Thermoluminescence dosimetry (TLD) in a 3 T magnetic resonance imaging (MRI) environment: implications for personnel exposure monitoring.

Thermoluminescent dosimeters (TLDs) serve as compact and user-friendly tools for various applications, including personal radiation dosimetry and radiation therapy. This study explores the potential of utilizing TLD-100 personal dosimetry, conventionally applied in PET/CT (positron emission tomography/computed tomography) settings, in the PET/MRI (magnetic resonance imaging) environment. The integration of MRI into conventional radiotherapy and PET systems necessitates ionizing radiation dosimetry in the presence of static magnetic fields. In this study, TLD-100 dosimeters were exposed on the surface of a water-filled cylindrical phantom containing PET-radioisotope and positioned on the patient table of a 3 T PET/MRI, where the magnetic field strength is around 0.2 T, aiming to replicate real-world scenarios experienced by personnel in PET/MRI environments. Results indicate that the modified MR-safe TLD-100 personal dosimeters exhibit no significant impact from the static magnetic field of the 3 T PET/MRI, supporting their suitability for personal dosimetry in PET/MRI settings. This study addresses a notable gap in existing literature on the effect of MRI static magnetic field on TLDs.

137Cesium (137Cs) assessment in wild boars from northwestern Italy.

Radionuclide contamination is a serious health issue caused by nuclear experiments and plant accidents, as seen for the Chernobyl and Fukushima nuclear plants. Italy has been especially interested in northwestern alpine regions, as have several other nations. The aim of this work was to indagate 134Cs and 137Cs contamination in wild boars, which were considered bioindicators sampled in the Chisone/Germanasca Valley and the Pellice Valley districts (Piedmont, Italy) in two hunting seasons (2014 and 2016). In the 2014 season, only the livers of the animals (n = 48) were sampled, whereas in 2016, five different anatomical sampling sites were sampled for each animal (n = 16). The analyses were conducted in an accredited laboratory (Agenzia Regionale per la Protezione dell'Ambiente-ARPA) by the aid of an HPGe detector (Ortec) with a relative efficiency of 50%. In general, the contamination levels registered in 2014 were under the detection limit for 134Cs and low for 137Cs (Chisone/Germanasca valley: min: 0.0, max: 23.9 median 11.0 Bq/kg vs Pellice valley: min 0, max: 31.7, median: 9.6 Bq/kg) and no health concern can be supposed. In the first-year samples, the liver showed a negative correlation between age and contamination level. In the second year of sampling, low levels were confirmed (min: 3.1 Bq/kg, max: 113.3; median 17.7 Bq/kg). Multiple sampling from the same animal showed that the diaphragm (median = 27.7 Bq/kg) kidney (27.4) and tongue (27.6) were more contaminated than the liver (17.7) and spleen (15.3). Moreover, a linear mixed model revealed a negative organ-by-age interaction, meaning that interorgan differences in contamination level were greater in younger (5-11 months) than in older (18-36 months) animals. Different feeding habits can be the explanation. Our paper shows that muscle sites (diaphragm and tongue) can be useful for radionuclide pollution surveillance in wild boar populations and that younger animals show more interorgan variability in contamination levels than older animals. More investigations are needed to confirm this correlation and to fulfill the request for more data to achieve better risk assessment.

Individual patient radiation dose tracking: Perceptions of radiographers in South Africa.

INTRODUCTION: Medical imaging examinations that make use of ionising radiation provide valuable information towards patient management. Literature suggests that there is a significant rise in the number of patient referrals for such examinations. The concept "individual patient radiation dose tracking" (IPRDT) is introduced to optimise radiation monitoring. Many countries across the globe explored and implemented methods to enhance and promote the justification and optimisation principles essential for patient radiation safety. In South Africa (SA), however, attention to IPRDT is limited. METHODS: A qualitative research design was employed. Radiographers in the Western Cape Province of SA were purposefully sampled for participation in one-on-one, semi-structured interviews. Thematic analysis was applied to the transcribed interview data. RESULTS: This paper presents a theme developed from the radiographer cohort of ten (10) participants. The theme: the need for creating awareness and implementing legislative support structures, was developed from the data, with the following supporting subthemes: 1) stakeholder awareness and 'buy-in' 2) continuous professional development and 3) mandated practice. CONCLUSION: This study provides findings that are of value for patient radiation safety in SA by giving a voice to local stakeholders. Other countries that are conducting similar research investigations toward the integration of an IPRDT model, method, or framework, may also benefit from these findings. IMPLICATIONS FOR PRACTICE: The effective integration of IPRDT into the clinical environment requires unison amongst the relevant stakeholders and clarity on the various professionals' roles and responsibilities. The findings of this study furthermore suggest the involvement of regulatory organisations for the provision of a mandated form of practice at national and international levels.

Investigation of natural and artificial radioactivity levels in travertines of the Cappadocia region in Turkey.

This study determined natural and artificial radionuclide concentrations to evaluate natural radioactivity and health risk levels of nine travertines in the Yaprakhisar and Balkayasi regions in Turkey. The samples coded B1-M, B2, B5, B7, B8, and B10 represent waste derived from the Yaprakhisar travertines, as well as samples T5-M, T12, and Z1 travertines derived from Balkayasi. The levels of natural and artificial radionuclide concentrations (232Th, 40K, and 137Cs) were measured using a high-purity germanium (HpGe) detector system. The travertine activity ranged from 2.09 to 12.07 Bq kg-1 for 232Th, 4.21 to 13.41 Bq kg-1 for 40K, and 0.42-3.26 Bq kg-1 for 137Cs. The results showed that the activity concentration values for 232Th, 40K, and 137Cs were coherent with the travertine analysis results in the UNSCEAR, 2000; 2008 publications. The values obtained were lower than the average values in the UNSEAR reports. The radiological hazard parameters calculated in this study were absorbed gamma dose rate (D), radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), exposure dose (ER), total annual effective dose (AEDEtotal), excess lifetime cancer risk (ELCRtotal), gamma representative level (GRL), internal hazard index (Hin) and external hazard index (Hex).

Analysis of population distribution for anticipating radiological consequences of nuclear power plant program in West Kalimantan.

The potential establishment of a nuclear power plant (NPP) in the West Kalimantan is under consideration to address low electrification rates. This research assesses the demographic characteristics and population growth in the vicinity of the proposed NPP site in West Kalimantan. The investigation focuses on demographic aspects, population density, and anticipated growth during the operational phase of the reactor. The study area encompasses districts within a 25 km radius of the site. Employing a descriptive quantitative approach, this research integrates verified population data and utilizes spatial and temporal analysis. The exponential method is employed to forecast population growth throughout the operational lifespan of the reactor, to anticipate population increases in around NPP site. Reactor operation has potential radiological consequences. Results reveal that the suggested NPP site adheres to regulations concerning population density away from densely populated areas. Projected population growth is notable in specific regions, necessitating monitoring and policy attention. A gender-specific analysis highlights the higher female populations, with sensitivity to radiation exposure. These findings offer essential information for evaluating the radiological impact of the NPP on the population, so meeting NPP siting requirements. The study contributes valuable insights for decision-making regarding NPP development and safety considerations in West Kalimantan.

Factors influencing the increased 90Sr radioisotope migration in highly alkaline groundwater at Chornobyl NPP site.

This paper analyses the formation of high Sr2+ concentration in strong alkaline (pH = 9.5-12.5) groundwater using data of the 27 years of observations around the destroyed Chernobyl NPP Unit 4. It appears that the formation of strong alkaline groundwater in different monitoring wells is consistent with the distribution of 90Sr, pH and main ions. The reason for the increase in 90Sr concentrations is the process of its migration from the sources of contamination - leaks of highly active water localized in certain premises inside the «Shelter ¼ object. These computational experiments showed that for the groundwater in pH range 9.5-12.4, the concentration of strontium in the form of SrOH + increases and in the form of Sr2+ - decreases. In addition, the fraction of 90Sr in the form of a soluble neutral complex compound SrCO30, which is not sorbed, reaches 14-35%. Increased fractions of 90Sr in forms of SrOH+ and SrCO3 are factors which reduce the isotope ability to be sorbed by soils and therefore increase its migration ability. In strongly alkaline groundwater a sharp increase in 90Sr volumetric activity may also be caused by ionic strength (IS) increase above 5 mmol/L. Thus, the factors that influence the increase in 90Sr volumetric activity in strongly alkaline groundwater are the formation of its complex compounds and an increase in ionic strength (IS), which reduces the thickness of the double electric layer and, as a result, reduces the sorption capacity of soils.

Radioactivity from oil and gas produced water accumulated in freshwater mussels.

Legacy disposal of oil and gas produced water (OGPW) to surface water has led to radium contamination in streambed sediment creating a long-term radium source. Increased radium activities pose a potential health hazard to benthic organisms, such as freshwater mussels, as radium is capable of bioaccumulation. This project quantifies the impact of OGPW disposal on adult freshwater mussels, Eurynia dilatata, which were examined along the Allegheny River adjacent to a centralized waste treatment facility (CWT) that historically treated and then discharged OGPW. Radium isotopes (226Ra and 228Ra) were measured in streambed sediment, mussel soft tissue, and mussel hard shell collected upstream, at the outfall, 0.5 km downstream, and 5 km downstream of the CWT. Total radium activity was significantly higher (p < 0.05) in mussel tissue (mean = 3.44 ± 0.95 pCi/g), sediment (mean = 1.45 ± 0.19 pCi/g), and hard shell (mean = 0.34 ± 0.11 pCi/g) samples 0.5 km downstream than background samples collected upstream (mean = 1.27 ± 0.24; 0.91 ± 0.09; 0.10 ± 0.02 pCi/g respectively). Mussel shells displayed increased 226Ra activities up to 5 km downstream of the original discharge. Downstream soft tissue and hard shell 87Sr/86Sr ratios, as well as hard shell metal/calcium (e.g., Na/Ca; K/Ca; Mg/Ca) and 228Ra/226Ra ratios demonstrated trends towards values characteristic of Marcellus OGPW. Combined, this study demonstrates multiple lines of evidence for radium retention and bioaccumulation in freshwater mussels resulting from exposure to Marcellus OGPW.

Quantitative estimation of dust transport in the desert region of northwest China by plutonium isotopes.

Dust is an important source of atmospheric pollution, and quantitative estimation of desert dust transport is crucial for air pollution control. In this study, five typical sandy soil profiles in the Tengger Desert were collected and analyzed for 239,240Pu concentration and 240Pu/239Pu atomic ratios in order to identify the source of 239,240Pu in this area and explore the sedimentary characteristics of dust in different profiles. The results revealed that the concentrations of 239,240Pu in the soil profiles were between 0.002 and 0.443 mBq/g with an exception of the deep layer soil at one site. The measured atomic ratios of 240Pu/239Pu are at the global atmospheric fallout level with a mean of 0.184 ± 0.020, indicating that global fallout is the dominant source of plutonium in this region. The total inventories of 239,240Pu in the reference sites in this area were estimated to be 39.2-44.6 Bq/m2, this is in agreement with the value from the global fallout of atmospheric nuclear weapon tests at the similar latitude (30-40 °N: 42 Bq/m2). The estimated erosion rate in the erosion profile utilizing soil erosion intensity mode is 2491 t/km2/yr and the soil erosion depth is 9.86 cm, While, the stacking rate of the accumulation profile is 1383 t/km2/yr, and the depth of accumulation is estimated to be 5.48 cm. The difference between the erosion and accumulation profiles indicated that approximately 1107 t/km2/yr of dust was exported from the Gobi landform area of the Tengger Desert, which might be transported long distance in the downwind direction.

Impact of flight route changes on cosmic ray exposure: consequences of the conflict between Ukraine and the Russian federation.

This work investigates the impact on cosmic ray exposures to aircrew due to changing flight routes operated in the context of the recent conflict between Ukraine and the Russian Federation. All analyses were done based on Paris-Tokyo and Tokyo-Paris flights taken as examples, and differences in radiation exposures were quantified by comparing the situation before and after the beginning of the conflict. Regarding space weather scenarios, a quiet solar period and an extreme solar event (ground level enhancement (GLE) 5) were considered in the study. Analyses showed that the new Paris-Tokyo flight route established after the beginning of the conflict results in a smaller radiation dose to aircrew than that operated before the conflict, particularly during solar events. In contrast, for Tokyo-Paris flights the new high-latitude route crossing the Atlantic Ocean and North America increases the dose significantly (+ 50% in the worst case). Although this analysis is limited only to flights connecting Paris and Tokyo, it allowed for an evaluation of the consequences of new routes (particularly polar ones) on ambient dose equivalent values.

Influence of rock type and geophysical properties on radon flux density.

The most significant source of human exposure to ionizing radiation is the radioactive gas radon (basically 222Rn) and its daughter decay products, creating more than half of the effective dose from all natural sources. Radon enters buildings mainly from dense rocks, which are below building foundations at depths of 1 m and more. In this paper long-term measurements of radon flux density are analyzed, with radon exhalation from the surface of the most common rocks-loams, sandy loams, clays, clay shales, several types of sandy-gravel-pebble deposits, clay and rocky limestone. The influence of geophysical properties of rocks on radon flux density due to exhalation from surfaces of those rocks was studied. Based on the results obtained, a method of local assessment of the hazard from radon and its progeny in buildings is proposed, which is based on the geophysical properties of rocks below the foundations of those buildings.

Long-term radiological assessment of a Mediterranean freshwater ecosystem surrounding a nuclear power plant.

The radionuclide concentration of man-made radionuclides on non-human biota in freshwater ecosystems has been extensively studied in environments affected by the Chernobyl and Fukushima accidents, in both humid continental and subtropical climates, respectively. However, there are very few studies that assess the long-term effects of operating nuclear facilities in Mediterranean environments. In the present study, a temporal analysis of the impact on carp, cattail, and bulrushes in the cooling pond of the currently operating Almaraz nuclear power plant was investigated for the period 2000-2020. The results do not show a general trend in man-made radionuclide concentrations. Instead, depending on their availability and the type of organism, trends decrease over time. This is also reflected in the effective half-lives obtained, which are lower than the physical half-life for some radionuclides. Transfer coefficients for the main man-made radionuclides detected were obtained, and it was found that these were significantly lower than the typical ranges found for benthic fish and vascular plants in freshwater ecosystems. Finally, the internal and external doses received by the carp have been evaluated using ERICA tool, and it has been observed that the main contribution to the total dose is due to the internal dose (0.65-7.04) × 10-4 µGy/h.

Automatic measurements with the Pille-ISS thermoluminescent dosimeter system on board the International Space Station (2003-2021).

The health risk of staying in space is a well-known fact, and the radiation doses to the astronauts must be monitored. The Pille-ISS thermoluminescent dosimeter system is present on the International Space Station (ISS) since 2003. We present an analysis of 60000 data points over 19 years from the 90 min automatic measurements and show a 4-day-long segment of 15 min measurements. In the case of the 15 min we show that the mapping of the radiation environment for the orbit of the ISS is possible with the Pille system. From our results the dose rates inside the South Atlantic Anomaly (SAA) are at least 1 magnitude higher than outside. From the 90 min data, we select orbits passing through the SAA. A statistical correlation in the SAA between the ISS altitude and monthly mean dose rate is presented with the Spearman correlation value of ρSAA=0.56. The dose rate and the sunspot number show strong inverse Pearson correlation (R2=-0.90) at a given altitude.

Radiological complexity of nuclear facilities: an information complexity approach to workplace monitoring.

Nuclear energy is crucial for achieving net-zero carbon emissions. A big challenge in the nuclear sector is ensuring the safety of radiation workers and the environment, while being cost-effective. Workplace monitoring is key to protecting workers from risks of ionising radiation. Traditional monitoring involves radiological surveillance via installed radiation monitors, continuously recording measurements like radiation fields and airborne particulate radioactivity concentrations, especially where sudden radiation changes could significantly impact workers. However, this approach struggles to detect incremental changes over a long period of time in the radiological measurements of the facility. To address this limitation, we propose abstracting a nuclear facility as a complex system. We then quantify the information complexity of the facility's radiological measurements using an entropic metric. Our findings indicate that the inferences and interpretations from our abstraction have a firm basis for interpretation and can enhance current workplace monitoring systems. We suggest the implementation of a radiological complexity-based alarm system to complement existing radiation level-based systems. The abstraction synthesized here is independent of the type of nuclear facility, and hence is a general approach to workplace monitoring at a nuclear facility.

Potential risk assessment: a model for quality evaluation in fluoroscopy-guided interventional procedures.

This study presented a model applied for potential risk assessment in an interventional radiology setting. The model of potential risk assessment (MARP) consisted of the creation of a scale of indicators ranging from 0 to 5. The radiation levels were categorized according to gender, kind of procedure, value of kerma air product (Pka), and accumulated radiation dose (mGy). The MARP model was applied in 121 institutions over 8 y. A total of 201 656 patient radiation doses (Dose-area product and accumulated kerma) data were launched into the system over time, with an average of 22 406 doses per year. In the context of the workers (cardiologists, radiographers, and nurses) monitored during the MARP application, 8007 cases (with an average of 890 per year) of occupational radiation doses were recorded. This study showed a strategy for quality evaluation in fluoroscopy using a model with a compulsory information system for monitoring safety.

Assessment of the impact of Tianwan Nuclear Power Plant on the adjacent marine ecosystem.

Based on the monitoring data of 137Cs and 90Sr in Tian Bay in 2005-2023, the impacts of the operation of Tianwan Nuclear Power Plant on the marine ecosystem were assessed. The 137Cs and 90Sr activity concentrations in the seawater and sediment varied within the background ranges. The radiation dose rates derived from 137Cs and 90Sr for the marine organisms ranged from 2.4 × 10-5 to 2.2 × 10-4 nGy/h, it was far below the most conservative screening dose rate (10 µGy/h). The committed effective dose for humans was 0.070-0.094 µSv, 1/1500th of the world's mean annual effective dose (0.12 mSv) from ingesting food containing uranium and thorium series nuclides. Radiation risk assessment showed no radiation risk for the long-term discharge of nuclear wastes in the future. Overall, the long-term normal operation of TNPPs has almost no radiation impact on the adjacent marine ecosystem.

Cosmic-ray exposure assessment using particle and heavy ion transport code system: case study Douala-Cameroon.

According to UNSCEAR, cosmic radiation contributes to ~16% (0.39 mSv/y) of the total dose received by the public at sea level. The exposure to cosmic rays at a specific location is therefore a non-negligible parameter that contributes to the assessment of the overall public exposure to radiation. In this study, simulations were conducted with the Particle and Heavy Ion Transport code System, a Monte Carlo code, to determine the fluxes and effective dose due to cosmic rays received by the population of Douala. In minimum solar activity, the total effective dose considering the contribution of neutron, muon+, muon-, electron, positron and photon, was found to be 0.31 ± 0.02 mSv/y at the ground level. For maximum solar activity, it was found to be 0.27 ± 0.02 mSv/y at ground level. During maximum solar activity, galactic cosmic rays are reduced by solar flares and winds, resulting in an increase in the solar cosmic-ray component and a decrease in the galactic cosmic-ray component on Earth. This ultimately leads to a decrease in the total cosmic radiation on Earth. These results were found to be smaller than the UNSCEAR values, thus suggesting a good estimation for the population of Douala city located near the equatorial line. In fact, the cosmic radiation is more deflected at the equator than near the pole. Muons+ were found to be the main contributors to human exposure to cosmic radiation at ground level, with ~38% of the total effective dose due to cosmic exposure. However, electrons and positrons were found to be the less contributors to cosmic radiation exposure. As regards the obtained results, the population of Douala is not significantly exposed to cosmic radiation.

Prospective dose monitoring using a manual dose management system: experience in brain computed tomography from a tertiary hospital in Nigeria.

A manual radiation dose management system was developed to track the radiation dose and scan parameters of patients for brain computed tomography (CT). Radiation dose in volume computed tomography dose index (CTDIvol) and dose length product (DLP) were monitored to identify procedures that may require optimisation using notification values. The data were analysed and compared with national and international diagnostic reference levels (DRLs). A total of 596 brain CTs were monitored and grouped as <1: 36, 1-<5: 38, 5-<10: 25, 10-<15: 31 and adult: 466. The CTDIvol notification value identified the following number of examinations having high CTDIvol in <1 y: 1, 1-<5: 1, 5-<10: 0, 10-<15: 0 and adult (>15): 11. Furthermore, the DLP notification values identified the following examinations with high DLP in <1 y: 1, 1-<5:1, 5-<10:1, 10-<15: 1 and adults (>15): 18. The established local paediatric DLP DRLs were 2-3 times higher than the international paediatric DLP DRLs. This calls for a total protocol review and optimisation considering the local CT practices for paediatric imaging.

Radiological environmental impact analysis of the uranium mining site in Mika, Nigeria using time series forecast model.

This study employs time series forecasting, specifically Seasonal Auto-Regressive Integrated Moving Average, to predict the radiological impact of uranium mining in Mika, Nigeria. By utilizing meteorological data to model the dispersion of radioactive emissions to receptors, allowing for a comprehensive assessment of potential health and environmental consequences. The study observed a slight change in the Total Effective Dose Equivalent (TEDE) at the nearest residence northeast receptor between the actual and the forecasted data. The findings could be largely because of the basement complex rock formations that characterized the Mika region. The study recommend proper monitoring and evaluation should be done before full-scale mining can be carried out. However, the TEDE is generally below the International Atomic Energy Agency recommended level of 1 mSv per y for public exposure. The research demonstrates the significance of predictive modeling in managing and mitigating the radiological risks associated with uranium mining activities. Findings contribute to informed decision-making and sustainable resource extraction practices in Mika, Nigeria.

Vertical distribution of 241Am in the southern Baltic Sea sediment profiles.

The contamination of the Baltic Sea with radioactive substances occurred due to the global fallout of atmospheric nuclear weapon tests and the Chernobyl disaster. The knowledge of 241Am in the sediments of the Baltic Sea is limited. Thus, this study aimed to determine 241Am in sediment cores collected from the southern Baltic Sea. Time-based distributions were derived from age-depth profiles using the 210Pb dating method and further corroborated by 137Cs profiles. The activities of 241Am were measured by alpha spectrometry after radiochemical purification. The results show divergences in the concentrations of 241Am at the local level, varying from 0.017 ± 0.001 Bq·kg-1 at the Gotland Basin station to 3.19 ± 0.23 Bq·kg-1 in the Gdansk Basin. These findings enhance our understanding of the radioactive contamination levels in the Baltic Sea and serve as a crucial reference dataset for future assessments and management strategies to mitigate the environmental impact of radionuclides in the region.

A pioneering study of the radiological mapping in the world's largest mangrove forest (the Sundarbans) and implications for the public and environment.

Coastal Mangroves are facing growing threats due to the harmful consequences of human activities. This first-ever detailed study of natural radioactivity in soil samples collected from seven tourist destinations within the Sundarbans, the world's largest mangrove forest, was conducted using HPGe gamma-ray spectrometry. Although the activity levels of 226Ra (11 ± 1-44 ± 4 Bq/kg) and 232Th (13 ± 1-68 ± 6 Bq/kg) generally align with global averages, the concentration of 40K (250 ± 20-630 ± 55 Bq/kg) was observed to surpass the worldwide average primarily due to factors like salinity intrusion, fertilizer application, agricultural runoff, which suggests the potential existence of potassium-rich mineral resources near the study sites. The assessment of the hazard parameters indicates that the majority of these parameters are within the recommended limits. The soil samples do not pose a significant radiological risk to the nearby population. The results of this study can establish important radiological baseline data before the Rooppur Nuclear Power Plant begins operating in Bangladesh.