City
Radon levels in Thunder Bay homes from the 2024 survey, and C-NRPP certified testing and mitigation providers with a business address in Thunder Bay, dated.
Photo: Robin Férand, CC BY 3.0, cropped, via Wikimedia Commons.
34.3
%Share of properties in the Thunder Bay, ON reporting unit with radon at or above 200 Bq/m³ in the 2024 Cross-Canada Radon Survey.
5
Businesses with a business address in Thunder Bay and at least one active C-NRPP credential, as of 2026-10-18. Providers based elsewhere may also serve Thunder Bay.
Survey figures for the Thunder Bay, ON reporting unit
| Measure | Value |
|---|---|
| Properties below 100 Bq/m³ (%) | 34.9 |
| Properties from 100 to 199 Bq/m³ (%) | 30.8 |
| Properties at or above 200 Bq/m³ (%) | 34.3 |
| Geometric mean (Bq/m³) | 130.1 |
| Highest observed (Bq/m³) | 32,321 |
| Sample | population 123,258 (2021 Census); approximately 750-999 properties with radon data |
2024 Cross-Canada Survey of Radon, Version 1.1 (CCSR.24.1.1), section XII, Table 1, page 43
Sorted alphabetically by business name. Every C-NRPP certified business is listed free, and payment never affects the order.
C-NRPP
Service area
Thunder Bay
Last registry check
C-NRPP
Service area
Residential Measurement, Mitigation, and CRNCH: Thunder Bay
Last registry check
C-NRPP
Service area
Not stated by the provider
Last registry check
C-NRPP
Service area
Not stated by the provider
Last registry check
C-NRPP
Service area
Residential and Commercial Measurement: Thunder Bay and Northwestern Ontario
Last registry check
Grant
Up to $1,500 toward home radon mitigation. Radon is named as eligible. Current. As of 2026-09-01.
Forgivable loan
Varies by service manager, roughly $15,000 to $25,000. Radon is not named. Varies by service manager.. As of 2026-09-18.
Warranty coverage
Up to $50,000 where the Agreement of Purchase and Sale was signed after 1 February 2021, otherwise $15,000. Radon is named as eligible. Current for qualifying homes.. As of 2026-09-18.
Free or subsidized testing
Radon is named as eligible. Current. As of 2026-09-18.
Province or territory
Radon by census division, and every certified provider in Ontario.