The Canadian guideline for radon in indoor air for dwellings is 200 Becquerels per cubic metre (200 Bq/m3). A Becquerel is a unit that measures the emission of radiation per second. The radon level in a dwelling should not be above the guideline. It is the choice of each homeowner to decide what level of radon exposure they are willing to accept.
The chart below compares the risk of dying of radon-induced lung cancer to other better-known risks such as car accidents, carbon monoxide and house fires. The annual death rate in Canada from exposure to radon-induced lung cancer is 3,200 deaths, higher than carbon monoxide 1,898 deaths, car accidents 300 deaths and house fires 109 deaths combined. The only way to know your radon level is to test and if high levels are found take action to reduce.