Thorium Activity Research Articles

A comparison of the chemo- and radiotoxicity of thorium and uranium at different enrichment grades

Uranium and thorium are heavy metals, and all of their isotopes are radioactive, so it is impossible to study chemical effects entirely independent of the radiation effects. In the present study, we tried to compare the chemo- and radiotoxicity of both metals, taking into account deterministic radiation damages reflected by acute radiation sickness and stochastic radiation damages leading to long-term health impairments (e.g., tumor induction). We made at first a literature search on acute median lethal doses that may be expected to be caused by chemical effects, as even acute radiation sickness as a manifestation of acute radiotoxicity occurs with latency. By simulations based on the biokinetic models of the International Commission on Radiological Protection and using the Integrated Modules for Bioassay Analysis software, we determined the amounts of uranium at different enrichment grades and thorium-232 leading to a short-term red bone marrow equivalent dose of 3.5 Sv considered to cause 50% lethality in humans. Different intake pathways for incorporation were considered, and values were compared to the mean lethal doses by chemotoxicity. To assess stochastic radiotoxicity, we calculated the uranium and thorium amounts leading to a committed effective dose of 200 mSv that is often considered critical. Mean lethal values for uranium and thorium are in the same order of magnitude so that the data do not give evidence for substantial differences in acute chemical toxicity. When comparing radiotoxicity, the reference units (activity in Bq or weight in g) must always be taken into account. The mean lethal equivalent dose to the red bone marrow of 3.5 Sv is reached by lower activities of thorium compared to uranium in soluble compounds. However, for uranium as well as thorium-232, acute radiation sickness is expected only after incorporation of amounts exceeding the mean lethal doses by chemotoxicity. Thus, acute radiation sickness is not a relevant clinical issue for either metal. Concerning stochastic radiation damages, thorium-232 is more radiotoxic than uranium if incorporating the same activities. Using weight units for comparison show that for soluble compounds, thorium-232 is more radiotoxic than low-enriched uranium in the case of ingestion but even more toxic than high-enriched uranium after inhalation or intravenous administration. For insoluble compounds, the situation differs as the stochastic radiotoxicity of thorium-232 ranges between depleted and natural uranium. For acute effects, the chemotoxicity of uranium, even at high enrichment grades, as well as thorium-232 exceeds deterministic radiotoxicity. Simulations show that thorium-232 is more radiotoxic than uranium expressed in activity units. If the comparison is based on weight units, the rankings depend on the uranium enrichment grades and the route of intake.

Identification of mixing water source and response mechanism of radium and radon under mining in limestone of coal seam floor

With the gradual increase of the coal mining depth, the mixing of multiple water sources intensifies and the activity of radium and radon in groundwater increases. Identifying the source of mine water inrush by using radium and radon isotopes is a new choice. In this paper, the mathematical statistics method, radioactive isotope decay theory, the mass conservation principle, and the numerical simulation method are used to analyze the influence of total dissolved solids (TDS), pH, and the hydrochemical ion content in groundwater on the isotope activity of radium, radon, uranium, thorium, and lead. The activity of thorium and lead is lower than the detection limit of the instrument, and the influence of coal mining activities on it is small. The simulation of the radium–radon mass balance in groundwater shows that the greater the adsorption coefficient (k) of solid particles in groundwater is, the more obvious the adsorption effect and the greater the influence on the radium–radon activity balance are. The radium–radon dating method is used to calculate the groundwater age. Results show that the groundwater age in the closed pit coal mining area is generally older than that in the mining coal mining area. Combined with the 222Rn, 226Ra, and 234U radioactive isotopes and temperature, a mixing water source identification model of limestone in the coal seam floor is constructed. The model shows that the radium activity and temperature of the groundwater are inversely proportional to the mixing ratio of the Permian sandstone water. From the closed pit coal mining area to the mining coal mining area, the radium radon activity of the groundwater increases gradually, the groundwater age decreases significantly, the water cycle is accelerated, the mixing ratio of the Permian sandstone water decreases gradually, the mixing ratio of the Ordovician limestone water increases gradually, and the risk of coal mine water inrush increases. The research results prove the feasibility of the new method for accurately discriminating the mixing water sources in coal mine areas, which is of great significance to the improvement of the theory of coal mine water disaster prevention and control.

Preliminary Assessment of Anomalously High Background Radioactivity in Makinit Hot Spring, El Nido, Philippines

Hot springs in the Philippines are found mostly near volcanic regions and are the least places with possibly high background radiation. However, Makinit hot spring in El Nido, Palawan exists not only on the tectonically stable northern Palawan Microcontinental Block but also records anomalously high natural radioactivity. To quantify and determine the nature of radioactivity, this study conducted a preliminary radiological and geochemical study in the vicinity of this hot spring. The measured average specific activities of uranium and thorium were 1528.62 and 920.96 Bq/kg, and these exceed world median values on terrestrial radionuclides in the soil of 35 and 30 Bq/kg by 44 and 31 times higher, respectively. The average values of all seven calculated radiological risk parameters – namely, dose rate with an amount of 13.77 mSv/y, radium equivalent of 2862.10 Bq/kg, external and internal hazard indices of 7.73 and 11.86, respectively, absorbed gamma dose rate of 1271.42 nGy/h, annual effective dose equivalent of 1.56 mSv/y, and excess lifetime cancer risk of 5.46 x 10–3 – go beyond reference limits set by the UNSCEAR. The preliminary assessment of spring water physicochemical properties showed that the water temperature is greater than 55 °C and the pH averages around 6.62, indicating weak acid-neutral hot waters and a low to moderate temperature geothermal system. The sediments surrounding the Makinit hot spring were analyzed to be travertine, composed only of calcite, suggesting that the uranium and thorium ions are potentially bonded or are associated with the Ca-bearing mineral. This study can serve as a baseline for further research regarding the source of radioactivity and geothermal heat source and as a consideration for the development of the Makinit hot spring area.

Assessment of the Naturally Occurring Radioactive Materials (Norm) In Jos North, Nigeria. A Case Study of the Utan Artisanal Tin Mining Sites

Tin mining and milling can be an avenue for economic and technological development. Mining of this mineral contributes significantly to the distortion of the natural distribution of radioisotopes in the environment. This study assesses the concentration of natural radioactivity due to radioactive elements such as 40K, 238U and 232Th. Soil samples were taken from 20 distinct locations within the Utan mining sites, Jos North, Plateau State, Nigeria. Potassium, radium, and thorium in soil samples from mining sites were determined by measuring their concentration activities using the gamma-ray spectroscopy method. Activity concentrations of potassium, radium and thorium were determined. In soil samples, activity concentrations of 40K, 226Ra and 232Th were established. 40K 196.07±4.91 to 608.07±1.44 with an average of 386.48, 226Ra 0.71±0.02 to 5.11±0.07 with an average of 2.35 and 232Th 14.91±0.74 to 63.71±0.97 with average activity concentrations of 54.78. The average concentration activity of potassium and thorium was slightly above the world recommended average of 370.00 and 40.00 respectively, while radium was below the recommended average. The mines mean absorbed and annual effective dose rates were 14.27-nGy h−1and 18.62 μSvy-1, respectively. This average calculated absorbed dose rate in the air was found to be much less, than the global average of 57-nGy h−1. The absorbed dose is considered low compared to the external natural radiation of about 2000 μSv.y-1, to which no harmful effect is expected directly. However, the mean measured dose rate and calculated dose parameters for the mine were higher than the regulatory limit for public exposure.

Assessment of Radioactive Materials in Albite Granites from Abu Rusheid and Um Naggat, Central Eastern Desert, Egypt

The present study aims to assess Abu Rusheid and Um Naggat albite granite’s natural radioactivity in the Central Eastern Desert, Egypt, using an HPGe laboratory spectrometer. A total of 17 albite granite samples were detected for this study. The activity concentrations were estimated for 238U (range from 204 to 1127 Bq/kg), 226Ra (range from 215 to 1300 Bq/kg), 232Th (from 130 to 1424 Bq/kg) and 40K (from 1108 to 2167 Bq/kg) for Abu Rusheid area. Furthermore 238U (range from 80 to 800 Bq/kg), 226Ra (range from 118 to 1017 Bq/kg), 232Th (from 58 to 674 Bq/kg) and 40K (from 567 to 2329 Bq/kg) for the Um Naggat area. The absorbed dose rates in the outdoor air were measured with average values of 740 nGy/h for Abu Rusheid albite granite and 429 nGy/h for Um Naggat albite granite. The activity concentration and gamma-ray exposure dose rates of the radioactive elements 238U, 226Ra, 232Th and 40K at Abu Rusheid and Um Naggat exceeded the worldwide average values that recommend the necessity of radiation protection regulation. Moreover, the corresponding outdoor annual effective dose (AEDout) was calculated to be 0.9 and 0.5 mSv y−1 for Abu Rusheid and Um Naggat albite granite, respectively, which are lower than the permissible level (1 mSv y−1). By contrast, the indoor annual effective dose (AEDin) exceeded the recommended limit (3.6 and 2.1 for Abu Rusheid and Um Naggat, respectively). Therefore, the two areas are slightly saving for development projects concerning the use of the studied rocks. The statistical analysis displays that the effects of the radiological hazard are associated with the uranium and thorium activity concentrations in Abu Rusheid and Um Naggat albite granites.

Monitoring of natural radionuclides by alpha scintillometry and gamma spectrometry techniques in soil of district Palwal, Southern Haryana, India

ABSTRACT Forty soil samples from district Palwal of Southern Haryana, India were collected to estimates the radon/thoron exhalation rate using scintillation detector-based SMART RnDuo out of which twenty samples were tested to estimate the activity of 226Ra, 232Th and 40K using high purity germanium (HPGe) gamma-ray spectrometry. The radon mass exhalation rate (mBqkg−1h−1) was observed as {range (mean)} {16 ± 1–48 ± 3 (28 ± 8)} and thoron surface exhalation rate (Bqm−2h−1) was observed as {1800 ± 198–6331 ± 205 (3850 ± 850)}. Activities of radium (226Ra), thorium (232Th) and potassium (40K) were {range (mean)} observed as {28.4–48.4 (40.0 ± 1.4)}, {49.7–75.0 (62.7 ± 1.6)} and {432–698 (522.9 ± 17.6)}, respectively. It is observed that the radium in 75% samples while thorium and potassium in all samples were found to higher than the world’s average values of 35, 30 and 400 Bqkg−1, respectively, as reported by UNSCEAR. Average of radon mass exhalation and thoron surface exhalation rates exceeded the world’s mean value 57 mBq kg−1 h−1 and 3600 Bq m−2 h−1, respectively. Health hazard index is well below the unity (< 1), which indicates that there are no gamma radiation hazards associated with samples collected from the study region.

Soil radioecological study in the Lomonosov diamond mining area (Arkhangelsk region, Russia)

The aim of the study was to obtain new data and on their basis to analyze soil radioactivity in the Lomonosov diamond mining area (Arkhangelsk region, Russia).&#x0D; Location and time of the study: Field studies were carried out in the summer of 2018 in the Lomonosov diamond mining area (Arkhangelsk region, Russia).&#x0D; Methodology: To accomplish the task, 10 soil profile pits were cut, and 69 soil samples were taken from them. In the field, a description of soil morphology was carried out. Under laboratory conditions, the samples were dried at 105° C to constant mass. After weighing, the soil samples were placed in a Marinelli vessel to measure the specific activity of isotopes (cesium (137Cs), potassium (40К), radium (226Ra) and thorium (232Th)) by gamma spectrometry. Registration of gamma radiation from a counting soil sample, as well as processing of spectra was carried out using the Progress-gamma software and hardware complex FVKM.412131.002-03. The energy calibration of the gamma spectrometer to control the safety of the setup parameters was carried out after each measurement using a combined control source OISN-137-1 in a Marinelli vessel. The minimum exposure time of the counting sample was 3600 seconds. However, depending on the activity of the sample, the exposure time in individual samples with weak activity increased.&#x0D; Main results: As a result of field studies, it was found that Podzols, characteristic of the northern taiga, prevail in this area. The maximum activity of 137Cs was concentrated in the litter-peat (11.4–71.8 Bq/kg) and the humus horizon (26.7–105 Bq/kg). In the podzolic and Al-Fe-humus horizons there was a sharp decrease in the activity, reaching the lowest measured values in the parent rock (2–3 Bq/kg). The general tendency for the accumulation of natural isotopes 40K, 226Ra, and 232Th in the soil horizons was found to be weakly related to soil type or subtype. In some soil pits an increase in the natural radionuclides with depth was observed, being mostly the characteristic of 40K as its activity changed downwards from 82.6 to 652 Bq/kg. The 226Ra and 232Th activities in the soil profiles varied from 2.4 to 47.2 Bq/kg and from 2.9 to 40.6 Bq/kg, respectively. This is due to the fact that thorium is strongly sorbed by soil; therefore, its migration along the soil profile is poorly expressed, and the element is deposited in soils in the form of hydroxides. Loamy and clayey soils, were shown to be more enriched in radium, whereas sandy soils were poor in this element. The amount of radioactive elements, contained in a soil, is largely determined by the concentration of their isotopes in the underlying rocks. &#x0D; Conclusion: The peaks of increasing concentration in the Al-Fe-humus horizons (BF, BFg) were associated with an increase in the content of the clay fraction, Fe, Al hydroxides, which increase the sorption capacity of soils. The litter-peat and the humus horizon act as a biogeochemical barrier that retains radioactive elements in the soil for a long time. Due to the high filtration capacity of podzols, the underlying horizons are not reliable barriers. 137Cs and other radioisotopes can bind with humic substances, oxides and hydroxides of iron and aluminum, form humus-ferruginous complexes, precipitate as new soil formations, e.g. become part of the mineral composition of hard pans. The distribution of natural radioisotopes 40K, 226Ra and 232Th was found to be more chaotic and more related to the composition of the constituent rocks. The mobility and accumulation of radionuclides along soil profiles depends on the particle size distribution, the content of organic matter, sesquioxides, mineralogical composition, as well as on the temperature and water regime.

Influence of background characteristics on the optimal sample filling height in gamma-ray spectrometry

The minimum detectable activity (MDA) for gamma spectrometric measurements was studied as a function of filling height for two detectors having different background characteristics and for two sample matrices: a water sample with a low content of natural radionuclides, and zircon sand, with high activities of uranium and thorium. The zircon sand is also a material in which the self-attenuation of low-energy gamma photons will be high. The results show that for the water sample it is always favourable to completely fill the sample container. However, due to the inherent content of naturally occurring radionuclides in the zircon sand the MDA may not necessarily improve with the filling height, since an increased amount of sample will increase the background in the spectrum as well.

Concentration of Uranium and Thorium in Granite Rock in Kadugli, Sudan Using γ - ray Spectroscopy

The aim of the present study is to determine the elemental concentration in (ppm) and specific activity in (Bqkg-1) of Uranium (238U) and Thorium (232Th) contained in the granite rock of a special geological area in Sudan (Kadugli).&#x0D; The elemental concentrations and specific activity of 238U and 232Th in granite rock were determined by using the gross gamma counting technique (γ-ray spectroscopy). The analyses were performed for daughter decaying of 238U and 232Th; which are Pb-214, Bi-214 for 238U and Tl-208, Ac-228 for 232Th.&#x0D; The experiments were carried out at the Nuclear Laboratory, Physics Department, Universiti Teknologi Malaysia using the facilities of gamma ray spectroscopy system with high purity germanium detector (HPGe) of efficiency 20%.&#x0D; Granite samples were collected from Hagar El-Mlik area, 2 km from the central of Kadugli city in southern Kordofan state, Sudan. The rock was crushed and ground to fine powder and sieved with a particle size less than 120 μm. To calculate the concentrations of 238U and 232Th in the granite rock, standard reference materials provided by International Atomic Energy Agency (IAEA) was used.&#x0D; The average of elemental concentrations and specific activity of uranium were obtained in the range (1.8 ± 0.11) to (0.80 ± 0.08) ppm, and (22.11 ± 1.30) to (9.79 ± 0.98) Bqkg-1 respectively, while (16.22±1.84) to (7.45±1.34) ppm and (65.42±7.40) to (29.50 ± 5.39) Bqkg-1 are the average concentration and specific activity of thorium. Moreover, average activity concentrations (Bqkg-1) for granite samples have been compared with the typical values of different countries.&#x0D; 232Th shows high activity concentration (65.42±7.4) Bqkg-1 whereas, 238U activity value is distinctly lower than the corresponding ones obtained from other countries and, in general, all results are acceptable and fall within the range given in UNSCEAR report 1993.

Natural Radioactivity Levels in Some Milk Samples available in Local Markets in Babylon Governorate

The Uranium (238U), Thorium (232Th) and Potassium (40K) activity of specific in (Bq/kg) are measured (10) differentness types of milk which are available in market-place of Iraqi. Aspectrometry gamma ray of methodic with a NaI(Tl) detector its using for radiometric measurements. Also calculates the hazard of radiation indicates (radium equivalent activity and internally hazardous index tab) and effectiveness of Ingestion dose every sampler.&#x0D; The activity of specifics in a sampler of milk was varied between from (0.274±0.158) Bq/kg to (7.851±0.877) Bq/kg, for 238U, For 232Th between from (0.821±0.273) Bq/kg in (3.067±0.569) Bq/kg and for 40K between (266.558±5.018) Bq/kg to (485.740±7.197) Bq/kg. In addition to, it is found that radium equivalent activity and internally hazard indexing to the sampler of milk ranged between (27.341) Bq/kg to (48.035) Bq/kg and from (0.07867) to (0.14720) respectively. So, the range summations ingestive effectiveness dose was variedly between (4.861×10-5) Sv/y to (1.541× 10-4) Sv/y. This search proves that the radioactivity of natural, hazard of radiation references and dose of effective ingestion was lower than the safekeeping, except some value of potassium.

Measurements of thorium and uranium daughters in radioenvironmental samples using [formula omitted]-coincidence spectrometry

We present the performance of a γγ-coincidence spectrometer for measuring the activities of thorium and uranium daughters in environmental samples. The spectrometer consists of two NaI(Tl) detectors facing each other inside a low-background passive shield. We present coincidence gating schemes for achieving the best signal-to-noise ratios, coincidence detection efficiencies, background levels, and minimum detectable activities. The spectrometer is simulated using Geant4 to correct sample efficiencies for self-absorption effects. The device is used to measure thorium and uranium daughter activities in Brazil nuts, potting mix, and magazine paper. Our results for Brazil nuts agree with some, but not all, previous measurements. Thorium or uranium daughter activities have previously not been reported for commercial potting mix. For magazine paper, our measured activities are lower than most previously determined values.

Activity Reduction of 232Th and 40K from Simulated Underground Water Using a Clay-Based Membrane

In this research, the activities of 232Th and 40K in simulated underground water were reduced using inexpensive clay-based membrane. Starch (10 and 15 wt%) was added to the clay, compacted and fired up to 1300°C to produce the porous membranes. The characterization of the raw clay and the produced membranes was conducted using XRF, XRD, TGA/DTA, BET and FESEM. The activities of 232Th and 40K in the waste and permeated water were counted using gamma spectroscopy. The produced membranes were having pore sizes in the range 39.68-46.10nm; from the BET isotherm, it shows the membranes produced are mesoporous. Also, the steady flux of the filtered water was found to be in the range 3.83×10-7-1.77×s10-6 m3m-2s-1. Activities of thorium and potassium in the permeated water were found to be 4.57-5.61 Bq/l and 15.49-25.19 Bq/l respectively. This shows that inexpensive clay can be used to reduce the activities of thorium and potassium in underground water from mining, fracking and produced water from oil and gas.

Natural Radioactivity Measurements in Vegetables at Al-Diwaniyah Governorate, Iraq and Evaluation of Radiological hazard

The effective technique of γ-spectroscopy using high purity germanium detector (HPGe) has been applied to determine the specific activity of 226Ra, 232Th and 40K in essential vegetable samples collected from farms of Al-Diwaniyah governorate in the south of Iraq. The specific activity of natural radionuclides was measured in Tomato, Cucumber, Okra, Potato, Radish, Turnip, Spinach, Lettuce, Cauliflower and Onion. The results show that the highest specific activity of 226Ra, 232Th and 40K in potato product was (11.46, 9.12 and 120.54) Bq/kg, respectively. The average value of specific activity of radium, thorium and potassium in vegetable samples was (7.67, 5.75 and 98.39) Bq/kg, respectively. The results of the radiological hazards were compared with the published data and they were found to be within the safety levels.

Synthesis, Characterization and Antibacterial Activity of Thorium(IV), Dioxouranium(VI), Cobalt(II), Nickel(II), Copper(II) and Zinc(II) Complexes with Picolinoyl Hydrazones

Synthesis, Characterization and Antibacterial Activity of Thorium(IV), Dioxouranium(VI), Cobalt(II), Nickel(II), Copper(II) and Zinc(II) Complexes with Picolinoyl Hydrazones

Influence of terrestrial radionuclides on environmental gamma exposure in a uranium deposit in Paraíba, Brazil

One of the main natural uranium deposits in Brazil is located in the municipality of Espinharas, in the State of Paraíba. This area may present high levels of natural radioactivity due to the presence of these radionuclides. Since this is a populated area, there is need for a radioecological dosimetry assessment to investigate the possible risks to the population. Based on this problem, the objective of this study was to estimate the environmental effective dose outdoors in inhabited areas influenced by the uranium deposit, using the specific activities of equivalent uranium, equivalent thorium and 40K and conversion factors. The environmental assessment was carried using gamma spectroscopy in sixty-two points within the municipality, with a high-resolution gamma spectrometer with HPGe semiconductor detector and Be window. The results obtained ranged from 0.01 to 19.11 mSv y−1, with an average of 2.64 mSv y−1. These levels are, on average, 23 times higher than UNSCEAR reference levels and up to 273 times the reference value of the earth's crust for primordial radionuclides. Therefore, given the high radioactivity levels found, we conclude that there is need for further investigation to evaluate the levels of radioactivity in indoor environments, which will reflect more closely the risks of the local population.

Measurement of radium, thorium, potassium and associated hazard indices from the soil samples collected from Northern India

The presence of radium, thorium and potassium in soil and building materials impose radiological hazards to human population. Both alpha and gamma radiation are produced from the decay chain of uranium and thorium while potassium is itself a source of gamma radiation. The measurement of these radionuclides in soil is important to prevent the general public from health hazards. The measurement of radium, thorium and potassium from soil samples collected from some locations of Northern India was carried out to assess the various radiological hazard indices using sodium iodide-based gamma ray spectroscopy. The observed specific activities of radium, thorium and potassium varied from 13 to 175, 141 to 399 and 276 to 1581 Bq/kg with an average of 78, 231 and 525 Bq/kg, respectively. The mean values from soil samples under study are more than the corresponding worldwide average values (35, 30 and 400 Bq kg−1 for 226Ra, 232Th and 40K) but less than the recommended limits. The measured radium, thorium and potassium activity from the soil samples were used to find out the various hazards index and absorbed dose. The results show the soil of the study area does not pose any health hazards to people residing in this area.

Nuclide Spectra of Activities of Thorium, Uranium Series and Application in Gamma-spectrometry of Point Technogenic Samples

The radioactive nuclei decay of the nuclides in the 232Th, 235U and 238U series is under consideration. The Bateman-Rubinson system of differential equations is applied. The activity of any n-th nuclide of the series has been calculated. The standard nuclide spectra are found and are compared with experimental nuclide spectra of activities. The results of the measurements are the time parameters, which determine the event date. The examples of the measurement of the experimental nuclide spectra in the nuclear gamma spectrometry of the point technogenic samples have been considered.

Factors controlling 226Ra, 228Ra and their activity ratio in groundwater – an application in Polish Carpathian mineral waters

The influences of aquifer formations and water chemical composition on the occurrence and activity ratio of radium isotopes in groundwater are discussed. Based on the model of desorption/adsorption processes of natural radionuclides in the rock-water system, the concentrations of radium isotopes and their activity ratio in groundwater are evaluated by the numerical Monte Carlo method (MC). In cases where the groundwater is of a similar age, limited flow (up to several meters/year), the physical conditions and the uranium and thorium activity ratios in host water formations are similar, the activity concentrations of radium isotopes (226Ra, 228Ra) and their activity ratio (226Ra/228Ra) are the highest in the water of high desorption coefficient for chloride sodium water (domination of Cl− , Na+ ions), medium in water of moderate desorption (bicarbonate water – HCO3 − , Ca2+) and the lowest in waters with a low desorption coefficient (sulfate ions prevailing – SO4 2−, Ca2−). The statements are well confirmed in the case of the natural mineral waters from the Polish Outer Carpathians. The total dissolved solids (TDS) of the Polish Carpathians waters varies from several hundred milligrams per liter to several tens of thousands milligrams per liter. The minimum, maximum and average concentrations of 226Ra, 228Ra and their activity ratio (226Ra/228Ra) are 82, 1340, 456 mBq/L, 19, 1240, 354 mBq/L and 0.89, 7.6 and 2.0 for chloride waters; 4, 140, 45.8 mBq/L, 12, 171, 62.7 mBq/L and 0.3, 1.7 and 0.70 for bicarbonate waters and 0.8, 9.3, 3.6 mBq/L, 5.3, 54, 20.1 mBq/L and 0.1, 1.0, 0.3 for sulfate ones, respectively. The desorption coefficients are the highest for the Cl-Na, moderate for the HCO3-Ca and the lowest for the SO4-Ca waters (in contrast to the adsorption properties of these waters).

Long-term monitoring of natural radionuclides in Uzhgorod city, Ukraine

The goal of the present work is to determine the specific activity of terrestrial thorium, uranium and potassium in Uzhgorod city and to predict the values of specific activity over the whole area of Uzhgorod city. The following values for the average specific activity in 2006–2012 were found for different radioisotopes from the surface soils (in Bq kg−1): 40K = 304.0 ± 12.3; 232Th = 24.2 ± 2.1; 238U = 19.2 ± 1.2. The average value of the absorbed dose was equal to 36.3 ± 2.3 nGy h−1. The average value of the external hazard index was equal to 0.22. The average annual effective dose of natural radionuclides was equal to 4.5 ± 0.3 10−5 Sv.

Study of radioactivity levels in detergent powders samples by gamma spectroscopy

This study focuses on the evaluation of the natural radioactivity levels in ten samples of the detergent powders that available in Iraqi markets. We have determined the specific activities of uranium, thorium and potassium using gamma spectroscopy and calculation of radiation hazard indices. The results of the activities of radionuclides (238U, 232Th, 40K) for detergent powders samples, are found that the 238U specific activities were varied from (11.489 ± 2.089) Bq/kg to (36.062 ± 2.478) Bq/kg, while the 232th specific activities were varied from (1.411 ± 0.609) Bq/kg to (9.272 ± 1.642) Bq/kg and 40K were varied from (8.189 ± 2.339) Bq/kg to (91.888 ± 4.164) Bq/kg. These values are always lower than those of raw materials, what is explained by the conservation of radioactive material throughout the manufacturing process. The radium equivalent activity Raeq, the external hazard index Hex and the internal hazard index Hin dose due to natural radioactivity estimated below the regulatory standard recommended which are (370 Bq/kg, 1 and 1) according to OECD 1979 and ICRP 2000, allows us to show that Detergent powders samples products are not contaminated by radioactivity, are healthy and do not have harmful radiological impact on the consumer.