Radioactivity in soils and horticulture products near uranium mining sites

Abstract

Uranium mining in Portugal was performed mainly in small mines spread over a wide and populated region in the Centre-North of the country. In villages near old uranium mines, soils are used for horticulture production and to provide pasture for livestock grazing. Soil samples as well as agriculture products including cabbage, potatoes, oranges, and other fruits were analyzed for alpha emitting radionuclides. Samples from areas far from uranium mining sites were also included in the survey. Results of uranium series radionuclides showed that soils of regions with different geology may contain very different radionuclide concentrations. Concentrations of radionuclides in soils and vegetables of reference areas may display values similar to those near uranium mining sites in the same geological province, indicating that enhancement of radionuclides in the terrestrial food chain, with the exception of 226Ra, generally is not high. Concentrations in soils and horticulture products of these uranium counties generally were two orders of magnitude higher than concentrations measured in soils and vegetables in a sedimentary region in the South of Portugal.