Depending on where you live in North America, your location may be more prone to Radon Gas than other parts where it can be less common. I became familiar with the term Radon years ago but never really paid much attention to it, and you may have done the same. All I knew was that you could have an invisible, odorless gas that was dangerous coming from under your house, so now, 20 years later, I decided to look into it.
Somewhere in the late 1970s, an early test by the Environmental Measurement Laboratory of the US Department of Energy (who knew they even existed) conducted a detailed Radon test for an indoor structure. This survey produced valuable detailed information. The US Radon Industry was formed in 1984 when accelerated concentrations of radon were found in the Northeastern part of the United States.
Radon is a concern because it is invisible, odorless and colorless; that said, all of the major health organizations, Centers for Disease Control and Prevention, the American Lung Association and the World Health Organization all agree that lung cancer deaths in mainly at risk patients is greater when radon is present in the structure.
How This Affects How We Build
Masonry products made of clay, marble and granite typically do not exhibit high levels of radon or naturally occurring radioactivity. Studies have shown that the decay of the listed materials can increase radon levels, but honestly, decay (only when actually underwater or repeatedly underwater) is typically not as big an issue as what naturally occurs in the soil.
Uranium naturally exists in soil and bedrock at low levels, over time as uranium decays and the byproduct is radon gas. Other sources include various soil types, natural ground water, natural gas and, in some cases, building materials used low in the structure.
Radon enters the structure from the soil to the crawl space or the basement through various construction joints, foundation cracks, pipe penetrations in the foundation or footing. Slabs poured on grade actually emit less gas due to the way they are constructed.
If you monitor or test for radon, you will learn that the units for measurement may not seem familiar. The units for measurement are pCi/l. The units are pico Curie per liter which is the measurement of radioactivity in a liter of water. This occurs because of the radon gas that is broken down and dissolved in the groundwater.
When testing your ground water for radon, 10,000 pCi/l will contribute 1 pCi/l to the air found inside your home. The safe measure of radon is 4 pCi/l.
So, if you have a home that accesses water from an onsite water well or experiences excessive ground water from time to time, it may be beneficial to pick up a Radon test monitor and have a look at your home’s readings. The colder months can produce varied readings from the summer due to ground moisture, so it will be important to do your readings over at least a six-month period.