Environmental Radioactivity in the Sabugal Region and Impact of Past Uranium Mining

An environmental radioactivity survey carried out in the Sabugal region, Portugal, showed enhanced radioactivity levels in surface water streams related to water discharges from old uranium mines. Water from irrigation wells in this region displayed variable radionuclide levels due to natural occurrence of radionuclides and also to contamination by mine water drainage. Horticulture products grown near the uranium mine sites contained elevated radium (226Ra) concentrations but lower concentrations of uranium and other radionuclides. Despite relatively elevated radioactivity in irrigation water, the absorption and accumulation of radionuclides in plants was limited. Taking into consideration the volume of uranium waste piles, the improved management of mine waste and mine drainage is needed in order to prevent the increase of environmental radioactivity in the area.