Soil concentrations of “emanating radium-226” and the emanation of radon-222 from soils and plants

Abstract

The emanation of radon-222 from soils has been studied. Factors investigated which affect the rate of emanation include wind speeds across the surface, atmospheric turbulence, soil moisture, soil type and location. Values of emanation and concomitant variation in these factors are reported. An investigation of radon-222 release from leaf surfaces has been initiated; preliminary results of this study are reported. Measured values of radium-226 in the soil capable of giving rise to diffusing radon were found to vary 70-fold in different geological regions but were uniform in Champaign County, Illinois, the content being (0.64 ± 0.09) × 10−12 grams of “emanating radium-226” per gram of soil. The emanation rate of radon-222 from soils into the atmosphere varied 1000-fold among geographical regions but was shown to be uniform in Champaign County, averaging (140 ± 73) × 10−18 curies per square centimeter per second. The findings of the research indicate that radon-222 may be used successfully as a cost-free tracer in studies of vertical diffusion in Champaign County, Illinois.DOI: 10.1111/j.2153-3490.1966.tb00282.x