scholarly journals VZTAH MEZI PŘIROZENOU RADIOAKTIVITOU HORNIN A PŮD NA NICH VYTVOŘENÝCH – ZÁKLADNÍ PROBLÉM INTERPRETACE DAT ZÍSKANÝCH LETECKOU A TERÉNNÍ GAMASPEKTROMETRIÍ

Author(s):  
Jiří Zimák

The objective of this study was to assess the amount of natural radionuclides in fresh parent rocks and their effect on natural radioactivity of soils developed from them. Forty-five fresh rocks consisting mainly of granitoids, syenitoids, acid to basic metavolcanites, mica schists, gneisses, quartzites, serpentinites, sandstones, graywackes, and limestones and their corresponding overlying soils were sampled for laboratory gamma-ray spectrometric analysis. Contents of potassium, uranium and thorium were converted to mass activity of 226Ra equivalent (am) and terrestrial gamma radiation dose rate (D). Data are tabled and discussed. The highest am values occured in syenitoids (386–441 Bq·kg-1) followed by granitoids, mica schists, greywackes and gneisses, whereas the lowest am values were found in quartzose sandstones (15–36 Bq·kg-1) followed by limestones (less than 15 Bq·kg-1) and serpentinites (less than 6 Bq·kg-1). The natural radioactivity of soils is usually slightly lower than that of parent rocks due to the lower content of potassium, uranium and thorium in soils. This is typical for granitoids, syenitoids and rocks of similar mineralogical composition. In soils developed on granitoids and syenitoids were found increased concentrations of all three elements in the grain size fraction below 0.063 mm. Soils developed on rocks with low natural radioactivity (such as limestones and serpentinites) tend to have significantly higher natural radioactivity than their parent rocks. This may complicate the interpretation of data obtained by airborne gamma-ray spectrometry.

2021 ◽  
Vol 11 (14) ◽  
pp. 6471
Author(s):  
Nasser M. Moghazy ◽  
Amira M. El-Tohamy ◽  
Mona M. Fawzy ◽  
Hamdy A. Awad ◽  
Hesham M. H. Zakaly ◽  
...  

The present study was carried out on commercial types of Aswan granite used as building and decorative materials. Nearly 29 granitic rocks samples from 11 classes (black Aswan, red Aswan, dark Rosa, light Rosa, yellow Verdi, grey Shirka, Gandolla, Forsan, red Nefertiti, Royal, and white Halayeb) were collected from three stations near Aswan city for petrographical description and assessment of natural radioactivity. The petrographical study of granites was conducted by polarized-light microscope in order to determine their mineralogical composition and investigate their texture; the activity of the natural radionuclides 238U, Ra226, 232Th, and 40K was measured by gamma-ray spectrometry with a NaI(Tl) detector. The average values of the activities, 52.2 Bq kg−1, 57.8 Bq kg−1, 31.2 Bq kg−1, and 1055.7 Bq kg−1 of U-238, Th-232, Ra-226, and K-40, respectively, were higher than that the world average values of 35 Bq kg−1, 30 Bq kg−1 and 400 Bq kg−1 for 226Ra, 232Th, and 40K, respectively, according to the recommended levels from UNSCEAR reports. The minimum and maximum values obtained were compared with the value ranges from other locations in the Eastern Desert, highlighting the fact that that the maximum values obtained in this work are higher than those in other areas. According to the radiological hazards indices results, most samples lie in the permissible level ranges, suggesting their favorability for use as building materials. In contrast to that, some samples have some environmental parameters higher than the international levels, indicating their unsuitability as building materials.


2019 ◽  
Vol 26 (1-2) ◽  
Author(s):  
Jiří Zimák

The paper deals with natural radioactivity of soils on the map sheet 24-22 Olomouc and compares contents of natural radioactive elements in soils and in their parent rocks (soilforming substrates). Three main types of parent rocks can be distinguished in the studied area: i) siliciclastic flysch sediments of the Moravo-Silesian Palaeozoic, ii) Quaternary sediments of the river Morava floodplain, iii) Quaternary loesses. Contents of potassium, uranium and thorium were measured using a laboratory gamma–ray spectrometer in 1 077 soil samples. It is evident from calculated values of mass activity of 226Ra equivalent (am) that natural radioactivity of the studied soils is low. The average am of soils developed on siliciclastic flysch sediments is 142 Bq.kg-1, 133 Bq.kg-1 on fluvial sediments of the river Morava and 148 Bq.kg-1 on loesses. The average am values calculated for soils developed on siliciclastic flysch sediments and for soils on loesses are almost the same as average am values calculated for their parent rocks. The soils of the river Morava floodplain show higher am values compared to their parent material (sands and pebbles dominate) due to higher uranium and thorium contents.


Author(s):  
I. Hossain ◽  
N. M. Yussuf ◽  
M. A. Saeed ◽  
M. O. Alzanbaqi ◽  
H. Wagiran

This paper has explained the contamination of natural radionuclides in various water testers using gamma ray measurement which is very significant as part of health scrutiny programs to progress the ecological knowledge. Natural radioactivity was determined in five groups of water samples (rain, mine, tap, drinking and mineral) from different places at Johor, Malaysia by means of gamma-ray spectrometry tool. The annual cumulative effective doses were estimated 6.05 mSv /yr for rain, 9.49 mSv/ yr for mine, 6.39 mSv /yr for tap, 5.67 mSv /yr for drinking, and 6.01 mSv/yr for mineral water. Among the five samples, mine water gave the highest value in annual effective dose measurement. The measured data are compared with the reported value. The activity concentrations of five water samples provided that bottled drinking water was the lowest than other water samples. This research is useful to provide some information to the public about the amount of radionuclide content uranium, thorium and potassium that present in water.


2021 ◽  
Vol 56 (4) ◽  
pp. 659-672
Author(s):  
Sk. A. K. Arafin ◽  
Md. Sapan Bhuiyan ◽  
Jannatul Ferdous ◽  
M. Ashraful Hoque ◽  
A. K. M. Rezaur Rahman ◽  
...  

The study aimed to investigate natural radioactivity levels and Transfer Factors of natural radionuclides from soil to some plants in Chittagong, Bangladesh. The concentrations of naturally occurring and anthropogenic radionuclides in soil and plants were measured in this work to determine the absorbed dose rate and the transfer factors of radionuclides from soil to plant. Plants (Spinach and Vegetables) and corresponding soil samples were collected from three different locations in Chittagong (Nasirabad, Sitakunda, and Halda Agrotechnology), and the concentrations of activity of natural radionuclides were measured using gamma-ray spectrometry. The average absorbed dose rate in the soil of Nasirabad, Sitakunda, and Halda Agrotechnology are 49.84 nGyh-1, 37.4 nGyh-1, and 45.6 nGyh-1. The average transfer factor from soil to plants, recorded for 238U, 232Th, and 40K of these study areas, are 0.461, 0.400, and 3.10, respectively. The ratio of soil to plant transfer factor for the present study compared with some previous work. The Transfer Factor of 40K gives some high value but does not exceed the limit of the different published values. Because there are no existing databases for the natural radioactivity in soil and plants from Chittagong, Bangladesh, our results are establishing a database for the Chittagong, Bangladesh soil and plants. This data may be used as a database for further investigation for the betterment of public health.


1963 ◽  
Vol 03 (02) ◽  
pp. 175-182 ◽  
Author(s):  
Bo Bergman ◽  
Rune Söremark

SummaryBy means of neutron activation and gamma-ray spectrometry the concentrations in the human mandibular articular disc of the following elements have been determined: Na, Mn, Cu, Zn, Rb, Sr, Cd, W, and Au. The discs were obtained at necropsy from seven men and nine women, ranging in age from 56 to 71 years.The activation was carried out in a thermal neutron flux of about 1.7 XlO12 neutrons × cm−2 × sec.−1 for about 20 hours. A chemical group separationwas performed before the gamma-ray spectrometry. Quantitative data based on the dry weight of the cartilage samples were obtained by comparing the photo-peak area of the identified elements with those of appropriate standards.


Author(s):  
Ondřej Šálek ◽  
Milan Matolín ◽  
Petr Tábořík ◽  
Petra Štěpančíková

2020 ◽  
Vol 27 ◽  
pp. 121
Author(s):  
Filothei K. Pappa ◽  
Christos Tsabaris ◽  
Dionisis Patiris ◽  
Georgios Eleftheriou ◽  
Effrossini G. Androulakaki ◽  
...  

Radionuclides are characterized by their nuclear and chemical behavior. Additionally, the geochemical characteristics of radionuclides result in their accumulation in the sediments via sorption processes. In this work the radionuclide activity concentrations obtained by gamma-ray spectrometry (HPGe detector) were converted to metal concentrations as described in [1]. The results were compared with the measured metal concentrations obtained by atomic spectrometry (X-ray fluorescence system-XRF). The samples originate from the coastal environment of two Greek areas, characterized by elevated values of natural radionuclides (e.g. 226Ra) and metals. The preliminary study revealed a good agreement among the concentrations of potassium calculated via activity concentrations of 40K and those of XRF measurement, while a great divergence was observed for the thorium case. These differences can be attributed to the low statistics, as well as to the calibration set-up of Th XRF measurement.


2017 ◽  
Vol 24 (1-2) ◽  
Author(s):  
Jiří Zimák

The paper deals with natural radioactivity of metamorphic and igneous rocks and Palaeozoic sediments within the map sheet 14-33 Polička. Studied rocks belong to three geological units: the Hlinsko Zone (phyllites and quartzites of the Mrákotín Fm., flysch sediments of the Hlinsko-Rychmburk Fm.), the Svratka Crystalline Complex (mainly mica schists, paragneisses, orthogneisses and migmatites, also amphibolites, skarns, erlans and quartzites) and the Polička Crystalline Complex (mica schists, paragneisses to migmatites and the Variscan granitoids are dominant). Concentrations of potassium, uranium and thorium were measured using a laboratory gamma-ray spectrometer in 805 rock samples. Data are tabled and discussed. Natural radioactivity of rocks is evaluated on the basis of the calculated values of mass activity of 226Ra equivalent (am). Slightly increased am values were found in migmatites and orthogneisses of the Svratka Crystalline Complex (187 Bq.kg-1 on average), granites and granodiorites of the Budislav Pluton (216 Bq.kg-1), granodiorites and rocks of a tonalite suite of the Miřetín Pluton (199 and 194 Bq.kg-1). Increased concentrations of uranium and thorium were found in some samples of pegmatite and aplite. Radioactivity of rocks of the Hlinsko-Rychmburk and Mrákotín Fms. can be assessed as relatively low.


2019 ◽  
Vol 184 (3-4) ◽  
pp. 359-362
Author(s):  
Mudassir H Yarima ◽  
M U Khandaker ◽  
A Nadhiya ◽  
M A Olatunji

Abstract Uranium, thorium and potassium are the most abundant naturally occurring radioactive materials (NORMs) found in soils and other environmental media including foodstuffs. Since the human exposures to NORMs is an unavoidable phenomenon, in such a way that they can easily find their way to human being via food chain, detailed knowledge on their presence in foodstuffs is necessary to assess the radiation dose to the population. Thus, the present study concerns the assessment of natural radioactivity in maize, a staple foodstuff for Nigerian, via HPGe gamma-ray spectrometry. Activity concentrations (Bq/kg) in the maize samples were found to be in the range of 6.1 ± 0.6–8.2 ± 1.3, 2.2 ± 0.4–5.1 ± 0.7 and 288 ± 16–401 ± 24 for 226Ra, 232Th and 40K, respectively. Measured data for 226Ra and 232Th show below the world average values of 67 Bq/kg and 82 Bq/kg, respectively, while the activity of 40K exceeds the global average of 310 Bq/kg. The annual effective dose via the maize consumption was found to be far below the UNSCEAR recommended ingestion dose limit of 290 μSv/y, and the estimated lifetime cancer risk show lower than the ICRP (1991) cancer risk factor of 2.5 × 10−3 based on the additional annual dose limit of 1 mSv for general public, thus pose no adverse health risk to the Nigerian populace.


2020 ◽  
Vol 190 (3) ◽  
pp. 324-330
Author(s):  
C K Wanyama ◽  
F W Masinde ◽  
J W Makokha ◽  
S M Matsitsi

Abstract Radiological hazards associated with naturally occurring radionuclides in materials from Rosterman gold mine were assessed by analysis of 30 samples. The gamma-ray spectrometric analysis of tailing samples reported an average activity concentration of 263 ± 13, 123 ± 6 and 84 ± 4 Bq kg−1 for 40K, 232Th and 226Ra, respectively. The average absorbed dose rate was 124 ± 6 nGy h−1, while the annual effective dose of 0.4 ± 0.02 mSv y−1 for indoor and 0.3 ± 0.01 mSv y−1 for outdoor were reported. The mean and range of radiological parameters (external and radium equivalent) calculated from the tailing samples were within the permissible limits and hence mining of gold at Rosterman has no significant radiological health implication on the miners and the surrounding population.


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