Understanding radon | Department of Public Health & Environment

Radon

Radon Infographic.
Radon has no color, odor or taste and doesn't cause short-term symptoms of illness.
Radon causes cancer.
- It's estimated to cause about 21,000 lung cancer deaths per year in the United States.
- It's the second leading cause of lung cancer in the United States, according to the surgeon general.
- Only smoking causes more lung cancer deaths.

Radon is a naturally occurring radioactive gas that comes from the breakdown of uranium in the soil.
- It's a gas that moves up through the soil to the atmosphere.
High radon levels have been found in all 50 states and in all parts of Colorado.
In Colorado, about half the homes have radon levels higher than the U.S. Environmental Protection Agency recommended action level of 4 picocuries per liter (pCi/L):
Colorado radon zones.
Map of radon zones fact sheet.

Radon moves from uranium-bearing granite deposits in the soil to the atmosphere.
- Your home sits on radon's pathway from the soil to the atmosphere.
- Your home is usually warmer and has lower air pressure than the surrounding soil, so gases in the soil, including radon, move into your home.
- The most common routes are:
  - Spaces between basement walls and the slab.
  - Cracks in foundations and/or walls.
  - Openings around sump pumps and drains.
  - Construction joints and plumbing penetrations.
  - Crawl spaces.
  - Well water with high radon concentrations.
The age and/or type of home doesn't matter when it comes to whether high levels of radon are present.

Schools are at risk from radon just like homes.
Colorado statute requires all schools to test for radon and to maintain records of the test results for disclosure on request.
- The statute doesn’t require schools to mitigate, so it’s up to the school district and its constituents to address mitigation issues.
Schools
Child care facilities.