Radon Testing: Elevated Levels at Some City Facilities

As part of a study conducted by the Occupational Cancer Research Centre, 45 radon detectors were placed in 18 City of Greater Sudbury buildings from December 2022 to March 2023.

Results received on July 18 showed that one location – the west side of the basement at the Onaping Community Centre – had a radon reading of 263 becquerels per cubic metre (Bq/m³). This is higher than the Canadian guideline for indoor dwellings, which is 200 Bq/m³.

The Radiation Safety Institute of Canada has indicated there is no immediate danger to past or current users of the area and no need to evacuate or stop using the area. However, in an abundance of caution, the City is temporarily closing the basement while remediation work is done. The area will be retested once mitigation measures have been implemented.

While there are a number of groups who use Onaping Community Centre, community use of the basement area is limited. City staff are communicating directly with affected user groups.

The other 44 radon detectors – including three others within the Onaping Community Centre – recorded levels that fall within the Canadian guidelines. Five of those showed readings between 100-200 Bq/m³. While this is within the guidelines, the City will proactively explore mitigation measures for these areas in an attempt to reduce levels as much as possible.

Please see the Frequently Asked Questions for more details. Updates will be provided throughout the remediation process. If you have additional questions, please contact 311 by phone or live web chat (311.greatersudbury.ca).