10.3 Environmental Hazards & Indoor Air Quality
Key Takeaways
Keep suspect asbestos material undisturbed and recommend qualified assessment before work.
Use a representative radon test of at least 91 days. Health Canada recommends reducing results above 200 Bq/m³ within a year and sooner at higher levels.
Investigate the source and extent of moisture before deciding how to handle mould.
A suspected tank warrants records and specialist review. Reporting, remediation and designated-site orders have different statutory tests.
Separate a visible clue from the finding it suggests
A general home inspection can flag suspect materials, moisture or past alterations. A specialist may need to identify a material, test indoor air or investigate soil and groundwater. Ask about prior reports, repairs, notices and permits, and match the scope and deadline of any purchase condition to the investigation. RECA Rules 1(1)(t) and 57(i) govern known material latent defects for a seller’s sole agent. A visible clue, the age of a building or the label for a product does not alone establish a known hidden defect. Record what was observed, what the seller or documents establish and what remains uncertain. Escalate any instruction to suppress a required disclosure to the broker.
Asbestos, lead and older insulation
Some vermiculite insulation, pipe insulation, flooring or other older materials may contain asbestos. Breathing airborne fibres can cause serious lung disease. The risk rises when material is damaged or disturbed. An older attic with loose vermiculite warrants caution even if it looks undamaged. Keep suspect material undisturbed and recommend a qualified assessment before renovation. Appearance cannot identify the fibres. Canada’s federal prohibition regulates asbestos and products containing it and generally does not require removal of material already installed.
Older coatings and plumbing can be sources of lead. Sanding or scraping lead paint can release contaminated dust. In drinking water, lead may enter through a service line, solder, fittings or fixtures. Ask the water utility about service-line material on both sides of the property line and obtain advice on suitable sampling. Health Canada’s drinking-water guideline is 0.005 mg/L for total lead, measured using the appropriate sampling protocol at the tap. The result of a suitable test is more informative than an assumed cut-off date for a building or pipe.
The Canada Consumer Product Safety Act lists foamed-in-place urea formaldehyde thermal insulation (UFFI) among prohibited products. Older installations can still be encountered. A record of historical installation does not establish current exposure. If there is a concern about moisture, material condition or indoor air, seek qualified advice and apply the contract, known-defect duties and actual findings to the property.
Test radon over a period that represents exposure
Radon is a naturally occurring radioactive gas that can enter from soil through openings at foundations, slabs, sumps and penetrations. Levels vary over time and across homes. Long-term exposure increases lung cancer risk. Health Canada recommends a long-term measurement of at least 91 days, ideally with at least 91 days during the heating season, on the lowest level with normal occupancy. A suitable long-term detector or electronic monitor can be used according to the guide. A 48-hour reading cannot establish the annual average.
The Canadian guideline is 200 Bq/m³. If a representative long-term result exceeds it, Health Canada recommends reducing levels within one year and taking action sooner for higher results. A certified radon professional can assess options such as active soil depressurization, which draws soil gas away from the building, and advise on follow-up testing. For example, with a long-term result of 260 Bq/m³ at the lowest occupied level, discuss the report, mitigation and a follow-up measurement. A buyer facing a short inspection period can seek an appropriate written arrangement and decide how to handle a test that will outlast the original condition.
Find and correct the moisture source
Moisture from leaks, condensation, flooding or poor drainage can support mould growth. A stain, musty smell or thermal anomaly warrants investigation. These clues do not establish the affected area or cause. A qualified assessor may use a moisture meter and other evidence to investigate. Address the source and damage. For a large patch, recurring growth or suspected concealed contamination, obtain expert assessment. Health Canada’s household guidance uses the extent and pattern of growth to help decide when professional help is appropriate. Its guidance is distinct from legal disclosure and workplace requirements.
Unusual ventilation alterations, electrical tampering, heavy moisture damage or chemical residues can justify inquiry into past use. These clues have other possible causes. If an active illicit lab is suspected, leave and contact police from a safe location. For reported past use, request any authority notices and documents showing investigation, remediation and clearance. A historical label and evidence of a current hazard raise different questions.
Investigate a possible buried fuel tank
Old fill and vent pipes, former fuel lines, heating records and seller information may point to a buried tank. They do not confirm a tank or a release. Ask a qualified environmental consultant which scope fits the evidence:
| Investigation | Question it helps answer |
|---|---|
| Phase 1 environmental site assessment | What do past uses, records and site observations suggest about potential contamination? |
| Phase 2 environmental site assessment | Where sampling is warranted, is contamination present and what are its nature and extent? |
Check the required tank closure or removal records with the authority and verify financing and insurance for the specific property.
Section 2 of Alberta’s Environmental Protection and Enhancement Act (EPEA) sets out its purpose of protecting, enhancing and wisely using the environment, including protection of human health and sustainable development. The Act’s release and remediation provisions can affect the investigation, cost and timing of a sale. Sections 110–111 address reporting qualifying releases and the parties responsible for reporting. Sections 112–113 address remedial duties and orders directed to a person responsible for the substance. Under sections 107 and 129, the current site owner can be among the persons responsible for a designated contaminated site. The Director considers available evidence such as when the substance appeared, what a purchaser knew or ought to have known, pre-purchase due diligence and who caused or contributed to the release. Ownership does not by itself decide which order, duty or private liability applies. Seek environmental and legal advice when the facts indicate a release or an order. An agreement about who pays between buyer and seller does not determine the regulator’s powers.
A buyer’s inspection condition expires next week. The inspector has a 48-hour radon reading from the lowest regularly occupied level. What can the buyer conclude under Health Canada guidance?
The reading does not establish annual exposure. Plan a test of at least 91 days, ideally with at least 91 days in the heating season, and address the timing with the buyer.
A low result after 48 hours establishes that the annual level is below 200 Bq/m³.
A 48-hour result above the guideline automatically condemns the property.
A test during a heating season is invalid because radon cannot enter from frozen ground.
An inspector identifies vermiculite attic insulation in an older Edmonton bungalow. The buyer plans renovations that would disturb it. What should the licensee advise?
Remove it with an ordinary shop vacuum before closing.
Confirm from colour alone that it is free of asbestos.
Treat its presence as a federal ban on selling the home.
Leave it undisturbed. Explain that some vermiculite contains asbestos and recommend qualified assessment before work.
A buyer sees capped fill and vent pipes at a home that once used heating oil. No tank-removal or contamination records have been found. How should the buyer’s licensee address the finding?
Treat the absence of a record as proof that the soil is clean.
Conclude that the registered owner must pay all costs regardless of whether a tank or release exists.
Seek records and a qualified environmental assessment, check lender and insurer requirements, and obtain legal advice if a release or order is indicated.
Assume the Real Estate Assurance Fund will cover the investigation and cleanup.
Sections you finish are checked off in the contents.