How Radon Causes Lung Cancer

Radon is the most potent carcinogen in your home

You cannot see radon gas. And you cannot smell it or taste it. But it may be a problem in your home. As the only gas in the decay chains of radioactive heavy metals, radon and its floating radioactive products can easily get into human body by inhalation. Whenever you breathe in air containing radon, it increases your risk of getting lung cancer. The National Academy of Sciences and the Environment Protection Agency (2003) estimate that in the U.S., radon in homes causes 21,100 lung cancer deaths each year.

Radiation is called the "complete carcinogen" because, unlike chemical carcinogens, it alone can initiate, promote and propagate cancer. The primary site of radioactive exposure to most people is their home. The average person receives a higher radiation dose from radon at home than from all other natural or man-made sources combined.

Radon is a proven and very potent "Class A" carcinogen. Safety limits on toxins or carcinogens in food or water are set at levels thousand times less lethal than what is the risk from radon in an average American home. "Radon in homes causes more deaths than fires, drownings and airplane crashes combined." (EPA)

The lung cancer crisis

After smoking, "radon is the second leading cause of lung cancer." (Surgeon General) Among non-smokers, radon is the No. 1 cause of lung cancer deaths.

Lung cancer is the leading cancer killer of all Americans, both men and women, claiming 160,000 lives every year - more than breast cancer, prostate cancer, and colorectal cancer combined. Over 171,000 new lung cancers are diagnosed in the U.S. each year.

Children are more susceptible to radon

Children are known to be more radiosensitive than adults. Analysis of Hiroshima victims showed a higher incidence of lung cancer among those who were exposed to the radiation blast as children. A single x-ray to the abdomen of a pregnant woman in the first six weeks of pregnancy leads to a 50 percent increase in cancer and leukemia risks to the child. The gamma rays emitted by radon progeny are far more energetic than x-rays but the emitted alpha and beta particles are even more harmful.

Radiation risk to embryos is higher than to children, which in turn is higher than to adults. Children are more susceptible to radon-induced cancer due to their rapidly dividing cells and higher breathing rates. It is compounded by their heavier exposure to radon by spending more time inside the house and/or in the basement.

Recent research in Europe confirms that radon is much more harmful to children than to adults. Lung cancer incidence as a result of radon exposure is estimated to be about ten times higher for people exposed at the age of about 15 than at about 50.

However, the onset of lung cancer takes decades. EPA has not found convincing epidemiologic evidence of increased risks to children (except to the smallest ones) and its radon guidelines for homeowners are thus based solely on the lung cancer risks to adults.

Minimize the radon level in your home

Many of the 21,000 lung cancer deaths caused by radon in the U.S. each year are preventable. The "action" and "consider action" limits of 4 or 2 pCi/L are merely cost/benefit guidelines - EPA has left the radon mitigation decision and responsibility up to the individual homeowner. EPA has warns the public: "Any radon exposure has some risk of causing lung cancer. The lower the radon level in your home, the lower your family's risk of lung cancer."

You should always try to reduce the radon level in you home to a practical minimum. The target of the U.S. Radon Abatement Act is the natural level outdoors (average 0.4 pCi/L). Whether you current level is 30 or 3 pCi/L, or if a mitigation system is already installed, reducing radon in your home by 90 or 50 percent will reduce the risk to your family by 90 or 50 percent.