SOME ASPECTS OF THE INFLUENCE OF URANIUM EXPLOITATION ON THE ENVIRONMENT

Gamma-ray spectrometric measurements of samples of riverbed sediments and soil samples taken along the valley of a river, which runs very close to a uranium mine retaining dam are performed. The content of 238U, 226Ra, 210 Pb, 232Th, and 40K is analyzed. Up to a distance of about 6 km away from the retaining dam, 238U, 226Ra and 210Pb have high concentrations and the content in the sediments samples is consistently higher than the content in the soil samples. In the same interval are observed considerable fluctuations in the contents related to the swamping of the river. Receding at a greater distance from the retaining dam, the concentration of 238U, 226Ra and 210Pb decreases and has values close to the average ones. A very close correlation is established between the contents of the three radioactive nuclides. Regarding 232Th and 40K, the distribution characteristics along the profile are different in comparison with those of the 238U family members. The performed research contributes to the estimate of the radioactive contamination in a specific area situated in the vicinity of a uranium deposit exploited through underground mining

DENSITY AND POLARIZABILITY COEFFICIENT … 50 years University of Mining and Geology

ABSTRACT The rhyolite formation in the Rhodope massif is presented by Tertiary extrusive and effusive lava in the Western and Central Rhodopes. Data from measurements performed by the Department of Applied Geophysics, University of Mining and Geology, Sofia and other organizations are summarized. The values for the density and the polarizability coefficient are studied on samples from different areas of the Rodope massif -the Bratsigovo-Dospat depression, the Dospat anticline, the Southern Rhodope syncline, the Northern Rhodope syncline, the Smolyan depression and other more local structures as the Kovachevo syncline, the Batak syncline, the Vacha uplift, the Lyaskovo uplift and the Hvoina graben-syncline. Statistical analysis is applied for estimating the characteristics of sample packs from one and the same region, as well as for estimating the characteristics of the total set of available data. The surface distribution of the analyzed parameters is also studied. The compound analysis of the values for the density and the polarizability coefficient of the rhyolites in the Western and Central Rhodopes is proving that the detailed mapping according to these characteristics can efficiently enrich the information obtained by the traditional geological mapping

MODELS FOR ASSESSING AND PREDICTING THE SUBSURFACE TRANSPORT OF CONTAMINANTS FROM THE WASTEWATER IN THE EFFLUENT CHANNEL OF KCM AD - PLOVDIV, SOUTHERN BULGARIA

Until the end of the 20th century, the uncontrolled discharge of highly polluted emissions from the non-ferrous metals companies in Bulgaria was the cause of heavy contamination in vast areas around these industrial sites. In the last two decades, after the introduction of good environmental practices and the closure of polluting industries, a deceleration of the negative processes and a gradual cleaning of the already polluted waters and soils are observed. In order to evaluate and predict these processes, numerical 2D models of the conditions for the subsurface transport of contaminants from the wastewater in the effluent channel of KCM AD-Plovdiv are developed using the VS2DI computer programme. The scheme of convection-diffusion mass-transport is applied, taking into account the concomitant processes of reversible elimination, mechanical dispersion and mixing. Employing the developed models, the fate and transport of pollutants typical for this type of industrial sites – sulphate ions and cadmium (SO4 and Cd) are studied, taking into account their concentration in the wastewater before and after the application of modern technologies and equipment for remediation of contaminated water. The computer simulation encompasses the period from the construction of the effluent channel till 2035

QUANTITATIVE INTERPRETATION OF THE HORIZONTAL GRAVITY … 50 years University of Mining and Geology

ABSTRACT The applied method for quantitative interpretation of the gravitational field caused by semi-infinite horizontal slab structures is based on the horizontal gradient Uxz distribution on different levels. Representative characteristics are chosen, that can be obtained without ambiguity from the data after analysis of the measured gravitational field -the maximum value of the horizontal gradient Uxz max , the anomaly width ∆X1/2 for gradient value Uxz max /2 and the widths of the two branches of the horizontal gradient distribution -∆X1/2 − and ∆X1/2 + . Subject of the study is the relationship between these characteristics and the main parameters of a semi-infinite edged horizontal slab -the depth h1 to the slab structure, the thickness of the slab ∆h (∆h=h2-h1) and the angle of the edge α. On the base of statistical studies for a wide range of different model parameters are obtained correlation ties suitable for the aims of the quantitative interpretation

Mutational Signature Analysis Reveals NTHL1 Deficiency to Cause a Multi-tumor Phenotype

Biallelic germline mutations affecting NTHL1 predispose carriers to adenomatous polyposis and colorectal cancer, but the complete phenotype is unknown. We describe 29 individuals carrying biallelic germline NTHL1 mutations from 17 families, of which 26 developed one (n = 10) or multiple (n = 16) malignancies in 14 different tissues. An unexpected high breast cancer incidence was observed in female carriers (60%). Mutational signature analysis of 14 tumors from 7 organs revealed that NTHL1 deficiency underlies the main mutational process in all but one of the tumors (93%). These results reveal NTHL1 as a multi-tumor predisposition gene with a high lifetime risk for extracolonic cancers and a typical mutational signature observed across tumor types, which can assist in the recognition of this syndrome

Mutational signature analysis reveals NTHL1 deficiency to cause a multi-tumor phenotype

Biallelic germline mutations affecting NTHL1 predispose carriers to adenomatous polyposis and colorectal cancer, but the complete phenotype is unknown. We describe 29 individuals carrying biallelic germline NTHL1 mutations from 17 families, of which 26 developed one (n = 10) or multiple (n = 16) malignancies in 14 different tissues. An unexpected high breast cancer incidence was observed in female carriers (60%). Mutational signature analysis of 14 tumors from 7 organs revealed that NTHL1 deficiency underlies the main mutational process in all but one of the tumors (93%). These results reveal NTHL1 as a multi-tumor predisposition gene with a high lifetime risk for extracolonic cancers and a typical mutational signature observed across tumor types, which can assist in the recognition of this syndrome