La Plata County is one of 12 counties in the state to be upgraded to high risk for radon.
Radon, a colorless, odorless, radioactive gas produced by the decay of uranium in rocks and soil, is the No. 1 cause of lung cancer in nonsmokers and the second leading cause of cancer overall in the United States.
Half the homes in Colorado test above the recommended mitigation level, Chrystine Kelley, manager of the radon program at the Colorado Department of Public Health and Environment, said by telephone Monday.
In some areas, 60 to 70 percent of homes fall into that category, she said.
The danger lies in breathing what are called radon daughters – microscopic particles that bind with dust and smoke or collect on walls.
Prolonged exposure to radon causes 350 to 1,400 deaths in Colorado annually, said Wendy Rice with the Colorado State University Cooperative Extension Office.
Houses can become radon storerooms because they create a vacuum, which sucks radon from the soil through cracks in a foundation or a crawl space. Radon is likely to be more prevalent in winter because houses often are closed against the cold.
“Any building can have radon, but houses are the main concern because that’s where we spend the most time,” said Kate Lemon with the Hazardous Materials and Waste Management Division of the Colorado Department of Public Health and Environment.
“Radon is found all over the country,” Lemon said. “But in Colorado, we’re at high risk because of all the natural rock.”
Testing for radon is done by placing a bag with a sensor to collect radon in the lowest living level of a dwelling for various periods, from 48 hours to a year, Kelley said.
The bag is sent to a laboratory for analysis, the result of which is mailed to the homeowner. The health department gets its statistics from the labs, Kelley said.
High risk means an estimated indoor radon average of more than 4 picocuries per liter of air (the measure of gas released by decaying radium). At that level, the Colorado Department of Public Health and Environment and the Environmental Protection Agency recommend that homeowners test their house and consider installing mitigation equipment.
A few counties and cities address radon-resistant materials and mitigation equipment in their building code, Lemon said.
Mitigation is the only way to protect against radon infiltration, Lemon said. It’s done by installing pipes that collect radon from crawl spaces or slab foundations and, with a suction fan, vent it outside.
The addition of the 12 counties to the high-risk category puts all 64 Colorado counties at the same level, Kelley said. An early study was done in the 1980s, but the latest radon-distribution map was plotted with data gathered starting in 2005.
Data came from homeowner do-it-yourself test kits that were sent to laboratories for analysis, Kelley said. The health department calls the labs once a year for their findings.
The newcomers to the high-risk list, in addition to La Plata County, are Alamosa, Archuleta, Conejos, Costilla, Eagle, Hinsdale, Mineral, Rio Grande, Routt, Sagauche and San Juan counties.
“The problem has always been with us,” Rice said. “But the (radon distribution) map created in the late 1980s was based on very limited information. The entire state is now listed as high risk.
“Based on numbers we’re getting, two out of three tests need further study,” Rice said. “Numbers (radon readings) seem higher, with numbers in the 40s to 50s range.”
daler@durangoherald.com
