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The work aimed to show the applicability of geological studies to the investigation of radiation risk assessment due to the presence of naturally occurring radionuclides of terrestrial origin in the soil. Soil samples were taken from a Tatra Mountains area for which geological maps were available. The concentration of selected radionuclides incl. 40K, 238U and 232Th was determined by gamma-ray spectrometry with a HPGe-detector. Radioactivities and calculated absorbed dose rates were co-related to complex bedrock matrices based on an original methodology. The correlations were proved by performing a Principal Component Analysis (PCA). The rocks that had a significant impact on the rate of absorbed dose from the soil were strongly related to the radioactivity of the uranium series. The share of the following fractions was the most significant: granite with pegmatite, gneiss, granitoid and gneiss, coquina, marl and glauconite, hard limestone, dolomite and limestone. The rock types additionally showed good correlation with radioisotopes from the thorium series. Granitoids with potassium feldspar, on the other hand, contributed the largest share of 40K radioisotope content.

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RESUMEN

The aim of this work was to prove the use of radionuclides deposited in sediment core taken from an overgrowing dystrophic lakes surrounded by marsh-peat vegetation to estimate sedimentary conditions. Sediment core samples were taken from the Toporowe Stawy Lakes (Nizni (TSN) and Wyzni (TSW); Tatra Mountains). The sampling was done using a Limnos corer. After the physical sample preparations, gamma measurements were performed. Radiochemical analysis was applied with the aim of determining 210Pb radioactivity by means of 210Po. The mean values for TSN lake are as follows: 137Cs ~ 123 Bq∙kg-1, 40 K ~ 389 Bq∙kg-1, 228Th ~ 55 Bq∙kg-1, 226Ra ~ 86 Bq∙kg-1, 241Am ~ 5 Bq∙kg-1, and 210Pbuns ~ 180 Bq∙kg-1. For TSW lake, the radioactivity levels of 226Ra and 241Am are comparable to the TSN. The mean values of 137Cs, 40 K, and 228Th are almost twice as high as in TSN. The level of 210Pb in uppermost layer of TSN is higher than in TSW. Sediments were dated by use of 210Pb method, and the rate of sedimentation of each layer was also estimated. Basic chemometric tools were used to confirm the way of deposition of radionuclide, find the correlations between variables, and compare analyzed lakes. It was concluded that the presented type of lakes are a valuable source of information and the vertical distribution of radionuclide can be used to interpret the source of material supply and factors that influence the sedimentation process in recent 150-200 years.

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The analyzed sediments were taken from the man-made reservoirs (Velka Richnava, Rozgrund and Vindsachta) located in an area intensively mined for polymetallic ores since the end of the eleventh century (Banska Stiavnica region, Central Europe). The aims of this study were to determine the radioactivity of natural (226Ra, 228Th, 210Pb) and artificial (137Cs and 241Am) radionuclides, compare the radionuclides' distribution, and indicate the correlation of radioisotopes and their origin related to sediment properties. Two analytical techniques were used. 228Th, 226Ra, 241Am, and 137Cs were measured by means of gamma spectrometry and 210Pb was determined by its daughter radionuclide 210Po using alpha spectrometry. The results showed that the highest mean level of 226Ra (42.6 Bq·kg-1), 228Th (49.7 Bq·kg-1) and 210Pb (75.2 Bq·kg-1) was in the sediments collected from Rozgrund. The radioactivity of 137Cs and 241Am were present at a higher level in the layer related to Chernobyl (1986) accident and nuclear weapon test (1950/1960). The distribution of natural radionuclides was quite similar in all reservoirs. Chemometric analysis confirmed the radionuclides' origin and correlation between the analyzed parameters.

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The aim of the study is to present the results of determination of radioactivity of artificial 137Cs and natural 40K and certain heavy metals in soil samples collected from the eastern part of the Main Ridge of Carpathians, including the Beskid Niski Mts and the Bieszczady Mts. The evaluation of level of radionuclides was based on the bulk density analysis of the soil. A valuable finding of the study was a good linear correlation between the level of 137Cs concentration and bulk density of the soil as well as an inverse correlation between radioactivity of natural 40K and tested soil density. This might indicate though a high competitiveness of these elements between each other. Moreover, a good correlation between the concentrations of artificial element 137Cs and Pb has been also observed in soil samples collected from the Beskid Niski Mts. In most cases, the level of artificial 137Cs was lower comparing to an average 137Cs concentration established for soils in Poland.