Estimated Background Values Maps of Uranium in Santiago Island Topsoil and Stream Sediments

We present maps of estimates of background values of uranium in the soils and stream sediments of Santiago Island, Cape Verde, delineate their main sources, relate them with the geology of the island, and assess their environmental risks. We use an index to numerically access the environmental risk of U, which we denominate by Environmental Risk Index. Values of this index higher than one were only found in three soil sampling points, all for agricultural purposes. So, U in Santiago topsoil and stream sediments has a geogenic origin and there is no contamination of uranium in these two sampling media.