The Ontario Mining Exposure Database

Status: in progress


In order to better understand the potential risks to workers in the mining industry and to inform prevention activities, the OCRC created a database of exposure measurements collected in mines in Ontario. The objective was to create a database that will serve as a valuable tool for exposure surveillance and prevention in the Ontario mining industry.

Now completed, the database is being used to:
• Examine trends in mining exposures over time
• Evaluate the effect of historical interventions, such as regulation or technological change, on exposure levels
• Examine differences in exposure related to mine type and location
• Explore the construction of job-exposure matrices for common mining exposures


In 2011, there were 38 mines operating in Ontario with over 18,000 people employed in mining operations. Workers in the mining industry may be exposed to carcinogens, including radon, crystalline silica, diesel engine exhaust, arsenic, nickel, and chromium. Many of these exposures can also negatively impact the respiratory health of workers. Despite this, there was previously no centralized or accessible database of exposure measurements from mines in Ontario, and therefore no easy way to track exposures across the mining sector. Records of exposure measurements are often stored in paper form, and may be subject to damage or loss. Digitalizing these records in an electronic database provides long-term data security and allows for the identification of exposure trends over time and across Ontario.


Data from the Ministry of Labour, research organizations, health and safety associations, and mining companies has been identified across Ontario. The OCRC enters into a legally binding data sharing agreement with each organization that agrees to submit their data for entry into the database.  Hard copies of the exposure data are transported to the OCRC office for thorough review, entry into the database, and subsequent analysis.


Analyses using the database will increase our understanding of exposures in the mining industry and help target prevention efforts where they will have the greatest impact on workers’ health. Additional future applications of the database include designing interventions to minimize exposures that will have the biggest impact on workers’ health and improving research methods for assessing exposures as part of ongoing cohort studies of mining-related disease.

Progress (updated May 2019):

Early in the project, OCRC worked closely with the Ontario Ministry of Labour and other organizations, including Workplace Safety North (WSN) and Laurentian University, to locate exposure data and enter it into an electronic database. The database is complete and analyses are now underway. Descriptive statistics and exposure trends over time have been explored. Several models using various determinants of exposure have been investigated. Currently, we are exploring the feasibility of linking with other databases to create a job-exposure matrix for silica in Ontario mines.


  • In the 2012 Bridging the Gap competition, the Occupational Cancer Research Centre (OCRC) was awarded funding to assess the feasibility of creating the database.
  • Funding for completion of the full database was received from the Ontario Ministry of Labour: Demers PA, Arrandale VH, Lightfoot NE, Genesove LJ. Creation of the Ontario Mining Exposure Database. 2014-2015.
  • Funding for analysis of the database was also awarded by the Ontario Ministry of Labour:
    Demers PA, Arrandale VH, Lightfoot NE. Occupational Exposure Surveillance in the Ontario Mining Industry. 2015-2017.

Research team:

Paul A Demers
Nancy E Lightfoot (Laurentian University)
Leon J Genesove (Ontario Ministry of Labour)
Victoria H Arrandale
Nicola Blagrove-Hall
Colin Berriault
Kate Jardine