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As an inert radioactive gas, 222Rn could be easily transported to the atmosphere via emanation, migration, or exhalation. Research measurements pointed out that 222Rn activity concentration changes during the winter and summer months, as well as during wet and dry season periods. Changes in radon concentration can affect the atmospheric electric field. At the boundary layer near the ground, short-lived daughters of 222Rn can be used as natural tracers in the atmosphere. In this work, factors controlling 222Rn pathways in the environment and its levels in soil gas and outdoor air are summarized. 222Rn has a short half-life of 3.82 days, but the dose rate due to radon and its radioactive progeny could be significant to the living beings. Epidemiological studies on humans pointed out that up to 14% of lung cancers are induced by exposure to low and moderate concentrations of radon. Animals that breed in ground holes have been exposed to the higher doses due to radiation present in soil air. During the years, different dose-effect models are developed for risk assessment on human and non-human biota. In this work are reviewed research results of 222Rn exposure of human and non-human biota. [ABSTRACT FROM AUTHOR]

The Sentinel Lymph Node (SLN) or Sentinel Lymph Node Biopsy (SLNB) technique involves various professionals from different departments in clinical settings to manage breast cancer patients properly. Tracing the nodular involvement of breast cancer patients requires radiation source Tc 99m labeled with colloidal albumin to be injected at the tumor site. The patient becomes a radiation source for a sufficient time, which concerns the Nuclear Medicine (NM) and surgical staff. The study aims to provide the radiation doses of staff in the NM department during the SLN scintigraphy procedure and obtain an empirical model for calculating the radiation doses to staff in the surgical department from that particular patient. Radiation doses in SLN technique for breast cancer patients are minimal, and a sufficient number of SLN biopsy procedures can be performed by hospital staff within the category of non-radiation workers., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

In this study, mass activity of naturally occurring radioactive materials were measured in twenty-three building material samples, use extensively in the area exposed to a high level of natural background radiation (Mahallat, Iran), to determine the radioactivity index and changes to the level of indoor gamma radiation. The mass activity of 232Th, 226Ra and 40K were within the ranges from 18 ± 3 to 44 ± 10 Bq/kg (average of 27 ± 6 Bq/kg), 22 ± 5 to 53 ± 14 Bq/kg (average of 34 ± 6 Bq/kg) and 82 ± 18 to 428 ± 79 Bq/kg (average of 276 ± 58 Bq/kg), respectively. The gamma dose rates for population were estimated between 48 ± 9 and 111 ± 26 nGy/h with exception of radon exhalation from building materials. Since the air kerma rate in the town varies from 0.8 to 4 μGy/h, the attenuation coefficient was calculated for buildings made of the aforementioned materials. Additionally, the annual gamma radiation doses for inhabitants were calculated based on time spent outdoors and indoors.

Testing cell a hot cell is responsible for inspecting the spent fuel elements in open pool type reactor. Because the spent fuel elements examination in the testing cell would result in rising in radiation dose level, a previous precaution should be estimated to ensuring the radiation protection safety and the prevention of radiation hazard for the workers during the process. The most efficient precaution against these kinds of work is the estimation of the predicted radiation dose level around the hot cell during the inspection process. In this regard, a MCNP model was performed to simulate the spent fuel element inspection inside the hot cell to estimate the radiation dose level around the testing cell during the process. The dose rate, during the inspection of the spent fuel element, would be estimated at different decay times for different burn-up. The calculations show that the minimal decay times required to manipulating the spent fuel element would range between 120 to 270 days for burn-up ranging between 18745 and 101224.4 MWD/TU.

The controversy of adjuvant radiotherapy of meningiomas is at least partially due to the insufficient understanding on meningioma cells' response to irradiation and the shortage of radiosensitivity-promotion methods. MicroRNA-221 and microRNA-222 were identified as critical regulators of radiosensitivity in several other tumors. However, their effect in meningiomas has yet to be confirmed. Therefore, the malignant meningioma IOMM-Lee cells were adopted, transfected with microRNA-221/222 mimics or inhibitors, and irradiated with different dosages. The effects of radiation and microRNA-221/222 were then assessed in vitro and in vivo. Radiation dose increases and microRNA-221/222 downregulation synergistically inhibited cell proliferation and colony formation, prevented xenograft tumor progression, and promoted apoptosis, but antagonistically regulated cell invasiveness. Pairwise comparisons revealed that only high-dose radiations (6 and 8 Gy) can significantly promote cell invasiveness in comparison with unirradiated counterparts. Further comparisons exhibited that downregulating the microRNA-221/222 expression can reverse this radiation-induced cell invasiveness to a level of untransfected and unirradiated cells only if cells were irradiated with no more than 6 Gy. In addition, this approach can promote IOMM-Lee's radiosensitivity. Meanwhile, we also detected that the dose rate of irradiation affects cell cycle distribution and cell apoptosis of IOMM-Lee. A high dose rate irradiation induces G0/G1 cell cycle arrest and apoptosis-promoting effect. Therefore, for malignant meningiomas, high-dose irradiation can facilitate cell invasiveness significantly. Downregulating the microRNA-221/222 level can reverse the radiation-induced cell invasiveness while enhancing the apoptosis-promoting and proliferation-inhibiting effects of radiation and promoting cell radiosensitivity.

The results of modeling the conversion factor from rainfall-deposited unit activity of gamma-emitting radon and thoron daughter decay products to their created gamma-radiation dose rate as a function of height above the Earth’s surface using the Geant4 toolkit are presented in this paper. Thin layers of water, soil, and air, with the height of 0.1–10 mm, are considered as the source in order to examine whether the composition of the radiation source environment affects the simulation result. Cases with different absorber-atmosphere densities are simulated. The contribution of each radionuclide 212Bi, 214Bi, 212Pb, 214Pb and 208Tl to the total gamma background was determined. The dependence of dose rate growth during the precipitation period on the detector position in relation to the area covered by precipitation was investigated numerically. The obtained conversion factors are universal values, because do not depend on soil type (material) on which radionuclides are deposited by precipitation. These coefficients can be used for solving both direct tasks of radiation background recovery during precipitation and inverse tasks of determining the intensity and amount of precipitation by the known gamma background, as well as tasks to decipher the gamma background by the shape of the response to various phenomena. Also in this work, it is shown how thoron decay products can affect the response shape of gamma background on atmospheric precipitation.

Objective To investigate the effects of high-energy X-rays irradiation at different dose rates on the plating efficiency, survival fraction and radiobiological parameters of cervical cancer HeLa cell line. Methods Human cervical cancer Hela cell line in exponential growth phase were treated with 0, 1, 2, 4, 6, 8Gy at 2, 6, 10Gy/min dose rates. After irradiation for 12 days in the incubator, 0.5% crystal violet staining was fixed, and the number of clones larger than 50 cells was counted. The data was analyzed and dose-survival curves were plotted following the standard linear-quadratic model using GraphPad Prism 5.0 software to get the values of radiobiological parameters. Differences of survival fraction with different dose rates were tested with analysis of variance by SPSS19.0 software. Results After 2, 6, 10 Gy/min of high-energy X-rays irradiation, the differences between the plating efficiency and survival fraction of HeLa cells were statistically significant (P=0.03 and 0.04). The average α/β values were 3.28Gy, 3.35Gy, 3.93Gy, SF2 were 0.79, 0.78, 0.75. Three dose rates showed no statistically significant difference in the biological parameters, α/β, D0, Dq or SF2 (P > 0.05). Conclusion With the increasing dose rate of high-energy X-rays (2, 6, 10Gy/min), the survival rate of HeLa cells gradually decreases while the biological effect gradually increases.

Abstract Background This study evaluated the effect of radiation dose rate in patients with hematolymphoid malignancies undergoing myeloablative conditioning with total body irradiation (TBI), for hematopoietic stem cell transplantation. Methods The incidence of pulmonary toxicity (PT) and treatment efficacy were compared between the conventional (≥ 6 cGy/min) and reduced dose rate (

Introduction: Nuclear radiation is potentially harmful to humans and soil contamination with radionuclides is the main source of human radiation exposure. These radionuclides can., enter to human body through the food chain. In this study, 34 soil samples were collected from between Arak city and Shazand Power Plant over 20 km length and analyzed. Materials and Methods: The specific activities of 226Ra, 232Th, 40K, and 137Cs were measured in soil samples, using gamma-ray spectrometry and a high-purity germanium (HPGe) detector. For all the samples, we calculated radiological hazards such as radium equivalent (Raeq), dose rate in air (D), internal and external hazard indices (Hin, Hex), annual gonadal dose equivalent (AGDE), and excess lifetime cancer risk. Results: The specific activities of 226Ra, 232Th, 40K, and 137Cs in the soil samples varied from 18.92 to 43.11, 25.31 to 54.27, 230.17 to 728.25, and from in and Hex wereless than unity. Excess lifetime cancer risk of the samples ranged from 0.21×10-3 to 0.31×10-3, which are close to the mean world value (0.29×10-3) butlower than the acceptable value (10-3). Conclusion: The radiological parameters estimated from the specific activities of the radionuclides in soil were within the acceptable range, and therefore, radiation exposure poses no significant risks to the resident population in the vicinity of the power plant.

Abstract Background Prostate-specific membrane antigen (PSMA)-targeted therapy with 177Lu-PSMA-617 is a therapeutic option for patients with metastatic castration-resistant prostate cancer (mCRPC). To optimize the therapy procedure, it is necessary to determine relevant parameters to define radiation protection and safety necessities. Therefore, this study aimed at estimating the ambient radiation exposure received by the patient. Moreover, the excreted activity was quantified. Results In total, 50 patients with mCRPC and treated with 177Lu-PSMA-617 (mean administered activity 6.3 ± 0.5 GBq) were retrospectively included in a bi-centric study. Whole-body dose rates were measured at a distance of 2 m at various time points after application of 177Lu-PSMA-617, and effective half-lives for different time points were calculated and compared. Radiation exposure to the public was approximated using the dose integral. For the estimation of the excreted activity, whole body measurements of 25 patients were performed at 7 time points. Unbound 177Lu-PSMA-617 was rapidly cleared from the body. After 4 h, approximately 50% and, after 12 h, approximately 70% of the administered activity were excreted, primarily via urine. The mean dose rates were the following: 3.6 ± 0.7 μSv/h at 2 h p. i., 1.6 ± 0.6 μSv/h at 24 h, 1.1 ± 0.5 μSv/h at 48 h, and 0.7 ± 0.4 μSv/h at 72 h. The mean effective half-life of the cohort was 40.5 ± 9.6 h (min 21.7 h; max 85.7 h). The maximum dose to individual members of the public per treatment cycle was ~ 250 ± 55 μSv when the patient was discharged from the clinic after 48 h and ~ 190 ± 36 μSv when the patient was discharged after 72 h. Conclusions In terms of the radiation exposure to the public, 177Lu-PSMA is a safe option of radionuclide therapy. As usually four (sometimes more) cycles of the therapy are performed, it must be conducted in a way that ensures that applicable legal requirements can be followed. In other words, the radiation exposure to the public and the concentration of activity in wastewater must be sub-marginal. Therefore, in certain countries, hospitalization of these patients is mandatory.

The environment around us is radioactive due to background radiation emitted from the sky, earth's crust, food, water, and building materials. The human body gets exposed to radiation doses of about 82%, which are out of control; they arise from background radiation sources such as terrestrial, cosmic, and exposure to internal radiation. The background dose from cosmic radiation depends on the altitude, and regions with high altitude have high radiation doses. Natural radioactivity is present in the earth and is present in the different environment geological formations in the rocks and soils. Gamma radiation emitted from naturally occurring radioisotopes, such as 40K and the radionuclides from the 232Th and 238U series and their decay products which exist as trace levels in all ground formations, represents the main external source of irradiation to the human body. Their concentrations in rocks, soils, and sands depend on the local geology of each region in the world. Naturally occurring radioactive materials have terrestrial-origin radionuclides since the creation of the earth. The dose rate of background radiation increases because of the existence of some quarries and springs in some regions which are called high-level background radiation regions. The type of construction materials used in houses can be affecting the dose rate of background radiations. Study of radioactivity in the environment is important to monitor the levels of radiation to which human is exposed directly or indirectly. Recently, several international studies have been done and different values were measured. In this article, a review and literature survey of background radiations such as terrestrial, cosmic, and food radiation was carried out.

Tarapur Atomic Power Station-3 is 540 MWe pressurized heavy water reactor in India, it achieved first criticality on May 5, 2006 and then operated at full power. The control of dose rates and collective dose of radiation worker is most important for the best performance of reactor. This article discusses the sudden rise in radiation levels on primary heat transport (PHT) pipelines and equipment. The radionuclide contributed to high radiation levels was Ag-110 m. Finding obtained during the route cause analysis used for the station operation and removal of Ag-110 m from PHT system using special type of resin (macroporous). The purification of the system using special type of resin has been enhanced. Ag-110 m activity in the PHT fluid has been controlled. PHT pipelines and equipment shielded for exposure control. The postirradiation examination of steam generator (SG) manhole gasket showed the presence of sulfur. The PHT fluid sample analysis revealed the presence of oil content in PHT fluid which was ingressed from buffer tank and FT D2O tank in PHT system. Oil containing sulfur was responsible for erosion of silver from SG manhole gasket in the form of silver sulfide and its ultimate transport to reactor core and neutron activation of silver.

A new radiological risk containment procedure, developed to manage the radiological risk in potentially contaminated areas, is presented here. This new methodological approach, systematically employed in sampling and site inspection activities in unknown areas from an environmental point of view, allowed the discovery of eight 226Ra orphan sources buried under the road surface, in a good state of conservation, in an industrial area of the Calabrian territory, southern Italy, and they are reported here as a case study. For workers performing sampling activities in areas for which information regarding the possible presence of contaminated material is missing, an in situ radiometric check is usually carried out as a potential radiological risk prevention, by measuring the levels of environmental radioactivity. Other than this, the procedure described in this article includes, as novelty, a series of progressive operations never carried out before all together for outdoor activities: the assessment of the presence (if any) of hot spots by recording radiometric anomalies, outdoor gamma spectrometry measurements in order to identify the radionuclides generating those anomalies, the sources unearthing activities, the management of the material found and the application of a risk containment protocol.

Les avancées sur le plan physique, technologique et biologique ont fait de l'oncologie radiothérapie une discipline en constante progression. De nouveaux axes de recherche actuels pourraient être transférés en clinique dans un favenir proche. Dans cette revue, sous la forme d'interviews, différentes thématiques prometteuses pour notre spécialité sont décrites, telles que le microbiote intestinal, les organoïdes tumoraux (ou avatar), l'intelligence artificielle, les thérapies connectées, les nanotechnologies et le laser plasma. La prédiction individuelle du meilleur index thérapeutique combinée à l'intégration de nouvelles technologies permettra idéalement le traitement hautement personnalisé des patients pris en charge en oncologie radiothérapie. Advances in physical, technological and biological fields have made radiation oncology a discipline in continual evolution. New current research areas could be implemented in the clinic in the near future. In this review in the form of several interviews, various promising themes for our specialty are described such as the gut microbiota, tumor organoids (or avatar), artificial intelligence, connected therapies, nanotechnologies and plasma laser. The individual prediction of the best therapeutic index combined with the integration of new technologies will ideally allow highly personalized treatment of patients receiving radiation therapy. [ABSTRACT FROM AUTHOR]

A new technique can determine far-field X-ray spectra produced by intense pulsed electron beams (e-beams). Dose-rate measurements at three different angles of observation determine the e-beam voltage, current, and angle of incidence, all as functions of time. A Monte-Carlo code using the inferred e-beam parameters can then calculate the far-field spectrum at any point in space and time. The technique is described using a 2-MV example (Gamble II) and an 8-MV example (radiographic integrated test stand (RITS)-6). Error-propagation analyses estimate the uncertainty in the parameters inferred from the dose-rate measurements. [ABSTRACT FROM AUTHOR]

Cooling water as a radiation shield from a reactor core originates from the reactor core. In the case of an accident, when the cooling water level inside a pressure vessel decreases, the function of water as a radiation shield decreases as well. After the time passage of the reactor shutdown, the strength of gamma (γ) radiation source from the reactor core decreases. The combination of the decrease of the water that reduces the function of radiation shielding and the decrease of the source strength will affect the pattern of dose rate in the reactor service area (RSA) after an accident takes place. This paper discusses γ dose rate in an RSA of an advanced pressurized water reactor (PWR) (AP- 1000) nuclear power plant (NPP) based on the accident of Fukushima No. 1 reactor. The referred accident is the decrease in the level of cooling water until the it reached half of the height of the reactor core. The reactor core was not damaged since the γ source is still trapped in the matrix of the reactor core. The highest dose rate occurs when the water level decreases to the upper level of the reactor core. The dose rate above the pressure vessel at the RSA prior to the decrease of the water level was 0.7 rad/h, while the dose rate reached 740 rads/h when the water level reaches to the middle of the reactor core. Indeed, the dose rate at a point of 17.5 m horizontally from the center of the core tank was 0.057 rad/h. This condition requires highly selective control to enable entry to the area of the accident. Indeed, a large γ radiation rate due to a decline in the surface horizontal distance is around 6,404 times greater than those of cosmic and natural γ rays. [ABSTRACT FROM AUTHOR]

Gamma radiation, neutrons, protons, and alphas particles shielding competences for gallium germanate-tellurite (GeO 2.TeO 2.Ga 2 O 3) glasses doped with Pr 6 O 11 were tested. The investigated glasses were named as GTGPr1, GTGPr2, GTGPr3, and GTGPr4. Mass attenuation coefficients (MAC) for the proposed glasses were calculated utilizing Phy-X/PSD program and simulated by MCNP5 simulation codes in the photon energy range of 0.015–15 MeV. With the help of MAC values, the linear attenuation coefficient (LAC), half value layer (HVL), mean free path (MFP), and effective atomic number (Z eff) were calculated. Moreover, the absorbed dose received from 137Cs with activity 10 μCi was calculated in presence of the studied glasses. Buildup factors (BUFs) include exposure buildup factor (EBF), and energy absorption buildup factor (EABF) for all investigated glasses were also calculated. Results reflected that the GTGPr4 glass has the highest MAC, LAC values and lowest HVL among other selected germanate glasses. The values of Z eff were around 0.04 MeV varied between 43.07 and 48.19, while at 1.5 MeV were between 18.70 and 21.25. The GTGPr1 possesses the highest values of BUFs around the studied range of energy, while GTGPr4 glasses possesses the lowest values. Moreover, the fast neutron removal cross section was (Σ R = 0.02151 and 0.01942 cm2 g−1) for GTGPr1 and GTGPr4, respectively. The investigated glasses can be useful to construct superior radiation shielding materials to use in nuclear medicine applications. [ABSTRACT FROM AUTHOR]

The gamma-ray spectrum equipped with a high-purity germanium detector was used to measure the naturally occurring radioactive materials of groundwater samples resources from the petroleum-producing communities of Ma'rib Province—Yemen. Thirty-five samples were collected from different sites. The 40K, 232Th, and 226Ra activity concentrations of groundwater samples for oil and non-oil communities were measured. The annual effective doses due to 40K, 232Th, and 226Ra were calculated and did not show a significant health impact. These results can contribute to building a database and provide a general background of the detectable TENORMs for studied areas, which will be useful in any radiological emergency. Significantly, the Ma'rib region is rich in oil and gas. [ABSTRACT FROM AUTHOR]

The study presents a radiometric survey of Background Ionizing Radiation (BIR) dose levels in ten quarry sites located in Ebonyi State, Nigeria. In-situ BIR dose rate measurements, by means of nuclear radiation survey meter, at 1 m above ground level were carried out at the excavation section (ES) and quarrying section (QS) of the investigated quarry sites. The obtained results indicated dose rates ranging from from 0.14 to 0.18 µSv/h with mean of 0.15±0.01 μSv/h at the ES and 0.16 to 0.19 μSv/h with mean value of 0.18±0.01 μSv/h at the QS. While the values obtained at the QS are respectively higher than those measured at the ES, they are all higher than the worldwide average value of 84 nSv/h signifying BIR elevated environments. The estimated mean annual effective dose (AED) and excess lifetime cancer risk (ELCR) are 0.27±0.03 mSv/y and 0.94x10-3 respectively at the ES and 0.31±0.02 mSv/y and 1.07x10-3 at the QS. The obtained AED values for all the sites are well above the outdoor worldwide average value of 0.07 mSv/y but lower than the International Commission on Radiological Protection recommended permissible limits of 1.0 mSv/y for the general public. Generally, the BIR levels of the quarry sites are within acceptable limits and no immediate radiological health threat may be derived from the current levels. However, long-term health effects due to continuous exposure to low-level radiation doses may manifested in future over a lifetime exposure of 70 years as indicated by the ELCR values. [ABSTRACT FROM AUTHOR]

Standard approaches to the construction of maps of radioactive contamination do not provide errors in map data, so such maps do not, in fact, guarantee the accuracy of the map information. In this paper, based on the fact that the characteristics of radioactive contamination at a particular point in the territory have a lognormal probability distribution, a methodology for creating maps with a guaranteed confidence level of the provided information has been proposed and tested. There are considered two ways of creating maps, based on the results of "direct" measurements of radioactive contamination characteristics and in the combination of "direct" and "indirect" measurements of values statistically related to the mapping characteristic. The approaches and use of kriging methods proposed in the article allow to create maps with a given level of confidence and, accordingly, to take into account the risks caused by the uncertainty of measurements of radioactive contamination characteristics and uncertainty of their approximation. [ABSTRACT FROM AUTHOR]

The controversy of adjuvant radiotherapy of meningiomas is at least partially due to the insufficient understanding on meningioma cells' response to irradiation and the shortage of radiosensitivity-promotion methods. MicroRNA-221 and microRNA-222 were identified as critical regulators of radiosensitivity in several other tumors. However, their effect in meningiomas has yet to be confirmed. Therefore, the malignant meningioma IOMM-Lee cells were adopted, transfected with microRNA-221/222 mimics or inhibitors, and irradiated with different dosages. The effects of radiation and microRNA-221/222 were then assessed in vitro and in vivo. Radiation dose increases and microRNA-221/222 downregulation synergistically inhibited cell proliferation and colony formation, prevented xenograft tumor progression, and promoted apoptosis, but antagonistically regulated cell invasiveness. Pairwise comparisons revealed that only high-dose radiations (6 and 8 Gy) can significantly promote cell invasiveness in comparison with unirradiated counterparts. Further comparisons exhibited that downregulating the microRNA-221/222 expression can reverse this radiation-induced cell invasiveness to a level of untransfected and unirradiated cells only if cells were irradiated with no more than 6 Gy. In addition, this approach can promote IOMM-Lee's radiosensitivity. Meanwhile, we also detected that the dose rate of irradiation affects cell cycle distribution and cell apoptosis of IOMM-Lee. A high dose rate irradiation induces G0/G1 cell cycle arrest and apoptosis-promoting effect. Therefore, for malignant meningiomas, high-dose irradiation can facilitate cell invasiveness significantly. Downregulating the microRNA-221/222 level can reverse the radiation-induced cell invasiveness while enhancing the apoptosis-promoting and proliferation-inhibiting effects of radiation and promoting cell radiosensitivity. [ABSTRACT FROM AUTHOR]

Many experimental studies are carried out to compare biological effectiveness of high dose rate (HDR) with that of low dose rate (LDR). The rational for this is the uncertainty regarding the value of the dose rate effectiveness factor (DREF) used in radiological protection. While a LDR is defined as 0.1 mGy/min or lower, anything above that is seen as HDR. In cell and animal experiments, a dose rate around 1 Gy/min is usually used as representative for HDR. However, atomic bomb survivors, the reference cohort for radiological protection, were exposed to tens of Gy/min. The important question is whether gamma radiation delivered at very high dose rate (VHDR—several Gy/min) is more effective in inducing DNA damage than that delivered at HDR. The aim of this investigation was to compare the biological effectiveness of gamma radiation delivered at VHDR (8.25 Gy/min) with that of HDR (0.38 Gy/min or 0.79 Gy/min). Experiments were carried out with human peripheral mononuclear cells (PBMC) and the human osteosarcoma cell line U2OS. Endpoints related to DNA damage response were analysed. The results show that in PBMC, VHDR is more effective than HDR in inducing gene expression and micronuclei. In U2OS cells, the repair of 53BP1 foci was delayed after VHDR indicating a higher level of damage complexity, but no VHDR effect was observed at the level of micronuclei and clonogenic cell survival. We suggest that the DREF value may be underestimated when the biological effectiveness of HDR and LDR is compared. [ABSTRACT FROM AUTHOR]

The present paper is about an experimental evaluation of the terrestrial silicon single-crystalline solar PV module behavior under low gamma radiation. The simultanous proliferation of radioactive sources in Burkina Faso dominated by gamma type and the photovoltaic (PV) systems installations in both urban and rural areas justify this study. There is also high background radiation compared to normal in some region of the country. It has been shown that the photocurrent and the electric power increase while the photovoltage stays constant for an extremely low gamma radiation doses. This work proves that long time exposition to any low radiation can cause the reduction of the performance of the solar PV module. However for greater values of the dose, the photocurrent, the photovoltage and the electric power decrease. Hence, it is so important to protect PV equipments against gamma radiation by adjusting the PV installation height from the ground where high background radiation is notified or by putting reinforced concrete at their bottom faces. The two ways can be combinated adding the respect to radiation protection principle As Low As Reasonably Achievable (ALARA). [ABSTRACT FROM AUTHOR]

OBJECTIVE: Several physical factors such as dose rate and photon energy may change response and sensitivity of polymer gel dosimeters. This study aims to evaluate the R2-dose response and sensitivity dependence of PASSAG-U gel dosimeters with 3% and 5% urea on dose rate and photon energy. MATERIALS AND METHODS: The PASSAG-U gel dosimeters were prepared under normal atmospheric conditions. The obtained gel dosimeters were irradiated to different dose rates (100, 200, and 300 cGy/min) and photon energies (6 and 15 MV). Finally, responses (R2) of the PASSAG-U gel dosimeters with 3% and 5% urea were analyzed by MRI technique at 1, 10, 14 days after the irradiation process. RESULTS: The findings showed that the R2-dose responses of PASSAG-U gel dosimeters with 3% and 5% urea do not vary under the differently evaluated dose rates and photon energies. The R2-dose sensitivity of PASSAG-U polymer gel dosimeter with 3% urea does not change under the differently evaluated dose rates and photon energies, but it changes for PASSAG-U polymer gel dosimeter with 5% urea. The dose resolution values ranged from 0.20 to 0.86 Gy and from 0.27 to 2.20 Gy for the PASSAG-U gel dosimeter with 3% and 5% urea for the different dose rates and photon energies, respectively. Furthermore, it was revealed that the R2-dose response and sensitivity dependence of PASSAG-U gel dosimeters with 3% and 5% urea on dose rate and photon energy can vary over post irradiation time. CONCLUSIONS: The study results demonstrated that dosimetric characteristics (dependence of dose rate and photon energy, and dose resolution) of PASSAG-U gel dosimeter with 3% were better than those of PASSAG-U gel dosimeter with 5% urea. [ABSTRACT FROM AUTHOR]

Being known with its agricultural fertility, the soil of the Nile Valley of Egypt was subjected to degradation due to fast urbanization and increased industrial activities in recent years. The quality of the agricultural soil and associated radiological health hazards to farm workers in the Northeastern Nile Valley was assessed based on the trace metal analyses (Hg, Cd, Zn, Pb, Cu, Mn, and Fe) and natural radionuclide measurements (238U, 226Ra, 232Th, 40K, and 210Pb) of twenty soil samples. Results indicated that the agricultural soil has concentrations of trace elements below the soil world average. However, a significant enrichment in Cd and Cu content was observed in some soil sites. The enrichment in some trace elements contents, especially the Cd metal, was attributed to the effects of the natural and human factors, including the occurrence and distribution of silt and clay deposits, the extensive use of municipal wastewater and pesticide, the incineration of agricultural wastes, and the emission from bricks factories and mazut-fired thermal power plants around the area. The estimated contamination and ecologic risk indices revealed that some soils in the area are uncontaminated with trace elements; others are "moderately contaminated" soil to "contaminated." Results from the radiological measurements revealed that the activity concentrations of the investigated radionuclides were also below the world median activities of soil. The total annual effective dose rates from the different exposure pathways were calculated. The estimated excess lifetime cancer risk values for farm workers were greatly higher than that of the soil world average. This implies a high probability of introducing cancer over the lifetime of farmers in the study area. [ABSTRACT FROM AUTHOR]

Purpose: Radiation therapy (RT), by using ionizing radiation (IR), destroys cancer cells inducing DNA damage. Despite several studies are continuously performed to identify the best curative dose of IR, the role of dose-rate, IR delivered per unit of time, on tumor control is still largely unknown. Materials and methods: Rhabdomyosarcoma (RMS) and prostate cancer (PCa) cell lines were irradiated with 2 or 10 Gy delivered at dose-rates of 1.5, 2.5, 5.5 and 10.1 Gy/min. Cell-survival rate and cell cycle distribution were evaluated by clonogenic assays and flow cytometry, respectively. The production of reactive oxygen species (ROS) was detected by cytometry. Quantitative polymerase chain reaction assessed the expression of anti-oxidant-related factors including NRF2, SODs, CAT and GPx4 and miRNAs (miR-22, -126, -210, -375, -146a, -34a). Annexin V and caspase-8, -9 and -3 activity were assessed to characterize cell death. Senescence was determined by assessing β-galactosidase (SA-β-gal) activity. Immunoblotting was performed to assess the expression/activation of: i) phosphorylated H2AX (γ-H2AX), markers of DNA double strand breaks (DSBs); ii) p19Kip1/Cip1, p21Waf1/Cip1 and p27Kip1/Cip1, senescence-related-markers; iii) p62, LC3-I and LC3-II, regulators of autophagy; iv) ATM, RAD51, DNA-PKcs, Ku70 and Ku80, mediators of DSBs repair. Results: Low dose-rate (LDR) more efficiently induced apoptosis and senescence in RMS while high dose-rate (HDR) necrosis in PCa. This paralleled with a lower ability of LDR-RMS and HDR-PCa irradiated cells to activate DSBs repair. Modulating the dose rate did not differently affect the anti-oxidant ability of cancer cells. Conclusion: The present results indicate that a stronger cytotoxic effect was induced by modulating the dose-rate in a cancer cell-dependent manner, this suggesting that choose the dose-rate based on the individual patient's tumor characteristics could be strategic for effective RT exposures. [ABSTRACT FROM AUTHOR]

Absorbed dose rates in air for 20 residential areas in Odisha were measured using a vehicle-mounted NaI(Tl) scintillation spectrometer. The average values and standard deviations of absorbed dose rate in air for seaside and inland areas were 230 ± 116 nGy h−1 and 123 ± 18 nGy h−1, respectively. The annual external effective dose ranged from 0.43 to 4.59 mSv y−1 with the average value of 1.29 mSv y−1; this indicated there were wide deviations. Analysis of measured data showed that 232Th and 238U were concentrated in the seaside area. [ABSTRACT FROM AUTHOR]

Direct irradiation may cause malfunctioning of cardiac implantable electronic devices (CIEDs). Therefore, a treatment plan that does not involve direct irradiation of CIEDs should be formulated. However, CIEDs may be directly exposed to radiation because of the sudden intrafractional movement of the patient. The probability of CIED malfunction reportedly depends on the dose rate; however, reports are only limited to dose rates ≤8 Gy/min. The purpose of this study was to investigate the effect of X-ray dose rates >8 Gy/min on CIED function. Four CIEDs were placed at the center of the radiation field and irradiated using 6 MV X-ray with flattening filter free (6 MV FFF) and 10 MV X-ray with flattening filter free (10 MV FFF). The dose rate was 4–14 Gy/min for the 6 MV FFF and 4–24 Gy/min for 10 MV FFF beams. CIED operation was evaluated with an electrocardiogram during each irradiation. Three CIEDs malfunctioned in the 6 MV FFF condition, and all four CIEDs malfunctioned in the 10 MV FFF condition, when the dose rate was >8 Gy/min. Pacing inhibition was the malfunction observed in all four CIEDs. Malfunction occurred simultaneously along with irradiation and simultaneously returned to normal function on stopping the irradiation. An X-ray dose rate >8 Gy/min caused a temporary malfunction due to interference. Therefore, clinicians should be aware of the risk of malfunction and manage patient movement when an X-ray dose rate >8 Gy/min is used for patients with CIEDs. [ABSTRACT FROM AUTHOR]

We confirmed the effect of ion recombination using a parallel-plate ionization chamber: dose monitor for clinical use and the Advanced Markus chamber. A 290 MeV/u carbon-ion beam was irradiated using the continuous spot-scanning method in a field size of 5 cm by 5 cm with 2 mm spacing. We tested three beam intensities (1.35 × 108, 2.69 × 109, and 4.03 × 109 particle per second (pps)) at two linear energy transfers (12 keV/μm and 200 keV/μm). The charge (Q) was measured by changing the voltage of the Advanced Markus chamber and that of the dose monitor. Then, Boag's method was used to calculate the saturated charge (Q sat ). For the Advanced Markus chamber, 300 V is a sufficient potential to collect charge. For the dose monitor, Q sat / Q at 2500 V was 1.024 for 4.03 × 109 pps, indicating that the general recombination correction cannot be ignored when high dose rate treatment is performed using a carbon-ion scanning beam. [ABSTRACT FROM AUTHOR]

Purpose: Ionizing radiation has been used for developing new cultivars of diverse plant species, including Cymbidium orchid species. The effects of the total dose on mutation induction have been investigated; however, there is relatively little research on the influence of the dose rate or irradiation duration. Materials and methods: Thus, we analyzed the effects of the total dose and irradiation duration on the growth of Cymbidium hybrid RB001 protocorm-like bodies (PLBs). We completed a genotyping-by-sequencing analysis to compare the induced SNPs among five γ-irradiated populations with similar growth responses (LD50) to γ-rays. Results: The optimal time to assess the effects of the γ-irradiation was at 6 months after the treatment. On the basis of the survival rate of γ-irradiated PLBs, the optimal doses (LD50) for each irradiation duration were estimated: 1 h, 16.1 Gy; 4 h, 23.6 Gy; 8 h, 37.9 Gy; 16 h, 37.9 Gy; and 24 h, 40.0 Gy. The estimated optimal doses were duration-dependent at irradiation durations shorter than 8 h, but not at irradiation durations exceeding 8 h. A SNP comparison revealed a lack of significant differences among the mutations induced by γ-irradiations. Conclusions: These results indicate the irradiation duration affects PLB growth in response to γ-rays. Moreover, the mutations induced by a short-term treatment may be similar to those induced by a treatment over a longer period. [ABSTRACT FROM AUTHOR]

The effects of different dose rates on the degradation of 2,6-dichlorophenol (2,6-DCP) in aqueous solution were investigated at about 2 × 104 Gy absorbed dose, using a 10 MeV electron beam accelerator. It was found that the removal efficiency decreased with increasing dose rate at all initial concentrations of 0.5, 1 and 2 g L−1, and the effect was significantly diminished by addition of P25 TiO2 nanoparticles. Alkaline medium were unfavorable for degradation of 2,6-DCP. Hydrogen peroxide (H2O2) could promote the removal efficiency at a lower dose rate rather than at a higher one. [ABSTRACT FROM AUTHOR]

Terrestrial gamma radiation is mostly due to radionuclides in soil and rocks, primarily the 238U, 235U and 232Th radioactive families and 40K. This radiation contributes 15% to public exposure from all ionizing radiation sources, considering global population. Moreover, it can be used to estimate radon flux and included as one of the quantities relevant to the geogenic radon hazard model. Therefore, effort has been put into developing maps of terrestrial gamma dose rate at the regional, national or European scale, using different input data and methods. In the present work, two distinct approaches to map terrestrial gamma dose rate have been tested in the Euganean Hills district of NE Italy. The first one is based on 41 in situ measurements of ambient dose equivalent rates using a rate meter equipped with a NaI scintillator probe. The second one estimates terrestrial gamma dose rate from the U, Th and K activity concentrations in rock samples collected at the same locations of the dose rates measurements. The results obtained indicate good agreement between the two approaches, and as such suggest that the UNSCEAR 2008 prescription to derive ambient dose equivalent rate from laboratory gamma measurements produces reliable data, provided that cosmic and fall-out contributions are included. Moreover, the study proved that mapping the ambient dose equivalent rate (or terrestrial gamma dose rate) using only one database – i.e. either measured data or estimates derived from radionuclide activity concentration – yields valid results. [ABSTRACT FROM AUTHOR]

Gamma irradiation technology plays a very important role in the development of agriculture, due to its various advantages, such as the inhibition of germination, the appearance of new varieties, preservation...etc. To properly control and characterize irradiation operations, the dose rate distribution in the irradiation cells must be well controlled, The Monte-Carlo method was used for experiments the high cost to map the dose rate distribution in the irradiation cell each time, and to its precise dosimetric calculation. In this study the MCNPX code was used to simulate the irradiation cell of the National Institute of Agricultural Research (NIAR) of Tangier Morocco, the validation of the latter was based on a comparative assessment between the dose rates absorbed in the area calculated by MCNPX (Gy/min) and those measured values by alanine dosimeters. The comparative results showed a good agreement between the experiment and the simulation. [ABSTRACT FROM AUTHOR]

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For the purpose of diverse utilizations of environmental radiation surveys based on ground-based and mobile gamma-ray spectrometry, a multipurpose system equipped with two LaBr3(Ce) detectors was developed to efficiently collect comprehensive results with consistent data. This system can be simply mounted on a tripod, backpack, or airborne systems by using brackets for multipurpose use. Its performance with respect to consistency in diverse survey platforms was evaluated in a well-characterized site with the use of an HPGe detector to compare the survey results of the ambient dose rate and the dose rates of six detected natural radionuclides. A good agreement was achieved among the results of the HPGe detector and the developed multipurpose system with two kinds of survey platforms, such as tripods and backpack surveys. In addition, an airborne survey that used a drone equipped with the multipurpose system was conducted at various survey heights above the site of which 137Cs was distributed on the ground. All of the survey results of the dose rate were corrected to those 1 m above the ground, and the data consistency of the ambient dose rate and dose rate of 137Cs were kept for survey heights. [ABSTRACT FROM AUTHOR]

• Activated dust from ITER vacuum-vessel entails a significant radiation source when isolated. • Remote-handling tools accessing the vessel to manage components within will require maintenance with human intervention. These tools will be contaminated with dust. Radiation exposure to workers must be controlled and minimised. • SURF-UNED methodology to evaluate nuclear responses produced by superficial radiation sources on complex geometries according to a surface-dependent and user-defined intensity distribution. • Scoping analysis on the amount of dust deposited on the Divertor Remote Handling System during the transfer and decontamination process within the ITER Hot Cell for radiological limits compliance. Activated dust produced by the erosion of plasma-facing components entails a significant radiation source for ITER and, generally, for all tokamaks aiming for operation under high neutron exposure. In-Vessel remote-handling operations will mobilise the dust, which will be deposited on the remote-handling tools used, for which hands-on maintenance is expected. To ensure safe maintenance of the remote-handling equipment, a dedicated decontamination process in the Hot Cell is required. Evaluating the radiation fields produced by the contaminated equipment is central to minimising radiation exposure to personnel. In this study, we present a nuclear analysis of the Divertor Remote Handling System during its transfer and decontamination process. Past computational limitations regarding superficial sources definition and high uncertainties on the dust model have been overcome by implementing a novel methodology and following an alternative approach. Two surface-dependent dust distributions over the complex geometry surfaces were considered to evaluate the dose rates according to the different contamination levels during the process phases. A scoping analysis was performed to determine the amount of dust that would comply with project requirements in each phase of the process. Improvement margins were identified in the quantification of the amount of dust and Hot Cell layout. [ABSTRACT FROM AUTHOR]

The precipitation of solutes is the primary factor that leads to the occurrence of irradiation hardening and embrittlement, thus limiting the service life of reactor pressure vessel (RPV) steels. In this study, four model alloys (Fe-1.35Mn-0.75Ni, Fe-1.35Mn-0.20Si, Fe-0.75Ni-0.20Si and Fe-1.35Mn-0.75Ni-0.20Si) were used to investigate the influence of solute elements on grain size, hardness, irradiation hardening, and defect clustering behavior. The materials were irradiated with 3.5 MeV Fe ions to doses of 0.1, 0.3, 1.0, and 3.0 dpa at 290 °C. Results indicated that the addition of solute Mn resulted in grain refinement while the addition of solutes Ni and Si led to grain coarsening. The strength of the model alloys was affected by the change in grain size. A definite dose rate effect was found in all four model alloys under irradiation, where irradiation with a higher dose rate led to a lower irradiation hardening effect and irradiation with a lower dose rate induced a higher hardening effect. Atom probe tomography (APT) results revealed that the precipitated solutes were always coupled with interstitial defect clusters. Solute Mn had a strong influence on cluster nucleation and a weak influence on cluster size. Solutes Si and Ni significantly promoted the nucleation and growth of clusters, and Ni had a greater influence on the nucleation and growth of clusters than Si. Meanwhile, solute Si consistently exhibited a low fraction in the clusters when the solute Mn element was presented in the alloys. [ABSTRACT FROM AUTHOR]

Relative biological effectiveness is a radiobiological parameter relevant in radiotherapy planning and useful in evaluating the physiological impact of radiation in different tissues. Targeted radionuclide therapy allows the selective and specific deposition of higher radiation doses in a noninvasive way and without collateral effects through the administration of radiopharmaceuticals. L u − D O T A − 177 (h y d r a z i n y l n i c o t i n o y l − L y s − (N a l) − N H − C O − N H − G l u) also called L u − i P S M A 177 is a third generation radiopharmaceutical composed by a peptide that recognizes the prostate-specific membrane antigen (PSMA), a membrane protein overexpressed in several types of cancer and that mediates the radiopharmaceutical's recognition of cancer cells. The present study reports radiobiological parameters of L u − i P S M A 177 and demonstrates the superiority of targeted radiopharmaceuticals over external radiotherapy treatment options in terms of their relative biological effectiveness. The relative biological effectiveness value of 1.020 ± 0.003 for the LINAC, estimated by fitting the linear-quadratic model equation to the resulting survival curves, was like those of 1.25 ± 0.04 , 1.060 ± 0.005 a n d 1.00 ± 0.04 obtained by an alternative method in relation to the mean lethal doses at 90, 80 or 60 survival percent respectively. While the relative biological effectiveness values of 5.65 ± 0.13 , 4.72 ± 0.27 a n d 2.87 ± 0.19 estimated for L u − i P S M A 177 were significantly higher than those for the LINAC. The results confirm that the biological effect produced by the deposition of a radiation absorbed dose delivered by the LINAC can be induced with a quarter of that dose using L u − i P S M A 177 due to the energy distribution, dose-rate and energy fluence. • LNCaP cells recover proliferative capacity 72h after a 6Gy irradiation with Cobalt-60 source. • A 4Gy radiation dose of L u − i P S M A 177 overrides LNCaP cell survival. • The low dose rate of L u − i P S M A 177 is overcome by its high energy fluence. • The estimated RBE of L u − i P S M A 177 is four times higher than that of LINAC. • Selectivity of L u − i P S M A 177 reduces the radiological risk of high RBE therapeutic options. [ABSTRACT FROM AUTHOR]

A rapid and efficient photo-bleaching process was demonstrated with a high-energy nanosecond pulse to recover existing and/or revealed color centers on 10 kGy Gamma-irradiated Yb-doped optical fiber. Multi-mJ pulsed laser based on an optical parametric amplifier system operating at wavelengths of 532 nm, 680 nm and 793 nm was used. The photo-bleaching performance is investigated as a function of the wavelength and energy of the pulsed light source. It was observed that the photo-bleaching level of the Yb-doped optical fiber increased when the exposure time of the pulsed laser light and the photon energy was increased. The maximum PB occurred in the pulsed laser of 532 nm wavelength in the optical fiber. Also, a drastically increase in the PB was observed due to the increasing laser energy at the wavelength of 532 nm and 680 nm pulsed laser. The results show that the recovery levels of color centers in the Yb-doped optical fibers could be reached up to 96 % in a shorter time (h) by using the pulsed laser compared to that of the studies using continuous laser. • A rapid photo-bleaching (PB) was demonstrated γ -irradiated Yb-doped optical fiber. • Multi-mJ pulsed laser based on an OPA at wavelengths of 532, 680 and 793 nm was used. • Maximum PB occurred in the pulsed laser of 532 nm wavelength in the optical fiber. • The recovery levels in the Yb-doped optical fibers reached up to 96% in a short time. • An increase in the PB was observed due to the increasing laser energy. [ABSTRACT FROM AUTHOR]

The present SF management concept in Lithuania envisages that spent RBMK-1500 fuel will be stored in dry storage containers for 50 years, before being disposed of in a deep geological repository. However, the risk that a deep geological repository will not be constructed at the planned time should be taken into account, and the extension of SF storage over 50 years should be considered. This paper presents a comparison of gamma and neutron dose rate distributions and variations with planned and extended storage times for cast iron and metal–concrete containers loaded with RBMK-1500 SF. All calculations were performed using the SCALE computer codes system. The modeling results show that the overall shielding properties of the CONSTOR® RBMK-1500 container containing the same neutron and gamma sources are better than those of the CASTOR® RBMK-1500 container. During an extended storage period (from 50 to 300 years), the total dose rate would decrease considerably and the dose rate due to neutrons would become dominant for both containers.