Archuleta County now considered high risk for radon exposure


Staff Writer

Archuleta County, along with 12 other Colorado counties, has been upgraded from moderate to high risk for radon exposure.

Radon is a colorless, odorless radioactive gas that is a natural byproduct of decaying uranium.

Radon exposure is credited as the second leading cause of lung cancer in the United States, right behind smoking. Archuleta County residents who are smokers are at especially high risk for the disease.

Because Colorado has an abundance of uranium in its soil, the problem of radon exposure has been plaguing the state for decades.

The recent upgrade to high-risk for Archuleta and subsequent counties does not necessarily mean that radon exposure has increased.

Greg Brand, environmental health director for the San Juan Basin Health Department in Durango, said in a phone interview Tuesday that the high-risk rating can likely be attributed to better collection sampling from the area, leading to a better understanding of the level of risk residents face.

“The important thing to realize is that all counties in Colorado are considered to be at high-risk for radon,” Brand stated.

“We’ve always known radon was a problem in Colorado,” Chrystine Kelley, manager of the radon program at the Colorado Department of Public Health and Environment (CDPHE) was quoted as saying in a recent press release.

“But this new data confirms a need for heightened awareness, more testing and a more proactive mindset, such as building new homes with radon-resistant construction from the start,” Kelley added.

According to the CDPHE website, “Approximately 50% of the homes in Colorado have radon levels in excess of the EPA’s recommended action level of 4 picocuries, (a unit of measurement for the rate of radioactive decay of radon), per liter of air.”

Homes in Colorado are at high risk for excess levels of the gas due to their foundations being on radon gas emitting rock and/or soil.

The radon gas rises out of the ground and becomes trapped underneath the foundation of the building; because the air pressure inside of homes tends to be less than the air pressure beneath the foundation, the gases are forced up through the floor and walls, often becoming trapped and concentrated within the building.

Radon can also enter a home through well water, which releases some of the element into the air.

The only way to know if your home contains an unhealthy level of radon is by performing a radon test.

Brand recommends tests be administered in January or February, when radon concentrations are likely to be the highest; however, tests can be performed at any time.

According to Brand, there are two main reasons January and February are ideal months for testing.

First, homes tend to be sealed tightest during the colder months, decreasing the amount of fresh air residents receive.

Second, the ground is mostly frozen during the colder months, channeling the radon gas towards the path of lease resistance — which is often a crawlspace or basement and up into a home.

Radon tests can be purchased and administered by the homeowner and kits can be ordered online or from the hardware store. Tests range in price and it is important to keep in mind that not all kits include the lab processing fee in the purchase price.

Roberta Tolan, Archuleta County CSU Extension Office director, said the office recommends that homeowners test their residence for radon and mitigate, if necessary.

If a residence is found to have an unhealthy level of radon, the best way to fix the problem is by installing a mitigation system.

According to, a website dedicated to radon education, the radon mitigation “system draws the radon-laden soil gas from beneath the foundation and exhausts it outside of the building, far enough away from windows and other openings that it will not reenter.”

If you are interested in learning more about radon exposure and the testing process, education classes are offered each year, usually in December, January and February, informed Brand.

While classes at the extension office have concluded for the season, there is a plethora of information about radon and radon exposure, including a citizen’s guide, on the CDPHE website under the hazardous materials and waste management division. The easiest way to access the page is to go to and search for “radon”.

The Radon Outreach page offers links for ordering online kits, finding certified contractors for mitigation installation and information about radon exposure. There is a mail-in coupon available for radon test kits on the site, as well.

The 12 counties now considered at high risk for radon exposure are Alamosa, Archuleta, Conejos, Costilla, Eagle, Hinsdale, La Plata, Mineral, Rio Grande, Routt, Saguache and San Juan.

The changes in classification of these 12 counties brings the entire state of Colorado into the Zone 1 classification. Zone 1 is the radon zone designation of the highest priority.