A re-evaluation of the US EPA radon risk categorization for Unicoi County, Tennessee

by Parsons, William Grant.

A Re-evaluation of the US EPA Radon Risk Categorization for Unicoi County, Tennessee by William Grant Parsons Effective risk communication is based on appropriate risk characterization. A reevaluation of the 1987 US EPA radon risk categorization of Unicoi County, Tennessee was conducted using in-home radon concentrations, determined in a long-term monitoring study. Radon concentrations were measured in 69 homes using Electret Passive Environmental Radon Monitors (E-PERM’s), following standard methods. Radon concentrations determined in this study (avg. 4.03 + 3.04) were significantly higher than those measured in the USEPA study (avg. 1.96 + 1.08). Using this study’s data, the risk categorization was recalculated with the US EPA Radon Index Matrix Model. The model re-categorized Unicoi County from a moderate to a high risk zone classification. These results suggest that the health risks associated with in-home radon concentrations are inaccurately categorized and communicated to the citizens of Unicoi County, Tennessee. 2