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Original research
Neurodegenerative diseases among miners in Ontario, Canada, using a linked cohort
  1. Xiaoke Zeng1,2,
  2. Nathan L DeBono1,2,
  3. Anne M Harris1,3,
  4. Victoria H Arrandale1,2,
  5. Paul A Demers1,2
  1. 1Occupational and Environmental Health Division, University of Toronto, Toronto, Ontario, Canada
  2. 2Occupational Cancer Research Centre, Ontario Health, Toronto, Ontario, Canada
  3. 3School of Occupational and Public Health, Ryerson University, Toronto, Ontario, Canada
  1. Correspondence to Xiaoke Zeng, Occupational and Environmental Health Division, University of Toronto, Toronto, ON M5S, Canada; xiaok.zeng{at}


Objectives We examined employment in mining occupations and industries and its association with neurological disease incidence in a linkage cohort from Ontario, Canada. Outcomes included Alzheimer’s disease (alone and with other dementias), Parkinson’s disease, parkinsonism, motor neuron disease and amyotrophic lateral sclerosis (ALS).

Methods The Occupational Disease Surveillance System cohort was created by linking workers’ compensation data and healthcare usage records. This analysis included over 1.1 million male workers, followed between 1999 and 2016. Neurological diseases were ascertained using physician billing and hospital discharge records. Adjusted Poisson regression models were used to estimate incidence rate ratios (RR) comparing mining to non-mining workers overall and by ore (industry) and occupation group.

Results Suggested elevations in incidence rates were observed for ALS among workers of metal mines (RR 2.21, 95% CI 1.04 to 4.69) and for motor neuron disease among those employed in mining occupations within metal mining industries (RR 1.96, 95% CI 1.01 to 3.79), though these were based on relatively few cases. In miscellaneous metal mines, workers who held mining occupations had an elevated rate of Alzheimer’s disease (RR 1.27, 95% CI 0.92 to 1.77). Parkinson’s disease rate was elevated among workers with rock and soil drilling occupations (RR 1.60, 95% CI 1.04 to 2.45).

Conclusions Mining hazards may be associated with elevated rates of neurodegenerative diseases among workers in mining occupations and industries. More work is needed to better understand mining exposures and their associations with neurodegenerative diseases.

  • epidemiology
  • health surveillance
  • metals

Statistics from


  • Contributors XZ, NLD and PAD planned the study. XZ conducted all analyses and drafted the manuscript. NLD assisted in the analyses and provided critical review of the manuscript. AMH, VHA and PAD provided direction on the study design, assisted the interpretation of results and provided critical review of the manuscript.

  • Funding This project was funded by Ontario’s Ministry of Labour, Training and Skills Development (#14-R-29 R-29), and the Public Health Agency of Canada (#1516-HQ-000066).

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval This study obtained ethics approval from the University of Toronto Health Sciences Research Ethics Board (protocol number 39013).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Certain data are available on reasonable request.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.

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