Natural Radioactivity in Clay Ceramics and their Raw Materials in Latvia
Natural radionuclides K-40, and Th-232, U-238 (Ra-226) decay chain products contained in building materials are the main source of radiation dose received by population and the only source of indoor radiation exposure. Present work contains results of the study of natural radionuclide activity level in clay, clay ceramics and silica bricks used in Latvia. Obtained data show that radionuclide content in different clay products can differ up to five times. However, determined activity index values for all tested materials, except fireproof bricks, were below radionuclide concentration level permitted by EU and Latvian national regulations. Comparison with analogous data from other North European and Baltic countries shows that average concentrations of natural radionuclides and activity index values for clay and clay bricks used in Latvia are on the same level as in other countries, except Sweden.
Gundars Mežinskis, Līga Grase, Ruta Švinka, Ilona Pavlovska, Jānis Grabis, Kęstutis Baltakys and Irina Hussainova
D. Riekstina et al., "Natural Radioactivity in Clay Ceramics and their Raw Materials in Latvia", Key Engineering Materials, Vol. 788, pp. 51-55, 2018