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Study including 61 differentiated thyroid cancer (DTC) patients who received ablative doses of I-131 after total thyroidectomy. Biodosimetry was performed by dicentric chromosomes analysis before and after treatment, determining dicentric yield and blood absorbed dose. An increased yield of dicentrics after treatment was demonstrated. With an average administered activity of 4.32 ± 0.879 GBq, the absorbed dose in bone marrow was 0.28 Gy (0.25–0.30 95% CI). These data were compared with the administered I-131 activity and body mass index. Increased genotoxic effects were observed, with a slightly higher dicentric yield rising along I-131 activity. No correlation was found between administered activity and BMI. No significant risk of myelotoxicity due to dose regimens of I-131 intended for ablative purposes in "de novo" treated patients was found among the ranges of activities used in clinical practice. Biodosimetric data was included in patients' Clinical History, which translates into a more detailed dosimetric report. With this information, physicians can take a more patient-specific approach. Personalized administration would be of special consideration in the event of re-treatments, be it due to recurrent disease or I-131 refractory DTC patients. • Significant increase in dicentric chromosomal aberrations was found. • Myelotoxicity risk induced by therapeutic regimens of I131 was discarded. • No relation between body mass index and estimated dose was demonstrated. • In some cases metastases were identified before clinical signs. • Precaution is advised in the event of retreatments. [ABSTRACT FROM AUTHOR]

The expansion of the nuclear industry has led to various radioactive effluents, originating from routine operations or catastrophic incidents such as those at Three Mile Island (USA), Chernobyl (Ukraine), and Fukushima (Japan). Research conducted after these events emphasizes Cesium-137 (137Cs) and iodine 131 (131I) as major contributors to harmful airborne dispersion and fallout. These isotopes infiltrate the human body via inhalation, ingestion, or wounds, posing significant health risks. Understanding contamination mechanisms and devising effective countermeasures are crucial in mitigating nuclear incident consequences. We propose that concurrent administration of Pru-Decorp™/Pru-Decorp-MG and potassium iodide (KI) could synergistically reduce the levels of 137Cs and block uptake of 131I, respectively, in nuclear incident scenarios. Pru-Decorp™ capsules contain insoluble ferric hexacyanoferrate(II) and are equivalent to USFDA-approved Radiogardase®-Cs, offering radiation exposure mitigation for Cs and Tl contamination. Pru-Decorp-MG capsules consist of insoluble PB and magnesium hydroxide, serving as a prophylactic measure to reduce the risk of internal Cs and Tl contamination for rescue responders. Pru-Decorp™/Pru-Decorp-MG binds Cs/Tl ions in the gastrointestinal tract, hindering absorption and promoting excretion, while KI saturates the thyroid gland with stable iodine, decreasing the uptake of radioactive iodine isotopes. Our hypothesis is supported by studies demonstrating the effectiveness of combination therapies, such as calcium alginate, iron(III) ferrocyanide, and KI , in decreasing the retention of radioisotopes in vital organs. To test this hypothesis, we propose a comprehensive research plan, including in vitro studies simulating gastrointestinal conditions, animal studies to evaluate the efficacy of both drugs simultaneously, and safety clinical trials comparing Pru-Decorp™/Pru-Decorp-MG alone, KI alone, and their combination. Expected outcomes include insights into the synergistic effects of Pru-Decorp™/Pru-Decorp-MG and KI, guiding the development of optimized treatment protocols for simultaneous administration during radioactive contamination incidents. This research aims to address significant critical gaps in nuclear incident preparedness by providing evidence-based recommendations for concurrent antidote use in scenarios involving multiple isotope contamination. Ultimately, this will enhance public health and safety during nuclear emergencies. [Display omitted] • Explore interactions between Pru-Decorp™, Pru-Decorp-MG, and potassium iodide (KI). • Concurrent administration may have synergistic effects. • Lack of existing studies on Prussian blue and potassium iodide interaction. • Safety and efficacy studies of combination therapy of KI and Prussian Blue. • Challenges include ethical concerns in clinical trials for combined therapy. [ABSTRACT FROM AUTHOR]

Radionuclides from the reactor accident Fukushima Daiichi nuclear power plant were observed in the airborne aerosols at CTBT International Monitoring System (IMS) stations (MRP43, CMP13) in Africa. The maximum activity concentrations in the air measured in Mauritania were 186.44 10−6 Bq.m−3, 264.16 10−6 Bq.m−3 and 1269.94 10−6 Bq.m−3 for 134Cs, 137Cs and 131I respectively, and in Cameroon 16.42 10−6 Bq.m−3, 25.53 10−6 and 37.58 10−6 Bq.m−3 respectively for 134Cs, 137Cs and 131I. The activity ratio of 134Cs/137Cs is almost constant throughout the period of time relevant to this study due to their long half-lives of 30.2 years for 137Cs and 2.06 years for 134Cs. Whereas the 131I/137Cs activity ratio varies in time according to the radioactive decay with a half-live of 8.06 days for 131I and different removal rates of both radionuclides from the atmosphere during transport. The EMAC atmospheric chemistry-general circulation was used to simulate the emission and transport of the isotope 137Cs and map the deposition of the 137Cs deposition over Africa. • IMS stations in Africa (MRP43, CMP13) detected first 131I, caesium isotopes appearing with a delay of 6 days in Cameroon and 4 days for 134Cs in Mauritania. • The highest activity concentrations of fission products were found in Mauritania. • The EMAC atmospheric chemistry-general circulation was used to simulate the emission and transport of the isotope 137Cs and map the deposition of the 137Cs deposition over Africa. [ABSTRACT FROM AUTHOR]

Safety analysis applied to Nuclear Engineering is fundamental to support projects for units that handle radioactive material. Estimates of dose rates resulting from radioactive releases allow emergency responses to be obtained in risk scenarios, aiming to mitigate accidents arising from facilities containing radioactive material, such as nuclear power plants. The purpose of this article is to calculate the radioactive dose rate of Iodine-131 released in a hypothetical accident at a PWR-type nuclear power plant, using the Gaussian plume dispersion method, using the HotSpot codes and MCNP (Monte Carlo N -Particle), in a rural setting, with stable atmospheric conditions and potential individuals exposed at 500 m and 1000 m in relation to the source. The results indicate that the dose rate calculated by HotSpot codes, in the center of the plume, close to the source, is conservative, varying between 35 % and 72 %, when compared with the MCNP calculations. [ABSTRACT FROM AUTHOR]

Hyperthyroidism, often accompanied by hepatic insufficiency (HI), poses significant clinical challenges, highlighting the necessity for identifying optimal treatment strategies and early diagnostic biomarkers to improve patient outcomes. This study aimed to determine the optimal iodine-131 (131I) intervention dose for alleviating hyperthyroidism with HI and to identify serum metabolic biomarkers for early diagnosis using UPLC-Q/TOF-MS technology. A mouse model for early 131I intervention was established to monitor changes in physiological response, body weight, fur condition, thyroid, and liver function. Metabolite identification was achieved through UPLC-Q/TOF-MS and further analyzed via MetaboAnalyst. Six biomarkers were identified and subjected to ROC analysis. Early intervention with 80 μCi 131I per gram of thyroid tissue effectively controlled hyperthyroidism and improved liver function. Metabolomics analysis uncovered 63 differentially abundant metabolites, six of which (L-kynurenine, Taurochenodesoxycholic acid, Glycocholic acid, Phytosphingosine, Tryptamine, and Betaine) were identified as early warning biomarkers. Post-intervention, these biomarkers progressively returned to normal levels. This study demonstrates the efficacy of UPLC-Q/TOF-MS in identifying metabolic biomarkers for early diagnosis of hyperthyroidism with HI and highlights the therapeutic potential of early 131I intervention in normalizing these biomarkers. [ABSTRACT FROM AUTHOR]

The investigation of micro or nano plastics behavior in the environment is essential to minimize the hazards of such pollutants on humans. While the conventional method requires sophisticated procedures and a lot of animal subjects, the nuclear technique confers a sensitive, accurate, and real-time method using radiolabeled micro or nano plastics as a tracer. In this study, polystyrene sulfonate-based microplastic (PSM) was developed with a size of around 3.6 μm, followed by radiolabeling with iodine-131 (131I) or zinc-65 (65Zn) for microplastic radiotracer model. After a stability study in seawater, phosphate buffer saline (PBS), and human serum albumin (HSA) for fifteen days, PSM-131I remained stable (>90 %), except in HSA (50–60 % after day-9), while PSM-65Zn was unstable (<50 %). • Microplastic models can be prepared from styrofoam waste. • Iodine-131 and zinc-65 are used for the radiolabeling of micropolystyrene sulfonate. • Iodine-131 labeled micro polystyrene sulfonate is stable in phosphate buffer saline and seawater. [ABSTRACT FROM AUTHOR]

Brachytherapy is considered to be an unparalleled form of conformal radiation therapy, which involves the delivery of radiation directly to tumor lesions or the postoperative cavity. With the development of specific applicators, the exploitation of in situ drug-delivery platform introduces opportunities for the synchronous administration of radiosensitizers. In this study, an iodine-131 (I131)-labeled injectable thermosensitive methoxy poly(ethylene glycol)- b -poly(tyrosine) hydrogel (denoted as PETyr-I131) was developed via a facile method. The radioactive source of I131 was immobilized at the subcutaneous injection site and monitored via single-photon emission computed tomography in real time, and hematological and histopathological analyses revealed no obvious side effects. Additionally, the SmacN7 peptide conjugated with cell membrane-permeable oligosarginine (denoted as SmacN7-R9) was used to enhance the radiosensitivity of cancer cells, as confirmed by the results of reactive oxygen species detection, DNA damage assay, cell apoptosis assay, and clonogenic evaluation. Importantly, a synergistic brachytherapy treatment effect on tumor-bearing nude mice was achieved. The proposed thermosensitive supramolecular hydrogel platform, which conformally immobilizes radionuclides and delivers radiosensitizers by virtue of its proximity to the site of the primary tumor or the postoperative cavity, has great potential for achieving synergistic treatment outcomes with reduced radiation-related side effects. In this work, a kind of radioiodinated thermosensitive supramolecular hydrogel was developed, which was facilely used as the radioactive source for brachytherapy. Meanwhile, SmacN7-R9 peptide was combined as a model radiosensitizer to facilitate the activation of tumor cell apoptosis pathways and promotion of radiation-induced cytotoxicity. Synergistic brachytherapy outcomes were achieved from the in vitro and in vivo evaluations. Therefore, from the practical standpoint, this thermosensitive supramolecular hydrogel platform holds great potential for the 3D-conformally immobilizing radionuclide and delivering radiosensitizer by virtue of its proximity to the site of primary tumor lesions or postoperative cavity, resulting in synergetic treatment outcomes with reduced radiation associated side effects. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Aptamers which are promising and effective molecular probes, can deliver either fluorescent materials or radionuclides to tumors. This study aimed to develop a novel both fluorescent and radionuclide dual-modality probe based on a truncated aptamer and evaluate its stability and binding affinities in vitro. The aptamer JHIT2 with binding specifically to HepG2 cells was previously generated by Cell-SELEX. Using mfold and RNAstructure software to predict the secondary structure folded by a middle random sequence to truncate the primer sequences at both ends of the aptamer JHIT2 to yield the aptamer JHIT2e, with a similar secondary structure to JHIT2 and the same specificity and affinity as JHIT2. Attaching carboxyfluorescein (FAM) readily to the aptamer JHIT2e and then attaching iodine-131 to the FAM moiety which has multiple sites for iodine labeling to develop a novel both fluorescent and radionuclide dual-modality probe, termed 131I-FAM-JHIT2e. Cell uptake and fluorescence imaging assays in vitro confirmed that 131I-FAM-JHIT2e had both FAM fluorescence signal and radio-activity signal and maintained specific binding ability to the human hepatoma cell line HepG2. This work formed a basis for aptamer-based, dual-modality imaging probe that contains both fluorescent and radionuclide tags, which also is potential for theranostics. Image 1 • Truncating the primer sequences at both ends of aptamer JHIT2 to yield JHIT2e. • JHIT2e has the same specificity and affinity as JHIT2. • 131I-FAM-JHIT2e was prepared by attaching iodine-131 to FAM of FAM-JHIT2e. • 131I-FAM-JHIT2e has both FAM fluorescence and radio-activity signal. • 131I-FAM-JHIT2e has specific binding ability to HepG2 cells. [ABSTRACT FROM AUTHOR]

Lung targeting was developed by synthesising pyrazolone derivatives 6a-f under solvent-free and thermal conditions by reacting azo coumarins 4a-c with hydrazines 5a and b using maltose as a biodegradable catalyst. Different spectral data characterized the synthesized agents as proton-NMR, FT-IR, and mass spectra. Direct radioiodination with iodine-131 was performed and optimized to reach the highest radiochemical purities (92 ± 0.47 to 98 ± 0.21%) using chloramine-T, a moderate oxidizing agent. The 131I-pyrazolone derivatives were confirmed based on HRMS. Furthermore, radioiodinated nitro-derivatives accumulated well in the lung of normal mice during in vivo evaluation, and the better uptake was for nitrophenyl-derivative 7f, about 30.06 ± 0.04% at 30 min after injection. Consequently, synthesized radioiodinated derivatives may be employed as prospective tracers for lung perfusion scans. • Synthesis and radiolabeling of a new pyrazole derivatives were done. • The effect of various reaction conditions on the percent radiochemical yield of radiolabeled derivative was studied. • The in vivo bioevaluation in normal mice showed good accumulation of radioiodinated pyrazole derivative in lung. • The synthetized pyrazole could be used as a potential lung imaging agents. [ABSTRACT FROM AUTHOR]

Abstract A radiotracer investigation was carried out in a wastewater stabilization pond using radiotracer technique. Residence time distribution (RTD) of wastewater was measured using Iodine-131 as a radiotracer. The measured RTD was treated and mean residence time (MRT) was determined. The measured MRT was compared with the theoretical MRT and dead volume was estimated. It was found that about 93% of the geometric volume within the anaerobic pond was dead. The measured RTD was modeled using various RTD models and eventually a suitable model was identified to describe and visualize the flow pattern of wastewater within the pond. Based on the measured MRT, estimated dead volume and identified flow patterns, it was concluded that the hydraulic performance of the anaerobic pond was very poor and not suitable for its intended purpose. Highlights • A radiotracer investigation was carried out in a wastewater anaerobic pond. • RTD of the wastewater was measured using Idoine-131 as a radiotracer. • Mean residence and dead volume were estimated. • Measured RTD was modeled using a complex flow model. • Flow patterns of wastewater were identified. [ABSTRACT FROM AUTHOR]

Abstract Background Gamma camera count rate saturation and high-rate dead time are the most important problems of quantitative measurement in dosimetric studies. In this study, we aimed to assess an algorithm for correction of the measured counting rates in the entire energy spectrum (327–400 keV) for camera dead-time effects. Methods In our study, whole body (WB) scan was performed by using a tissue-equivalent phantom, and that the radioactive Iodine (I-131) source with activities of 0.3, 0.6, 1.2, 1.5, 2.07, 2.7, 3.7, and 5.55 GBq was applied. WB scans of the 20% width energy windows were acquired for 420 s. Results Camera dead-time parameters were obtained from different activities of I-131 in a tissue-equivalent thyroid Phantom, then the saturation curve and coefficients α and β were obtained by using those parameters. Conclusions We concluded that in high-administered activity, it is possible to determine actual count rate of the system in saturation areas. Operation and accuracy of our gamma camera were determined for high activities of iodine-131, which can contribute to various applications of dosimetry in different fields. [ABSTRACT FROM AUTHOR]

Abstract Radiotracer investigations were carried out in two identical phosphoric acid production reactors and a triple super phosphate (TSP) production reactor in three different plants in Tunisia. The main objective of the study was to investigate and compare their flow behavior and identify flow abnormalities, if any. Residence time distribution (RTD) of the process material (ore pulp) was measured in the three reactors using Iodine-131. The measured RTDs were treated and analyzed to obtain flow parameters such as the mean residence time (MRT), dead volume, and extent of bypassing. The treated RTD curves were modeled using a suitable mathematical model, and the values of the parameters were obtained. The results of the investigations were used to evaluate and compare the flow performance of the reactors, quantify the degree of mixing, and visualize the prevailing flow patterns. The results of the investigations are expected to be used to make necessary modifications to enhance the efficiency and optimize the performance of the reactors or the production process. Highlights • Radiotracer investigations were carried out in phosphate fertilizer production reactors. • RTD of process fluid was measured using Iodine-131 as radiotracer. • Mean residence time and dead volume were estimated. • A tank-in-series model with bypass was used to model the measured RTD. • Extent of bypassing was estimated, and flow patterns in the reactors were identified. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the whole body dose H p (10) and extremity dose H p (0.07) of nuclear medicine personnel who administered liquid I-131 by using manual and fabricated semi-automated dispenser system. The semi-automated dispenser system comprises of peristaltic pumps and a motor controller was developed for dispensing liquid I-131. Optically stimulated luminescent dosimeters (OSLD) were used on two radiopharmacists to evaluate the whole body dose H P (10). NanoDot dosimeters were placed on personnel fingers to measure extremity dose H P (0.07). The mean doses were calculated for both manual and automated dispensing techniques. The findings revealed a significant 87.65%–92.31% reduction in both whole body and extremity doses when utilising semi-automated dispenser system compared to manual dispensing. Additionally, the semi-automated dispenser system demonstrated high accuracy with ≤5% error in dispensing the prescribed amount of liquid I-131. The use of the semi-automated system resulted in a significant reduction in whole body and extremity doses due to less contact between personnel and the source, and high accuracy of the prescribed amount of I-131. • Personnel receive higher radiation exposure in their extremities during manual dispensing of radiopharmaceutical. • Semi-automated dispenser system reduces the dispensing time of radiopharmaceuticals in comparison to manual dispensing. • The use of semi-automated dispenser leads to reduction in whole body and extremity doses. [ABSTRACT FROM AUTHOR]

This paper discusses use of Monte Carlo simulations to facilitate testing and calibration of a gaseous effluent monitor (GEM). MCNP5 was used to simulate responses of the 131 I and 41 Ar GEM detecting units exposed to specific radioactive sources. The agreement between the MCNP5 predictions and experimental measurements is good enough to validate the MCNP5 model. It has been demonstrated that the Monte Carlo code is a powerful and useful tool to determine accurate detector responses and facilitate the calibration process of this type of the monitors. [ABSTRACT FROM AUTHOR]

A bilateral comparison between ENEA-INMRI (Italy) and NCBJ RC POLATOM (Poland) of 131 I-solution activity measurements was organized in the year 2015 and piloted by POLATOM, which provided the sources for the comparison. The 131 I master solution was standardized independently at both institutes by using Liquid Scintillation Counting and ionization chamber techniques. The 131 I master solution was then sent by POLATOM to the BIPM International Reference System (SIR). The comparison was registered as an EURAMET.RI(II)-K2.I-131 key comparison allowing the ENEA-INMRI result to enter in the SIR database. [ABSTRACT FROM AUTHOR]

Background For the evaluation of macromolecular drug delivery systems suitable pre-clinical monitoring of potential nanocarrier systems is needed. In this regard, both short-term as well as long-term in vivo tracking is crucial to understand structure-property relationships of polymer carrier systems and their resulting pharmacokinetic profile. Based on former studies revealing favorable in vivo characteristics for 18 F-labeled random (ran) copolymers consisting of N-(2-hydroxypropyl)methacrylamide (HPMA) and lauryl methacrylate (LMA) – including prolonged plasma half-life as well as enhanced tumor accumulation – the presented work focuses on their long-term investigation in the living organism. Methods In this respect, four different HPMA-based polymers (homopolymers as well as random copolymers with LMA as hydrophobic segment) were synthesized and subsequent radioactive labeling was accomplished via the longer-lived radioisotope 131 I. In vivo results, concentrating on the pharmacokinetics of a high molecular weight HPMA- ran -LMA copolymer, were obtained by means of biodistribution and metabolism studies in the Walker 256 mammary carcinoma model over a time-span of up to three days. Besides, a direct comparison with the 18 F-radiolabeled polymer was drawn. To consider physico-chemical differences between the differently labeled polymer ( 18 F or 131 I) on the critical micelle concentration (CMC) and the size of the polymeric micelles, those properties were determined using the 19 F- or 127 I-functionalized polymer. Special emphasis was laid on the time-dependent correlation between blood circulation properties and corresponding tumor accumulation, particularly regarding the enhanced permeability and retention (EPR) effect. Results Studies revealed, at first, differences in the short time (2 h) body distribution, despite the very similar properties (molecular structure, CMC and size of the micellar aggregates) of the non-radioactive 19 F- and 127 I-functionalized polymers. Long-term investigations with the 131 I-labeled polymer demonstrated that, despite a polymer clearance from the blood within 72 h, there was still an increase in tumor uptake observed over time. Regarding the stability of the 131 I-label, ex vivo biodistribution experiments, considering the uptake in the thyroid, indicated low metabolism rates. Conclusion The observed in vivo characteristics strongly underline the EPR effect. The findings illustrate the need to combine information of different labeling approaches and in vivo evaluation techniques to generate an overall pharmacokinetic picture of potential nanocarriers in the pre-clinical setting. Advances in knowledge and implications for patients The in vivo behavior of the investigated HPMA- ran -LMA copolymer demonstrates great potential in terms of an effective accumulation in the tumor. [ABSTRACT FROM AUTHOR]

The present paper describes measurement of flow rates of cooling water in two large diameter pipelines in a thermal power plant using radiotracer dilution method. The objectives of the measurements were to validate the pumping efficiencies of the Vertical Turbine (VT) pumps used for pumping sea water through the pipelines and also calibrate the installed flow meters. Iodine-131 in the form of sodium iodide dissolved in aqueous solution was employed as radiotracer for flow rate measurements. The measurements were carried out at two different pumping units (Unit-1 and Unit-2) with single as well as with simultaneous operation of the two different, but identical pumps. The measured flow rates in Unit-1 and Unit-2 were found to be 15.4 ± 0.46 m 3 /s and 14.1 ± 0.43 m 3 /s, respectively with operation of a single VT pump. Whereas the measured flow rates in Unit-1 and Unit-2 were found to be 27.5 ± 0.82 m 3 /s and 24.55 ± 0.78 m 3 /s with simultaneous operation of the two identical VT pumps. The measured pumping efficiency of each individual pump was found to be quite close to the theoretically predicted pumping efficiency, i.e. 15 m 3 /s. The measured flow rates were also found to be quite different from the flow rates shown by the installed flow meters. [ABSTRACT FROM AUTHOR]

A radiotracer investigation was carried out in an activated sludge process (ASP) system of an effluent treatment plant in a pulp and paper industry. The system consists of an aeration tank and a secondary clarifier connected in series. The primary objective of the investigation was to measure mean hydraulic retention times (MHRTs) of wastewater and investigate the hydraulic performance of the ASP. Residence time distributions (RTD) of the wastewater were measured in an aeration tank and a secondary clarifier of the system using Iodine-131 as a radiotracer. The measured RTD data was treated and MHRTs were estimated. No bypassing was found to exist in the aeration tank and the secondary clarifier. However, the dead volume in the aeration tank and the secondary clarifier was found and estimated to be 2.34% and 4.6%, respectively. The treated curves were further simulated using suitable hydraulically representative mathematical models and detailed flow patterns in the aeration tank and the secondary clarifier were deciphered. [ABSTRACT FROM AUTHOR]

The microplastics amount in the environment is significantly increasing due to human activity, and the hazards are still being investigated. To evaluate the fate of microplastics in organisms, an accurate, fast, and sensitive method is required. Nuclear technology harnessing radiotracer is one of the most sensitive and accurate method for bioaccumulation, biodistribution and biokinetic study. Here, we developed a preparation method for radioiodinated polyvinyl chloride (PVC) as a potential radiotracer of microplastics. Iodine-131 (131I) as a potential radiotracer for microplastic was used in this experiment (activity of 98.05–221.63 MBq). The 131I-PVC was prepared using the Conant-Finkelstein reaction with a solvent combination of phosphate buffer (B), acetone (A), and tetrahydrofuran (T). Such preparation method resulted in spherical 131I-PVC with sizes ranging from 608.6 to 5457.0 nm. Our study showed that acetone is the most suitable solvent for the radioiodination process, resulting in a stable 131I-PVC for up to six days. • Radiolabelled micro-PVC is required for bioaccumulation study in marine biota. • Production of micro-PVC-131I based on the Conant-Finkelstein reaction • Stability of micro-PVC-131I sufficient for bioaccumulation study on marine biota [ABSTRACT FROM AUTHOR]

[Display omitted] • Green synthesis of MnFe 2 O 4 nanoparticles using plant extracts was reported. • Piper nigrum extract played a vital role as a weak base source and stabilizing agents. • MnFe 2 O 4 exhibited a particle size of 21 nm and a magnetization value of 19.3 emu/g. • Nimotuzumab was conjugated and labeled as Iodine-131-labeled-nimotuzumab-MnFe 2 O 4 NPs. • Iodine-131-labeled-nimotuzumab-MnFe 2 O 4 NPs represent excellent radiochemical purity. Manganese ferrite nanoparticle (MnFe 2 O 4 NPs) has introduced a versatile platform to develop a multifunctional nanosystem for Magnetic Resonance Imaging (MRI) and Single-Photon Emission Computed Tomography (SPECT) modalities. Herein, we develop novel iodine-131-labeled-nimotuzumab conjugated with MnFe 2 O 4 NPs as multimodalities of MRI and SPECT nanoprobe. The synthesis of MnFe 2 O 4 NPs was mediated by Piper nigrum seed extract (PNE) consisting of alkaloids and terpenoids which play essential roles as a weak base source and stabilizing agent in the formation of MnFe 2 O 4 NPs. anti-epidermal Growth Factor Receptor (EGFR) nimotuzumab was conjugated with MnFe 2 O 4 NPs via a heterobifunctional PEG-linker. The radiolabeling of nimotuzumab/MnFe 2 O 4 with iodine-131 was performed using the iodogen method. The vibrational, optical, magnetic, and morphological properties of MnFe 2 O 4 NPs were characterized. MnFe 2 O 4 NPs exhibited a spherical shape with an average particle size of 21 nm with a magnetization value of 23.4 emu/g. The vibrational and structural analyses verify that the MnFe 2 O 4 -nimotuzumab was conjugated using a linker. As a result, 131I-labeled-MnFe 2 O 4 -nimotuzumab NPs represents an excellent radiochemical purity of 99.32 ± 0.22 %, suggesting that radiopharmaceutical product generates a high imaging quality and unnecessary radiation. In this study, we offer a novel approach to design 131I-labeled-MnFe 2 O 4 -nimotuzumab NPs for potential dual-modality MRI and SPECT imaging nanoprobe. [ABSTRACT FROM AUTHOR]

Radioimmunotherapy is an established treatment modality in Non-Hodgkin's lymphoma. The only two commercially available radioimmunotherapies – 90 Y-ibritumomab tiuxetan is expensive and 131 I-tositumomab has been discontinued from commercial production. In resource limited environment, self-labelling 131 I-rituximab might be the only viable practical option. We reported our pioneer experience in Malaysia on self-labelling 131 I-rituximab, substituting autologous haematopoietic stem cell transplantation (HSCT) and a patient, the first reported case, received high dose 131 I-rituximab (6000 MBq/163 mCi) combined with BEAM conditioning for autologous HSCT. [ABSTRACT FROM AUTHOR]

During the early stages of the Fukushima nuclear accident, the temporal variations of 131 I deposited on the ground and of 131 I accumulated in cropland soil were monitored at a fixed location in Japan. Moreover, concentrations of long-lived radioactive iodine ( 129 I) in atmospheric deposits and soil were measured to examine the feasibility of retrospectively reconstructing 131 I levels from the levels of accident-derived 129 I. The exceptionally high levels of 131 I in deposits and soil were attributed to rainfall-related deposition of radionuclides. In the crop field studied, the losses of deposited 131 I and 129 I due to volatilization were small. The atomic ratio 129 I/ 131 I in the topsoil corresponded to the same ratio in deposits. The 131 I concentrations measured in the topsoil were very consistent with the 131 I concentrations reconstructed from the 129 I concentrations in the soil. [ABSTRACT FROM AUTHOR]

During the production of iodine-131 from neutron irradiated tellurium dioxide by the dry distillation, a considerable amount of 131 I vapor is dispersed to the indoor air. People who routinely work at the production area may result in a significant risk of exposure to chronic intake by inhaled 131 I. This study aims to estimate the inhalation dose for individuals manipulating the 131 I at a radioisotope production. By using an application installed on smartphones, we collected the time-microenvironment data spent by a radiation group during work days in 2015. Simultaneously, we used a portable air sampler combined with radioiodine cartridges for grabbing the indoor air samples and then the daily averaged 131 I concentration was calculated. Finally, the time-microenvironment data jointed with the concentration to estimate the inhalation dose for the workers. The result showed that most of the workers had the annual internal dose in 1÷6 mSv. We concluded that using smartphone as a motion detector is a possible and reliable way instead of the questionnaires, diary or GPS-based method. It is, however, only suitable for monitoring on fixed indoor environments and limited the targeted people. [ABSTRACT FROM AUTHOR]

30 years after the Chernobyl Nuclear Power Plant (CNPP) accident, its radioactive releases still remain of great interest mainly due to the long half-lives of many radionuclides emitted. Observations from the terrestrial environment, which hosts radionuclides for many years after initial deposition, are important for health and environmental assessments. Furthermore, such measurements are the basis for validation of atmospheric transport models and can be used for constraining the still not accurately known source terms. However, although the “Atlas of cesium deposition on Europe after the Chernobyl accident” (hereafter referred to as “Atlas”) has been published since 1998, less than 1% of the direct observations of 137 Cs deposition has been made publicly available. The remaining ones are neither accessible nor traceable to specific data providers and a large fraction of these data might have been lost entirely. The present paper is an effort to rescue some of the data collected over the years following the CNPP accident and make them publicly available. The database includes surface air activity concentrations and deposition observations for 131 I, 134 Cs and 137 Cs measured and provided by Former Soviet Union authorities the years that followed the accident. Using the same interpolation tool as the official authorities, we have reconstructed a deposition map of 137 Cs based on about 3% of the data used to create the Atlas map. The reconstructed deposition map is very similar to the official one, but it has the advantage that it is based exclusively on documented data sources, which are all made available within this publication. In contrast to the official map, our deposition map is therefore reproducible and all underlying data can be used also for other purposes. The efficacy of the database was proved using simulated activity concentrations and deposition of 137 Cs from a Langrangian and a Euleurian transport model. [ABSTRACT FROM AUTHOR]

Intakes of radionuclides can be estimated through in vivo measurements, and the uncertainties associated to the measured activities should be clearly stated in monitoring program reports. This study aims to evaluate the uncertainties of in vivo monitoring of iodine 131 in the thyroid. The reference values for high-energy photons are based on the IDEAS Guide. Measurements were performed at the In Vivo Monitoring Laboratory of the Institute of Radiation Protection and Dosimetry (IRD) and at the Internal Dosimetry Laboratory of the Regional Center of Nuclear Sciences (CRCN-NE). In both institutions, the experiment was performed using a NaI(Tl) 3′′3″ scintillation detector and a neck-thyroid phantom. Scattering factors were calculated and compared in different counting geometries. The results show that the technique produces reproducibility equivalent to the values suggested in the IDEAS Guide and measurement uncertainties is comparable to international quality standards for this type of in vivo monitoring. [ABSTRACT FROM AUTHOR]

Discharge rates of water were measured in a canal using radiotracer methods with an objective to validate the efficacy of Concrete Volute Pumps (CVPs) installed at various pumping stations along the canal. Pulse velocity and dilution methods were applied to measure the discharge rates using Iodine-131 as a radiotracer. The discharge rate measured in one of the sections of the canal using the pulse velocity method was found to be 22.5 m 3 /s, whereas the discharge rates measured using the dilution method in four different sections of the canal varied from 20.27 to 20.62 m 3 /s with single CVP in operation. The standard error in discharge rate measurements using dilution method ranged from ±1.1 to ±1.8%. The experimentally measured values of the discharge rate were in good agreement with the design value of the discharge rate (20 m 3 /s) thus validating the performance of the CVPs used in the canal. [ABSTRACT FROM AUTHOR]

Using NIST-calibrated solutions of 131 Ba and 131 I in the 5 mL NIST ampoule geometry, measurements were made in three NIST-maintained Capintec activity calibrators and the NIST Vinten 671 ionization chamber to evaluate the suitability of using 133 Ba as a calibration surrogate for 131 I. For the Capintec calibrators, the 133 Ba response was a factor of about 300% higher than that of the same amount of 131 I. For the Vinten 671, the Ba-133 response was about 7% higher than that of 131 I. These results demonstrate that 133 Ba is a poor surrogate for 131 I. New calibration factors for these radionuclides in the ampoule geometry for the Vinten 671 and Capintec activity calibrators were also determined. [ABSTRACT FROM AUTHOR]

The radiation exposure of thyroid glands due to 131 I as a consequence of the Chernobyl accident was investigated retrospectively based on 129 I and 137 Cs inventories in soils in Northern Ukraine. To this end, soil samples from 60 settlements were investigated for 129 I, 127 I, and 137 Cs by AMS, ICP-MS and gamma-spectrometry, respectively. Sampling was performed between 2004 und 2007. In those parts of Northern Ukraine investigated here the 129 I and 137 Cs inventories are well correlated, the variability of the individual 129 I/ 137 Cs ratios being, however, high. Both the 129 I and 137 Cs inventories in the individual 5 samples for each settlement allowed estimating the uncertainties of the inventories due to the variability of the radionuclide deposition and consequently of the retrospective dosimetry. Thyroid equivalent doses were calculated from the 129 I and the 137 Cs inventories using aggregated dose coefficients for 5-year old and 10-year-old children as well as for adults. The highest thyroid equivalent doses (calculated from 129 I inventories) were calculated for Wladimirowka with 30 Gy for 5-years-old children and 7 Gy for adults. In 35 settlements of contamination zone II the geometric mean of the thyroid equivalent doses was 2.0 Gy for 5-years-old children with a geometric standard deviation (GSD) of 3.0. For adults the geometric mean was 0.47 Gy also with a GSD of 3.0. In more than 25 settlements of contamination zone III the geometric means were 0.82 Gy for 5-years old children with a GSD of 1.8 and 0.21 Gy for adults (GSD 1.8). For 45 settlements, the results of the retrospective dosimetry could be compared with thyroid equivalent doses calculated using time-integrated 131 I activities of thyroids which were measured in 1986. Thus, a critical evaluation of the results was possible which demonstrated the general feasibility of the method, but also the associated uncertainties and limitations. [ABSTRACT FROM AUTHOR]

Brain cancer is a challenging disease to treat using conventional approaches. The present investigation aimed to develop a radiopharmaceutical targeting brain cancer based on natural isovanillin. Different parameters were optimized, resulting in high radiolabeling efficiency (97.3 ± 1.2%) and good stability (<48 h). The tracer was formulated for intranasal delivery in a chitosan nanoparticles system with a mean particle size of 141 ± 2 nm, a polydispersity index of 0.23 ± 0.02, and a zeta potential of −17.4 ± 0.3 mV to enhance nasal uptake and surmount the blood-brain barrier. The system was characterized and assessed in-vitro for suitability and specificity and evaluated in-vivo in normal and tumorized mice. The biodistribution profile in brain tumor showed 20.5 ± 0.4 %ID/g localization and cancer cell targeting within 60 min. Improvement in brain tumor uptake resulted from both the nanoformulation and nasal administration of iodoisovanillin. Overall, the reported results encourage the potential use of the nanoformulated labeled compound as an anticancer agent. • [131I]-isovanillin was obtained at high radiochemical yield (∼97.3%), and good stability (<48h). • [131I]-Isovanillin-chitosan nanoparticles system was prepared to enhance nasal uptake and surmount the blood-brain barrier. • The labeled nanoparticles showed a good specific cytotoxic effect versus the human U-25 cell line. • The biodistribution profile of labeled nanoparticles showed ∼20.5% localization and preferential brain tumor targeting. [ABSTRACT FROM AUTHOR]

Mixer-setters units are widely used in uranium purification processes. For efficient operations of mixer-settler units, it is essential to measure the hydrodynamics parameters of the different phases involved. The residence time distribution (RTD) measurement is commonly used method to estimate the hydrodynamics parameters of process reactors. In the present study, RTD of the aqueous phase was measured in different stages mixer-settler unit (mixers, settlers and mixer-settler units) used for stripping operation using Iodine-131 as a radiotracer. For the RTD measurements, radiotracer was injected as an impulse in aqueous phase feed line and its movement was monitored at different locations in the stripping unit using NaI(Tl) detectors. The mean residence times (MRTs) of the aqueous phase were estimated from measured RTD curves. For quantification of the degree of mixing, suitable flow models were proposed based on design and nature of the measured RTD curves and subsequently used for simulation. Based on the results of the RTD study, the mixing of aqueous phase was characterized and design of the stripping unit and its sub-units were validated. The optimum conditions were identified for efficient for the operation of the stripping unit. • The aqueous phase RTD in stripper unit and its sub-units was measured. • The MRT of the aqueous was estimated at different operating conditions. • Different flow models were used to quantify degree of mixing of aqueous phase. • The operating conditions of the stripping unit were optimized. [ABSTRACT FROM AUTHOR]

The diagnosis of intermittent claudication (IC) is challenging. Imaging with radiopharmaceuticals provides a new method for detecting acute IC. Pentoxifylline improves blood flow to ischemic tissues via increasing erythrocyte elasticity and inhibiting platelet aggregation. Pentoxifylline was radio-iodinated with radioiodine-131 (131I) through a direct electrophilic substitution reaction. Furthermore, various factors that might influence the radiolabeling strategy were investigated. The radiochemical yield of [131I]iodopentoxiphyline was evaluated by using paper chromatography and HPLC methods. The biodistribution pattern of [131I]iodopentoxiphyline was studied, where Swiss albino mice was used as a model of acute limb ischemia-reperfusion. The maximum radiochemical yield of pentoxifylline was found to be 94.11 ± 2.35%. The biodistribution findings revealed that [131I]iodopentoxiphyline was significantly deposited at the ischemic site (left hind limbs), with encouraging target/non-target (T/NT) ratios. At 0.25 and 1 h post injection, the uptake of [131I]iodo-pentoxifylline was 5.30 ± 0.30 and 9.98 ± 1.12%, respectively. Also, the maximum T/NT ratio for [131I]iodo-pentoxifylline (9.45 ± 0.26) was obtained at 0.25 h post injection. Due to safety and selectivity, [131I]iodo-pentoxifylline may be a good prospective diagnostic tool for early identification of IC. Moreover, the outcome of this study can be expected to apply to I-123 as well. • Pentoxifylline radiolabeled with iodine-131. • Various factors affecting radiochemical yield percentage were studied. • In vivo biodistribution pattern of [131I]iodopentoxiphyline was studied. • [131I]iodopentoxiphyline showed a marked accumulation at the ischemic site. [ABSTRACT FROM AUTHOR]

Anti-miRNA oligonucleotide (AMO) has been used most widely to inhibit miRNA for loss-of-function studies and function as therapeutic agents. Iodine-131 (131I) radiolabeled AMO may have multiple functions for specific imaging, genetic inhibition, and radiotherapy. This study is to prepare a radioiodinated anti-miRNA-21 AMO by one-step synthesis for preliminary imaging in tumor xenografts and in vitro radiotherapy. A tyrosine was conjugated at the 3' end of AMO via a C6 linker for labeling with 131I. After the molecular mass of AMO was confirmed by mass spectrometry, AMO was labeled with 131I by the chloramine-T method with high labeling yield (95.5% ± 3.1%). By gel electrophoresis, the radioactive distribution of 131I-AMO was located exactly where was AMO, verifying the successful radiolabeling. 131I-AMO presented high stability during 24 h of incubation in fresh human serum. The cellular uptake of 131I or FAM-labeled AMO in DU145 was significantly higher than that in PC-3 cells. After i.v. administration in mice, single-photon emission tomography (SPECT) imaging showed that increased 131I-AMO was found in DU145 tumor from 4 h to 24 h gradually. H&E staining of major organs validated the biocompatibility of 131I-AMO in vivo. Furthermore, the ability of 131I-AMO to inhibit cell growth is superior to that of 131I, along with stronger apoptosis in DU145 cells than in PC-3 cells. Therefore, AMO can be labeled with 131I via one-step synthesis after tyrosine conjugation in this study. Its high labeling yield, stability, inhibitory effect, and tumor distribution provide the potential value in the targeted theranostic role. [Display omitted] [ABSTRACT FROM AUTHOR]

This study focuses on iodine-131 detected in milk samples from the Dairy Science Unit at Cal Poly, San Luis Obispo, California following events at the Fukushima Dai-ichi Nuclear Power Plant in March of 2011. The milk samples, collected between March 21 and April 11, 2011, were part of the Diablo Canyon Nuclear Power Plant Radiological Environmental Monitoring Program. A correlation is made between the integrated activity of iodine-131 found in milk and the integrated activities of iodine-131 of rainwater, vegetation and air samples that were collected from March 19 to April 18, 2011. A comparison is then made to previous studies conducted on dairy cattle that were administered controlled amounts of iodine-131 through ingestion. The comparison shows good agreement to the model which states that generally 1 percent of the activity of iodine-131 ingested by dairy cattle will be detected in harvested milk. Considering the environmental factors and the uncertainties involved, these data and calculated results derived from a real world situation provide an excellent application and confirmation of studies done under controlled settings. [ABSTRACT FROM AUTHOR]

131 I is widely used in nuclear medicine for diagnostic and therapy of thyroid diseases. Depending of workplace safety conditions, routine handling of this radionuclide may result in a significant risk of exposure of the workers subject to chronic intake by inhalation of aerosols. A previous study including in vivo and in vitro measurements performed recently among nuclear medicine personnel in Brazil showed the occurrence of 131 I incorporation by workers involved in the handling of solutions used for radioiodine therapy. The present work describes the development, optimization and application of a methodology to collect and analyze aerosol samples aiming to assess internal doses based on the activity of 131 I present in a radiopharmacy laboratory. Portable samplers were positioned at one meter distant from the place where non-sealed liquid sources of 131 I are handled. Samples were collected over 1 h using high-efficiency filters containing activated carbon and analyzed by gamma spectrometry with a high-purity germanium detection system. Results have shown that, although a fume hood is available in the laboratory, 131 I in the form of vapor was detected in the workplace. The average activity concentration was found to be of 7.4 Bq/m 3 . This value is about three orders of magnitude below the Derived Air Concentration (DAC) of 8.4 kBq/m 3 . Assuming that the worker is exposed by inhalation of iodine vapor during 1 h, 131 I concentration detected corresponds to an intake of 3.6 Bq which results in a committed effective dose of 7.13×10 −5 mSv. These results show that the radiopharmacy laboratory evaluated is safe in terms of internal exposure of the workers. However it is recommended that the presence of 131 I should be periodically re-assessed since it may increase individual effective doses. It should also be pointed out that the results obtained so far reflect a survey carried out in a specific workplace. Thus, it is suggested to apply the methodology developed in this work to other nuclear medicine services where significant activities of 131 I are routinely handled as an effective means to optimize individual exposures and improve occupational radiation protection safety. [ABSTRACT FROM AUTHOR]

This study develops and compares different, increasingly detailed anatomical phantoms for rainbow trout ( Oncorhynchus mykiss) for the purpose of estimating organ absorbed radiation dose and dose rates from 131 I uptake in multiple organs. The models considered are: a simplistic geometry considering a single organ, a more specific geometry employing additional organs with anatomically relevant size and location, and voxel reconstruction of internal anatomy obtained from CT imaging (referred to as CSUTROUT). Dose Conversion Factors (DCFs) for whole body as well as selected organs of O. mykiss were computed using Monte Carlo modeling, and combined with estimated activity concentrations, to approximate dose rates and ultimately determine cumulative radiation dose (μGy) to selected organs after several half-lives of 131 I. The different computational models provided similar results, especially for source organs (less than 30% difference between estimated doses), and whole body DCFs for each model (∼3 × 10 −3 μGy d −1 per Bq kg −1 ) were comparable to DCFs listed in ICRP 108 for 131 I. The main benefit provided by the computational models developed here is the ability to accurately determine organ dose. A conservative mass-ratio approach may provide reasonable results for sufficiently large organs, but is only applicable to individual source organs. Although CSUTROUT is the more anatomically realistic phantom, it required much more resource dedication to develop and is less flexible than the stylized phantom for similar results. There may be instances where a detailed phantom such as CSUTROUT is appropriate, but generally the stylized phantom appears to be the best choice for an ideal balance between accuracy and resource requirements. [ABSTRACT FROM AUTHOR]

[Display omitted] • Silver nanoparticles (AgNPs) were prepared and functionalized with Isatuximab, anti-MM monoclonal antibody (mAb). • The synthesized nanocomposite was radiolabelled with iodine-131 radionuclide. • The synergistic MM-proliferation inhibition efficacy of the radionanocomposite (131I-Isatuximab/AgNPs) was explored in-vitro. • The proliferation, apoptosis and caspase 3/7 of myeloma cells were investigated while using 131I-Isatuximab/AgNPs. • The results expressed 131I-Isatuximab/AgNPs as a potential new anti-MM agent. The goal of this article was to develop a new therapeutic strategy based on nanotechnology for multiple myeloma (MM) treatment which shows a synergism of different mechanisms. In this concern, 12.9 nm-sized silver nanoparticles (AgNPs) were prepared and functionalized with Isatuximab, anti-MM monoclonal antibody (mAb). Furthermore, the synthesized nanocomposite was radiolabelled with iodine-131 radionuclide and yielded 95.5 ± 1.5%. Then, the synergistic MM-proliferation inhibition efficacy of the radionanocomposite (131I-Isatuximab/AgNPs) was explored in-vitro in comparison to each single agent. The MTT investigation showed that the antiproliferation effect of 131I-Isatuximab/AgNPs increased by more than 1.5 fold if compared with Isatuximab, AgNPs, Isatuximab/AgNPs or 131I-Isatuximab. Additionally, 131I-Isatuximab/AgNPs exhibited an apoptotic effect on MM cells which was more than that of Isatuximab, AgNPs, Isatuximab/AgNPs or 131I-Isatuximab by 2, 1.8, 1.7 and 1.5 folds, respectively. In conclusion, the results expressed 131I-Isatuximab/AgNPs as a potential new anti-MM agent. [ABSTRACT FROM AUTHOR]

We treated patients under age 50 years with iodine-131 (131I)-anti-CD45 antibody combined with fludarabine and 2 Gy total body irradiation to create an improved hematopoietic cell transplantation (HCT) strategy for advanced acute myeloid leukemia or high-risk myelodysplastic syndrome patients. Fifteen patients received 332 to 1561 mCi of 131I, delivering an average of 27 Gy to bone marrow, 84 Gy to spleen, and 21 Gy to liver. Although a maximum dose of 28 Gy was delivered to the liver, no dose-limiting toxicity was observed. Marrow doses were arbitrarily capped at 43 Gy to avoid radiation-induced stromal damage; however, no graft failure or evidence of stromal damage was observed. Twelve patients (80%) developed grade II graft-versus-host disease (GVHD), 1 patient developed grade III GVHD, and no patients developed grade IV GVHD during the first 100 days after HCT. Of the 12 patients with chronic GVHD data, 10 developed chronic GVHD, generally involving the skin and mouth. Six patients (40%) are surviving after a median of 5.0 years (range, 4.2 to 8.3 years). The estimated survival at 1 year was 73% among the 15 treated patients. Eight patients relapsed, 7 of whom subsequently died. The median time to relapse among these 8 patients was 54 days (range, 26 to 1364 days). No cases of nonrelapse mortality were observed in the first year after transplantation. However, 2 patients died in remission from complications of chronic GVHD and cardiomyopathy, at 18 months and 14 months after transplantation, respectively. This study suggests that patients may tolerate myeloablative doses >28 Gy delivered to the liver using 131I-anti-CD45 antibody in addition to standard reduced-intensity conditioning. Moreover, the arbitrary limit of 43 Gy to the marrow may be unnecessarily conservative, and continued escalation of targeted radioimmunotherapy doses may be feasible to further reduce relapse. [ABSTRACT FROM AUTHOR]

Abstract: Using anthropomorphic phantom in Geant4, determination of β- and γ-absorbed fractions and energy absorbed per event due to 131I activity in thyroid of individuals of various age groups and geometrical models, have been carried out. In the case of 131I β-particles, the values of the absorbed fraction increased from 0.88 to 0.97 with fetus age. The maximum difference in absorbed energy per decay for soft tissue and water is 7.2% for γ-rays and 0.4% for β-particles. The new mathematical MIRD embedded in Geant4 (MEG) and two-lobe ellipsoidal models developed in this work have 4.3% and 2.9% lower value of S-factor as compared with the ORNL data. [Copyright &y& Elsevier]

Abstract: Iodine-131 is a major component of the atmospheric releases following reactor accidents, and the passage of 131I through food chains from grass to human thyroids has been extensively studied. By comparison, the fate and effects of 131I deposition onto lakes and other aquatic systems have been less studied. In this study we: (1) reanalyze 1960s data from experimental releases of 131I into two small lakes; (2) compare the effects of differences in lake trophic structures on the accumulation of 131I by fish; (3) relate concentrations in fish and fish tissues to that in the water column using empirically estimated uptake (L kg−1 d−1) and loss (d−1) parameters; and (4) show that the largest concentrations in the thyroids of trout (Oncorhynchus mykiss) may occur from 8 to 32 days after initial release. Iodine-131 concentration in trout thyroids at 30-days post release may be >1000 times that in the water. Estimates of cumulative radiation dose (mGy) to thyroids computed using an anatomically-appropriate model of trout thyroid structure within the Monte Carlo N-particle modeling software predicted cumulative thyroid doses that increased approximately linearly after the first 8 days and resulted in 32-day cumulative thyroid doses that ranged from 6 mGy g−1 to 18 mGy g−1 per 1 Bq mL−1 of initial 131I in the water depending upon fish size. The majority of this dose is due to beta emissions, and the dose varies with positions in the thyroid tissue. [Copyright &y& Elsevier]

Highlights: [•] p-Tertbutylcalix[4]arene nanoemulsion complexed with 99mTc, 131I &201Tl. [•] p-Tertbutylcalix[4]arene formulation shows wide spectrum decontamination. [•] The nanoemulsion is reasonably stable and skin-safe for application. [Copyright &y& Elsevier]

Abstract: Two methods for determination of internal dose due to 131I intake during the preparation and handling of iodine radiopharmaceutical products have been compared. The first method was based on the measurement of 131I in 24-hour urine samples while the second method was based on the measurement in vivo of 131I in thyroid. The results have shown that urine analysis method can be used as a screening test but not for internal dose assessment of exposed workers. Thyroid monitoring method was found to be more reliable and accurate method for assessing internal dose from 131I intake. In addition, the assessed internal dose showed that the annual internal effective dose for some workers was below 1mSv with no risk classification, whereas the results of other group of workers were between 1 and 6mSv with low risk classification. Only one worker reached 7.66mSv with high risk classification; and this worker must be monitored individually. [Copyright &y& Elsevier]

Abstract: Many kinds of vegetables were contaminated by a huge amount of radioactivity, such as 131I or 137Cs, derived from the Fukushima nuclear accident. The concentration of radioactivity in contaminated vegetables was higher than the value of the legal limit for shipment, therefore, we attempted to identify a simple and effective removal method for contaminated farm products to ensure the relief of farmers and the security of consumers. First, the radioactivity distribution and adhesion state of contaminated vegetables were investigated by an imaging plate (IP) image. As a result, there were two types of contamination, spot type or spread type, of vegetables. The removal of radioactivity by physical or chemical methods was investigated. As a result, radioactivity removal by water washing showed no significant difference between boiling water and cold water. There was no significant difference between hand washing and running water washing. The result of chemical removal showed that reducing agents removed radioactivity from vegetables by 70–80% for 131I and more than 80% for 137Cs. In particular, ascorbic acid is promising as a safe and versatile option. [Copyright &y& Elsevier]

Abstract: This paper describes modelling calculations carried out to determine the sensitivity of various rural and semi-natural environments to radionuclide contamination by 137Cs, 90Sr, and 131I released during a major nuclear accident. Depositions of 1000 Bq/m3 were assumed for each radionuclide. Four broad types of environments were considered: agricultural, forest or tundra, freshwater aquatic, and coastal marine. A number of different models were applied to each environment. The annual dose to a human population receiving most or all of its food and drinking water from a given environment was taken as a broad measure of sensitivity. The results demonstrated that environmental sensitivity was highly radionuclide specific, with 137Cs generally giving the highest doses during the first year, especially for adults, in terrestrial and freshwater pathways. However, in coastal marine environments, 131I and 239Pu were more significant. Sensitivity was time dependent with doses for the first year dominating those for the 2nd and 10th years after deposition. In agricultural environments the ingestion dose from 137Cs was higher for adults than other age groups, whereas for 90Sr and 131I, the ingestion dose was highest for infants. The dependence of sensitivity on social and economic factors such as individual living habits, food consumption preferences, and agricultural practices is discussed. [Copyright &y& Elsevier]

Abstract: Two weeks after the accident at the Fukushima-Daichi nuclear power plant, 131I, 137Cs and 134Cs activities were measured in two different stations located in Tenerife (Canary Islands), situated at 300 (FIMERALL) and 2400 (IZAÑA) m.a.s.l, respectively. Peak measured activity concentrations were: 1.851 mBq/m3 (131I); 0.408 mBq/m3 (137Cs) and 0.382 mBq/m3 (134Cs). The activities measured at the FIMERALL station were always higher than at IZAÑA station, suggesting that the radioactive plume arrived to the island associated with low altitude air masses. Simulations of potential dispersion of the radioactive cloud (137Cs) after the nuclear accident in reactor Fukushima I show that radioactive pollution reached remote regions such as the Canary Islands in the Eastern subtropical North Atlantic. The corresponding effective dose to the local population was 1.17 nSv, a value less than one millionth of the annual limit for the general public. Therefore, there was no risk to public health. [Copyright &y& Elsevier]

Abstract: The radioactivity released from the Fukushima Dai-ichi nuclear accident was transported around the globe by atmospheric processes. Several artificial radionuclides were detected and measured in aerosols and atmospheric surface depositions in the Lisbon area during late March and early April 2011. The highest concentrations measured in aerosols were those of particulate 131I, 1.39 ± 0.08 mBq m−3. Cesium-134, 137Cs and 132Te were also determined but at lower concentrations. The total atmospheric depositions on the ground were higher on the first week of April with values for 131I, 134Cs, and 137Cs of 0.92 ± 0.11, 0.59 ± 0.06, and 0.62 ± 0.12 Bq m−2, respectively. The four artificial radionuclides measurable, 131I, 132Te 134Cs, and 137Cs, caused little radiation exposure to the members of the public, that was five orders of magnitude lower than the ionizing radiation effective dose limits for members of the public for one year (1 mSv y−1). [Copyright &y& Elsevier]

Abstract: Following the Fukushima accident in March 2011, grass samples were collected from 42 sites around Great Britain during April 2011. Iodine-131 was measurable in grass samples across the country with activity concentrations ranging from 10 to 55 Bq kg−1 dry matter. Concentrations were similar to those reported in other European countries. Rainwater and some foodstuffs were also analysed from a limited number of sites. Of these, 131I was only detectable in sheep’s milk (c. 2 Bq kg−1). Caesium-134, which can be attributed to releases from the Fukushima reactors, was detectable in six of the grass samples (4–8 Bq kg−1 dry matter); 137Cs was detected in a larger number of grass samples although previous release sources (atmospheric weapons test and the 1986 Chernobyl and 1957 Windscale accidents) are likely to have contributed to this. [Copyright &y& Elsevier]

Abstract: Following the Fukushima nuclear accident, low-background gamma spectrometry measurements were performed with HPGe detectors at the PRISNA platform located at the CENBG laboratory in Bordeaux, France. Different kinds of samples were collected and measured between March 26 and May 14, 2011. The first fission product observed was 131I with maximum activity values of 2.4 mBq/m3 in atmospheric dusts in air, 3.5 Bq/L in rain water, 15 Bq/kg in grass and 0.9 Bq/L in cow milk. The 134,137Cs isotopes were also detected in air and in grass at a maximum level of 0.2 mBq/m3 and 0.7 Bq/kg respectively, around one order of magnitude less than 131I activity, but they were below detection limits in the other samples. All these activity values were consistent with others measured in France by IRSN and were well below those reported in May 1986 after the Chernobyl accident. [Copyright &y& Elsevier]

Abstract: Analyses of 131I, 137Cs and 134Cs in airborne aerosols were carried out in daily samples in Vilnius, Lithuania after the Fukushima accident during the period of March–April, 2011. The activity concentrations of 131I and 137Cs ranged from 12 μBq/m3 and 1.4 μBq/m3 to 3700 μBq/m3 and 1040 μBq/m3, respectively. The activity concentration of 239,240Pu in one aerosol sample collected from 23 March to 15 April, 2011 was found to be 44.5 nBq/m3. The two maxima found in radionuclide concentrations were related to complicated long-range air mass transport from Japan across the Pacific, the North America and the Atlantic Ocean to Central Europe as indicated by modelling. HYSPLIT backward trajectories and meteorological data were applied for interpretation of activity variations of measured radionuclides observed at the site of investigation. 7Be and 212Pb activity concentrations and their ratios were used as tracers of vertical transport of air masses. Fukushima data were compared with the data obtained during the Chernobyl accident and in the post Chernobyl period. The activity concentrations of 131I and 137Cs were found to be by 4 orders of magnitude lower as compared to the Chernobyl accident. The activity ratio of 134Cs/137Cs was around 1 with small variations only. The activity ratio of 238Pu/239,240Pu in the aerosol sample was 1.2, indicating a presence of the spent fuel of different origin than that of the Chernobyl accident. [Copyright &y& Elsevier]

Abstract: Caesium-137 and Iodine-131 radionuclides released after the Fukushima Dai-ichi nuclear power plant accident in March 2011 were detected at monitoring stations throughout the world. Using the CTBT radionuclide data and the assumption that the Fukushima accident was the only source of these radionuclides, it was possible to estimate their time-dependent source-term fourteen days following the accident by using atmospheric transport modelling. A reasonable agreement was obtained between the modelling results and the estimated radionuclide release rates from the Fukushima accident. [Copyright &y& Elsevier]

Abstract: Objective of the present study was to optimize decontamination lotion and to evaluate its relative decontamination efficacy using three radio-isotopes (Technetium-99m, Iodine-131 and Thallium-201) as contaminants with varying length of contaminant exposure (0–1h). Experiments were performed on Sprague Dawley rat''s intact skin and human tissue equivalent models. Rat''s hair was removed by using depilator after trimming with scissors. Relative decontamination efficacy of the optimized lotion was investigated and compared with water as control. Static counts were recorded before and after decontamination using single photon emission computed tomography (SPECT). Measured decontamination efficacy (DE) values were analyzed using one way ANOVA and Student''s t-test (p value<0.05) and were found statistically significant. Decontamination efficacy of the lotion was observed to be 90±5%, 80±2% and 85±2%, for the 131I, 201Tl and 99mTc radio-contaminants respectively on skin. Reduced contaminant removal was recorded for the skin which was cleaned by depilator (50–60%). Skin decontamination was found more efficacious for rat skin decontamination than the human tissue equivalent model. Decontamination efficacy of the lotion against 99mTc was recorded 70±15% at 0–1h on the tissue equivalent model. In vitro chelation efficacy of the lotion was also established by using the instant thin layer chromatography-slica gel (ITLC-SG) and >95% of 99mTc was recorded. Neither erythema nor edema was scored in the primary skin irritancy test visually observed for two weeks. [Copyright &y& Elsevier]