A note before you read. This article provides general health and home-testing information for homeowners and tenants in Saint-Jérôme and the Laurentians, drawn from publications of Health Canada, the Institut national de santé publique du Québec (INSPQ), the OACIQ, CARST, and the Canadian Cancer Society. It is not medical advice and not legal advice. See full disclaimers at the bottom of the page.
Saint-Jérôme, the principal city of the Basses-Laurentides, sits on Precambrian Canadian Shield bedrock in a region the INSPQ has designated as one of Quebec's higher-prevalence radon regions. The same Canadian Shield geology that produces high-prevalence zones in the Outaouais and the Saguenay also underlies the Laurentians. Quebec's radon prevalence, according to Health Canada's 2012 Cross-Canada Survey, sits at roughly the Canadian average — about 7% of homes at 200 Bq/m³ or higher — but the northern Laurentians show higher prevalence.
Whether you live in Saint-Jérôme, Prévost, Lafontaine, Bellefeuille, Sainte-Sophie, or elsewhere in the Basses-Laurentides, testing for radon is essential.
TL;DR for Saint-Jérôme homeowners and tenants
- Health Canada's residential guideline: 200 Bq/m³ (Health Canada — Radon). The Laurentians are designated by the INSPQ as a region with prevalence above the Quebec average.
- Test your home with a 91-day long-term alpha-track test at the lowest lived-in level, during the heating season (October–April).
- Order a long-term test kit for $89 →
- Quebec real estate is regulated by the OACIQ; the latent defect (vice caché) framework of the Civil Code generally engages disclosure of known elevated results.
Table of contents
- Why Saint-Jérôme is a higher-prevalence area
- What the Quebec and Laurentian data shows
- How to test your home
- Mitigation in Saint-Jérôme
- Real estate and OACIQ disclosure
- Tenants in Saint-Jérôme
- FAQ — Saint-Jérôme-specific questions
- Order your test kit
- Important disclaimers
- Sources and further reading
Why Saint-Jérôme is a higher-prevalence area
Saint-Jérôme and the Basses-Laurentides sit on Precambrian Canadian Shield bedrock — the same geology that underlies high-prevalence zones across Canada. The INSPQ identifies the northern Laurentians as one of the regions with prevalence above the Quebec average.
Three factors stack together:
- Geology. Canadian Shield bedrock with uranium-bearing parent material across several Laurentian sub-regions.
- Long heating season. Quebec winters drive months of continuous furnace operation, creating a strong stack effect.
- Housing stock. Saint-Jérôme and the Laurentians have many single-family homes with full basements used as living space.
What the Quebec and Laurentian data shows
Health Canada's 2012 Cross-Canada Survey places Quebec at roughly 7% of homes above the 200 Bq/m³ guideline. Regional INSPQ data identifies the Outaouais, the Estrie, and parts of the Laurentians as Quebec regions with prevalence above the provincial average.
How to test your home
Per Health Canada (Guide for Radon Measurements in Residential Dwellings), the Canadian residential standard is a long-term test of at least 91 days using an alpha-track detector, deployed at the lowest lived-in level during the heating season (October–April).
For most Saint-Jérôme homes:
- Finished basement if it serves as a bedroom, office, gym, or living space — that's where to test.
- Lowest sleeping level if the basement is unfinished.
- Ground floor only if the home has no basement.
Place the kit at breathing height (1 to 2 metres off the floor), away from drafts, exterior walls, and HVAC registers. Leave it in place for at least 91 days, then return it to the lab.
Order your long-term test kit for $89 →
Mitigation in Saint-Jérôme
If your test exceeds 200 Bq/m³, the standard Canadian solution is active sub-slab depressurization (SSD). Typical cost: $2,500 to $4,500 for a standard SSD installation.
Always use a C-NRPP-certified mitigation professional. Check the C-NRPP directory, filtering by Quebec. Saint-Jérôme is well served by Quebec's pool of C-NRPP-certified specialists, several of whom work out of the greater Montreal area.
For the full selection guide, see our How to Choose a Licensed Radon Mitigation Professional in Canada guide. After mitigation, run an independent post-mitigation test.
Real estate and OACIQ disclosure
Quebec real estate is regulated by the OACIQ. The Seller's Declaration form asks sellers to disclose known material defects. Quebec's latent defect (vice caché) framework under the Civil Code is more buyer-protective than the common law in force in other provinces. A confirmed elevated radon test is generally the kind of material information the doctrine can engage. Consult a Quebec notary or real estate lawyer for any specific transaction.
Tenants in Saint-Jérôme
Quebec's residential tenancy framework is administered by the Tribunal administratif du logement (TAL). The Civil Code generally requires landlords to deliver and maintain dwellings "in a good state of habitability." See our Radon for Canadian Renters (2026) guide.
FAQ — Saint-Jérôme-specific questions
Is radon worse in Saint-Jérôme than in Montreal? Yes — the Laurentians sit on the Canadian Shield, and the INSPQ identifies the region as having prevalence above the Quebec average. Saint-Jérôme is within that geological zone.
What is the action level for radon in Saint-Jérôme? 200 Bq/m³ — Health Canada's residential guideline.
How do I test my Saint-Jérôme home? Use a 3-month (≥91-day) long-term alpha-track test from a C-NRPP-recognized lab. Cost: $89 all-in for a RadonTest.ca kit.
How much does radon mitigation cost in Saint-Jérôme? Typical cost: $2,500 to $4,500 for a standard sub-slab depressurization (SSD) system.
Do Quebec sellers have to disclose radon? Quebec's latent defect (vice caché) framework under the Civil Code and the OACIQ Seller's Declaration generally require disclosure of known material defects. Consult a Quebec notary or lawyer.
Does the Tarion warranty cover mitigation for new homes in Saint-Jérôme? No — Tarion is the Ontario warranty. In Quebec, new-home warranties are administered by the Garantie de construction résidentielle (GCR).
Can I use the Lungs Matter grant in Saint-Jérôme? The Lungs Matter program offers up to $1,500 to eligible Canadian homeowners. Verify directly.
Should I retest after mitigation? Yes — Health Canada recommends retesting after mitigation and after major renovations.
What if my landlord refuses to act? Document everything in writing and consider a recourse to the Tribunal administratif du logement (TAL).
Order your test kit
Order your long-term test kit for $89 all-in →
91-day long-term alpha-track test kit. C-NRPP-listed device. Analysed at Lex Scientific in Guelph, Ontario — a Canadian lab, C-NRPP listed, ISO/IEC 17025 accredited by CALA. Tracked Canadian shipping both ways. PDF lab report delivered to your inbox.
Shipping throughout the Laurentians including Saint-Jérôme, Prévost, Lafontaine, Bellefeuille, Sainte-Sophie, and surrounding municipalities.
Important disclaimers
Not medical, legal, or warranty advice. Consult qualified Quebec professionals for any specific decision.
Statistics and citations. Quebec prevalence figures are drawn from Health Canada's 2012 Cross-Canada Survey and INSPQ regional publications. Figures reflect the sources as of May 2026.
Local data. The Laurentians show prevalence above the Quebec average per the INSPQ. Home-to-home variability is large. Test your home.
Mitigation cost. The $2,500 to $4,500 range reflects typical Canadian pricing in 2026. Actual prices vary.
Lungs Matter grant. Eligibility, amounts, and program availability may change. Verify directly at lung.ca before relying on the program.
No diagnosis or treatment claims. RadonTest.ca sells radon test kits. We do not diagnose, treat, or prevent any disease.
No warranty as to completeness. RadonTest.ca makes no warranty as to the completeness or accuracy of the information presented here and accepts no liability for decisions made in reliance on this article.
Sources and further reading
Quebec-specific
- INSPQ — Radon
- OACIQ
- Tribunal administratif du logement (TAL)
- Garantie de construction résidentielle (GCR)
Health Canada / national
- Health Canada — Radon
- 2012 Cross-Canada Survey
- Canadian Cancer Society — Radon
- Canadian Lung Association — Lungs Matter
- C-NRPP — Find a Professional
- CARST
- Take Action on Radon
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