What is Radon ?
- It is natural occurring, tasteless, colourless, odourless and radioactive
gas
- It is formed by the breakdown of uranium, a natural radioactive material
found in soil, rock and groundwater.
Why is it a problem ?
- According to National Cancer Institute of Canada, estimated deaths
from lung Canada in 2006 is 10,7000 men and 8,600 women. In 10 % of the
these cases, radon would have caused lung cancer.
- Exposure over time can increase the risk of lung cancer
- Health Canada recommends that remedial measures be taken in a
dwelling whenever the annual radon concentration exceeds 200 Bq/m3 in
the normal occupancy area. The actionable level of 200 Bq/m3 was change
in October 2006 from 800 Bq/m3.
- The average level of radon in outdoor air is about 10 Bq/m3.
However, levels can occasionally reach several times this amount for
short periods of time. Indoor radon levels typically range from about 30
to 100 Bq/m3, with an average concentration of 45 Bq/m3. However, in
some locations radon can readily exceed 200 Bq/m3 and in few cases,
levels have been found as high as 3000 Bq/m3.
How does it get into the house ?
- During much of the year, the air pressure inside the
home is lower than in the soil surrounding the foundation. This
difference in the pressures draws air and other gases in the soil,
including radon, into the house
- Soil gases containing radon can enter a house any
place it finds an opening where the house contacts the soil. These
openings can be present even in well-built and new homes.
- Potential entry routes for radon in homes with poured
concrete foundations includes
but no limited to
- Floor and wall joints
- Floor drains and sumps
- Cracks or flaws in floor stabs
- Hollow objects such as support posts
- Cracks or flaws in foundation walls
- Exposed soil or rock in crawlspaces
- Homes with concrete block foundation walls can have
other entry routes such as
- Missing mortar between blocks
- Unclosed voids at the top of exterior walls
- Unclosed voids at the top of interior block walls
which penetrate the floor slab
- Pores in the face of blocks
- Floor/walls joints
- Cracks through the blocks or along mortar joints
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What to do ?
- One way to determine whether your home has a high radon level is to test for
it. A short term test takes 2 days. Call us at 1-888-471-7827 for to arrange for a test.
- We are certified by National Environmental Health Association (NEHA)
for Radon Measurement which Health Canada has recognized. More
information on NEHA
here
Personal Evaluation of Exposure
- How much time do your family members spend at home. Guidelines assume that
75% of a person's time is spent at home.
- Do you have a bedrooms or home office in your basement ? Radon
concentrations tend to be greater on the lower levels of a home. A person who
sleeps or spends much of his/her waking hours in the basement is exposed to more
risk than others occupy higher levels in the same house..
- How long will you live in your home ? The guidelines in the
CMHC booklet
are
based on an exposure period of about 70 years.
How to reduce Radon in Existing Homes ?
Methods to reduce the
level of radon in your homes vary considerably in their complexity, long
term effectiveness and cost. The effectiveness of any one radon reduction
method will depend upon the unique characteristics of your home, the level
of radon, the routes of the radon entry and how thoroughly the job is done.
A single method may be sufficient but sometimes several methods must be
combined to achieve acceptable results (especially when levels are high).
Many radon reduction measures require installation by a professional
contractor or skilled homeowner. However, there are some steps many
homeowners can take to immediately, often at little cost.
These steps might not
always be sufficient by themselves, but they may give some reduction until
more comprehensive measures can be implemented.
- Close Major Entry Routes for Radon like
- Open sumps
- Cover exposed soil
- Seal voids in concrete block walls
- Reduce forces that draw Radon into the Homes.
- Depressurize the Soil around the foundations
- Seal any remaining entry routes for Radon.
- Increase Mechanical Ventilation of the Home like
installation of HRV.
Information provided here is taken from CMHC/Health
Canada publication on Radon -
"Radon - A guide for Canadian Homeowners"
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