To better understand the potential risk of radon exposure in Kentucky, Bethany Overfield of the Geologic Mapping Section has partnered with the Clean Indoor Air Partnership at UK’s College of Nursing. Radon is an invisible, odorless radioactive gas that can seep from some soils and rock formations and has the potential to build up in homes and other buildings. Prolonged exposure to radon can cause lung cancer, especially for people who also smoke. It is Kentucky’s second leading cause of lung cancer.
The collaboration began in 2013 when Overfield ran across a publication from the College of Nursing displaying radon exposures mapped in Kentucky by county boundaries. "We contacted them to open a dialogue about better ways to spatially assess radon potential based on geology (and not political boundaries) and they were extremely receptive," Overfield explained. "We eventually intersected 60,000 home radon detector readings they had with our digitized geology, and that gave us the ability to associate an average radon value with specific geologic formations."
Overfield initially created a pilot map that connected radon values in Boyle County to geologic formations in order to help demonstrate geologic controls on radon potential. She also did a statistical analysis of the radon data in higher-population areas of central and northern Kentucky to define those geologic units spatially associated with the high radon values. To help the Clean Indoor Air Partnership target its educational efforts, she has created 15 county maps associating varying radon values with geologic formations. They are printed in the Partnership’s handouts for local health-department training sessions in an effort to promote home radon testing.
Overfield says her work with the College of Nursing has also raised plenty of new questions about radon in Kentucky for further research. "We commonly associate higher radon with dark shales, such as Devonian shales, but the highest levels of radon were associated with Mississippian limestones and Ordovician Limestones in the Inner Bluegrass," she says. "We didn’t necessarily expect that. It seems to be directly correlative to karst areas. Karst dissolution creates ‘superhighways’ for radon to be able to move. I’d love to study that more."
Overfield says the application of geology to human health has added a new dimension to her KGS work. "I feel like it’s the component I’ve been missing so far in my career. I really enjoy the aspect of working in human health and medical geology." She adds that research and funding opportunities in the geology and human health arena have been expanding. "If I can do something to effect positive change, that’s extremely important to me, and I feel like I’m starting to do that."
The partnership between KGS and the College of Nursing was described in a paper in Geological Society of America’s Special Paper 520, "Radon Research Collaboration between the Kentucky Geological Survey and the University of Kentucky College of Nursing: An Innovative Partnership," published earlier this year.
Bethany Overfield developed this statewide map of radon levels, measured in picocuries per liter (pCi/L), for the Clean Indoor Air Partnership.