title: Occupational exposure to extremely low-frequency magnetic fields and neurodegenerative disease: a meta-analysis.
abstract: OBJECTIVE
  Previous studies reported associations of occupational electric and magnetic fields (MF) with neurodegenerative diseases (NDDs). Results differ between studies using proxy exposure based on occupational titles and estimated MF levels. We conducted a meta-analysis of occupational MF NDD, primarily Alzheimer disease (AD), and motor neuron diseases (MNDs) studies.
  
  
  METHODS
  We identified 42 peer-reviewed publications and focused our analysis on study characteristics, exposure metrics, and publication bias.
  
  
  RESULTS
  We found weak associations for occupational MF exposure proxies with AD and MND. Motor neuron disease risk was associated with occupational titles, whereas AD risk was associated with estimated MF levels. Results varied in study design, with dissimilar variation across diseases.
  
  
  CONCLUSIONS
  Our results do not support MF as the explanation for observed associations between occupational titles and MND. Disease misclassification, particularly for AD, and imprecise exposure assessment affected most studies.
authors: Department of Epidemiology, University of California-Los Angeles (UCLA) Fielding School of Public Health, Los Angeles, CA, USA. xvergara@epri.com
authors: Ximena
authors: X
authors: Vergara
authors: Leeka
authors: L
authors: Kheifets
authors: Sander
authors: S
authors: Greenland
authors: Sona
authors: S
authors: Oksuzyan
authors: Yong-Sung
authors: YS
authors: Cho
authors: Gabor
authors: G
authors: Mezei
mesh_terms: D000544:Alzheimer Disease / Q000209:etiology*; D005189:False Positive Reactions; D006801:Humans; D060526:Magnetic Fields / Q000009:adverse effects*; D016472:Motor Neuron Disease / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D009790:Occupations; D017594:Publication Bias