If you breathe them in, they continue to decay in the lungs, damaging the fragile tissues. Smokers who are exposed to high levels of radon are at greater risk of developing lung cancer than non-smokers. These health hazards have created a heightened state of alert in the U.S., where its more common for homeowners to test for radon, and to take measures to eliminate it if the gas if found to be present. The lower level of concern in Canada may have something to do our health officials' higher threshold of tolerance for the gas. The World Health Organization's safe exposure guidelines are also five times lower than Canada's.
Radon is more common in some areas than others.
For instance, you may have little cause to worry if you live in Montreal or Vancouver. Yet Winnipeg, Regina, Sudbury, Fredericton and Halifax tend to have more radon. There are also problems in B.C. Interior communities such as Nelson. The U.S. government recommends all homes below the third floor be tested for radon. The most popular radon detectors, such as charcoal canisters, are exposed to the air for several days and then sent to a laboratory for analysis.