trend <0.001, and in the time window 15+ years OR = 0.9, 95%CI = 0.6-1.3, p linear trend = 0.44 in the highest exposure categories 2.75+ and 6.59+ μT years, respectively.
  
  
  CONCLUSIONS
  An increased risk in late stage (promotion/progression) of astrocytoma grade IV for occupational ELF-EMF exposure was found.
authors.affiliation: Faculty of Medicine and Health, Department of Oncology, Örebro University, Örebro, Sweden.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0002-7816-0755
authors.initials: M
authors.lastname: Carlberg
authors.affiliation: Department of Labour Environment and Safety, Tallinn University of Technology, Tallinn, Estonia.
authors.forename: Tarmo
authors.initials: T
authors.lastname: Koppel
authors.affiliation: Department of Information Technology and Media, Mid Sweden University, Sundsvall, Sweden.
authors.forename: Mikko
authors.initials: M
authors.lastname: Ahonen
authors.affiliation: Faculty of Medicine and Health, Department of Oncology, Örebro University, Örebro, Sweden.
authors.forename: Lennart
authors.initials: L
authors.lastname: Hardell
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000453:epidemiology* / Q000209:etiology*; D016022:Case-Control Studies; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005260:Female; D005909:Glioblastoma / Q000453:epidemiology / Q000209:etiology; D005910:Glioma / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D012042:Registries; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
keywords: ELF-EMF; RF-EMF; astrocytoma; electromagnetic fields; glioma; occupational exposure; risk factors; wireless phones