²²⁶Ra is a natural radioactive isotope belonging to the natural radioactive family of ²³⁸U. Its radioactive decay causes the emanation of a radioactive gas, ²²²Rn. These isotopes are widely distributed in a natural and heterogeneous way in the earth's crust, so their presence in groundwater has a natural origin where their accumulation or concentration depends on several of factors such as: chemical nature of the rocks that surround the aquifer, geological characteristics of the land, the physicochemical processes that occur in the aquifer, among others, as well as an anthropogenic origin (due to mining activities or the use of fertilizers). Their determination in drinking water is important because they are a source of internal contamination with a high radiological health risk, so are the short-term high-energy alpha emitters Radon decay products. The purpose of this work is to determine the activity concentration of ²²⁶Ra and its daughter ²²²Rn in non-treated drinking water from sources distributed along the coast and Alpujarra of Granada to know their environmental implications, to determine their natural or anthropogenic origin, as well as to know if they comply the limits established by regulatory bodies (Directive 2013/51 / EURATOM and RD 314/2016) for their consumption. The Radiometric Techniques used to monitor both radionuclides have been Gamma Spectrometry with High Purity Intrinsic Germanium Detector (HPGe), and Liquid Scintillation Counter (TRI-CARB 1500).

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