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Safe Air for Denver Homes

Residents asked tough questions about their air quality. Teaming up with researchers, they found some answers–and more questions.


by Kathleen Pierce


Dangerous levels of radon and the chemical tetrachloroethylene (PERC) are known to be present in Denver-area air, soil, and groundwater. Community concerns over these health threats led the Denver community group Taking Neighborhood Health to Heart (TNH2H) to establish a partnership with the Thriving Earth Exchange and the Air Quality Research Group at the University of Colorado, Boulder, to allay their fears about potential radon and PERC contamination in their homes.


The team wanted to know if residents did, in fact, have something to fear. Scientists, residents, and students, worked together to design and crowdfund a project testing radon and PERC levels in 15 homes in the TNH2H neighborhoods. In addition, they tested whether a new, far less expensive testing method (dosimeter tubes, which cost $8) could measure PERC levels as accurately as the current standard method, passive diffusion tests, which cost $100. Their hope was that if the lower-cost PERC tests were effective, many more people would be able to check their homes for this often-hidden toxic contaminant.


When the results came in, several things were clear. First, the bad news: nearly all the homes (80%) had radon levels that were higher than the EPA’s recommended “action level” of 4 pCi/L. Only one home was below the EPA’s acceptable level of <2 pCi/L. The second result was good news, however: all of the homes had PERC levels below the Colorado recommended action level of 41 mcg per cubic meter.


The last conclusion was that more studies are needed to determine whether the $8 dosimeter tubes can replace the $100 passive diffusion tests for detecting PERC. The dosimeter tubes gave much more variable results compared with the passive diffusion tests, which could indicate that the tubes were reacting to another contaminant in the home, or that the exposure time of three weeks was too long for the tubes to remain effective.




The team is determined to solve the mystery of the dosimeter tube results. They are currently conducting additional research, including Total Indicator Compound reports and variance testing, to pinpoint the source of the discrepancy.


However, the initial study goals have been reached: residents have the information they need to make decisions and improve their indoor air quality. The researchers hope the results can encourage other Denver-area residents to do the same.


In addition to raising awareness about the specific issue of air quality in Denver, the team also hopes their story encourages more residents to feel empowered to solve problems in their communities. “I hope this project serves as an example for how communities can take on questions about their local environment, as well as how researchers can support these efforts,” said Ashley Collier, a graduate research assistant, sponsored by a CU Engage Graduate Fellowship, who conducted the study.


Kathleen Pierce is a contributing writer for Creative Science Writing and the Thriving Earth Exchange.