This is a common question we get both from buyers and sometimes real estate agents. There is quite a bit of confusion regarding what radon is, what (if any) the health risks associated with it are, and what to do about it. Today’s blog is part 1 of a multi-part series to help you understand radon and to make an informed decision about testing and mitigation.
Like carbon monoxide, radon is a colorless, odorless gas, so you have no way of knowing by looking at a home if the radon level is elevated or not. Unlike carbon monoxide, radon is a naturally occurring element. If you recall from your high school chemistry class, the period chart lists all elements, and (fun fact of the day) radon’s symbol is “Rn” with an atomic number of 86.
Unfortunately, radon is radioactive. It’s not quite like uranium in terms of health effects, but it does have some impact to our health. Radon is a natural byproduct of uranium decay, and when uranium in the earth gives off radon, the radon is in the form of a gas. It is only one of many “earth gases” that occur naturally, and as a gas it seeps up through the dirt and rocks and eventually enters the atmosphere.
That might be a problem if the half-life of radon were really long, but it is not (it’s measured in hours rather than days or even years), so it breaks down rather quickly.
One more unfortunate thing about radon is that when it decays it gives off sub-atomic particles (the radioactive aspect of radon) that can damage our lungs. It should be obvious that if we inhale radon that subsequently decays while in our lungs, that’s not a great thing!
So here’s the punchline: homes with elevated levels of radon have a much higher chance of contributing to lung cancer than homes with low radon levels. Radon is the second leading cause of lung cancer in the U.S., a distant second to smoking.
Next blog we’ll talk about why modern homes have radon levels elevated above that found outside.
Why are radon levels higher inside a home than outside?
This was actually the main question I had when I began to learn about radon. With the naturally occurring level outside of a home lingering at an average of 0.4 pCi/L, why would radon levels become elevated in a home? What was it that trapped radon inside?
To answer the question, you really just need to think briefly about the workings of a furnace or air conditioner, commonly known as the HVAC (heating, ventilation, and air conditioning) system. The HVAC system pulls air into the air handler (the sort of cabinet looking thing in your basement, attic, or closet), and conditions it. The “pulling” is done by an electric motor that dries a blower, or “fan”. Especially in the winter, when natural gas systems use gas as they burn, the HVAC system creates a low pressure suction- sort of like a really low-power vacuum cleaner. This lower pressure inside the home creates suction that pulls in the earth gases. Remember, earth gases have radon in them. Once inside the home, the earth gases are pretty much trapped, unlike out of doors, where they can dissipate and float away.
As you can imagine, homes that do not “breathe” well do not have a high transfer of air to and from the exterior. This is one of the reasons modern construction homes often tend to be higher than their older counterparts in the same neighborhood- all of the sealing and insulation also tends to trap the air inside the home. Great for energy efficiency but not quite as great for indoor air quality.
Drafty homes tend to be lower for radon levels, but we’ve seen plenty of 100-plus year old homes that still come back high, simply because radon in Southern Indiana tends to be pretty high. Remember last blog about the geology under our area.
One other reason that has led to a greater awareness of radon and its health effects is simply the information that is now available. A few decades ago, studies were performed on miners to try to determine why they had a higher incidence of lung cancer. Some of this research led to the understanding of the negative health effects of radon, and as people have become aware of it the population at large has become better educated.
Til next time- if you have any questions at all about radon, radon testing, mitigation, or anything at all involving your home, just give us a call at (812) 645-4010.