title: Occupational exposure in parkinsonian disorders: a 43-year prospective cohort study in men.
abstract: BACKGROUND
  Several occupations and occupational exposures have been investigated for associations with Parkinson's disease. Common findings are increased risk associated with pesticide exposure and no association between Parkinson's disease and welding.
  
  
  METHODS
  We explored the association between a broad range of possible occupational risk factors and Parkinson's disease as well as Parkinson's disease plus other forms of Parkinsonism (referred to as Parkinsonian disorders), using prospectively collected data in the population-based Swedish Twin Registry. A cohort of 14,169 Swedish men was followed for up to 43 years. We identified 234 Parkinsonian disorder cases including 204 Parkinson's disease cases with complete data. We assessed exposure to 14 chemical and biological compounds through a job exposure matrix. Hazard ratios (HR) with 95% confidence intervals (CI) adjusted for age, smoking, and education were used to estimate the relative risk of disease associated with exposure.
  
  
  RESULTS
  Exposure to inorganic dust was associated with increased risk of Parkinson's disease and Parkinsonian disorders, HR 1.6 (95% CI 1.1-2.4) and 1.5 (1.0-2.2) respectively. There was no association between Parkinson's disease or Parkinsonian disorders and occupational exposure to pesticides, welding smoke, metal dust, wood dust, animal handling, stone and concrete dust, chrome and nickel dust, quartz dust, organic dust, oil, asbestos, organic solvents and irritating gas.
  
  
  CONCLUSIONS
  Inorganic dust should be explored further as a potential risk factor for Parkinson's disease. Occupational exposure to pesticides and twelve other compounds explored in this study may not be associated with risk of Parkinson's disease in Swedish men.
authors: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. adina.feldman@ki.se
authors: Adina L
authors: AL
authors: Feldman
authors: Anna L V
authors: AL
authors: Johansson
authors: Gun
authors: G
authors: Nise
authors: Margaret
authors: M
authors: Gatz
authors: Nancy L
authors: NL
authors: Pedersen
authors: Karin
authors: K
authors: Wirdefeldt
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003252:Construction Materials / Q000009:adverse effects; D004391:Dust; D005500:Follow-Up Studies; D006801:Humans; D007287:Inorganic Chemicals / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced / Q000453:epidemiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D020734:Parkinsonian Disorders / Q000139:chemically induced / Q000453:epidemiology*; D012307:Risk Factors; D014427:Twins
chemical_list: D004391:Dust; D007287:Inorganic Chemicals