RADON CONTAMINATION IN FRACTURED GROUNDWATER AQUIFERS OF THE TALLADEGA METAMORPHIC BELT

An unusual number of leukemia and lymphoma diagnoses between 2013 and 2017 in the small, rural Cleburne County, Alabama, communities of Fruithurst and Muscadine prompted an investigation into potential causes linked to water quality. The investigation revealed radon levels higher than the U.S. EPA advisory level (4,000 pCi/L) in about 16% of private groundwater wells tested in the study area. Many residents in these communities rely on private wells for access to potable water for drinking and other household tasks. Wells in the area draw from aquifers located in the fractured metamorphic rocks of the Talladega Metamorphic Belt and are subject to potential natural and anthropogenic contaminants (e.g., trace elements, radioactive elements, and PFAs) present in the surrounding rocks. Building on the previous investigation, this project continues to examine the long-term efficacy of residential scale 5-stage reverse osmosis (RO) and 2-stage activated carbon water filtration systems in attenuating radon in groundwater supplies and adds a 24-hour stress test for the 5-stage system. These results suggest that the RO filters can effectively capture radon at early fresh stages, but the capacity gradually decreases over time or quickly reduces during high water use. Additionally, we seek to explore potential geological sources of uranium, thorium, and radium—potential radioactive parents of radon—through XRD and LA-ICP-MS analysis of outcrop and core samples collected throughout Cleburne County.