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Is Radon a risk in your home?

By Sandra Madray, PCN Board of Directors

When you hear the phrase ‘odourless, colourless, tasteless gas’, what is the first thing that comes to mind? I bet it’s carbon monoxide.

Good answer, but radon is another gas that can be lethal – and very few Canadians are even aware of it as a potential threat. When present in our homes, radon increases the risk of developing lung cancer and, in fact, is the second leading cause of lung cancer after smoking.

Health Risks

Radon is released as a natural breakdown product from uranium found in soils and rocks. It is generally not a concern outdoors because of its low concentration, but when radon seeps into enclosed spaces such as basements or water systems, it can increase to levels that may put our health at risk.

Not everyone exposed to radon will develop cancer, of course – not all smokers get cancer either. But exposure over time in higher than average concentrations of radon are important factors for cancer. Just as with many other malignancies, it may take many years of exposure to radon before cancer will appear. Unlike regular exposure to tobacco smoke, contact with radon does not result in coughing or headaches, symptoms that can serve as early warning signs of more serious health problems.

Radon and tobacco smoke work together to increase your risk of lung cancer,. more than if you were exposed to these substances separately. Those exposed to second hand smoke are also at higher riskof lung cancer when radon is present.

Sources of exposure in the home

Radon from soil and rock below a house can seep into the building in various ways: through cracks in foundation walls and basement floors, basement drains and sumps, gaps around support posts and service pipes, and construction joints. Also, radon can be trapped in well water and get released into the air when water is turned on.

Generally, radon concentrations in the home are greater in fall and winter because of reduced air circulation – we shut our doors and windows to keep the cold out.

Testing & acceptable limits for radon

First, let’s assure you that ‘something can be done’ if your home tests positive for radon. But the first step is testing – every Canadian home should be tested periodically – it’s even a requirement in some US states, but rarely recommended here.

Because there may be a big variation in the concentration of radon in a home at any given time, Health Canada recommends that radon be measured over longer periods to give a more accurate picture. Winter testing is best, with a minimum test period of 3 months, and 12 months the optimum. At the very least, have your home tested using a 7-day monitor such as the one certified by the Radiation Safety Institute of Canada.

The preferred area for testing should be the lowest lived-in level of your home that is normally occupied for at least 4 hours per day, such as a lower level bedroom. Other areas might include dens, playrooms, family rooms and living rooms.

There are detection methods currently recognized by Health Canada as being acceptable for measuring radon in homes and public buildings. At present, the guideline used for the average annual radon concentration is 200 becquerels per cubic metre (200Bq/ m³) in a dwelling.

Remedial measures

Remedial action should be taken when the average radon levels in a home exceeds Health Canada’s guidelines. The higher the concentration, the sooner remedial measures should be initiated.

When building a new home, construction techniques to minimize radon seeping into the building can and should be applied – so be sure to ask your contractor. There is also the possibility that radon levels may have to be decreased after construction of the home. If so, the contractor should ensure that the design of the house would easily facilitate the normal procedures for radon reduction.

Health Canada recommends that Canadians choose a service provider that has been certified with either National Environmental Health Association (NEHA) , or National Radon Safety Board (NRSB).

Some questions to ask a radon tester include:

• What type of radon test device will be used – short term or long term?
• Are you certified or trained to provide radon measurement services?
• Are you familiar with Health Canada’s revised Canadian guideline for radon exposure in indoor air?
• Do you follow / are you familiar with Health Canada’s measurement protocols for radon?

• Health Canada’s website – Radon section
• Health Canada’s radon protocol for homes

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