Specific Activity Concentration Research Articles

Technical note: Quantifying radionuclide residues in hospital wastewater: A case study on [131I]I and [177mLu]Lu/[177Lu]Lu.

Historically, [131I]I has been a common isotope in radionuclide therapy, with [177Lu]Lu-labelled radiopharmaceuticals now seeing a surge in use. These can include no-carrier-added or carrier-added [177Lu]Lu with slight impurities of [177mLu]Lu with a significantly longer half-life than [131I]I. Wastewater from therapy wards can contain a mixture of these radioisotopes. In some countries, national regulations require wastewater to be stored in dedicated systems before it is discharged into the public sewage system. To fulfill legal requirements, the nuclide specific activity concentration must be verified. We evaluate a method for determining the activity concentration of [177mLu]Lu /[177Lu]Lu at equilibrium and [131I]I in pure and mixed samples in order to prove that the determined values are reliably below the limits for release. We analysed the emitted energy spectrum of 1L samples with a wastewater counter using an energy window-based approach by evaluating measurements from two different time points. Based on the law of decay and the time and energy-dependent measured values, equation systems were set up to calculate the count rates for [131I]I and [177mLu]Lu, which were converted into activity concentration using calibration factors. There is strong linear correlation between the nominal and determined activity concentrations (correlation coefficients R=0.99; coefficient of determinations R2=0.99). We underestimate the actual activity concentration by a median of -1.4% for [177mLu]Lu and overestimate the activity concentration for [131I]I by a median of 7.1%. We show that an undercut of the clearance levels for material release is measurable. We analyse and determine activity concentrations of mixed samples consisting of [131I]I and [177mLu]Lu/[177Lu]Lu in equilibrium. The method is simple to implement using a conventional wastewater counter, however with a slightly increased effort, as two samples and measurements are required. The methodology can be adapted for the analysis of other nuclide mixtures.

Assessment of Natural Radioactivity and Associated Radiological Indicators in Water and Surface Soils Around Beta Glass Plc and Its Environs, Ughelli, Delta State, Nigeria

A radiometric assessment was conducted around Beta Glass plc using sodium iodide detector (3×3-inch NaI (TI)). The study collected 14 soil and 13 water samples from June to July 2022, analyzing radioactivity concentrations of 40K, 238U, and 232Th. The mean specific activity concentrations of 40K, 238U, and 232Th were 184.00±29.73 Bqkg-1, 14.55±2.50 Bqkg-1, and 8.60±1.04 Bqkg-1, respectively, in soil samples, but these elements' concentrations in water were 27.429±5.633 BqL-1, 6.661±1.421 BqL-1, and 2.518±0.361 BqL-1, respectively. The average activity concentrations of 40K, 238U, and 232Th were lower than the safe limit, and the corresponding radiation hazard indices for soil samples were all below the UNSCEAR-recommended acceptable limits. The mean activity concentrations of radionuclides in water samples were higher than the UNSCEAR's recommended international limits for 40K, 238U, and 232Th. Nonetheless, elevated radiological health hazards imply that cumulative dosages may cause cancer, even though these values might not pose an immediate health concern to the local community's people or the workforce.

Comprehensive Analysis of Contaminants in Powdered Milk Samples Using an HPGe for γ Radiation.

Aims: This study aimed to assess the activity concentrations and cancer risk assessments of 232Th and 40K in powdered milk samples collected from various suppliers in Pakistan, considering the increasing concern about cancer risks associated with environmental radiological effects related to food consumption. Subjects and Methods: Specific activity concentrations were determined using a high-resolution, high-purity germanium γ-spectroscopy system. Results: The specific activity levels of 40K and 232Th in the analyzed powdered milk samples were found to be 230.86 and 6.87 Bq/kg, respectively, well within the safe limits recommended by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The hazard index (0.074 Bq/kg) and radium equivalent (27.58 Bq/kg) were calculated as indicators of radiation hazard, along with absorbed dose (26.26 nGy/h), annual effective dose (0.13 nGy/h), and excess lifetime cancer risk (0.45). These parameters provide insights into the potential health risks associated with powdered milk consumption. Conclusions: The findings collectively affirm the radiological safety of the analyzed powdered milk samples, providing valuable insights into the potential health risks associated with their consumption.

Calibration of buried NaI(Tl) scintillator detectors for natural radionuclide measurement based on Monte Carlo modelling

Measurements of naturally occurring concentrations of 40K, and of the decay series of 238U and 232Th, are of interest in the earth sciences in general, and in particular, scintillator-based gamma spectrometers can be used for the low cost determination of burial dose rates in natural geological samples. We are currently developing a robust, portable, wireless detector specifically intended for field measurement of natural radionuclide concentrations and hence, the calculation of dose rates. One of the challenges in developing and applying such an instrument is reliable calibration. Most calibrations of field instruments depend on access to non-finite matrices of known K, U, Th activity concentrations, in either a 4π or 2π geometry; these are only available at a few facilities around the world. Here we investigate an alternative approach, based on the measurement of small samples containing well-known activity concentrations of only K or U or Th, and Monte-Carlo radiation transport modelling to convert the observed spectra into those expected from specific activity concentrations in a non-finite 4π geometry. We first validate our modelling procedure by simulating these observed spectra. The non-finite matrix calibration spectra are then predicted, and least-squares fitted to the spectrum observed at the centre of a 1 m3 of granite chips; the resulting predicted U, Th and K activity concentrations are compared with independently known values.

Evaluation of Radioactivity Levels in Soil Samples from Assosa City in Benishangul Gumuz Region, Ethiopia

The specific activity concentrations of naturally occurring radionuclides in soil samples collected from suburban areas of Assosa City was measured using a High purity Germanium (HPGe) detector. The average specific activity concentrations of 238U and 232Th exceed the recommended safe value of 35.0 and 30.0 Bq kg−1, respectively. For 40K, the average activity concentration is below the recommended safe value of 400.0 Bq kg−1. The calculated mean value of the absorbed dose rate is 72.8 ± 3.72 nGy h−1 which exceed the recommended safe value of 59 nGy h−1. The calculated mean annual effective dose equivalent values for indoor and outdoor are 2.11 ± 0.1 mSv y−1 and 0.52 ± 0.02 mSv y−1, respectively. The calculated mean values of the internal hazard index, external hazard index, and gamma index are 0.43 ± 0.013, 0.56 ± 0.01, and 0.5 ± 0.01, respectively, and those values are below the recommended safe value of one. The mean value of excessive lifetime cancer risk is above the threshold value of 0.29 × 10−3. From this study, it is recommended that Assosa soil needs further investigations.

MEASUREMENT OF NATURAL RADIOACTIVITY IN TAP WATER SAMPLES FOR SELECTED REGIONS IN ADEN GOVERNORATE, YEMEN

In the present work, we have measured specific activity concentrations of in eleven tap water samples for selected regions in Aden governorate by using high purity germanium detector (HPGe). The (HPGe) detector (CANBERA-model 7229N, USA) with an efficiency of 35% and energy resolution (2.6keV) at energy (1332.6keV) for 60Co, the high purity N-type semiconductor detector with physical characteristics of (geometry closed-end coaxial, (3×3 inch). The results have shown that, The highest value of specific activity concentration of 226Ra was found in in T7 Daar-Saad region which was equal to (0.525±0.29)Bq/L, while the lowest value of specific activity concentration of 226Ra was found in T11 Aden Assughra region which was equal to (0.017±0.006)Bq/L with an average value of (0.228±0.13)Bq/L. The highest value of specific activity concentration of 232Th was found in in T5 Khor-makser region which was equal to (0.319±0.18)Bq/L, while the lowest value of specific activity concentration of 232Th was found in T11 Aden Assughra region which was equal to (0.009±0.001)Bq/L with an average values of (0.129±0.089)Bq/L. The highest value of specific activity concentration of (40K) was found in in T2 (Al-Ma,allah) region which was equal to (0.4±0.26)Bq/L, while the lowest value of specific activity concentration of (40K) was found in T11 Aden Assughra region which was equal to (0.027±0.004)Bq/L with an average values of (0.141±0.021)Bq/L respectively. The annual ingestion effective dose (AED) ranged from (3.05 to 98.77μSv/y), (5.67 to 178.16μSv/y), and (3.41 to 119.08μSv/y), with average values of 42.65μSv/y, 78.62μSv/y and 48.62μSv/y, for infants, children and adults respectively. The excess lifetime cancer risk (ELCR) have been calculated, its values were lower than the world’s average value of (0.29×10−3) as reported by EPA. The overall annual effective dose and cancer risks corresponding to radionuclide intake in tap water were below the recommended maximum values. It was inferred from the findings of this study that the water used as the sample does not have any significant radiological impacts to human body and is safe to be used as drinking water.

Assessment of radiation dose level and excess lifetime cancer risk associated with dust samples collected from selected nursery and primary schools in Ife Central and Ife East, Osun State, Nigeria.

Abstract Primordial radionuclides are, among others, sources of radiation exposure to man. In this study, dust from some 24 nursery and primary schools in Ife Central and Ife East Local Government Areas (LGA) of Osun State were collected and analysed for 238U, 232Th, and 40K using CsI scintillation detector connected to a Universal Radiation Spectrum Analyser (URSA II) for spectrum analysis. From the specific activity concentrations of 238U, 232Th, and 40K, absorbed dose rates and radiological parameters were calculated. The mean activity concentrations of 238U, 232Th, and 40K in Bq/kg were found to be (45±2, 46±2), (56±5,60±5) and (669±76, 744±86) respectively for Ife Central and Ife East LGAs, however, the difference between the data sets from the two communities were not statistically significant. The total mean ± S.D (standard deviation) calculated over the whole study area were as follows; 238U= 45±11; 232Th=58±15 and 40K=702±196. The values of these radionuclides’ activities were higher than the world averages of 33, 45, and 420 for 238U, 232Th, and 40K respectively set by UNSCEAR. The mean absorbed dose rate in the air (in nGy/h) for Ife Central was 85±7 while for Ife East was 92±8. Both values were higher than the world average of 55 nGy/h. Also, the excess lifetime cancer risk was 1.66 × 10-3 for Ife Central and 1.8 × 10-3 for Ife East LGAs. Generally, Ife East LGA has higher activity concentrations than Ife Central LGA although the difference is not statistically significant.

Radiation risk assessment of quarry pit soil as construction material in Abeokuta, Nigeria: implications for environmental and public health

ABSTRACT Environmental and health risks posed by radionuclides in quarry pit soils are of great concern in environmental health monitoring. The current investigation was aimed at determining the natural radionuclide activity concentration (in Bq kg–1) of the understudied quarry pit granules used as construction materials. The collection and preparation of pit soil samples from Abeokuta quarry sites were done using standard methods, analysis of radiological parameters was carried out using hyperpure germanium (HPGe) spectrometer. Specific activity concentrations of 226Ra, 232Th, and 40K were measured. The values obtained were greater than the world weighted average of 35, 30, and 400 Bq kg–1 for 226Ra, 232Th, and 40K, respectively. The absorbed dose, the annual effective dose, and the radium equivalent were calculated and demonstrated significant values. The radionuclide content of the samples is relatively high and the use of pit soils as a building material, therefore, raises radiological concerns for dwellers in this area and requires periodic monitoring and undergoing a radiation protection program.

Assessment of radioactivity levels and radiological hazard indices in phosphate and phosphate mine waste samples from Algeria.

Phosphate ore is the starting raw material for production of all phosphate products including fertilisers phosphate waste. It can be of sedimentary, volcanic or biological origin. Like any other geological material found in nature, it contains various amounts of naturally occurring primordial radionuclides, such as 238U series, 232Th series and 40K. Gamma-ray spectrometry was used to assess natural radioactivity levels and radiological hazard indices in phosphate samples. In this paper, the specific activity concentrations of 226Ra, 232Th and 40K of phosphate ores, merchant and mine waste samples were determined. Based on the activity concentrations, the radiation hazard indices (Raeq, Hex, Hin and I𝛾𝑟), and the radiation doses (D, AED and ELCR) were calculated. The results were discussed and compared with those from other studies as well as recommended safety limit values.

Evaluation of Specific Activity Concentration of 238U, 232Th and 40K in Soil and Rice Grains from Solid Mineral Mining Sites in Ikwo Area of Ebonyi State, Nigeria

Evaluation of specific activity concentration of 238U, 232Th and 40K in soil and rice grains from solid mineral mining sites in Ikwo area of Ebonyi state was carried out using a Digilert-200 Radiation Meter. The radiological impact of the radionuclides was calculated. The average value concentrations of radionuclides obtained were 170.53, 9.26 and 8.81 (in Bq.Kg-1) for 40K, 238U and 232Th respectively in soil samples and 113.77, 5.86 and 7.08 (in Bq.Kg-1) for 40K, 238U and 232Th respectively in rice grain. These values are below the world permissive value of 400, 35 and 30(in Bq.Kg-1) respectively. All the health risk parameters calculated in soil and rice were below world permissive values. For the radionuclides in rice samples, the average annual committed effective doses(in mSvy-1) for ages (<1 year), (1 – 7 years), (7 – 12 years), (12 – 17 years) and (>17 years) are 0.37, 0.05, 0.04, 0.03, 0.02 respectively. These results are less than the world permissive value of 1.00 mSvy-1. Generally, the study shows that the rice consumption was relatively safe radiologically with little contamination which could be attributed to human activities but there is tendency for long term health hazards in future such as the cancer due to doses accumulation. It is recommended that the various human activities that raise the activity concentration in soil in Ikwo mining area that should be reduced. The activity concentration of radionuclides level in the area should be periodically assessed.

The Activity of Natural Radionuclides Th-232, Ra-226, K-40, and Na-22, and Anthropogenic Cs-137, in the Water, Sediment, and Common Carp Produced in Purified Wastewater from a Slaughterhouse

In the immediate vicinity of a slaughterhouse, a fishpond was built that uses treated wastewater from the slaughterhouse, and in this way integrates a new value chain in the form of purification and use of slaughterhouse wastewater in an aquaculture production system. The negative aspect of such integrated production systems is the concern related to the safety of fish meat produced in these systems. The aim of this research was to determine the activity level of Cs-137, K-40, Ra-226, Th-232, and Na-22 in water, sediment, and carp harvested from a pond that received purified water from a slaughterhouse. All samples were collected in spring and in autumn. The activity concentrations of selected radionuclides were determined by gamma spectrometry (HPG-e detector). The activity of K-40 in water samples ranged from 8.4 to 15.6 Bq L−1. The specific activity concentrations of the Ra-226 in water samples ranged between 1.02 ± 0.11 and 2.76 ± 0.49 Bq kg−1. The results of the activity of natural radionuclides (Bq kg−1) in the sediment samples were in the following ranges: 440–629 for K-40, 10.7–15 for Th-232, 20.2–44.4 for Ra-226, and 1.08–2.04 for Na-22, with average values of 531.75, 12.3, 32.97, and 1.75, for K-40, Th-232, Ra-226, and Na-22, respectively. The average content of Th-232 (12.3 Bq kg−1) did not exceed the world UNSCEAR average value of 45, while the average content of Ra-226 (32.97 Bq kg−1) slightly exceeded the UNSCEAR value of 32 Bq kg−1. The K-40 concentration activity of 531.75 Bq kg−1 was much higher than the UNSCEAR weighted average value of 420 Bq kg−1. In the fish samples, natural radionuclide Na-22 was detected only in autumn (2.74 ± 0.32 Bq kg−1). Results of Cs-137 and Th-232 concentrations were below the method detection limit in all samples, ˂0.5 Bq kg−1 and ˂2 Bq kg−1, respectively. The activity of K-40 was in the range from 121 to 160 Bq kg−1. The activity concentrations of the Ra-226 in carp samples ranged between 9.5 and 54.4 Bq kg−1. The results indicate that consumption of fish meat obtained from this integrated system does not pose a significant health concern in the case of the usual consumption rate that is typical for the population of Serbia. Almost no statistically significant seasonal variations were observed.

Acetylcholinesterase Adsorption on Modified Gold: Effect of Surface Chemistry on Enzyme Binding and Activity.

Surface chemistry plays a crucial role in the performance of biosensors and biocatalysts, where enzymes directly interact with a solid support. In this work, we investigated the effect of surface charge and hydrophobicity on the binding and activity of acetylcholinesterase (AChE) following direct adsorption to modified gold surfaces. Surface modifications included self-assembled monolayers (SAMs) terminated with -COO-, -NH3+, -OH, and -CH3 functional groups at varying mole %. We also investigated the effects of positively and negatively charged helical peptides covalently coupled to the SAM. Using spectroscopic ellipsometry, we measured the surface concentration of AChE on each modified surface after 1 h of adsorption. We found that surface concentration was directly proportional to surface hydrophobicity (r = 0.76). The highest binding was observed on the more hydrophobic surfaces. We also measured the specific activity of AChE on each surface using a colorimetric assay and found that activity was inversely proportional to surface hydrophobicity (r = -0.71). The highest activity was observed on the more hydrophilic surfaces. Plotting specific activity versus surface concentration showed a similar relationship, with the highest activity observed at low AChE densities (∼20% of a monolayer) on surfaces terminated with 50% -COO- or -NH3+ and 50% -CH3 functional groups. Interestingly, this is similar to the approximate composition of hydrophobic versus hydrophilic amino acid residues on the surface of AChE. These surfaces also exhibited the highest total activity: a ∼100% improvement over bare gold due to a combination of moderate binding and high activity retention. This work highlights the importance of developing new attachment strategies beyond direct adsorption that promote, tune, and optimize both high binding and high activity retention.

The New Conception of Radiological Sustainability Possibilities by Reutilization of Residues Products and Building Materials

The concept of radiological sustainability has been reviewed using the possibility of the reutilization of NORMs regarding the 2050 sustainable development concepts. This study is reviewing the capability of re-production of NORM residues based on their properties and the applicable treatment before reutilization. Linking the waste producers and construction materials industry as mineral end-users could contribute to the creation of industrial symbiosis and result in waste reduction and preserving natural resources on one hand, and CO2 reducing and energy saving on the other hand. According to EU-BSS (European Basic Safety Standards Directive), the characterization of NORMs as a secondary raw material for use as construction materials is necessary, however as an additive or secondary material their radiological behavior and material properties are quite important regardless of their origin. This is to say that the reutilization of NORM residues provides a better financial and environmental solution while reducing possible radiological effects on humans. NORM residue or waste could become a high material resource for the cement industry. In this regard, the assessment of radium equivalents (Raeq) and external and internal indexes (I-indexes) are useful tools to classify NORM residues before their inclusion in building products. This assessment and/or indexes reflect the risk of external exposure much better than the specific activity concentration of Ra-226, Th-232 and K-40. Equally, building material properties such as density and thickness should be taken into consideration when designing building materials that contain NORM residue. Furthermore, mixtures or additives of NORM residues are proven to result in the reduction of activity concentration in the raw residue with other raw materials, and this offers flexible reuse options depending on the final product. By integrating radiological considerations into sustainable development initiatives, we can work towards a safer, healthier and more sustainable future.

Naturally Occurring Radioactive Materials in the Soil of Near Basra Oil Company Fields

The present study aimed to determine the levels of contamination with Natural Occurring Radioactive Materials NORM in one of the south oil company fields. The external gamma absorbed dose rate Dγ measured in units of µSv/h was caused by gamma rays of Radium 222, Radium 228 (Thorium 232), and Potassium 40, respectively. The largest value is 9.220 µSv/h. It was found that the highest specific activity (concentration) for Radium 226 is 1136 Bq/kg and the lowest is 0.06 and the highest specific activity for Radium 228 is 721 Bq/kg and the lowest is 0.02 Bq/kg. As for Radium 224, its highest specific activity is 631 Bq/kg and the lowest is 0.02 Bq/kg. Radium-228 is higher than that of Radium-224 or Radium-226, as the Radium-224 is from the Uranium-232 series, and the Radium-228 and Radium-224 are from the Thorium-232 series, meaning that the percentage of the daughters of the Thorium chain is lower than the percentage of the daughters of the Thorium chain Uranium, because the half-life of Radium-226 is 1600 years, which is greater than the half-life of Radium-228, which is 5.75 years. A comparison was made between the local results with the results of soil in Amman. Methods of treating pollution with natural radioactive materials in the oil industry were also discussed.

Specific Uptake in the Bone Marrow Causes High Absorbed Red Marrow Doses During [177Lu]Lu-DOTATATE Treatment.

Bone marrow suppression is a common side effect after [177Lu]Lu-DOTATATE treatment of neuroendocrine neoplasms. Neuroendocrine neoplasms share expression of somatostatin receptor type 2 with CD34-positive hematopoietic progenitor cells, potentially leading to active uptake in the radiosensitive red marrow region where these cells are located. This study aimed to identify and quantify specific red marrow uptake using SPECT/CT images collected after the first treatment cycle. Methods: Seventeen patients diagnosed with neuroendocrine neoplasms were treated with [177Lu]Lu-DOTATATE. Seven of them had confirmed bone metastases. After the first treatment cycle, each patient went through 4 SPECT/CT imaging sessions 4, 24, 48, and 168 h after administration. Monte Carlo-based reconstructions were used to quantify activity concentrations in tumors and multiple skeletal sites presumed to house red marrow: the T9-L5 vertebrae and the ilium portion of the hip bones. The activity concentration from the descending aorta was used as input in a compartment model intended to establish a pure red marrow biodistribution by separating the nonspecific blood-based contribution from the specific activity concentration in red marrow. The biodistributions from the compartment model were used to perform red marrow dosimetry at each skeletal site. Results: Increased uptake of [177Lu]Lu-DOTATATE was observed in the T9-L5 vertebrae and hip bones in all 17 patients compared with activity concentrations in the aorta. The mean specific red marrow uptake was 49% (range, 0%-93%) higher than the nonspecific uptake. The median (±SD) total absorbed dose to the red marrow was 0.056 ± 0.023 Gy/GBq and 0.043 ± 0.022 Gy/GBq for the mean of all vertebrae and hip bones, respectively. The patients with bone metastases had an absorbed dose of 0.085 ± 0.046 Gy/GBq and 0.069 ± 0.033 Gy/GBq for the vertebrae and hip bones, respectively. The red marrow elimination phase was statistically slower in patients with fast tumor elimination, which is in line with transferrin transport of 177Lu back to the red marrow. Conclusion: Our results suggest that specific red marrow uptake of [177Lu]Lu-DOTATATE is in line with observations of somatostatin receptor type 2-expressing hematopoietic progenitor cells within the bone marrow. Blood-based dosimetry methods fail to account for the prolonged elimination of specific uptake and underestimate the absorbed dose to red marrow.

Assessment of the Natural Radioactivity Levels of Soil Samples in IT1 Oil Reservoirs in Kirkuk City, Northeast Iraq

In this study, gamma-ray spectrometry with an HPGe detector was used to measure the specific activity concentrations of 226Ra, 232Th, and 40K in soil samples collected from IT1 oil reservoirs in Kirkuk city, northeast Iraq. The “spectral line Gp” gamma analysis software package was used to analyze the spectral data. 226Ra specific activity varies from 9 0.34 Bq.kg-1 to 17 0.47 Bq.kg-1. 232Th specific activity varies from 6.2 0.08 Bq.kg-1 to 18 0.2 Bq.kg-1. 40K specific activity varies from 25 0.19 Bq.kg-1 to 118 0.41 Bq.kg-1. The radiological hazard due to the radiation emitted from natural radionuclides in soil samples was also assessed. The average values of the radium equivalent (Raeq), external hazard index (Hex), internal hazard index (Hin), gamma index (I), absorbed dose rate (D), outdoor (AEDEout) and indoor (AEDEin) annual effective dose equivalent were 35.391 Bq.kg-1, 0.095, 0.128, 0.253, 16.118 nGy.h-1, 0.0197 mSv.y-1, and 0.0790 mSv.y-1, respectively. All values obtained for the activity concentrations for 226Ra, 232Th, and 40K and the radiological hazard were lower than the global values. This indicates that no harmful radiation effects are posed to the population who work and live near the study area.

Study on the Radioactivity Levels of Metal Tailings in the Lhasa Area of Tibet

The main purpose of this study was to determine the natural radioactivity level of raw radionuclides in the metal tailings of a mine in Lhasa, Tibet, and to conduct sampling and detection in 17 typical metal tailing mines in Lhasa, Tibet. The specific activity concentrations of 226Ra, 232Th, and 40K in the samples were calculated. The total αβχγ radiation, radon concentration, and outdoor absorbed dose rate in the air 1.0 m above the ground were measured. The γ radiation levels affecting miners and their surrounding residents were assessed. The results show that the radiation dose ranges from 0.08 μSv/h to 0.26 μSv/h, and the radon concentration ranges from 10.8 Bq/m3 to 29.6 Bq/m3, which does not exceed the national radiation-related standards, and the environmental hazard risk is low. The specific activity concentration of 226Ra ranged from 8.91 Bq/kg to 94.61 Bq/kg, the specific activity concentration of 232Th ranged from 2.90 Bq/kg to 89.62 Bq/kg, and the specific activity concentration of 40K was less than MDA to 762.89 Bq/kg. The average absorbed dose rate (DO) of the 17 mining areas was 39.82 nGy/h, the average annual effective dose rate (EO) was 0.057 mSv/y. The average external risk index of the 17 mining areas was 0.24, the average internal risk index was 0.34, and the average γ index was 0.31, all of which were less than the maximum permissible limit. This means that the metal tailings from all 17 mining areas were within the limit for γ radiation and, therefore, can be used in bulk as major building materials without posing a significant radiation threat to the residents of the study area.

ASSESSMENT OF GAMMA DOSE AND ANNUAL EFFECTIVE DOSE RATE FOR COMMONLY USED FERTILIZER SAMPLES IN AGRICULTURE FIELD WITH A STATISTICAL APPROACH.

In this present study, the activity concentration of the naturally occurring radionuclides 238U, 232Th and 40K have been measured in commonly used chemical fertilizers for agriculture by using gamma-ray spectrometry with NaI (TI) detector. Radiological hazard parameters have been calculated for samples. The mean specific activity concentration of the 238U, 232Th and 40K is 176, 5.75 and 4136Bqkg-1, respectively. Particularly, the mean value of 238U, as well as 40K, is higher than the world recommended value. Also, the average value of radium equivalent activity is 503Bqkg-1 and the absorbed dose rate (DR) is 282.93nGyh-1, which is greater than the permissible limit, whereas the annual effective dose rate (AEDR) is 0.316mSvy-1, which is lower than the world recommended value. Therefore, collected fertilizer samples significantly increase the activity concentration of natural radionuclides in the agricultural soils. Multivariate statistical techniques such as Pearson correlation and factor analysis are carried out for radioactive variables to understand the existing relationship between them. From obtained results reveals that these fertilizer samples increases the probability of adverse health effects due to natural radioactivity.

Preparation of Patient Doses of [177Lu]Lu-DOTATATE and [177Lu]Lu-PSMA-617 with Carrier Added (CA) and No Carrier Added (NCA) 177Lu.

[177Lu]Lu-DOTATATE and [177Lu]Lu-PSMA-617 used for targeted radionuclide therapy are very often prepared in the hospital radiopharmacy. The preparation parameters vary depending upon the specific activity of the 177Lu used. The aim of this study was to develop optimized protocols to be used in the nuclear medicine department for the preparation of patient doses of the above radiopharmaceuticals. 177Lu (CA and NCA) were used for radiolabeling DOTATATE and PSMA-617. Parameters studied are 177Lu of different specific activity and different peptide concentrations and two different buffer systems. Paper and thin layer chromatography systems were used for estimating the radiochemical yield as well as radiochemical purity. Solid-phase extraction was used for the purification of the labeled tracers. [177Lu]Lu-DOTATATE was prepared with CA 177Lu (n = 13) and NCA177Lu (n = 6). Four batches each of [177Lu]Lu-PSMA-617 were prepared using CA and NCA 177Lu. Radiochemical yields > 80% and final product with less than < 1% radiochemical impurity could be obtained in all batches which were used for therapy. Robust protocols for the preparation of clinical doses of [177Lu]Lu-DOTATATE and [177Lu]Lu-PSMA-617 were developed and used for the preparation of clinical doses. The quality of the SPECT images of both the tracers are consistent with the expected uptake in respective diseases.

TEMPORAL VARIATION OF POST-ACCIDENT 129I IN ATMOSPHERIC PARTICULATE MATTER COLLECTED FROM AN EVACUATED AREA OF FUKUSHIMA PREFECTURE, JAPAN.

To understand the behavior of atmospheric 129I that originated from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, activity concentrations of 129I in samples of atmospheric particulate matter (PM), comprising coarse (>1.1μm) and fine (<1.1μm) fractions (separated using a single stage impactor), were measured on a nearly monthly basis from October 2012 to October 2014 at a site in an area evacuated after the FDNPP accident. Total atmospheric 129I activity concentrations in PM at the site ranged between 0.15 and 2.17 nBq m-3. Specific activity concentration of 129I in total atmospheric PM ranged between 40.8 and 336 mBq kg-1, with a mean and standard deviation of 142 and 77.6 mBq kg-1, respectively. The specific activity in PM tended to be higher than not only the background values reported from soil collected before the FDNPP accident but also than those reported from the contaminated soil after the accident (range: 1.6-57 mBq kg-1; mean and standard deviation: 10.6 and 12.3 mBq kg-1, respectively). Total 129I/127I atomic ratios in PM ranged from 2.0×10-8 to 59.8×10-8, with a mean and standard deviation of 15.0×10-8 and 14.4×10-8, respectively. These ratios were generally lower than those of the contaminated soil collected after the FDNPP accident (range: 4.9×10-8-443×10-8; mean and standard deviation: 74.2×10-8 and 85.4×10-8, respectively). The 129I concentration and 129I/127I atomic ratio in atmospheric PM showed different characteristics from that of contaminated soils, suggesting that the presence of other atmospheric PMs plays a more important role as the host for 129I.