RADON GAS: WHY IS IT A CONCERN?
Radon gas is a naturally occurring radioactive material found in the soil and groundwater that develops from the chemical breakdown (decay) of uranium, thorium, and radium found in rocks and the soil. It is colorless, odorless, and soluble in (it mixes with) water. A fact I did not know is that uranium and other radioactive substances are found in the soil in nearly every part of the world. The United States is not exempt from the presence of radon nor are Americans immune to its effects on their health. Radon gas is ubiquitous in indoor and outdoor air. When radon is released into the outside air, it disperses into the atmosphere and is therefore harmless.
However, when radon gas is released into to a confined space, such as the basements and below-ground levels of a dwelling (home, apartment, etc.), the concentration of radon reaches critical levels that can have significant health consequences for the residents of that dwelling. The major concern is the known relationship between radon gas and lung cancer in both smokers and non-smokers. Several studies have concluded that radon exposure is the second leading cause of lung cancer, which in turn is the leading cause of cancer deaths worldwide. One study that included data from 66 countries stated that “lung cancer deaths from radon represent 3% of the total cancer deaths in these countries and a substantial proportion of lung cancer mortality [deaths] worldwide.” Radon exposure is more than just a casual problem. “The risk of lung cancer incidence increases with radon exposure,” especially in areas where higher concentrations are prevalent. “In smokers, lung cancer risk increases markedly [smokers exposed to radon are 8 times more likely to get lung cancer] as radon concentration increases.” Small cell lung cancer is the type of cancer caused by radon exposure.
How does radon get into a dwelling? Radon is the result of the decay of radioactive elements in the soil. Being a gas, it seeps through the soil and enters a building through cracks in the foundation structure. When released into the air, radon “gives rise to atoms of new elements, called radon progeny, which are electrically charged” and are found attached to indoor dust particles. Being confined to a closed space, these dust particle are inhaled into human lungs and begin emitting radiation that damages lung cells. Prolonged exposure and high concentrations of these progeny damage the DNA of lung cells with the end result being lung cancer. Radon is also found in the dwelling’s water if it is from a well.
The concentration of indoor radon in a dwelling is directly related to factors in the construction of the building. “The position of the lower floor of dwellings plays a significant role in determining the amount of radon entry into buildings.” The risks are higher in residential buildings than in public buildings because of the ventilation processes routinely used in public structures. “Aeration…promotes dilution of indoor radon concentration.” Public buildings have HVAC systems that better circulate the air and reduce radon concentrations. Other construction measures include special paints and screens, and “airboxes” which prevent the passage of radon from the ground to indoors.
Other Important factors are the number of people living in the dwelling, a younger age at first exposure to radon gas, the duration of exposure, the amount of time spent in areas of high concentration, and the cumulative dose of alpha radiation. The biggest additional factor is smoking and the use of tobacco products. The adverse effects of radon are multiplied eight times in people who also smoke.
A study from Canada estimated that 13.6% of lung cancer deaths could be attributed to radon in the region under study. Eighty-four percent of those who died were, or had been, smokers. So radon, like smoking, is no small problem. Scientists who study radon have been able to determine the concentrations that are safe and those that are harmful. Most homeowners, myself included, ignore the problem by only testing for radon when they sell their home.
Testing for radon is fairly simple. It can be done by the homeowner or through a request of the state radon office. Home test kits for “passive testing” can be purchased at hardware stores, Lowe’s, or Home Depot. The test device is placed in a basement or lowest living area for a period of time for radon detection. The test device is sent to a lab to confirm the presence and concentration of radon. Also available are testing monitors that give instant read outs of radon levels. A level below 4 picoCuries per liter is safe. At levels above 4, the EPA recommends steps be taken to reduce radon levels.
I’ve sold three homes all of which were new construction when we bought them. Our first home we sold after living in it for 27 years. It was built into the side of a hill and was loaded with radon when we tested it before selling. The testing was expensive, but the mitigation expense was worse. My thought at the time was “this is a racket making someone rich!” Our next home had a full basement and was 10 years old when we sold it. The radon test exceeded the upper limit by a small amount, and we still had to pay for the corrective measures, again. Our third experience was selling a house we lived in less than three years. It was brand new construction, too, and had a full basement. The radon test was a tenth of a point over the acceptable level, so for a third time, we paid the mitigation expense. It was then I definitely thought radon was a scam.
However, after reading the quoted reference and other documents, I no longer feel that way. It seems to me the radon experts and construction engineers need to come together to produce a preventive, protective product that is incorporated into the construction of homes and buildings and be proactive rather than reactive. In other words, if radon is ubiquitous, why not do something preventive during construction. Why not use this preventive product to seal the dwelling and prevent radon from getting into the confined space underground; something in likeness of a burial vault.
It hasn’t been proven conclusively, but there is sufficient concern by experts of a correlation of indoor radon to esophageal and stomach (gastric) cancers. That, of course, requires further investigation and if proven, increase concern about radon.
On the lighter side, is the story of “The Radon Chair.” I shouldn’t joke about this, but it was a tragic consequence, anyway. In the doctor’s lounge at St. Francis Hospital, there was a chair intermittently occupied by three doctors who sat there to smoke. One, or all, of these three sat in that chair every day. Each of these doctors later died of cancer—two of lung cancer, one of colon cancer. The coincidence was inescapable so one day a colleague named it “the radon chair.” That chair became a pariah that other doctors avoided completely. “The radon chair” spawned a blog of the same name.
As stated above, my opinion of radon has been changed by simply studying its consequences. It’s presence needs to be addressed by the construction industry before it causes problems, not after people unknowingly have had years of exposure. With radon being the second leading cause of lung cancer, one would think prevention would have been addressed already. If it has, it has escaped my awareness.
References: https://www.grainger.com/know-how/health/airborne-contamination-radon.
Nunes LJR, Curado A, da Graca LCC, Soares S, Lopes SI. Impacts of Indoor Radon on Health: A Comprehensive Review on Causes, Assessment and Remediation Strategies. Int J Environ Res Public Health 2022;19 3929.
