Radon Gas
Wednesday February 21st 2007, 1:30 pm

As if we don’t have enough to worry about, there is a silent killer in some of our homes, and most of us don’t even realize it. This killer is called radon gas, and it is an odourless radioactive gas which occurs naturally in our environment. It is a product of the natural radioactive decay of uranium found in rocks, soil and water. It usually escapes into the air where it is diluted to harmless concentrations. The problem is when this gas leaks into our homes and buildings through cracks, openings in walls and floors, and around pipes and drains, and becomes trapped due to inadequate ventilation. Radon gas is of great concern to Americans, but is virtually unknown to most Canadians. Canada is the world’s leading producer of uranium, so Canadians should be more aware of it.

It is estimated that 500,000 Canadians are living in homes that exceed the recommended safe guidelines for radon gas concentration in the air. The hot spots for radon in Canada include several areas in the British Columbia interior such as Clearwater, Barriere, Castlegar, Prince George, the Okanagan and the Kootenays. Kamloops isn’t affected because it’s clay soil acts as a buffer to the passage of the radon gas. Other areas in Canada include Winnipeg, Elliott Lake, Kirkland Lake, Port Hope and Kitchener-Waterloo, Ontario, Oka, Quebec, and some areas in Nova Scotia and Newfoundland. Nearly 1 out of 15 homes in the United States has elevated radon gas levels.

Radon gas kills 2,000 annually in Canada, and about 20,000 in the United States from lung cancer. Exposure to radon gas is the second leading cause of lung cancer, next to smoking. Inhaling it, in some buildings, is the same as smoking a pack or more of cigarettes a day. About 40 Nova Scotians die every year from lung cancer caused by long-term exposure to high levels of radon, based on a 1997 study.

The first time I heard about radon gas was a few years ago when the Province of Nova Scotia tested 14 schools for radon gas, and found six schools, which were located south of Halifax, to have high levels of it. At the time, the levels were below the 800 becquerels per cubic metre federal guideline for this gas, so there was little concern. The federal government is proposing to revise their guideline from 800 to 200 Bq/m3, which is more in line with the rest of the world. The United States has a guideline of 150 Bq/m3. Due to this change in the guideline, the Province of Nova Scotia will be investigating radon gas levels at all schools, hospitals and other public buildings over the next five years, and is encouraging homeowners to do the same. The hot spot for radon gas in Nova Scotia is south of Halifax, in areas such as Timberlea, Tantallon and St. Margarets Bay, where the bedrock contains uranium.

The only way to know whether your house has dangerous levels of radon gas is to test the air with a radon gas kit. These are available online for between $20.00 and $50.00. The testing takes 3 to 6 months, and should be done during the winter when doors and windows are closed. It should also be done on the lowest levels of the home, where the levels are the highest. The average cost to fix the problem is $1,200. to $1,500. and includes sealing cracks in concrete floors and walls, fitting airtight covers on sump pumps, installing special traps in the basement drains, covering over exposed soil and installing a ventilation system to remove the radon to the outdoors.

Once the new federal guideline is approved, it will be up to each province to decide how to apply it. It will have implications for building codes and real estate transactions. Mandatory testing for radon gas will probably be a condition of the sale of real estate, as it is in the United States.

During the 1970’s thousands of homes in Ontario and Newfoundland were built on top of uranium tailings left over from uranium mining. Also during that time, many homes in Canada, and especially in Ontario, were built using sand-like uranium tailings, which is pulverized rock, as construction materials. Newer homes have been built with amendments to building codes regarding damp-proofing and sealing floor slabs, and installing vent pipes under basement floors, which are attached to a fan for ventilation of the radon gas. A problem with newer homes is that they are so well insulated, it is difficult for trapped radon gas to escape.

Many people, who are aware of this problem, are afraid to test their homes because a positive test may mean a decrease in the value of their homes. Two houses which are side by side may have completely different readings depending on the construction of the home and the soil underneath the home. Other factors such as the house’s relation to prevailing winds, also has an effect on radon gas.

With more publicity and the availability of the test kits, testing will become something done more frequently. There is a continuous radon gas monitor available online for $120. This is the type of monitor which will be as common as a smoke detector in homes. Not everyone will be convinced that testing is necessary, so radon gas monitors maybe mandatory in the future, especially in certain hot spots. The area I live in isn’t near a hot spot, and has very hardpacked clay soil, which like Kamloops, may act as a buffer to any radon gas. The only way I will know for sure, is to get my house tested.

Anne