General Radon Information

Colorado specific radon and radon level information can be found throughout this site. You will be able to find information about certified radon inspectors in Colorado, as well as detailed radon level information for every county in Colorado.

Radon - You can't see it. You can't smell it. You can't taste it. It can kill you.

Radon is a Class A carcinogen and the second leading cause of lung cancer. Radon comes from the radioactive breakdown of naturally occurring radium found in most soils. As a gas in the soil, it enters buildings through small openings in the foundation. Since the building can hold the radon similarly to smoke trapped under a glass, indoor radon concentrations can increase to many times that of outdoor levels.

Thousands of preventable lung cancer deaths annually in the United States are attributable to indoor residential exposure to radon. Either smoking or radon exposure can independently increase the risk of lung cancer. However, exposure to both greatly enhances that risk. (At exposures to 4 pCi of radon per liter of air, the lifetime lung cancer risk attributable to radon rises from 2 cases per thousand in non-smokers to 29 cases per thousand in smokers).

The Radon program is funded by the State Indoor Radon Grant from the Environmental Protection Agency. The Radon program responds to telephone inquiries from the public (there were approximately 2400 calls last year) and mails out information in response to those calls.

In addition, the Radon program contracts with Colorado counties to provide technical assistance and project management for radon projects. The following are examples of how cities and counties conduct projects in their areas. As of January 1, 2005, the city of Fort Collins has a mandatory requirement to have radon resistant construction installed in new single family homes and provides information and test kits to its citizens, Jefferson County is offering courses for homeowners in radon reduction methods and provides radon testing for well water, the Colorado School of Mines offers a K-12 educational curriculum for teachers on "Do You Know Your 3 R's? Radiation, Radioactivity, and Radon," the geology museum has an interactive radioactivity exhibit on display on the campus for school children and visitors, and many other local health departments are conducting various public outreach activities.

According to a national residential radon survey completed in 1991, the average indoor radon level in the United States is 1.3 picocuries per liter (pCi/L). The average outdoor level is about 0.4 pCi/L. Excessive radon levels have been found in all of the 50 states. In Colorado between one-third and one -half of the homes have radon levels in excess of the EPA recommended action level of 4 picoCuries (pCi) of radon per liter of air. However, not all houses or buildings--even those in the same area or the same neighborhood--have the same radon level. The only way to find out what the radon level is in your house is to test for it. If a test indicates an elevated level of radon, reducing the level is usually easy and inexpensive. Sometimes homeowners can do the work themselves, although it is recommended that they seek professional guidance or have the work done by a professional, EPA-certified radon mitigator.

All houses should be tested for radon, if not during the sale or purchase, then after you take occupancy. Even houses in areas of low radon potential can have elevated radon levels. The probability of finding radon in your home is less in low radon potential areas; however, radon levels can differ dramatically from one home to the next. The only way to know if you have radon is to test your home.

If you are in a high or moderate radon potential zone, you should have the house tested for radon and if it has elevated radon (>4 pCi/L) contact a certified mitigator to get an estimate to install a radon system. The cost of fixing the problem could be a negotiating point, added to the mortgage amount, or paid for up-front, If on the other hand you really like the house and the seller is unwilling to negotiate you can buy the house knowing that if it has high radon it can be fixed for generally between $1800 and $3500 depending on the house size and complexity of the radon system. The important thing is to have the house tested prior to buying or test yourself after you move in.