Watch Out for Radon!

Dan Onion, MD, MPH

Mt. Vernon/Vienna Health Officer


November, 2018

A physician acquaintance of mine died this summer of lung cancer at a premature age of 61. He’d never smoked, nor had other family members. Lung cancer in non-smokers always seems strange to us in the field; and his cancer wasn’t the common squamous cell type, but instead was an adenocarcinoma, a type more often seen with radon than with smoking. His nurse daughter guessed the disease could be related to the very air-tight home he and his wife had built 25 years ago. She tested for radon in the air and found levels over 10 pCi/L (pico Curies per liter), a level well above the tolerable levels of 2-4. She probably found the culprit since, after chronic smoking and the second hand smoke others in the house are exposed to, radon exposure is the next most common cause of lung cancer in the US. When radon exposure is combined with cigarette smoking, lung cancer rates are 35 times higher than from smoking alone.

Radon is ubiquitous in our soils, gravels and rocks, but you can’t smell or taste it, even inside the house. It is a breakdown product from Uranium 236 and Radium 22, and is found all over Maine. Usually it is brought into a basement or house by air seeking the lower pressures there, through basement floor or walls, or up through fill or slabs from surrounding soil or rock. It also can contaminate water from drilled wells (not springs or other surface water), and thereby add to house contamination. Its radiation is carried by the heaviest type of particles, with 2 protons and neutrons, hence very “heavy” so they cannot go through even paper. But they can cause ionizing damage when they nestle against the lining of the lung, where they cause damage to the cell genetic material (DNA), and over time cause mutations that can allow cells to duplicate too fast, and thus become cancer.

You find out if you have a radon problem by testing the air in your house; you can also test the water, and especially should if you find elevated air levels. I did it when I moved into our house 35 years ago, and it was ok at readings of 1.5-2.7 pCi/L. Since then we have tightened up our house to save heat and put in a Heat Recovery Ventilator (HRV) system. Last month I took a sample and a repeat both in the basement (the recommended place) with the HRV off, to see where I was. Both values were 4.1, a level that should prompt abatement action, given its cancer risks. I now will check levels with the HRV on, since such a system is one of the remediation options for radon in the air. I will also test well water levels to be sure we aren’t drinking radon. I was feeling badly about my test results, when, coming out of the state lab, I met a co-worker, who had just dropped off her 2nd samples after getting an initial air reading of 9; she had never tested her new house bought 15 years ago. Bigger problem! Nowadays state laws require testing by an independent lab with the sale of any house. My daughter near Albany bought a new house and on testing found levels close to 20; she now has normal levels having installed a $5K system that shunts air coming into the basement to outside pipes, with air pumps at roof level where it exhausts.

Detecting and fixing radon elevations is a cost and a bother. Tests at the Maine State lab cost $30 per air test and the same for water; other commercial labs charge about the same. I tried a mail order one I bought at Home Depot, which cost $25 but $40 to ship to Texas! But the testing sure can pay off with less future disease risk.

And while you are at it, I’d also suggest testing water every 5 years for bacterial contamination, as well as for arsenic, another contaminant in our rocks and a cause of increased lung cancer risk ($20 each). Those are the basics; you can order those and many other water and air test packages at the Maine State water quality testing on line (

Stay safe!

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