Determination Of Radioactivity Research Articles

Determination of natural radioactivity and radiological hazards of sediment sands in Tiruchirappalli district, Tamil Nadu, India

Abstract In Tamil Nadu, India, sand from river beds are being used as a part of construction material. The radiological impact of natural radioactive materials present in river sands in Tiruchirappalli District are measured using gamma-ray spectroscopy. The average activity concentrations of 238 U, 232 Th and 40 K are measured to be 9.91 ± 4.74 Bq kg −1 , 18.30 ± 4.17 Bq kg −1 and 309.51 ± 23.23 Bq kg −1 , respectively. The average values of radiation hazards such as radium equivalent, hazard index, annual effective dose equivalent and annual gonadal dose equivalent are 55.29 ± 11.45 Bq kg −1 , 0.14 ± 0.02 and 0.19 ± 0.05 (Hex and Hin), 31.96 ± 5.85 µSv y −1 and 127.84 ± 23.4 µSv y −1 (outdoor and indoor) and 187.78 ± 30.60 µSv/y −1 , respectively. These values are compared with the international and Indian standard values and they lie below the recommended limits. Hence the sediment sand samples do not pose any significant radiological concern and could be used for construction purposes.

Determination of natural radioactivity and estimation of radiation hazard in cultivated soil samples in El-Minia governorate (Upper Egypt)

Determination of natural radioactivity and estimation of radiation hazard in cultivated soil samples in El-Minia governorate (Upper Egypt)

Determination of Heavy Metal and Radioactivity in Agaricus campestris Mushroom Collected from Kahramanmaraş and Erzurum Proviences

In this study, radioactivity and heavy metals accumulations in Agaricus campestris mushroom collected from Kahramanmaraş and Erzurum provinces was determined. HPGe gamma detector was used for the determination of radioactivity concentrations. Heavy metal content was measured using a ICP-MS. As radioactive element; natural (238U, 232Th 40K) and artificial radionuclide (137Cs) concentrations were determined. The values of the committed effective dose were calculated. Same measurements were made in soils. Absorbed dose and excess lifetime cancer risk were calculated. Amount of Mg, Al, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Pb206, Pb207 and Pb208 as heavy metals of mushrooms were determined. 238U, 232Th, 40K activity concentrations of mushroom collected from Erzurum was determined as 12.1 ± 0.8, 11.7 ± 0.9, 497.7 ± 17.8 Bq/kg, respectively and 137Cs was not detected by system. 232Th and 40K activity concentrations of mushroom collected from Kahramanmaraş was determined as 13.4 ± 0.5, 134.9 ± 6.3 Bq/kg, respectively, 238U and 137Cs was not detected by system similarly. The value of the committed effective dose collected from Erzurum and Kahramanmaraş were calculated as 75 and 29 μSv respectively and these values were found lower than 290 μSv accepted as world average. Absorbed dose and risk of lifetime cancer for Erzurum was determined as 37.39 nGy/h, 16.5 x 10-5; absorbed dose and excess lifetime cancer risk for Kahramanmaraş was determined as 30.92 nGy/h, 13.3 x 10-5 respectively. Amount of daily intake for each heavy metal was calculated. Radionuclide activity concentrations and accumulations of heavy metal were not founded threaten level to healthy, except from arsenic As (0.025 and 0.039 mg/kg) in mushroom collected from both provinces. They were found a bit higher than upper limit (0.015 mg/kg) in report which is prepared World Health Organization (WHO) and Food and Agriculture Organization of the United Nations (FAO) jointly.

First intercomparison among laboratories involved in COST Action-TU1301 “NORM4Building”: Determination of natural radionuclides in ceramics

This work describes the outcomes of the COST Action-TU1301 “NORM4Building” intercomparison on the determination of natural radioactivity in ceramics. Twenty-two laboratories involved in the intercomparison are evaluated for their performance using robust statistics. The reference values of 226Ra (214Bi and 214Pb) are determined to be 122 ± 11 Bq kg−1 and 124 ± 14 Bq kg−1, respectively and in secular equilibrium in the uranium chain while the reference values of 232Th (228Ac) is determined to be 61 ± 6 Bq kg−1 and that of 40K was determined to be 955 ± 40 Bq kg−1. Although the aim of the exercise was to determine the activity concentration of 226Ra, 232Th and 40K and evaluation of the “Activity Concentration Index”, laboratories were asked to report complete characterization of natural radionuclides. The results of this exercise pointed out a good performance among laboratories since the percentage of the acceptable results were above 90% for the radionuclides of interest. Based on these results, considering the systematic rejection of the results reported from a few laboratories we emphasize the need for quality control procedures.

Radioactivity determination of sealed pure beta-sources by surface dose measurements and Monte Carlo simulations

This study aims to determine the activity of a sealed pure beta-source by measuring the surface dose rate using an extrapolation chamber. A conversion factor (cGys−1Bq−1), which was defined as the ratio of surface dose rate to activity, can be calculated by Monte Carlo simulations of the extrapolation chamber measurement. To validate this hypothesis the certified activities of two standard pure beta-sources of Sr/Y-90 and Si/P-32 were compared with those determined by this method. In addition, a sealed test source of Sr/Y-90 was manufactured by the HANARO reactor group of KAERI (Korea Atomic Energy Research Institute) and used to further validate this method. The measured surface dose rates of the Sr/Y-90 and Si/P-32 standard sources were 4.615×10−5cGys−1 and 2.259×10−5cGys−1, respectively. The calculated conversion factors of the two sources were 1.213×10−8cGys−1Bq−1 and 1.071×10−8cGys−1Bq−1, respectively. Therefore, the activity of the standard Sr/Y-90 source was determined to be 3.995kBq, which was 2.0% less than the certified value (4.077kBq). For Si/P-32 the determined activity was 2.102kBq, which was 6.6% larger than the certified activity (1.971kBq). The activity of the Sr/Y-90 test source was determined to be 4.166kBq, while the apparent activity reported by KAERI was 5.803kBq. This large difference might be due to evaporation and diffusion of the source liquid during preparation and uncertainty in the amount of weighed aliquot of source liquid. The overall uncertainty involved in this method was determined to be 7.3%. We demonstrated that the activity of a sealed pure beta-source could be conveniently determined by complementary combination of measuring the surface dose rate and Monte Carlo simulations.

Determination of natural radioactivity and the associated radiation hazards in building materials used in Polur, Tiruvannamalai District, Tamilnadu, India using gamma ray spectrometry with statistical approach

The natural radioactivity in building materials collected from Polur, Tamilnadu has been determined using gamma ray spectrometer. The radiological parameters such as radium equivalent activity (Raeq), absorbed dose rate (DR), annual effective dose rate (HR), alpha index (Iα), gamma-index (Iγ), internal (Hin) and external hazard indices (Hex) were evaluated to assess the radiation hazard for people dwelling in the study area. The calculated radiological parameters were taken for multivariate statistical analysis to study the relation between radionuclides and radiological parameters. The values obtained in the study are within the recommended safety limits, showing that these building materials do not pose any significant radiation hazard and hence the use of these materials in the construction for dwelling purpose can be considered to be safe for the inhabitants.

Determinations of soil radioactivity, indoor radon concentration levels and their correlation in Oke-Ogun area, Southwestern Nigeria

Indoor radon concentration measurements in 116 rooms and gamma activity measurements in the soil samples around the rooms were carried out in Oke-Ogun area (Southwestern, Nigeria). The mean activity concentrations of 40K, 232Th, and 238U in the soil were 3±5, 25±7 and 212±99 Bqkg−1, respectively. The mean absorbed dose rate (D) and the effective dose estimated were 44±8 nGy h−1 and 45±8 μSv y−1, respectively. Radon concentrations in the rooms varied from 148 Bqm−3 to 627 Bqm−3 with mean of 282±99 Bqm−3. The estimated mean annual effective dose is 7±2 mSv y−1. It is therefore advisable for the inhabitants of the study area to ventilate their houses regularly, to reduce the possible risk of contracting lung cancer. Radon concentration in the rooms surveyed show a good correlation (R² = 0.702) with 238U/226Ra activity in soil samples.

Determination of natural radioactivity, 222Rn and 220Rn exhalation rates and radiation hazards of fly ash and fly ash brick used in Baotou, China

Natural radioactivity levels, 222Rn and 220Rn exhalation rates and radiation hazards of fly ash and fly ash brick used in Baotou, China were determined. The activity concentrations of 226Ra, 232Th, and 40K in fly ash samples ranged from 38.81 to 93.73, 40.34 to 135.17, and 66.92 to 290.86 Bq/kg with an average of 76.52, 109.95, and 170.72 Bq/kg, respectively; while in fly ash brick samples, these radionuclides ranged from 42.43 to 71.60, 76.65 to 208.37, and 94.32 to 489.42 Bq/kg with an average of 53.83, 101.93, and 266.48 Bq/kg, respectively. The exhalation rates of 222Rn and 220Rn in all determined samples were in the range of 1.13-20.50 and 15.60-113.00 mBq/m2s, respectively. The calculated results of the radium equivalent activity, external hazard index, internal hazard index, indoor annual effective dose and outdoor annual effective dose indicated that fly ashes and fly ash bricks collected from some brick factories of Baotou would pose excessive radiation risks to inhabitants and that they are not suitable for use in building construction. The natural radioactivity level of fly ash and fly ash brick needs to be constantly monitored considering the radiation safety of the local residents.

Determinations of soil radioactivity, indoor radon concentration levels and their correlation in Oke-Ogun area, Southwestern Nigeria

Determinations of soil radioactivity, indoor radon concentration levels and their correlation in Oke-Ogun area, Southwestern Nigeria

Cigarette smoke exposure impairs reverse cholesterol transport which can be minimized by treatment of hydrogen-saturated saline.

BackgroundCigarette smoke (CS) exposure impaired plasma lipid profiles by modification of apolipoproteins. Hydrogen (H2) has been proved effective on reducing oxidative stress or improving HDL functionalities in animal models or metabolic syndrome volunteers. This study was undertaken to explore the effects of CS exposure on reverse cholesterol transport (RCT) and the antioxidative effects of H2 treatment against CS exposure in mice transgenic for human cholesteryl ester transfer protein (CETP).Methods[3H]-cholesterol-laden macrophages were injected intraperitoneally into mice, and the samples of blood, bile, liver, and feces were collected for radioactivity determination to evaluate RCT. [3H]-cholesterol-laden macrophages were incubated with HDL isolated from different groups of mice, and the samples of cell medium supernatants were collected for evaluating the HDL functionality to elicit cholesterol efflux.ResultsCS exposure significantly decreased plasma HDL cholesterol level (HDL-C) by 22 % and increased LDL cholesterol level (LDL-C) by 21 % compared with the control group (p < 0.05, p < 0.01), while H2 treatment significantly improved the CS-impaired levels of TC, LDL-C and HDL-C by 10, 27 and 31 %, respectively, compared with the CS group (p < 0.05, p < 0.01 and p < 0.05). Besides, CS exposure significantly decreased [3H] tracer concentrations in liver, bile and feces by 17, 35 and 48 %, respectively, compared with the control group (p < 0.05 for liver and feces), while H2 treatment significantly improved them by 21, 72 % and 89 %, respectively, compared with the CS group (all p < 0.05). Furthermore, CS exposure significantly decreased the HDL functionality to elicit cholesterol efflux by 26 % (p < 0.05), while H2 treatment also improved it by 32 % (p < 0.05). We did not find any significant alterations in protein expressions of RCT involved genes.ConclusionsThese findings provided direct evidence supporting the notion that CS exposure in vivo impairs plasma lipid profiles, HDL functionalities and macrophage-to-feces RCT pathway in CETP transgenic mice, all of which can be minimized by treatment of H2-saturated saline.

Determination of natural radioactivity in irrigation water of drilled wells in northwestern Saudi Arabia.

The levels of natural radiation in bedrock groundwater extracted from drilled wells in selected farms in the northwestern part of Saudi Arabia were addressed. The investigated waters form a source of irrigation for vegetables, agricultural crops, wheat, and alfalfa to feed livestock consumed by the general public. Information about water radioactivity in this area is not available yet. Therefore, this study strives to contribute to the quality assessment of the groundwater of these wells that are drilled into the non-renewable Saq sandstone aquifer. Hence, gross alpha and beta activities as well as the concentrations of (224)Ra, (226)Ra, (228)Ra, (234)U, (238)U, and U(total) were measured, compared to national and international limits and contrasted with data quoted from the literature. Correlations between the activities of the analyzed radionuclides were discussed. The concentrations of gross alpha and beta activities as well as (228)Ra were identified by liquid scintillation counting whereas alpha spectrometry was used to determine (224)Ra, (226)Ra, (234)U and (238)U after separation from the matrix by extraction chromatography. The mean activity concentrations of gross α and β were 3.15 ± 0.26 Bq L(-1) and 5.39 ± 0.44 Bq L(-1), respectively. Radium isotopes ((228)Ra and (226)Ra) showed mean concentrations of 3.16 ± 0.17 Bq L(-1) and 1.12 ± 0.07 Bq L(-1), respectively, whereas lower levels of uranium isotopes ((234)U and (238)U) were obtained.

Determination of Natural Radioactivity and Associated Radiological Risk in Building Materials Used in Tabuk Area, Saudi Arabia

The concentrations of 226 Ra, 232 Th and 40 K in the commonly used building materials of Tabuk area, Saudi Arabia were measured using γ-ray spectrometry. The mean activity concentration with standard deviation was found to be 27.52±11.28, 37.44±14.51 and 175.52±113.87 Bqkg -1 and ranged from 11.11 to 52.58 Bqkg -1 , 10.99 to 59.72 Bqkg -1 , 60.70 to 394.46 Bqkg -1 for, 226 Ra, 232 Th and 40 K, respectively. The associated radiological hazards of natural radioactivity in the studied materials were evaluated by radium equivalent activity, external hazard index, internal hazard index, indoor air absorbed dose rate and annual effective dose rate. Basic statistics and frequency distributions for all radionuclides were used to describe the statistical characteristics of the radionuclide activities. This data will serve as the baseline level for naturally occurring radionuclides in the study area and will be useful for tracking and assessing any pollution inventory in the environment of this region.

Review of international normatives for natural radioactivity determination in building materials

Abstract Anthropogenic activities, such as high-altitude flights and living in buildings, have enhanced the public exposure to natural radiation. In particular, 40K and radionuclides belonging to 232Th and 238U decay chains are present even in building materials, and they may be considered as partially responsible for the effective dose coming from natural radioactivity. Scientists and governments have devoted great attention to the evaluation of the effects produced on the public by naturally occurring radionuclides. In this context, to evaluate the building materials acceptability, accurate and reliable methods for the measurement of the specific activity of natural radioactive isotopes in building materials have been developed. This paper aims to provide a clear and exhaustive review on natural radionuclide measurement procedures. Several standard national normatives (Dutch NEN 5697, Italian UNI 10797, Polish ITB 455), based on gamma spectrometry, have been considered and some critical issues were identified regarding the preparation and the radiometric measuring of the samples. Therefore, the direct measurement of 238U and 232Th by ICP-MS spectrometry as well as the extrapolation of the specific activities without waiting for secular equilibrium have been considered as two promising alternative approaches.

Calibration of HPGe detectors using certified reference materials of natural origin

The feasibility of using certified reference materials for the full energy efficiency calibration of p-type coaxial high-purity germanium detectors for the determination of radioactivity in environmental samples is discussed. The main sources of uncertainty are studied and the contributions to the total uncertainty budget for the most intense gamma lines are presented. The correction factors due to self-absorption and true coincidence summing effects are discussed in detail. The calibration procedure is validated for natural and artificial radionuclide determination in different matrices through an internal cross-validation and through the participation in a world-wide open proficiency test.

Design of an alpha-particle counting system at a defined solid angle at Turkish atomic energy authority-Sarayköy nuclear research and training center (TAEK-SANAEM)

Abstract The design details of an alpha-particle counting set-up at a defined solid angle (ACS-DSA) constructed in Radionuclide Metrology Department at TAEK-SANAEM for use in the primary standardization of radioactive solutions and determination of nuclear decay data of alpha-particle emitters is presented. The counting system is designed such that the solid angle is very well-defined and directly traceable to the national standards. The design involves mechanical construction of different parts like the source chamber, various coaxial flanges, and circular diaphragms in front of the passivated implanted planar silicon (PIPS®) detector, distance tubes, a digital caliper and a sliding piston to allow for different measurement configurations. All geometric configurations are easily changeable and characterisable with high accuracy which facilitates the solid angle calculation. A mixed alpha source was counted to check performance of assembled ACS-DSA system and good energy resolution and low peak tailing in the alpha energy spectrum was observed for small diaphragm apertures and far source-to-detector geometries.

The effect of sample stability on the determination of radioactivity for various radionuclides by liquid scintillation counting

For measuring a sample stored for a long period of time using liquid scintillation counting (LSC), it is necessary to study the long-term stability of the sample. The effect of sample stability on the determination of radioactivity for 241Am, 90Sr/90Y, 137Cs, 147Pm, 237Np/233Pa, and 3H by LSC has been investigated. The variation of quench level over time can be an indication of sample stability. If the variation in a sample is little, the effect of sample stability on the determination of the above radionuclides can be neglected. Otherwise, the sample stability will have impact not only on the counting efficiency (especially for low energy β emitters), but also on the results of α/β discrimination. For studying the stability of a sample, special attention should be paid to the radionuclides with chemical form apt to be adsorbed, because the quench level of a sample cannot be reflected by the quench index SQP(E) alone when significant physical quench exists. Shaking a sample stored for a long period of time and checking the LSC spectra can give the information on physical quench in the sample. In the range of this study, OptiPhase Hisafe 3 has much better quench resistance than Ultima Gold AB.

Natural radioactivity determination in some medicinal plants

Natural radioactivity determination in some medicinal plants

Determination of lead and radioactivity in cosmetics products: Hazard assessment

In the proposed work, an investigation on hazard assessment by lead element and natural radioactivity in cosmetic samples collected from various countries is presented. These samples were face powder, eyebrow paint and henna. The lead element in cosmetic samples was determined using particle-induced X-ray emission. Maximum natural radioactivity concentrations of Ra-226 and K-40 were found in khol and make-up cosmetic samples, respectively. The qualitative analysis of cosmetic samples showed that lead is the most toxic element found in eyebrow paint samples.

HPGe検出器を用いる1000cm3マリネリビーカーに充填された環境試料定量のための実用的自己吸収補正手法

HPGe検出器を用いる1000cm³マリネリビーカーに充填された環境試料定量のための実用的自己吸収補正手法

Crosslinked plastic scintillators: A new detection system for radioactivity measurement in organic and aggressive media

The measurement of radioactive solutions containing organic or aggressive media may cause stability problems in liquid and plastic scintillation (PS) techniques. In the case of PS, this can be overcome by adding a crosslinker to the polymer structure. The objectives of this study are to synthesise a suitable crosslinked plastic scintillator (C-PS) for radioactivity determination in organic and aggressive media. The results indicated that an increase in the crosslinker content reduces the detection efficiency and a more flexible crosslinker yields higher detection efficiency. For the polymer composition studied, 2,5-diphenyloxazole (PPO) is the most adequate fluorescent solute and an increase in its concentration causes little change in the detection efficiency. The inclusion of a secondary fluorescent solute 1,4-bis-2-(5-phenyloxazolyl) benzene (POPOP) improves the C-PS radiometrical characteristics. For the final composition chosen, the synthesis of the C-PS exhibits good reproducibility with elevated yield. The obtained C-PS also displays high stability in different organic (toluene, hydrotreated vegetable oil (HVO) and methanol) and aggressive media (hydrochloric acid, nitric acid and hydrogen peroxide). Finally, the C-PS exhibits high detection efficiency both in water and in aggressive media and can also be applied in organic media showing similar or even higher detection efficiency values.