Radon is the leading cause of lung cancer in Canada among
non-smokers
CBC News has obtained data showing the results of
approximately 14,000 radon tests in homes across the country, which show that
over 1,500 homes Health Canada tested had radon levels above the department's
guidelines.
Radon is the second leading cause of lung cancer in Canada
after smoking. It's a radioactive gas naturally emitted from the earth through
the breakdown of uranium in soil. It enters your home by seeping in through
cracks, pipes, windows and the foundation of your house.
What is radon?
It's a colourless, odourless gas. It is also radioactive.
It's formed by the disintegration of radium, which is produced when uranium
decays.
Radon gas and its byproducts occur naturally everywhere —
in soil, water and air. Rarely does it occur in concentrations that you need to
worry about. However, radon gas can accumulate in confined spaces such as
basements and crawl spaces in homes. If the levels are high enough, it can be a
health hazard.
As radon decays, it produces decay products called
"radon daughters." They also decay rapidly and emit alpha particles.
Your skin is normally enough to protect you from these particles. But when they
become attached to dust and you breathe them in, you could be at risk.
It's estimated that radon kills 3,000 Canadians a year.
The Canadian guideline for radon in indoor air is 200
becquerels per cubic metre (200 Bq/m3).
In 2012, Health Canada released a report showing that 6.9
per cent of Canadians are living in homes with radon levels above the current
guideline. The results were based on a two-year survey of approximately 14,000
homes across the country.
Test your home
It is not a requirement to test for radon or take any steps
if you have high levels. Radon levels can vary from one house to another and
Health Canada recommends that everyone test their home.
Of the homes that Health Canada tested in the survey,
approximately 1,557 of them had results above the guideline of 200 Bq/m3.
The World Health Organization recommends the guideline for
countries be 100 Bq/m3. Data obtained by CBC News through an Access to
Information request shows that 2,514 additional homes tested in Health Canada's
survey have radon levels between 100-199 Bq/m3.
According to the WHO, the risk
of lung cancer increases by 16 per cent per 100 Bq/m3 increase in radon
concentration.
Health Canada recommends that homes be tested for a minimum
of three months, ideally in the fall or winter. The cost of radon testing is
approximately $50 to $100.
In 2007, Health Canada considered making testing during real
estate transactions mandatory, but decided otherwise. According to a 2007 Canadian Real Estate
Association document, Health Canada "has abandoned this approach at the
present time due to concerns raised by industry groups, including CREA."
Health Canada says that such requirements would have to be
adopted at local level. "It's not going to be a requirement at least from
our perspective. It may very well happen that provinces or some municipalities
that know that they have high levels of radon in their area may decide to be
more proactive on radon and require it. And if that happens that's fine … but
it's not something that we're going to require," says Kelley Bush, head of
radon education and awareness with Health Canada.
How does radon get into your home?
Is your house airtight? Very few are, especially older
homes — and especially if the foundation or any of the walls are built
with concrete blocks, which are particularly porous to radon. But the gas can
also seep in through basement floor drains, cracks in the floor or foundation,
and under the furnace base. Radon can also become trapped in well water and
released into the air when the water is used.
Call a professional. They'll come to your house and take
samples of the air in your basement. The most common method is to use a
canister that contains activated charcoal. Activated charcoal absorbs radon
gas. The unit will be left in your home for several days before being sent to a
lab for analysis. You will receive an average radon level for the time the unit
was left in your home.
The soil around your home can also be tested if it's
suspected that there could be high levels of uranium.
If the test show higher than acceptable levels of radon you'll need to have the problem fixed. The federal
government recommends that if the radon concentration in your home is greater
than 600 Bq per cubic metre, work needed to reduce levels below 200 Bq per
cubic metre should be completed within a year. If levels are between 200 and
600 Bq per cubic metre, the work should be done within two years.
The report recommending lower radon levels suggested that
the federal government should offer some assistance to homeowners who need to
have work done on their homes. The government's revised guidelines did not
address that subject.
If there are unacceptable levels of uranium in the soil
around your house, the soil should be removed and replaced with clean fill. But
this is extremely rare.
Steps you can take inside your home:
- Sealing all cracks and openings in the walls and floors of
your basement as well as around drains and pipes.
- If your basement floor has a sub-floor, make sure it is
ventilated.
- Replace an earth floor with a concrete floor.
- Increase the ventilation in your basement or other enclosed
space where radon may accumulate.
- Paint basement floors and walls. Use a sealant on top of the
paint and add polyethylene sheets to basement walls.
Keep your family and home safe and get your home tested! For more information on how to reduce your exposure to radon, visit Health Canada.
