Radon in GTA    (Greater Toronto Area)

What is the likelihood of a High Radon Test in the GTA?

We are presently finding that an average of 1 in 10  of homes we have tested in the GTA and surrounding communities are above the ‘action levels’ set by Health Canada

OCCURRENCE OF RADON

Levels of radon vary from place to place and even from house to house within a given area. The higher the uranium content of the rocks that underlie an area, the greater the likelihood that houses in the area will contain elevated levels of radon. The only way to know if you have a radon problem is to test. It's quick, easy, and inexpensive.

At present there is no Radon map of the Greater Toronto Area but we might infer some things from the map of the United States below. Please be reminded that levels of Radon vary from place to place and even from house to house within a given area. The USA data seems to show that there is generally a lower average of high tests in homes very close to the great lakes (5-10 miles). Geologists have suggested this may be because these homes are built on old lake bottoms with clay silt layers.  These lower averages still result in a percentage of homes above  ‘action levels’ for Radon Gas. Remember, the only way to know is to test.

Do not use this map as "don’t need to test for radon here". Our two highest levels in homes 16650 bq/m3 and 8775 bq/m3 were found in homes that were in the elevated and guarded areas on this map.
Every home old or new, big or small, has the potential to be high in radon please test your home and fix it if you have a high test.   
Please be reminded that levels of Radon vary from place to place and significant differences from house to house within a given area. If your neighbour has had a low test it doesn’t mean that your home will be low as well.

Remember, the only way to know is to test.

EVALUATING RADON POTENTIAL

By evaluating the geology in an area, scientists can evaluate the radon potential of the rocks and soils at housing sites or other areas of interest. The factors listed below can increase the probability that an area will have above-average levels of radon.

1. Uranium-rich rocks underlie the area.
2. The site is located on a hill or slope.
3. Soils are well drained or dry most of the time.
4. Soils form deep cracks during dry time of the year.
5. Highly permeable soils are present.
6. The soils are thin and bedrock is close to the surface.
7. Underlying rocks are fractured.
8. The underlying rock contains limestone caverns.
9. High levels of indoor radon have been reported in the county or neighborhood.

The only way to know if you have high Radon Gas levels in your home is to test!