family playing under the covers 

Radon Sources & Health Risks

Radon comes from the natural radioactive breakdown of uranium in soil, rock, and water. Radon is an invisible, odorless, tasteless gas that moves through the ground to the air above. It enters buildings from cracks in solid floors or walls, construction joints, gaps in suspended floors, as well as around service pipes, cavities inside walls, and the water supply.

Radiation from radon enters the lungs on dust particles that lodge in the airways of the lungs and then expose and eventually damage lung tissue.

Radon in Boulder County

Naturally existing low levels of uranium occur widely throughout the earth's crust. Radon is found in all 50 states, and is prevalent in Colorado. The EPA has ranked Boulder County as "Zone 1," which means the average house will likely exceed the EPA's action level of 4.0 pCi/L.

Radon can be found in any building, but homes are the most concerning since that is where families spend the most time.

Test your home for radon.

Radon Exposure & Cancer

Radon is the leading cause of lung cancer among non-smokers. It is estimated to cause about 21,000 lung cancer deaths per year.

Radon Is Dangerous Because it Is Radioactive

radon alpha particles

Radiation can cause cancer. Like all radioactive substances, radon emits high-energy waves and particles that can bombard the cells in your body. Small amounts of radiation are generally harmless, which is why the occasional x-ray should not be a problem. But larger or long-term doses of radiation can damage your DNA, the genetic material in your cells.

Breathing in radon can expose your lung cells to dangerous levels of radiation. If the DNA in lung cells get too damaged, the cells can turn cancerous and start dividing out of control.

This picture shows a plastic chip from a passive radon test. This piece of plastic is magnified only 100 times and shows the damage to the plastic as a result of exposure to alpha particles after just 3 months exposure at 4 pCi/L.

Lung Cancer Facts

  • Anyone can get lung cancer.
  • Lung cancer kills more people than breast, prostate, colon, liver, kidney, and melanoma cancer combined.
  • The five-year survival rate for lung cancer is just 16% - a rate that has changed very little since the 1970s.
  • Nearly 60% of those diagnosed with lung cancer are people who never smoked or are former smokers.
  • Lung cancer surpassed breast cancer as the number one cancer killer for women in 1987.

Radon & Smoking Produce a Synergistic Effect

The risk of lung cancer from radon exposure is estimated to be approximately 10 -15 times greater for persons who smoke cigarettes in comparison with those who have never smoked. Get help quitting tobacco.

Each year, lung cancer caused by radon costs about $2 billion in medical care expenses and lost productivity.

Centers for Disease Control & Prevention (CDC) on Radon and Cancer

When air containing radon gas is inhaled, sensitive tissue can be exposed to alpha radiation, causing damage that increases the risk of cancer.

The Iowa Radon Lung Cancer Study tracked nearly 1,000 women who had lived in their homes for more than 20 years. The results of  the case-control study (after adjusting for age, smoking, and other factors) indicated that a 20-year exposure of radon levels at the EPA guideline of 4.0 pCi/L yielded an increased lung cancer risk of 50%.

For more information, see

Information from National Association of Counties, March 2006 County IAQ Newsletter

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