Radon is a naturally-produced radioactive gas caused by the disintegration of uranium in the earth’s crust. It is present throughout the planets entire surface although its production, and therefore its concentration is not uniform. Radon is odorless, colorless and tasteless. It is undetectable by the human senses.
The Canadian guideline regarding the level of radon in interior air is set at 200 Becquerel per square meter of air (Bq/m3).Beyond this level, it is recommended that action is taken to reduce exposure to the lowest concentration reasonably achievable. Nonetheless, anything over 100 Bq/m3 causes the risk to increase.
Whether your home is a recent or older construction, radon tends to accumulate in the lower and less ventilated rooms, where it can build up to high levels. Radon can seep into a home in a number of ways:
- Cracks in the foundation walls
- Dirt floors
- Construction joints
- Space around drainage pipes (e.g. pipe fittings), space around service pipes and support posts
- Between floor slabs, crawl spaces, floor drains and sump pits.
The only way to determine whether or not you have a radon problem is to measure its level in your home.
The only known risk is the long-term development of lung cancer. The level of risk depends on radon concentrations and the number of years of exposure.
It is estimated that 10% of lung-cancer-related deaths in Quebec are linked to radon exposure.
Lifetime risks for a smoker exposed to radon
Radon concentration in Bq/m3.
The risk of developing lung cancer.
|solely to smoking||12%|
Before you purchase a home
You can demand that a radon measurement test is performed over a minimum period of 3 months. A short test period is never acceptable as a basis for deciding whether or not to take corrective measures.
The buyer may file an offer providing for the setting aside of a sum of money until the results are received. If the measured level of radon exceeds 200 Bq/m3, the buyer may use this sum to carry out the corrective measures.
During the construction of a home, the level of radon cannot be predicted. It is cheaper and simpler to adopt preventive measures during the construction stage than it is to act later. In the drawings and specifications of your new home, be sure to include the preventive measures that are provided for in the 2010 National Building Code, as a means of preventing the infiltration of underground gases.
On March 24, 2010, the Building Code was modified to meet Health Canada’s radon guidelines. The Code recommends that builders install the lines needed for the subsequent installation of a radon extraction system, in all constructions, regardless of their location. The 2005 Code already featured basic protection measures, including the installation of a vapor barrier.
In homes meeting the new standards, radon exposure will be less likely, and radon elimination, if necessary, will be easier. Other corrective and preventive measures are described in the CMHC guide.
As each home is unique, it should be inspected by a qualified contractor who will recommend one or more attenuation measures.
1- In most cases, these measures are simple, e.g.:
- Depressurize the ground underneath the house (suck up the gas) by installing a small ventilator that will exhaust the radon outside. This is the most effective and commonly used method.
- Increase mechanical ventilation and make sure the ventilation system is well balanced.
- Seal all cracks and openings in the foundation floors and walls, and around pipes and drains.
- Make sure there is always water in the floor drain.
2- In most cases, the cost of the radon attenuation work is relatively reasonable. It can add up to anywhere between $800 and $3,000.
According to CAA-Quebec — Residential, a homeowner with home maintenance skills can perform part of the work himself, with some guidance from them.
Choose your contractor carefully
Make sure he is duly certified and uses the attenuation methods that suit your home.
- Presently, Health Canada only recognizes the certification programs provided by the National Environmental Health Association (NEHA) and the National Radon Safety Board (NRSB).
- Furthermore, we encourage you to consult the document “Radon – A Guide for Canadian Homeowners” published by the Canada Mortgage and Housing Corporation (CMHC).
Questions designed to properly select your contractor
You have already performed a 3-month radon measurement in your home and your contractor would like you to do it again… Unnecessary! Have you asked to see proof of his NEHA or NRSB certification? To maintain his certification, the contractor must keep upgrading his skills. Consult the list of certified contractors on the NEHA-NRPP and NRSB Websites to make sure they meet certification requirements.
- Have you requested at least 3 quotes?
- Have you demanded references?
- Have you checked these references?
- Are you certain there are no legal actions pending against the contractor? To find out, contact the OPC (Office de la protection du consommateur).
- Is the contractor a member of CAA-Quebec? You should make sure no complaints have been filed against him.
- Have you demanded a written guarantee that results will be met? You have a right to demand it! Was this explained to you?