As many as 20,000 people in the US may die this year from excessive exposure to a naturally occurring radioactive gas called radon (US Environmental Protection Agency). Only tobacco smoke provides a quicker route to lung cancer.
What is Radon? — Radon is a tasteless, odourless and colourless radio-nuclear gas formed in rock and soil due to the natural breakdown or radioactive decay of uranium-238. It element makes up about 3 parts per million of the earth’s crust. Radon has been generated and released from uranium since the earth was formed. Radon gas is present to some extent everywhere. Each radioactive element decays at a characteristic rate known as a half life. As the material gives off radiation it is transformed into a different element. Since the half life of uranium-238 is about 4 and a half billion years it, and, its decay products, will linger forever as far as we are concerned.
How does it enter your home? — Radon readily seeps from the earth and rock beneath a home through tiny cracks and openings in the floors, foundation and basement walls. The concentration in a home depends on source strength, soil characteristics, mechanical systems in the house, occupants’ habits, the weather, and, many other factors. A low radon gas level in one home does not necessarily mean that homes nearby are okay. In addition, radon varies significantly day to day and over the course of months. Ten-fold changes are not unheard of. Significant concentrations can also be released into the home by way of well water. This can occur during activities such as showers or dish washing. To a lesser extent it can also be present in building materials and in fossil fuels, which may be burned in the house.
How serious can radon be? — The health risks associated with exposures to high concentrations of radon gas were first revealed with the experiences of uranium miners over the past few decades. A number of epidemiological studies of miners in the US, Canada, Germany, Czechoslovakia and elsewhere found a correlation between long term exposure to high levels of radon and radon daughters, and the incidence of lung cancer (Health Physics — 11/85). Long term exposure to radon increases the risk of developing lung cancer. Radon gas is the number two cause of lung cancer resulting in as many as 30,000 deaths per year (US National Cancer Institute). The health risks to humans show no immediate symptoms however about 10% of all lung cancer deaths are estimated to be radon related. Smokers are at higher risk of developing radon-induced lung cancer.
Accumulation of radon in an enclosed area, such as a home, can be very hazardous to your health. On average, Canada has 8 times the level of naturally occurring Radon than any other country in the World and more than twice compared with that found in the US (International Radon Symposium — Sweden 1995).