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Even today when nearly 80 years have passed after the atomic bomb (A-bomb) was dropped, there are still debates about the exact doses received by the A-bomb survivors. While initial airborne kerma radiation (or energy spectrum of emitted radiation) can be measured with sufficient accuracy to assess the radiation dose to A-bomb survivors, it is not easy to accurately assess the neutron dose including appropriate weighting of neutron absorbed dose. Particularly, possible post-explosion exposure due to the radioactive particles generated through neutron activation have been almost neglected so far, mainly because of a large uncertainty associated to the behavior of those particles. However, it has been supposed that contribution of such non-initial radiation exposure from the neutron-induced radioactive particles could be significant, according to the findings that the stable chromosomal aberration rates which indicate average whole-body radiation doses were found to be more than 30% higher for those exposed indoors than for those outdoors even at the same initial dose estimated for the Life Span Study. In this Mini Review article, the authors explain that such apparently controversial observations can be reasonably explained by assuming a higher production rate of neutron-induced radioactive particles in the indoor environment near the hypocenter.

The gastrointestinal tract (GIT) is the main critical organ during internal exposure of the body to radioactive particles (RPs). We performed an experimental study of the therapy for acute local injuries in the form of ulcerative gastroenteritis caused by irradiation of animals with artificial highly active RPs. The etiological factor was β-radiation emitted by 165Dy (42%), 142Pr (45%), and 90Y (13%) or 235U fission products caused by thermal neutrons, simulating the radioactive decay of 10-hour-old nuclear fission products. Study of the specific activity of various chemical or biological substances was carried out on Wistar rats, outbred guinea pigs, and Prekos sheep. Radioactive particles were suspended by sparging in a 2.5% potato starch gel and injected into rodents intragastrically through a metal probe using a syringe. In experiments with sheep, RPs were given to animals with food. The efficacy of drugs for treatment of radiation injury with different mechanisms of action was tested: (i) drugs that increase natural resistance, (ii) drugs that have a local wound-healing effect, (iii) a saline laxative, and (iv) cholinomimetics. To evaluate the efficiency of treatment for radiation gastroenterocolitis, clinical and morphological parameters as well as survival rates were used. Good therapeutic efficacy of Glauber's salt, vinylin, carbacholinum, and pilocarpine, in combination with dimethyl sulfoxide and prodigiosan in combination with carbacholinum and bicillin-5, was found. It was manifested by a significant decrease in the intensity of injury to the gastrointestinal mucosa, accelerated healing of radiation ulcers, and an increase in the survival rate of animals. Our results indicate the importance of further investigation of the treatments of local radiation injuries to the gastrointestinal tract caused by RPs, using new formulations, as well as complex application of pharmacological agents. [ABSTRACT FROM AUTHOR]

Using a model of artificial radioactive particles, the effectiveness of the use of a saline laxative, Glauber's salt, as an antidote therapy agent was studied. Internal irradiation of laboratory animals (guinea pigs) and sheep was carried out under laboratory conditions with oral intake of particles simulating the radiation characteristics of young nuclear fission products, at doses that cause medium, severe, and extremely severe forms of radiation ulcerative gastroenterocolitis. During the first four days after radiation exposure, Glauber's salt was administered to each animal once a day either as 3 mL of 20% aqueous solution (for guinea pigs) or as a 0.5 L of 12% aqueous solution (for sheep). In all animals, the drug demonstrated a statistically significant antidote effect. Glauber's salt decreased the severity of radiation-induced ulcerative damage to the gastrointestinal tract, enhanced the speed of healing of radiation ulcers, and increased the survival of animals. The approach applied can be used in the search for new antiradiation antidotes. [ABSTRACT FROM AUTHOR]

Parameterization of dry deposition is key for modelling of atmospheric transport and deposition of radioactive particles. Still, very simple parameterizations are often encountered in radioactive preparedness models such as the SNAP model (SNAP=Severe Nuclear Accident Program) of the Norwegian Meteorological Institute. In SNAP a constant dry deposition velocity (=0.2 cm/s) neglecting aerodynamic and surface resistances, is presently used. Therefore, two new dry depositions schemes (the Emerson scheme and the EMEP (European Monitoring and Evaluation Programme) scheme) have been implemented in SNAP to evaluate the benefits of including aerodynamic and surface resistances codes with respect to model prediction skills. The three dry deposition schemes are evaluated using 137Cs total deposition from soil sample data (n = 540) for a 60 km radial zone out from the Chernobyl Nuclear Power Plant (ChNPP) collected during the months after the accident. The present study capitalizes on high resolution meteorological data (2.5 km horizontal resolution), a detailed land-use data set with 273 sub-classes and the hitherto most comprehensive source term description for the Chernobyl accident. Based on our findings it is recommended to replace the present simple SNAP scheme with the Emerson or EMEP dry deposition scheme. [Display omitted] • New dry deposition codes evaluated for atmospheric dispersion modelling of 137Cs. • Comprehensive meteorological and land-use data as well as source term for Chernobyl accident. • Validation of model prediction skills using 540 soil sample data from near Chernobyl. • Advanced dry deposition schemes improved predictions compared to more simplistic approach. • Reduced dry deposition near Chernobyl and increased long-range transport with new schemes. [ABSTRACT FROM AUTHOR]

The intelligent detector for radioactive particles spread over large geographical areas refers to a method and a system for real-time detection of the presence of radioactive particles in the environment, interconnecting the universe of bees with their self-organizing capabilities as a carrier and transporter of radioactive particles with the universe of computers which processes information on their presence and nature and sends alert messages in case of radioactive contamination. It contains a local computer network with ionizing radiation sensors (GM and SiPM), a weather microstation module used to estimate the direction of movement of radioactive particles, a GPS module used to obtain information on the geographical location of the detector, a GSM module used to transmit alert messages in case of radioactive danger, a photovoltaic power supply module used to ensure energy autonomy. Experimental system use Layens beehives with 20 frames (440x340mm wide) and more than 70 000 bees and is located in the area of uranium mining in Tulghes-Grinties, Neamt County. The Layens hive is for successful overwintering and rapid spring colony buildup even in the cold climates in Romania. As environment bioindicator, bees are an excellent/robust sensor. Computer network is based on Embedded Linux Machine with ARM processors. [ABSTRACT FROM AUTHOR]

Aims: This study aimed to investigate the clinical value of 125I radioactive particle implantation combined with regional arterial chemotherapy perfusion in the treatment of pancreatic cancer.Subjects and Methods: The clinical data of 23 patients with pancreatic cancer were retrospectively analyzed, and the patients were divided into two groups. In the observation group, 11 patients were injected with radioactive particles in combination with regional arterial chemotherapy. In the control group, 12 patients were treated with simple regional arterial perfusion chemotherapy. Curative effect, pain relief, survival period, and adverse reactions were compared between the two groups.Results: The proportion of patients was significantly higher in the observation group (complete remission + partial remission) (72.73%) than in the control group (41.67%). The 6-month and 9-month survival rates in the experimental group were 91.7% and 50%, respectively, while those in the control group were 63.6% and 18.2%, respectively, with significantly statistical difference. The 12-month survival rate in the experimental group was 16.7% and was significantly higher than that in the control group (8.3%). The experimental group should greater improvement in pain symptoms than the control group, and there was no statistical difference between the two groups except in complications of 125I radioactive particle implantation.Conclusions: We conclude that 125I radioactive particle implantation combined with regional arterial perfusion chemotherapy is an effective and comprehensive treatment for advanced pancreatic cancer. [ABSTRACT FROM AUTHOR]

Even today when nearly 80 years have passed after the atomic bomb (A-bomb) was dropped, there are still debates about the exact doses received by the A-bomb survivors. While initial airborne kerma radiation (or energy spectrum of emitted radiation) can be measured with sufficient accuracy to assess the radiation dose to A-bomb survivors, it is not easy to accurately assess the neutron dose including appropriate weighting of neutron absorbed dose. Particularly, possible post-explosion exposure due to the radioactive particles generated through neutron activation have been almost neglected so far, mainly because of a large uncertainty associated to the behavior of those particles. However, it has been supposed that contribution of such non-initial radiation exposure from the neutron-induced radioactive particles could be significant, according to the findings that the stable chromosomal aberration rates which indicate average whole-body radiation doses were found to be more than 30% higher for those exposed indoors than for those outdoors even at the same initial dose estimated for the Life Span Study. In this Mini Review article, the authors explain that such apparently controversial observations can be reasonably explained by assuming a higher production rate of neutron-induced radioactive particles in the indoor environment near the hypocenter., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ohtaki, Otani and Yasuda.)

Since the 1956 completion of nuclear testing at the Montebello Islands, Western Australia, this remote uninhabited island group has been relatively undisturbed (no major remediations) and currently functions as high-value marine and terrestrial habitat within the Montebello/Barrow Islands Marine Conservation Reserves. The former weapons testing sites, therefore, provide a unique opportunity for assessing the fate and behaviour of Anthropocene radionuclides subjected to natural processes across a range of shallow-marine to island-terrestrial ecological units (ecotopes). We collected soil, sediment and biota samples and analysed their radionuclide content using gamma and alpha spectrometry, photostimulated luminescence autoradiography and accelerator mass spectrometry. We found the activity levels of the fission and neutron-activation products have decreased by ~hundred-fold near the ground zero locations. However, Pu concentrations remain elevated, some of which are high relative to most other Australian and international sites (up to 25,050 Bq kg−1 of 239+240+241Pu). Across ecotopes, Pu ranked from highest to lowest in the following order: island soils > dunes > foredunes > marine sediments > and beach intertidal zone. Low values of Pu and other radionuclides were detected in all local wildlife tested including endangered species. Activity concentrations ranked (highest to lowest) terrestrial arthropods > terrestrial mammal and reptile bones > algae > oyster flesh > whole crab > sea turtle bone > stingray and teleost fish livers > sea cucumber flesh > sea turtle skin > teleost fish muscle. The three detonations (one from within a ship and two from 30 m towers) resulted in differing contaminant forms, with the ship detonation producing the highest activity concentrations and finer more inhalable particulate forms. The three sites are distinct in their 240/239Pu and 241/239Pu atom ratios, including the Pu transported by natural process or within migratory living organisms. Unlabelled Image • 1950s nuclear tests have left a legacy of long-lived radionuclides. • Today, the sites have high value as marine and terrestrial habitats. • Pu is persistent, but in variable amounts across marine-to-terrestrial ecotopes. • The dominant Pu in all marine and terrestrial wildlife was locally-sourced. • Pu remains a long-term exposure concern to human visitors and wildlife. [ABSTRACT FROM AUTHOR]

Owing to the location of the pancreas and its complex anatomical relationship, it is difficult to perform radioactive Iodine-125 seed implantation in patients with pancreatic cancer as it can cause surgical side effects and further complications. To standardize the procedure of radioactive Iodine-125 seed implantation in the treatment of pancreatic cancer and reduce the occurrence of adverse reactions and complications during and after operation, the Chinese Medical Doctor Association of Radioactive Seed Implantation Technology Expert Committee, Committee of Minimally Invasive Therapy in Oncology, Chinese Anti-Cancer Association, and the Radioactive Seed Therapy Branch organized and helped establish an expert consensus in China regarding radioactive Iodine-125 seed implantation in the treatment of pancreatic cancer. This article aims at interpreting the adverse reactions and complications after the implantation of radioactive seeds. [ABSTRACT FROM AUTHOR]

Jiale Qian, Zhaohua Bao, Jun Zou, Huilin Yang Department of Orthopedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, People’s Republic of China Purpose: The aim of this study was to investigate the clinical efficacy of pedicle fixation combined with 125I brachytherapy in treating metastatic thoracolumbar tumors. Patients and methods: A retrospective analysis of the clinical data of seven metastatic thoracolumbar tumor patients who received pedicle fixation combined with radioactive 125I seed implantation brachytherapy in our department between January 2009 and December 2013 was performed. The visual analog scale (VAS) for pain and the Karnofsky performance status (KPS) score before the operation and 1, 6, and 12 months after the operation were observed and recorded. The changes in the scores at each time point were compared. Results: All the patients underwent a successful operation, without any complications during their hospitalization. All the patients received postoperative follow-up, and the duration of follow-up was 15–50 months, with an average of 32.2 months. One pancreatic cancer patient died of liver failure and hypoproteinemia 28 months post surgery. The VAS scores of patients before the operation and 1, 6, and 12 months after the operation were 7.43±0.98, 2.71±0.49, 3.00±0.82, and 4.29±0.98, respectively; the KPS scores were 52.9±9.5, 84.3±5.3, 75.7±5.3, and 72.9±4.9, respectively. These results suggest that the VAS score at each time point was significantly decreased compared with that before the operation, while the KPS score was significantly increased compared with that before the operation. Both differences had statistical significance (P

Purpose: The aim of this study was to investigate the clinical efficacy of pedicle fixation combined with 125I brachytherapy in treating metastatic thoracolumbar tumors. Patients and methods: A retrospective analysis of the clinical data of seven metastatic thoracolumbar tumor patients who received pedicle fixation combined with radioactive 125I seed implantation brachytherapy in our department between January 2009 and December 2013 was performed. The visual analog scale (VAS) for pain and the Karnofsky performance status (KPS) score before the operation and 1, 6, and 12 months after the operation were observed and recorded. The changes in the scores at each time point were compared. Results: All the patients underwent a successful operation, without any complications during their hospitalization. All the patients received postoperative follow-up, and the duration of follow-up was 15-50 months, with an average of 32.2 months. One pancreatic cancer patient died of liver failure and hypoproteinemia 28 months post surgery. The VAS scores of patients before the operation and 1, 6, and 12 months after the operation were 7.43±0.98, 2.71±0.49, 3.00±0.82, and 4.29±0.98, respectively; the KPS scores were 52.9±9.5, 84.3±5.3, 75.7±5.3, and 72.9±4.9, respectively. These results suggest that the VAS score at each time point was significantly decreased compared with that before the operation, while the KPS score was significantly increased compared with that before the operation. Both differences had statistical significance (P<0.05). Conclusion: As a therapy for advanced malignant tumors with thoracolumbar metastasis, pedicle fixation combined with 125I brachytherapy can effectively relieve short-term pain and improve patient's quality of life. [ABSTRACT FROM AUTHOR]

Homogeneity of the radioactivity distribution, composition and structure of radioactive phases were investigated for several samples of Chernobyl fuel-containing materials (Chernobyl “lava”) collected in different parts of the destroyed reactor building. The spatial distribution of the α- and of the total activity is homogeneous on the scale of tens microns. XAFS results suggest that the major fraction of U is dissolved in a glassy matrix. At the same time, SEM-EDX and X-ray tomography reveal a high concentration of inclusions and bubbles in the lava samples. The process of lava disintegration continues with different rates depending on environmental conditions around a particular lava stream in the reactor building. [ABSTRACT FROM AUTHOR]

Physical and chemical properties of radioactive matter which get to the atmosphere at accidents on the examples of accidents at Chernobyl and Fukushima nuclear power plants has been analyzed. The properties determining sedimentation intensity of radioactive matter by an atmospheric precipitation has been analyzed. The chemical composition and superficial properties of the radioactive matter released into the atmosphere has been determined by the accident mode process. The radioactive matter (emissions) has been shown to mainly consist of gaseous inert 133Xe, chemically inert "hot particles" in the form of a UxOy + ZrUxOy alloy, microparticles (organic and nonorganic) of dust with vapors of I2, TeOx, CsO2 radioactive matter condensed on their surface, and microparticles of radioactive graphite. [ABSTRACT FROM AUTHOR]

Radioactivity can induce charge accumulation on radioactive particles. However, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. A charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify the particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. The study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes. [ABSTRACT FROM AUTHOR]

Radioactive particles are aggregates of radioactive atoms that may contain significant activity concentrations. They have been released into the environment from nuclear weapons tests, and from accidents and effluents associated with the nuclear fuel cycle. Aquatic filter-feeders can capture and potentially retain radioactive particles, which could then provide concentrated doses to nearby tissues. This study experimentally investigated the retention and effects of radioactive particles in the blue mussel, Mytilus edulis . Spent fuel particles originating from the Dounreay nuclear establishment, and collected in the field, comprised a U and Al alloy containing fission products such as 137 Cs and 90 Sr/ 90 Y. Particles were introduced into mussels in suspension with plankton-food or through implantation in the extrapallial cavity. Of the particles introduced with food, 37% were retained for 70 h, and were found on the siphon or gills, with the notable exception of one particle that was ingested and found in the stomach. Particles not retained seemed to have been actively rejected and expelled by the mussels. The largest and most radioactive particle (estimated dose rate 3.18 ± 0.06 Gy h − 1 ) induced a significant increase in Comet tail-DNA %. In one case this particle caused a large white mark (suggesting necrosis) in the mantle tissue with a simultaneous increase in micronucleus frequency observed in the haemolymph collected from the muscle, implying that non-targeted effects of radiation were induced by radiation from the retained particle. White marks found in the tissue were attributed to ionising radiation and physical irritation. The results indicate that current methods used for risk assessment, based upon the absorbed dose equivalent limit and estimating the “no-effect dose” are inadequate for radioactive particle exposures. Knowledge is lacking about the ecological implications of radioactive particles released into the environment, for example potential recycling within a population, or trophic transfer in the food chain. [ABSTRACT FROM AUTHOR]

Abstract: The present work focuses on the use of micro-analytical techniques to demonstrate the heterogeneous distribution of radionuclides and metals in soils collected at Former Soviet Union mining sites in Central Asia. Based on digital autoradiography, radionuclides were heterogeneously distributed in soil samples collected at the abandoned uranium mining sites Kurday, Kazakhstan, Kadji Sai, Kyrgyzstan and Taboshar, Tajikistan. Using electron microscopy interfaced with X-ray microanalysis submicron – mm-sized radioactive particles and rock fragments with U, As, Se and toxic metals on the surfaces were identified in Kurday and Kadji Sai samples. Employing scanning and tomographic (3D) synchrotron radiation based micro-X-ray fluorescence (μ-SRXRF) and synchrotron radiation based micro-X-ray diffraction (μ-SRXRD) allowed us to observe the inner structure of the particles without physical sectioning. The distribution of elements in virtual crosssections demonstrated that U and a series of toxic elements were rather heterogeneously distributed also within individual radioactive TENORM particles. Compared to archived data, U in Kadji Sai particles was present as uraninite (U4O9+y or UO2+x ) or Na-zippeite ((Na4(UO2)6[(OH)10(SO4)3]·4H2O), i.e. U minerals with very low solubility. The results suggested that TENORM particles can carry substantial amount of radioactivity, which can be subject to re-suspension, atmospheric transport and water transport. Thus, the potential radioecological and radioanalytical impact of radioactive particles at NORM and TENORM sites worldwide should be taken into account. The present work also demonstrates that radioecological studies should benefit from the use of advanced methods such as synchrotron radiation based techniques. [Copyright &y& Elsevier]

Abstract: In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75m ground clearance and 120kph speeds to demonstrate the absence of sources greater than 5MBq 137Cs within large areas (10–20km2 h−1), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15m whilst maintaining speeds covering 1–2km2 h−1 can detect buried 137Cs sources of 0.5MBq or greater activity. A survey design to detect 100kBq 137Cs sources at 10cm depth has also been defined, requiring surveys at <15m ground clearance and <2ms−1 ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed. [Copyright &y& Elsevier]

PURPOSE: The aim of this study was to find a more precise and safe way to implant radioactive particles into the cranial base and orbital regions using the operation navigation system. METHODS: Eleven patients with invasive adenoid cystic carcinoma of the cranial base and orbital apex and a history of multiple surgeries were selected. A preoperative magnetic resonance scan was performed and the German BrainLAB surgical navigation system was used to aid the surgery. RESULTS: No intracranial injury or visual impairment occurred, and the response rate was 100% . CONCLUSION: This study indicates that the implantation of radioactive particles using the operation navigation system was an effective and safe method for treating tumors in the skull base and orbital apex, and should be considered for clinical use. [ABSTRACT FROM AUTHOR]

ABSTRACT After severe nuclear events, a major fraction of refractory radionuclides such as U and Pu are released to the environment in the form of radioactive particles. After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, Pu isotope ratio signals different from that of global fallout have been reported, indicating that spent fuel particles have been released from the reactors or reactor vessels. Radioactive particles containing 37Cs and other volatile radionuclides, as well as a series of stable refractory metals (Cs, Fe, Zn, U, etc.), have been identified by several authors claiming that these particles originated from the FDNPP fuel. If so, long-lived radioactive isotopes of the refractory metals should have been identified in these particles. It is therefore most probable that volatile radionuclides released as gases during the accidents have deposited on available surfaces such as fly ash, forming condensation particles during release or transport. If spent fuel particles have been deposited in the FDNPP surroundings, information on particle characteristics influencing ecosystem transport, uptake, and effects is essential for assessing environmental impact and risk. More emphasis should therefore be put on the identification of hot spots in the FDNPP environment followed by the characterization of radioactive particles using nanoanalytical-microanalytical techniques to support environmental monitoring, as recommended in the present study. Integr Environ Assess Manag 2016;12:687-689. © 2016 SETAC. [ABSTRACT FROM AUTHOR]

Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946–58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10 days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-, biological-, and environmental-specific impacts of residual high activity (hot) particle contamination. The aim of the present study was twofold; (i) to characterize the levels and distribution of residual contamination in the Fig-Quince zone, and (ii) to develop pertinent data on the frequency distribution, elemental and isotopic composition, and physico-chemical properties of hot particles isolated from surface soils from Fig-Quince with a view towards providing recommendations on the future management and possible cleanup of the site. Today, Runit Island remains under an administrative quarantine. [ABSTRACT FROM AUTHOR]