GEOLOGIC AND CLIMATIC CONTROLS ON THE RADON EMANATION COEFFICIENT

Geologic, pedologic, and climatic factors, including radium content, g rain size, siting of radon parents within soil grains or on grain coat ings, and soil moisture conditions, determine a soil's emanating power and radon transport characteristics. Data from field studies indicate that soils derived from similar parent rocks in different regions hav e significantly different emanation coefficients due to the effects of climate on these soil characteristics. An important tool for measurin g radon source strength (i.e., radium content) is ground-based and aer ial gamma radioactivity measurements. Regional correlations between so il radium content, determined by gamma spectrometry, and soil-gas or i ndoor radon concentrations can be traced to the influence of climatic and geologic factors on intrinsic permeability and radon emanation coe fficients. Data on soil radium content, permeability, and moisture con tent, when combined with data on emanation coefficients, can form a fr amework for development of quantitative predictive models for radon ge neration in rocks and soils. Copyright (C) 1996 Elsevier Science Ltd.