Soil gas radon compared to aerial and ground gamma-ray measurements at study sites near Greeley and Fort Collins, Colorado.

摘要

In 1985, a house located within the geological province known as the Reading Prong was discovered to have indoor Rn-222 concentrations exceeding 2000 pCi/l (picoCuries per liter) and other houses with elevated indoor radon concentrations were quickly identified in the same neighborhood (Gaertner, 1987). The state of Pennsylvania initiated a large program to determine the radon levels in homes within and near the Reading Prong (Gerusky, 1987). The results of this program showed that more than fifty percent of the houses measured had indoor radon levels exceeding the 4.0 pci/l guideline set by the US Environmental Protection Agency (EPA). Because the geological environment of the Reading Prong Province is not unique, potentially hazardous levels of radon are expected to occur across the United States. Because radon is part of the uranium-238 ((sup 238)U) decay series which can be measured by aerial and ground gamma-ray surveys, the nationwide data obtained as part of the National Uranium Resource Evaluation (NURE) Program sponsored by the U. S. Department of Energy may provide a means of rapidly assessing the potential for radon in soil gas on a regional scale. The purpose of the work being reported here is to investigate the validity of the NURE aerial gamma-ray data with regard to the estimated concentrations of uranium in the rocks and soils. This research also seeks to assess the use of surface gamma-ray measurements to estimate the relative amounts of radon in soil gas.