Exp 226 Ra Contamination of Soil and Foliage as a Function of Distance Downwind from Uranium Mill Tailings

摘要

This study concerned exp 226 Ra contamination of soils and foliage as a function of distance downwind from a uranium mill tailings pile. In soils the radium contamination was primarily associated with particle sizes < 0.045 mm and mainly found within the 0 to 0.6 cm soil horizon. The soil showed a decrease in activity concentration with distance. An attempt was made using ultrasonic washing to separate internal from external exp 226 Ra contamination in Artemisia tridentata. Internal contamination appeared to be a larger contributor to total contamination at distances less than or equal to 0.16 km downwind from the tailings pile. At distances > 0.16 km, external contamination became a larger contributor to the total exp 226 Ra contamination. In most soil samples exp 226 Ra concentrations approached background levels at a distance of 1.1 km from the tailings pile. Total vegetation contamination approached background at 6.6 km. This study suggested that a combination of root uptake and foliar absorption were responsible for internal contamination and further studies were suggested. 19 references, 5 figures, 2 tables. (ERA citation 09:001230)