Radon Defined

Radon is a colourless, odourless radioactive gas that occurs naturally in our environment. It is a product of the natural radioactive decay of uranium found as a trace element in most rocks, soil and water.

Radon Risk Assessment

Radon risk evaluation includes consideration of the following issues:

• source (material capable of producing radon)
• transportation (means by which radon can travel from source into a dwelling)
• trap (restricted ventilation, which allows radon accumulation)

Radon Concentration Factors

The amount of radon in a building is dependent upon several factors. These factors include the geology, a driving force, pathways into the building, and the ventilation rate. As the concentration of uranium is in the underlying soil increases, so does the strength of the radon. Radon is transported to buildings more easily through permeable soils. Buildings can create pressure differentials that will draw in the soil gases. Radon can enter the building through many paths such as cracks in the foundation, utility penetrations, sumps, and floor drains. The ventilation rate of the building affects the final radon concentration.

The EPA has made the recommendation of no long-term radon exposures above 4 pico couries/liter (pCi/L). This action level was based on both health and economics. The only way to tell if a building has elevated levels of radon is to have it tested.  Radon test kits are inexpensive and easy to use.