# IAQ Solutions

> Certified radon testing and mitigation for homes and new builds from Windsor to Brantford. An early reading in 2 weeks, the full result at 91 days to Health Canada protocol, sub-slab mitigation systems, and verified results.

IAQ Solutions (indoorairqualitysolutions.ca) is a radon testing and mitigation company based in London, Ontario, Canada, serving Windsor-Essex, Chatham-Kent, Lambton, Huron-Perth, Waterloo Region, London, Middlesex, Elgin, Oxford, Norfolk and Brant, and also Hamilton, Ancaster, Haldimand and the Niagara Region. Phone (226) 271-4667, email hello@iaqsolutions.ca. Content is sourced to Health Canada, Canadian standards and peer-reviewed research; each page links its sources.

## Key facts (sourced)

- Health Canada's radon guideline is 200 Bq/m³ (long-term average in any area occupied more than 4 hours a day). Reduce within 2 years for 200–600 Bq/m³ and within 1 year above 600 Bq/m³. Source: https://www.canada.ca/en/health-canada/services/environmental-workplace-health/radiation/radon/government-canada-radon-guideline.html
- Canada lowered its radon guideline from 800 Bq/m³ (1988) to 200 Bq/m³ in June 2007. Source: https://www.canada.ca/en/health-canada/services/environmental-workplace-health/radiation/radon/government-canada-radon-guideline.html
- Radon is attributed to about 16% of lung cancer deaths in Canada, more than 3,000 per year. Source: https://www.cmaj.ca/content/195/24/E850
- About 13.6% of lung cancer deaths in Ontario (~850 per year) are attributed to radon. Source: https://pmc.ncbi.nlm.nih.gov/articles/PMC3824583/
- The 2024 Cross-Canada Survey estimated about 1 in 8 Ontario homes (12.4%) at or above 200 Bq/m³; ~17.8% nationally. Source: https://crosscanadaradon.ca/survey/
- The Windsor-Essex County Health Unit's 2015 to 2018 Radon: Know Your Level study found about 11% of homes tested above the guideline: 18% in Essex County and 6% in the City of Windsor. Source: https://www.wechu.org/node/4514/printable/print
- Health Canada survey data tabulated by Cancer Care Ontario by public health unit (2009 to 2013) put the share of homes tested at or above 200 Bq/m³ at 13.8% in Windsor-Essex, 18.4% in Chatham-Kent, 8.4% in Lambton, 12.0% in Perth and 4.0% in the Region of Waterloo. Source: https://www.cancercareontario.ca/en/cancer-facts/risk-residential-radon-exposure-varies-geographically
- A Hamilton public health survey found 42 of 294 homes (about 14%) above the guideline. Source: https://globalnews.ca/news/7465954/radon-levels-hamilton-homes
- Rural residents were exposed to about 30% more radon than urban residents in a 2024 study of 42,051 Canadian homes, linked mostly to drilled wells. Source: https://doi.org/10.1038/s41598-024-53458-6
- Long-term radon tests should run at least 91 days (3 months), ideally October–April, on the lowest level occupied more than 4 hours a day. Source: https://www.canada.ca/en/health-canada/services/publications/health-risks-safety/guide-radon-measurements-residential-dwellings.html
- C-NRPP defines a short-term radon test as 48 hours to under 3 months and recommends following any short-term result with a long-term test. Source: https://c-nrpp.ca/wp-content/uploads/2018/11/C-NRPP-Short-Term-Testing-Guideline-Final-2018.pdf
- Short tests are most reliable far from the action level: 7–10 day winter basement tests flagged homes above 148 Bq/m³ about 88% of the time (Iowa), and a 2024 review of 20 studies found one-week tests over 95% reliable at low levels but about 50% at moderate levels. Sources: https://doi.org/10.1097/HP.0000000000000004 https://doi.org/10.3390/s24144575
- IAQ Solutions pairs every long-term test with a calibrated continuous monitor for the first 2 weeks, giving an early reading; the 91-day result is still the basis for decisions.
- Standards compared: Health Canada acts at 200 Bq/m³; the U.S. EPA at 148 Bq/m³ (4 pCi/L), and suggests considering a fix between 2 and 4 pCi/L; the WHO prefers 100 Bq/m³ and says reference levels should not exceed 300 Bq/m³. Sources: https://www.canada.ca/en/health-canada/services/environmental-workplace-health/radiation/radon/government-canada-radon-guideline.html https://epa.gov/radon/does-2009-world-health-organizations-recommendation-lower-radon-action-level-affect-epas https://www.who.int/publications/i/item/9789241547673
- 1 pCi/L = 37 Bq/m³. The U.S. EPA action level (4 pCi/L) is about 148 Bq/m³; the WHO reference level is 100 Bq/m³.
- Active soil depressurization (sub-slab depressurization) designed to CAN/CGSB-149.12 typically reduces indoor radon by 90% or more. Source: https://scc-ccn.ca/standardsdb/standards/4029149
- Under the 2024 Ontario Building Code (O. Reg. 163/24), new Part 9 homes require a soil gas barrier and a rough-in for a future sub-slab depressurization system. Source: https://www.hcraontario.ca/wp-content/uploads/2025/10/HCRA-Radon-Code-Brief.pdf
- Tarion's new home warranty covers radon remediation up to $50,000 for 7 years from possession when long-term tests (≥3 months) exceed 200 Bq/m³. Source: https://www.hcraontario.ca/wp-content/uploads/2025/10/HCRA-Radon-Consumer-Guide.pdf
- Typical Canadian cost for a single-family sub-slab radon mitigation system: roughly $2,000–$3,500; complex homes more.

## Core pages

- [Radon Testing & Mitigation in Southern Ontario | IAQ Solutions](https://indoorairqualitysolutions.ca/): C-NRPP certified radon testing and mitigation from Windsor to Brantford. An early reading in 2 weeks, 91-day tests to Health Canada protocol, and guaranteed results.
- [Radon Testing in Southern Ontario | Early Reading in 2 Weeks](https://indoorairqualitysolutions.ca/radon-testing/): Certified radon testing from Windsor to Brantford: an early reading in as little as 2 weeks, then the full 91-day result to Health Canada protocol.
- [Radon Mitigation in Southern Ontario | Guaranteed Results](https://indoorairqualitysolutions.ca/radon-mitigation/): Sub-slab radon mitigation built to CAN/CGSB-149.12. Fixed prices, most installs in a day, results guaranteed below 200 Bq/m³. Windsor to Brantford.
- [How Radon Testing & Mitigation Works | IAQ Solutions](https://indoorairqualitysolutions.ca/how-it-works/): Our radon process: identify where to test, an early reading at 2 weeks, the full 91-day result, a sub-slab fix if needed, and proof it worked. Step by step.
- [Radon Rough-Ins & Testing for Ontario Builders | IAQ Solutions](https://indoorairqualitysolutions.ca/builders/): 2024 Ontario Building Code radon rough-ins, inspection, activation and post-occupancy testing for builders from Windsor to Brantford. Fewer Tarion radon callbacks.
- [Book a Radon Test or Mitigation Quote | IAQ Solutions](https://indoorairqualitysolutions.ca/book/): Book a radon test (early reading at 2 weeks, full result at 91 days) or a mitigation quote from Windsor to Brantford. We reply within one business day.

## Services

- [Radon Testing in Southern Ontario | Early Reading in 2 Weeks](https://indoorairqualitysolutions.ca/radon-testing/): Professional long-term (91+ day) radon tests placed by C-NRPP certified technicians, with an early reading at 2 weeks from a calibrated continuous monitor; accredited lab analysis, written report; also real-estate screening and post-mitigation tests.
- [Radon Mitigation in Southern Ontario | Guaranteed Results](https://indoorairqualitysolutions.ca/radon-mitigation/): Active soil depressurization (sub-slab) radon mitigation to CAN/CGSB-149.12; communication testing, sealing, fan outside living space, manometer; most installs one day; guarantee of a follow-up result below 200 Bq/m³.
- [Radon Rough-Ins & Testing for Ontario Builders | IAQ Solutions](https://indoorairqualitysolutions.ca/builders/): Builder services: OBC 2024 radon rough-in design/install and inspection, activation on request, homeowner testing programs, warranty callbacks, subdivision data.

## Learn

- [What Is Radon? A Plain-Language Guide for Ontario Homes](https://indoorairqualitysolutions.ca/learn/what-is-radon/): Radon is a colourless, odourless radioactive gas that forms naturally when uranium in soil and rock breaks down. Outdoors it dilutes to very low levels, but it can seep into homes through foundations and build up, especially in basements. Long-term exposure is the leading cause of lung cancer in non-smokers. A long-term test is the only way to know your level.
- [Health Canada’s Radon Guideline: Why It Dropped from 800 to 200](https://indoorairqualitysolutions.ca/learn/health-canada-radon-guideline/): In June 2007, Health Canada lowered its radon guideline from 800 to 200 Bq/m³ after pooled studies of thousands of people in Europe and North America showed lung cancer risk rising at much lower indoor radon levels than previously assumed. The lower guideline also brought Canada in line with most other countries. Homes tested before 2007 should be re-tested against the 200 Bq/m³ guideline.
- [Radon and Lung Cancer: The Real Risk, Explained](https://indoorairqualitysolutions.ca/learn/radon-and-lung-cancer/): Radon is the second leading cause of lung cancer in Canada after smoking and the leading cause in people who have never smoked. It’s linked to about 16% of Canadian lung cancer deaths, more than 3,000 a year, and roughly 850 a year in Ontario. Risk depends on the concentration and the number of years you breathe it, and it is much higher for smokers.
- [How Radon Gets Into Your Home and Why Winter Is Worse](https://indoorairqualitysolutions.ca/learn/how-radon-enters-your-home/): Radon is drawn into homes by a small pressure difference: warm air rising and escaping through the upper floors lowers the pressure at the basement, so soil gas is pulled in through cracks, floor–wall joints, sumps, drains, and gaps around pipes. This “stack effect” is strongest in winter, which is why radon levels are usually highest in the heating season and on the lowest floor.
- [When Is Radon Dangerous? Levels, Time and Who’s at Risk](https://indoorairqualitysolutions.ca/learn/when-is-radon-dangerous/): Radon becomes a concern when the long-term average in a lived-in part of your home is above Health Canada’s 200 Bq/m³ guideline. Health Canada recommends reducing it within two years for 200–600 Bq/m³ and within one year above 600. Risk grows with both the level and the years of exposure, so basement bedrooms, smokers and young families matter most. There is no known completely safe level.
- [How to Test for Radon in Ontario (DIY vs Professional)](https://indoorairqualitysolutions.ca/learn/how-to-test-for-radon/): Use a long-term radon detector for at least 91 days, ideally between October and April. Place it on the lowest level where someone spends more than four hours a day, at breathing height, away from exterior walls, windows, drafts, heat sources and the sump. Then send it to the lab. A do-it-yourself kit works; a C-NRPP certified professional adds correct placement, a verified report, advice, and an early reading in as little as 2 weeks.
- [Radon Test Results in 2 Weeks? Early Reading vs 91-Day Test](https://indoorairqualitysolutions.ca/learn/radon-test-results-in-two-weeks/): Yes, you can have a useful answer in as little as 2 weeks. A calibrated professional monitor logs radon every hour, and a heating-season reading far above or below Health Canada’s 200 Bq/m³ guideline usually holds up over three months. A reading near 200 doesn’t. Health Canada bases decisions on a test of at least 91 days, so the long-term test always runs to the end.
- [Radon Test Results Explained: Bq/m³, pCi/L and What to Do](https://indoorairqualitysolutions.ca/learn/understanding-radon-test-results/): Compare your long-term average to Health Canada’s guideline of 200 Bq/m³. Below 200 needs no action. Between 200 and 600, reduce radon within two years; above 600, within one year. If your result is in pCi/L, multiply by 37 to get Bq/m³ (4 pCi/L ≈ 148 Bq/m³). Short-term results are screening only and should be confirmed with a 91-day test.
- [How Radon Mitigation Works: Sub-Slab Depressurization](https://indoorairqualitysolutions.ca/learn/radon-mitigation-explained/): The standard radon fix in Canada is active soil depressurization (also called sub-slab depressurization). A pipe is installed through the basement slab into the gravel below, and a small fan keeps the soil under the house at slightly lower pressure than the indoors. Radon is drawn into the pipe and vented outside instead of entering the home. Properly designed systems typically reduce radon by 90% or more.
- [Radon Mitigation Cost in Ontario: What to Budget (2026)](https://indoorairqualitysolutions.ca/learn/radon-mitigation-cost-ontario/): Most single-family sub-slab radon mitigation systems in Canada cost roughly $2,000 to $3,500 installed, including the fan, piping, sealing and a manometer. Homes with several foundations, finished basements that need careful routing, crawlspaces or multiple suction points can cost more. Long-term DIY test kits cost well under $100. Running costs are a small amount of electricity for the fan.
- [Radon in New Ontario Homes: 2024 Building Code & Tarion](https://indoorairqualitysolutions.ca/learn/radon-new-homes-ontario-building-code/): Under the 2024 Ontario Building Code, new Part 9 homes must include a soil gas barrier and a rough-in for a future sub-slab depressurization system: typically a capped, labelled pipe (at least 100 mm) through the slab into a gas-permeable layer. The rough-in is passive and does not lower radon by itself. Owners should test for at least three months after moving in; Tarion’s warranty covers radon remediation above 200 Bq/m³ for seven years.
- [Radon When Buying or Selling a Home in Ontario](https://indoorairqualitysolutions.ca/learn/radon-real-estate-ontario/): In an Ontario real estate deal there usually isn’t time for a 91-day test. Common approaches: sellers provide a recent long-term result or install a system in advance; buyers run a professional short-term screening test during the conditional period and negotiate a price adjustment or holdback; or the buyer tests long-term after closing. Radon is fixable, so it rarely needs to stop a sale.
- [9 Radon Myths We Hear in Southern Ontario (and the Facts)](https://indoorairqualitysolutions.ca/learn/radon-myths-southern-ontario/): The most common radon myths in Southern Ontario are that it only affects the Canadian Shield, that a neighbour’s low result applies to you, that new homes are immune, and that a few days of testing is enough. In fact, about 1 in 8 Ontario homes test at or above the guideline, results vary widely between neighbouring houses, newer homes have tended to test higher, and Health Canada recommends at least three months of testing.
- [How Radon Damage Works and Why It Can’t Be Undone](https://indoorairqualitysolutions.ca/learn/how-radon-damages-lungs/): Radon breaks down into radioactive particles that lodge in the airways and release alpha radiation, which can damage the DNA of lung cells. Cells repair most of it, but some mistakes are copied as cells divide, and nothing reverses them afterwards. You feel nothing, and cancer can show up many years later. Fixing radon stops new damage and lowers future risk, but it can’t repair what’s already happened.
- [Radon Risk by Age: Babies, Children, Adults and Seniors](https://indoorairqualitysolutions.ca/learn/radon-risk-by-age/): Radon causes lung cancer at any age, but there is no good breakdown of radon harm by age at exposure, and the risk models are built mostly on adults. What’s known: children’s lungs receive a higher estimated dose from the same air, they have the most years for damage to play out, and the effect takes decades to show. Older adults accumulate long exposure at home. Testing early matters most for infants and children.
- [Newborn Home Safety Checklist: Test for Radon First](https://indoorairqualitysolutions.ca/learn/radon-newborn-home-checklist/): Start the radon test as early in the pregnancy as you can. Health Canada’s test runs at least 91 days, ideally from October to April, and a fix has to follow it, so about four months before the due date is the latest to start comfortably. If the baby is due sooner, a professional 14-day early reading gives you a likely answer in time to act. The rest of the checklist covers sleep, alarms and hot water.
- [Radon and Older Adults: A Home Checklist for Seniors](https://indoorairqualitysolutions.ca/learn/radon-older-adults-checklist/): Older adults often spend most of the day at home, and Health Canada scientists estimate about 90% of radon-induced lung cancer risk comes from home exposure. Years of past exposure can’t be undone, but lowering radon stops new damage and still lowers risk, especially for smokers and former smokers. Test the rooms you actually use, particularly a basement suite or a bedroom moved downstairs, and retest after renovations.
- [Radon Guidelines Compared: Health Canada, EPA and WHO](https://indoorairqualitysolutions.ca/learn/radon-guidelines-compared/): Health Canada recommends action at 200 Bq/m³ (5.4 pCi/L). The U.S. EPA’s action level is 148 Bq/m³ (4 pCi/L), and it suggests considering a fix from 2 pCi/L up. The World Health Organization prefers a reference level of 100 Bq/m³ (2.7 pCi/L) and says it shouldn’t exceed 300. A result between 100 and 200 is under Canada’s guideline but above the WHO’s, and none of these numbers marks a safe level.

## Areas

- [Radon Testing & Mitigation in Windsor-Essex, Ontario](https://indoorairqualitysolutions.ca/radon/windsor-essex/): Windsor’s riverfront neighbourhoods and the Essex County towns along Lake Erie, on flat clay plain between the Detroit River and the lake. Most of Essex County is a flat lake plain: glacial lake clay and silt over till, with sandy beach ridges left by older lake shorelines and limestone and dolostone bedrock close to the surface in places along the Detroit River and the Lake Erie shore.
- [Radon Testing & Mitigation in Chatham-Kent, Ontario](https://indoorairqualitysolutions.ca/radon/chatham-kent/): One large municipality of flat farmland, river towns and shoreline on Lake Erie and Lake St. Clair, centred on Chatham on the Thames. Chatham-Kent is a flat plain of glacial lake clay and till, drained by ditches and tile and cut by the Thames and Sydenham rivers.
- [Radon Testing & Mitigation in Lambton, Ontario](https://indoorairqualitysolutions.ca/radon/lambton/): Sarnia and the St. Clair River, the Lake Huron shore from Point Edward toward Grand Bend, and farm country over the Kettle Point shale. Lambton sits on glacial clay plain and moraine ridges, with sandy dune and beach deposits along Lake Huron.
- [Radon Testing & Mitigation in London & Middlesex, Ontario](https://indoorairqualitysolutions.ca/radon/london-middlesex/): Our home base. Century homes in the core, fast-growing subdivisions on the edges, and sand-and-gravel valleys along the Thames. Glaciers left London sitting on layers of till, moraine ridges and old meltwater channels, with sand and gravel concentrated along the Thames valley and its former spillways around Byron, Komoka and Delaware.
- [Radon Testing & Mitigation in Elgin & St. Thomas, Ontario](https://indoorairqualitysolutions.ca/radon/elgin-st-thomas/): Railway-city heritage homes, rapid new growth around St. Thomas, and Lake Erie shoreline cottages turned year-round. Elgin sits on the Lake Erie lowland: glacial lake clays and silts near the shore, sandier ground and moraine ridges inland, and the Kettle Point black shale band running under the western part of the county toward Lake Erie.
- [Radon Testing & Mitigation in Huron-Perth, Ontario](https://indoorairqualitysolutions.ca/radon/huron-perth/): Stratford’s Avon River heritage core, St. Marys and its limestone, and Goderich on the Lake Huron bluffs, with farm country in between. The region is mostly glacial till plain and moraine, with sand and gravel along the Avon and Thames river valleys and the Maitland River cutting a deep valley to Lake Huron at Goderich.
- [Radon Testing & Mitigation in Oxford County, Ontario](https://indoorairqualitysolutions.ca/radon/oxford-county/): Woodstock, Ingersoll and Tillsonburg: manufacturing towns with heritage cores, new subdivisions, and rural homes on wells. Northern Oxford is till plain and moraine, cut by the Thames valley through Woodstock and Ingersoll, where river sand and gravel run close to the surface.
- [Radon Testing & Mitigation in Waterloo Region, Ontario](https://indoorairqualitysolutions.ca/radon/waterloo-region/): Kitchener, Waterloo and Cambridge on the Grand River, over the sand and gravel of the Waterloo Moraine, with farm country in the townships. Much of the region sits on the Waterloo Moraine, a ridge of sand, gravel and till that is also an important source of the region’s drinking water, and the Grand River and its tributaries run through all three cities.
- [Radon Testing & Mitigation in Norfolk & Haldimand, Ontario](https://indoorairqualitysolutions.ca/radon/norfolk-haldimand/): Sandy Norfolk farm country and Lake Erie ports to the west, Haldimand’s clay plain and Grand River towns to the east. The Norfolk Sand Plain is a vast delta of sand and silt left by glacial lakes, the reason this was tobacco country.
- [Radon Testing & Mitigation in Brant & Brantford, Ontario](https://indoorairqualitysolutions.ca/radon/brant-brantford/): Grand River valley city and towns, from Brantford’s older wards to Paris’s cobblestone heritage and new growth in St. George. The Grand River has cut through layers of glacial outwash, leaving sand and gravel terraces through Brantford and Paris.
- [Radon Testing & Mitigation in Hamilton, Ontario](https://indoorairqualitysolutions.ca/radon/hamilton/): Lower City on the old lake plain, the Mountain on the Escarpment, and growing suburbs from Ancaster to Stoney Creek. Hamilton is split by the Niagara Escarpment.
- [Radon Testing & Mitigation in Niagara Region, Ontario](https://indoorairqualitysolutions.ca/radon/niagara-region/): Twelve municipalities between two Great Lakes: escarpment benches, fruit-belt lake plain, the Fonthill hill and limestone along Lake Erie. North of the Escarpment, the fruit belt and St. Catharines sit on the Iroquois Plain: lake sands, silts and clays over red shale.
- [Radon Testing & Mitigation in Windsor, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/windsor-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Windsor home. The Windsor-Essex County Health Unit’s 2015 to 2018 study found about 6% of City of Windsor homes above the guideline, against 18% in Essex County. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, shallow or fractured bedrock and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Leamington, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/leamington-kingsville-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Leamington home. The Windsor-Essex County Health Unit’s 2015 to 2018 study found about 18% of Essex County homes above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, sandy or gravelly soils and shallow or fractured bedrock are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Chatham, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/chatham-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Chatham home. Health Canada survey data tabulated by Cancer Care Ontario put Chatham-Kent at 18.4% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, sandy or gravelly soils and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Sarnia, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/sarnia-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Sarnia home. Health Canada survey data tabulated by Cancer Care Ontario put Lambton at 8.4% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, nearby uranium-bearing shale, cracking clay soils and converted cottages and crawlspaces are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in London, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/london-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any London home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, Shield-derived glacial soils, sandy or gravelly soils and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Strathroy, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/strathroy-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Strathroy home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, nearby uranium-bearing shale, sandy or gravelly soils and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Komoka, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/komoka-middlesex-centre/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Komoka home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, new airtight construction and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Dorchester, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/dorchester-thames-centre/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Dorchester home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, Shield-derived glacial soils and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in St. Thomas, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/st-thomas-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any St. Thomas home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, century-home foundations and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Port Stanley, ON](https://indoorairqualitysolutions.ca/radon/port-stanley-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Port Stanley home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, converted cottages and crawlspaces, cracking clay soils and sandy or gravelly soils are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Aylmer, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/aylmer-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Aylmer home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, rural drilled wells, century-home foundations and sandy or gravelly soils are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Goderich, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/goderich-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Goderich home. A local health unit report put Huron County at 11% of randomly selected homes above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, Shield-derived glacial soils, cracking clay soils and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Stratford, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/stratford-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Stratford home. Cancer Care Ontario’s table of Health Canada survey data put Perth at 12.0% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, Shield-derived glacial soils, sandy or gravelly soils and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in St. Marys, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/st-marys-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any St. Marys home. Cancer Care Ontario’s table of Health Canada survey data put Perth at 12.0% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, Shield-derived glacial soils and sandy or gravelly soils are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Woodstock, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/woodstock-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Woodstock home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, Shield-derived glacial soils, sandy or gravelly soils and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Ingersoll, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/ingersoll-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Ingersoll home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, Shield-derived glacial soils and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Tillsonburg, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/tillsonburg-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Tillsonburg home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, lived-in basements and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Kitchener, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/kitchener-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Kitchener home. Cancer Care Ontario’s table of Health Canada survey data put the Region of Waterloo at 4.0% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, Shield-derived glacial soils and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Waterloo, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/waterloo-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Waterloo home. Cancer Care Ontario’s table of Health Canada survey data put the Region of Waterloo at 4.0% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, Shield-derived glacial soils and lived-in basements are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Cambridge, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/cambridge-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Cambridge home. Cancer Care Ontario’s table of Health Canada survey data put the Region of Waterloo at 4.0% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, sandy or gravelly soils and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Simcoe, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/simcoe-norfolk-county/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Simcoe home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, rural drilled wells and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Port Dover, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/port-dover-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Port Dover home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, converted cottages and crawlspaces, sandy or gravelly soils and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Caledonia, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/caledonia-haldimand-county/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Caledonia home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, rural drilled wells and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Brantford, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/brantford-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Brantford home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, century-home foundations and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Paris, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/paris-county-of-brant/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Paris home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, century-home foundations and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Hamilton, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/hamilton-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Hamilton home. A Hamilton public health survey found about 14% of 294 homes above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, sandy or gravelly soils and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Ancaster, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/ancaster-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Ancaster home. A Hamilton public health survey found about 14% of 294 homes above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, new airtight construction and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Grimsby, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/grimsby-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Grimsby home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, converted cottages and crawlspaces and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Beamsville, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/lincoln-beamsville-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Beamsville home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, century-home foundations and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in St. Catharines, ON](https://indoorairqualitysolutions.ca/radon/st-catharines-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any St. Catharines home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, sandy or gravelly soils and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in NOTL, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/niagara-on-the-lake/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any NOTL home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, century-home foundations, converted cottages and crawlspaces and cracking clay soils are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Thorold, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/thorold-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Thorold home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, lived-in basements and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Niagara Falls, ON](https://indoorairqualitysolutions.ca/radon/niagara-falls-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Niagara Falls home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, cracking clay soils and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Welland, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/welland-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Welland home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, century-home foundations and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Fonthill, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/pelham-fonthill-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Fonthill home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, new airtight construction and rural drilled wells are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Fort Erie, ON | IAQ Solutions](https://indoorairqualitysolutions.ca/radon/fort-erie-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Fort Erie home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, converted cottages and crawlspaces and century-home foundations are reasons to test. A 91-day test is the only way to know your home’s level.
- [Radon Testing & Mitigation in Port Colborne, ON](https://indoorairqualitysolutions.ca/radon/port-colborne-ontario/): Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Port Colborne home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, shallow or fractured bedrock, cracking clay soils and converted cottages and crawlspaces are reasons to test. A 91-day test is the only way to know your home’s level.

## Partners

- [Join Our Radon Contractor Network | Southern Ontario](https://indoorairqualitysolutions.ca/contractors/): Contractor network for C-NRPP certified radon measurement and mitigation professionals in Southern Ontario; pre-qualified jobs by region; requirements: C-NRPP, CAN/CGSB-149.12, $2M CGL, WSIB.

## Optional

- [Full text of guides and area pages](https://indoorairqualitysolutions.ca/llms-full.txt)
- [Glossary](https://indoorairqualitysolutions.ca/learn/glossary/)
- [FAQ](https://indoorairqualitysolutions.ca/faq/)
- [Sitemap](https://indoorairqualitysolutions.ca/sitemap.xml)