Get Help

Call the Lung Health Information Line

1-888-344-LUNG (5864)

Our certified respiratory
educators are ready to take your questions
(M-F 8:30am-4:30pm)

Radon Survey Of Workplaces In Ontario

Status: In Progress


Purpose of the survey:

  • This project investigates the levels of radon in Ontario in small to medium sized businesses as well as public buildings.
  • The objective of this study is to assess where hazardous levels of radon are present in Ontario workplaces in order to target prevention efforts.


  • Radon is a naturally-occurring radioactive gas formed by the breakdown of uranium in soil, rock and water.
  • Can’t see, touch, smell, or taste it and detected only by radon measurement devices.
  • Radon is responsible for approximately 13% of lung cancer deaths in Ontario and is the second leading cause of lung cancer after smoking.
  • The World Health Organization (WHO) recommends that radon exposure remain below 100 Bq/m3, while the Health Canada Guideline is 200 Bq/m3
  • Radon testing in workplaces has been inconsistent across Canada.

How it is conducted:

  • Radon samples will be collected in public buildings and small to medium sized businesses in nine Health Regions with high background levels of radon.
  • Additional samples will be collected in workplaces with potentially high radon risk (e.g. underground workplaces) in four Health Regions with low background levels of radon.
  • Approximately 800 radon measurements in roughly 500 workplaces will be collected.
  • Radon monitoring kits will be deployed for 3 months over the winter months, which is when radon levels are expected to be the highest.
  • Results will be analyzed to identify potentially high hazard areas and to model radon levels in workplaces across Ontario.
  • Workplaces with elevated levels will be provided with free educational materials and connected with remediation and mitigation resources.

What we hope to achieve:

  • This research will help fill crucial gaps in knowledge by generating new data on radon exposures and identifying regions in Ontario where levels of radon are elevated in the workplace. The data will also be used to produce radon maps.
  • The results from the study can be used to identify groups of workers who may be at increased risk of lung cancer due to radon exposure, and to target prevention efforts in regions with the greatest potential for improvements in occupational health and safety.
  • The research project will also increase radon awareness and health and safety knowledge among workers.
  • The study’s findings may be further used by governments and health professionals to help prioritize radon outreach and education efforts, and to encourage workplace testing and remediation where necessary.

Our progress (updated September 2018):

Summer – Fall 2018 – initiated recruitment of businesses
January 2018 – This project was recently funded and is getting underway.


  • A study FAQ for business owners and workplace managers
  • A fact sheet that describes radon, its health effects, and radon testing and mitigation in the workplace


This study is funded by a grant from the Ontario Ministry of Labour Research Opportunity Program:
Demers PA, Boksman L, McIntosh T, Nicol AM. Radon Survey of Workplaces in Ontario. 2017-2019.

Our investigators:

Paul A Demers (Occupational Cancer Research Centre, University of Toronto)
Laura Boksman (Radiation Safety Institute of Canada)
Tristan McIntosh (The Lung Association – Ontario)
Anne-Marie Nicol (CAREX Canada, Simon Fraser University)
Ela Rydz (Occupational Cancer Research Centre)

For more information:

If you would like more information or are interested in participating in the study, please contact Tristan McIntosh ( or Ela Rydz (