Hydrogeotoxicity from arsenic and uranium in the southern Duero Basin, Spain

As well as the HGT values, which are based on total concentrations, bioavailability of arsenic and uranium species was also considered in order to provide a comprehensive assessment of hydrogeotoxic risk over the study area. In all samples with HGTAs > 1, arsenic was present as As(V) inorganic form. Likewise, in samples with HGTU10 > 1, uranium appears as U(VI). This hydrogeotoxic anomaly must be related to both the chemical and radiological hazards.