Assessment and mitigation of radiation hazard for individuals engaged in reconnaissance survey in uranium exploration in Jharkhand, India.

The present study attempts to obtain an a priori estimate of the absorbed dose received by an individual engaged in the reconnaissance survey in Uranium exploration using a predictive mathematical regression analysis. Other radiation safety parameters such as excess lifetime cancer risk are also calculated. Study reflects that the proper handling of naturally occurring radioactive materials accounts for an absorbed dose significantly less than the prescribed limit.

Assessment of radiation dose due to 210Po in water and food samples of Chamarajanagar district, Karnataka, India.

Groundwater is in direct contact with the soil and rocks that dissolve many compounds and minerals including uranium and its daughter products. 210Po is one of the decay products of 238U series that cause internal radiation dose in humans when consumed in the form of water and food, including sea food. Therefore, activities of 210Po have been studied in ground and surface water, and in food samples that are commonly used in Chamarajanagar region of Karnataka, India. The average 210Po concentration in bore well water samples and surface water samples are 3.21 and 1.85 mBq L-1, respectively. In raw rice and wheat, the average values of 210Po are 96 and 41 mBq kg-1, respectively. In millets and pulses, the average activity of 210Po is 157 and 79 mBq kg-1, respectively. Among food items, the highest activity of 1.3 kBq kg-1 is observed in marine crabs and the lowest activity of 2.6 mBq kg-1 is found in milk samples. The average ingestion dose due to 210Po in ground and surface water are 2.8 and 1.62 µSv y-1, respectively. The ingestion dose due to various food samples to the population is also calculated. Total ingestion dose due to 210Po to pure vegetarian population and general population are 38.09 and 590.80 µSv y-1, respectively. The concentration of 210Po in water samples and food samples of this region are in a comparable range with the world and Indian average values and lies well below the recommended guideline level.

Assessment of indoor radon concentration in the dwellings of the industrial areas of Kannur District, Kerala.

All organisms on the earth-crest are exposed to natural background radiation since the evolution of the earth, as many environmental matrices such as soil, air, water bodies, vegetation, etc., act as the sources of natural radioactivity. The present study deals with the evaluation of indoor concentration of 222Rn (radon) in different dwellings with various construction materials used for the roof and floor in the industrial sites of Kannur district, Kerala. A pinhole-based dosemeter coupled with LR-115 Solid State Nuclear Track Detector and Direct Radon Progeny Sensor (DRPS) were respectively used for the measurement of indoor radon concentration and equilibrium equivalent concentration of radon. The indoor radon concentrations were found to vary from 102.30 Bqm-3 to 184.75 Bqm-3 and the values were within the recommended limits provided by International Commission on Radiological Protection (ICRP). The annual effective doses and excess lifetime cancer risks were observed in the range of 2.58-4.66 mSvy-1 and 7.68 × 10-3-15.60 × 10-3, respectively, and both exceed the world average values recommended by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000. The study shows that, the houses with marble floors and concrete roofs have comparatively higher values of radon concentration, which indicates the significant contribution of construction materials to the enhanced radiation levels inside the dwellings.

Technologies for retrospective radiation dosimetry.

Radiation dosimetry is an important task for assessing the biological damages created in human being due to ionising radiation exposure. Ionising radiation being invisible and beyond the perception of human natural sensors, the dosimetry equipments/systems are the utmost requirement for its measurement. Retrospective measurement of radiation doses is a challenging task as conventional radiation dosemeters are not available at the exposure site. The material/s in close proximity of exposed individual or individuals' biological samples may be used as retrospective radiation sensor for dosimetry purpose. Environment materials such as sand, bricks, ceramics, sand stones, quartz, feldspar, glasses and electronic chips have been utilised using TL (Thermoluminescence) techniques for retrospective gamma dose (min 10 cGy) measurement. Electron Spin Resonance techniques have been employed to human biological samples such as tooth enamel, bones, nails, hair, etc. and reported for dosimetry for ~20 cGy min dose measurement. Some commercial glasses have been found sensitive enough to measure the minimum gamma doses of the order of 100 cGy using TL techniques. For internal retrospective dosimetry, the radioactivity contamination assessment in food items, water, other edible product and ambient air are the prerequisites. The radioactivity concentration vis-à-vis their consumption rate may help in controlling the internal contamination and estimation of dose absorption in human body. Defence Laboratory, Jodhpur has been working extensively on the dosimetry techniques for external dose measurement using environmental material and developed portable contamination monitoring systems for food and water radioactivity measurement in the range of 50 Bq kg-1 to 1000 kBq kg-1 in 60 s measurement time. The recent research and development in the methodologies, equipments and systems undertaken towards capacity building and self-reliance in retrospective radiation dosimetry is reported in this paper.

Radiation dose due to uranium in groundwater to the population of Chamarajanagar district, Karnataka, India.

This paper presents the concentration of uranium in 67 groundwater samples of Chamarajanagar district, Karnataka, India, estimated using an LED fluorimeter. The age-dependent ingestion dose to the population of the district is also studied. The concentration of uranium in groundwater varied from 0.20 to 57.50 µg L-1 with an average of 4.40 µg L-1. The annual ingestion dose due to uranium varies from 0.18 to 142.68 µSv y-1, with an average of 7.11 µSv y-1. The ingestion dose received by the population in the study area is less than the recommended level of 100 µSv y-1 by the World Health Organization (2011).

Ambient gamma radiation level around Kaveri river basin, Karnataka state, India.

Studies on ambient gamma radiation in indoor and outdoor environment and their effect on human health have created interest among the researchers across the world. The present study represents the results of indoor and outdoor ambient gamma dose rates around the Kaveri river basin from Talakaveri (Madikeri district) to Mekedatu (Ramanagara district) by using portable Environmental Radiation Dosemeter. The annual effective dose in the present study area varies between 0.14 mSv.y-1 and 0.58 mSv.y-1 with an average value of 0.30 mSv.y-1 for indoor radiation. The outdoor annual effective dose ranged between 0.01 mSv.y-1 and 0.14 mSv.y-1 with an average value of 0.06 mSv.y-1. The total annual effective dose varies from 0.17 to 0.72 mSv.y-1 with an average value of 0.36 mSv.y-1. The calculated values of indoor and outdoor annual effective dose in the study area (are found to be lower than the world average values (1 mSv.y-1 and 0.48 mSv.y-1).

Studies on uranium concentration in groundwater samples and its associated health hazards to the residents of surrounding regions of Manchanabele reservoir, Bengaluru, Karnataka, India.

Uranium occurs naturally in groundwater and surface water. Being a radioactive element, high uranium concentration can cause impact on human health. The health effects associated with consumption of uranium through water includes increased cancer risk and kidney toxicity. In view of this, an attempt was made in the present study to establish the level of radiological and chemical toxicity of uranium. Radiological toxicity was evaluated in terms of lifetime cancer risk and chemical toxicity through hazard quotient. For the said purpose, groundwater samples from the selected villages of the surrounding region of the Manchanabele reservoir, southwest of Bengaluru, were collected. The collected groundwater samples were analysed for Uranium mass concentration using Light emitting diode (LED) fluorimeter and is found to range from 0.88 to 581.47 ppb with a GM of 20.82 ppb. The result reveals that ~ 66% of the samples show concentration of uranium within the safe limit of 30 ppb as set by the World Health Organisation. The radiological risk estimated in terms of lifetime cancer risk is in the range of 0.0028 × 10-3 to 1.85 × 10-3 with a GM of 0.066 × 10-3. The chemical toxicity risk measured as lifetime annual daily dose is found to range from 0.03 to 21.65 µg per kg per d with a GM of 0.77 µg per kg per d.

Mapping of uranium concentrations in groundwater samples of Davanagere district, Karnataka, India, and assessment of effective dose to the population.

The geomorphology, geohydrology, lithology and ecological features of the area influence the uranium content in groundwater. The groundwater samples were collected from 75 locations of Davanagere district, Karnataka, India. Uranium analysis in the water samples was done using LED fluorimeter, based on fluorescence of dissolved uranyl salts. The uranium concentration in water samples varied from 18.41 to 173.21 µg L-1 with a geometric mean of 39.69 µg L-1. Higher uranium concentration in groundwater was observed in Harapanahalli and Jagalur taluk of Davanagere district, which falls in the Eastern Dharwar Craton, which is generally known to contain more radioactive minerals than the Western Dharwar Craton. The effective ingestion dose and lifetime cancer risk to the population were calculated using the obtained uranium concentration in drinking water.

Measurement of radon exhalation rate and radiation doses in fly ash samples.

Coal based thermal power plants contribute about ~ 72% of the power generation in India. Indian coal is of bituminous type, having a high ash content with 55-60% ash. Due to considerable environmental importance the collected fly ash has become a subject of worldwide interest in recent years. In the present study radon exhalation rate and the activity concentration of 226Ra, 232Th and 40K radionuclides in fly ash samples from Kasimpur Thermal Power Plant, Aligarh, Uttar Pradesh, India have been measured by 'Sealed Can technique' using LR-115 type II detectors and a low-level NaI (Tl)- based gamma-ray spectrometer, respectively. Radon exhalation rate has been found to vary from 57.1 ± 5.3 to 119.4 ± 7.7 mBq m-2 h-1 with an average value of 87.3 ± 5.8 mBq m-2 h-1. Activity concentration of 226Ra ranged from 20.0 ± 8.5 to 30.0 ± 9.7 Bq kg-1 with an average value 23.4 ± 9.0 Bq kg-1, 232Th ranged from 17.0 ± 9.9 to 69.0 ± 13.8 Bq kg-1 with an average value of 46.5 ± 12.1 Bq kg-1 and 40K ranged from 130.0 ± 7.2 to 332.0 ± 11.1 Bq kg-1 with an average value of 177.0 ± 8.1 Bq kg-1.

Role of independent research at AERB for ensuring safety of nuclear facilities in India.

The mission of Atomic Energy Regulatory Board (AERB) of India is to ensure that the use of ionising radiation and nuclear energy in India does not cause unacceptable impact on the workers, members of the public and to the environment. AERB has the mandate to carry out detailed safety review for the siting, construction, commissioning, operation and decommissioning of nuclear and radiation facilities established within the country. To deliver and maintain a strong, credible and technically sound regulation, AERB has established the Safety Research Institute (SRI) at Kalpakkam with a robust technical infrastructure and wide knowledge base. This paper highlights the independent safety research activities carried out at SRI and its role to support and facilitate the decision-making process by AERB at various stages of regulatory review for ensuring safety of the nuclear facilities in India.

Assessment of radiation dose due to 238U, 226Ra, 222Rn and 210Po in groundwater of Kodagu district, India.

Natural radionuclides are universally spread and can be found in varying levels in rock, soil and water depending on the geology. A potential health threat may be caused by them to humans on consumption of water, food and inhalation of air due to the presence of radionuclides. In the present study, an attempt has been made to study the distribution of 238U, 226Ra, 222Rn and 210Po in groundwater samples of Kodagu district, India. The activity concentrations of 238U, 226Ra, 222Rn and 210Po were found to vary from 0.44 to 8.81 µg L-1, 0.71 to 7.66 mBq L-1, 1.54 to 9.61 Bq L-1 and 0.47 to 4.35 mBq L-1, respectively. The associated dose due to radiation was assessed and was observed to be below the recommended standards. The total effective dose to the population was calculated and was found to be less than the recommended WHO standard of 100 mSv.

Simultaneous indoor radon/thoron and in situ outdoor gamma dose measurements and estimation of annual effective dose in a tin mining area of Jos Plateau, Nigeria.

Radon, a radioactive gas can increase the risk of lung cancer when breathe in. Indoor Rn-222 and Rn-220 concentrations were determined using passive radon monitor in some dwellings in a Sn mining area of Jos Plateau. Outdoor gamma radiation was also measured with a hand-held survey meter. The range of Rn-222 and Rn-220 concentrations was from 7-53 Bq m-3 to 41-267 Bq m-3 with averages of 27 ± 17 and 92 ± 65 Bq m-3, respectively. The mean total effective dose due to Rn-222 + Rn-220 was estimated as 2.84 ± 1.57 mSv y-1. Rn-220 contributed between 50 and 95% to the total annual effective dose. There was no correlation between indoor Rn-220 and Rn-222 concentrations in the dwellings. Outdoor gamma radiation measured was between 0.31 ± 0.06 and 0.62 ± 0.08 µSv h-1, and mean annual effective dose calculated was 1.14 ± 0.21 mSv y-1. It is concluded from this study that thoron should not be neglected in dose assessment.

222Rn and 220Rn levels in drinking water, emanation, and exhalation assessment, and the related health implications in the U-bearing area of Poli-Cameroon.

The inherent radioactivity of radon gas presents potential exposure risks to human beings through ingestion and inhalation of its radioisotopes 222Rn (radon) and 220Rn (thoron) from water sources. Recent studies have been conducted to assess radon concentrations in different environmental matrices such as water, air, and soil, due to their detrimental impact on human health. As the main cause of lung cancer in non-smokers and an acknowledged contributor to stomach cancer when ingested, the present study aimed to preliminarily assess radon and thoron levels in the Uranium bearing area of Poli in the Faro division of Cameroon, known for its significant U-deposits. The assessment included measuring 220, 222Rn concentrations in drinking water, emanation, and exhalation, with a specific focus on evaluating the exposure of different age groups within the local population. The radon/thoron levels in water and their related exposure and cancer risk data indicated no immediate health hazards. However, continuous monitoring and prospective measures are deemed essential due to the area's abundant U-minerals. The emanation measurements showed sparsely distributed data with a singularity at Salaki, where the equipment recorded values of 8.14 × 1012 Bqm-3 and 3.27 × 1012 Bqm-3 for radon and thoron, respectively. Moreover, radon/thoron transfer coefficients from the soil to the air indicated levels below unity. While the calculated doses suggest minimum potential risk in line with WHO and UNSCEAR guidelines, the obtained results are expected to significantly contribute to the establishment of national standards for radon levels in drinking water, emanation, and exhalation. Furthermore, these findings can play a crucial role in monitoring radon/thoron levels to ensure public health safety.

Monitoring of surgical staff x-ray exposure in the operating room with DosiBadge.

Surgical procedures involving the use of x-rays in the operating room (OR) have increased in recent years, thereby increasing the exposure of OR staff to ionizing radiation. An individual dosimeter makes it possible to record the radiation exposure to which these personnel are exposed, but there is a lack of compliance in the wearing of these dosimeters for several practical reasons. This makes the dose results obtained unreliable. To try to improve the rate of dosimeter wearing in the OR, the Dosibadge project studied the association of the individual dosimeter with the hospital access badge, forming the Dosibadge. Through a study performed at the Tours University Hospital in eight different ORs for two consecutive periods of 3 months. The results show a significant increase in the systematic use of the dosimeter thanks to the Dosibadge, which improves the reliability of the doses obtained on the dosimeters and the monitoring of personnel. The increase is especially marked with clinicians. Following these results and the very positive feedback to this first single-centre study, we are then planning a second multicentre study to validate our proof of concept on different sites, with the three brands of individual dosimeters used in France i.e. dosimeters supplied by Dosilab; Landauer and IRSN.

Improving a regional project on diagnostic reference levels for interventional procedures (OPRIPALC) with the support of a dose management system for the protection of patients and staff.

Interventional radiology is a clinical practice with important benefits for patients, but which involves high radiation doses. The optimisation of radiation protection (RP) for paediatric interventional cardiology is a priority for both patients and staff. The use of diagnostic reference levels (DRLs) has been proposed by the International Commission on Radiological Protection to improve RP in imaging procedures. Dose management systems (DMSs) allow the automatic collection of dosimetric, geometric and technical data to assist the optimisation process, with a continuous audit of the procedures, generating alerts to implement corrective actions when necessary. Patient dose indicators may be analysed individually and for different radiation events (fluoroscopy and cine runs). Occupational doses per procedure may be analysed (if electronic dosimeters are available) and linked with patient doses for an integrated approach to RP. Regional optimisation programmes require data collection and processing from several countries to set and periodically update the DRLs. Patient data is anonymised, and each participating hospital has access to their data in a central computer server. Using DMSs may be one of the best ways to support these programs in the collection and analysis of data, raising alerts about high patient and occupational doses and suggesting optimisation actions.

A Gaussian-plume based Monte Carlo method for calculating radiation dose in the near field of buildings.

A Monte Carlo (MC) programme was written using the dose point kernel method to calculate doses in the roof zone of a building from nearby releases of radioactive gases. A Gaussian Plume Model (GPM) was parameterised to account for near-field building effects on plume spread and reflection from the roof. Rooftop recirculation zones and building-generated plume spread effects were accounted in a novel Dual Gaussian Plume (DGP) formulation used with the MC model, which allowed for the selection of angle of approach flow, plume release height in relation to the building and position of the release point in relation to the leading edge of the building. Three-dimensional wind tunnel concentration field data were used for the parameterisation. The MC code used the parameterised concentration field to calculate the contributions to effective dose from inhalation, cloud immersion from positron/beta particles, and gamma-ray dose for a wide range of receptor dose positions in the roof zone, including receptor positions at different heights above the roof. Broad trends in predicted radiation dose with angle of approach flow, release position in relation to the building and release height are shown. Alternative approaches for the derivation of the concentration field are discussed.

Analysis of radon mitigation methods: 10-year review.

Exposure to the radon gas within a building can result in an increased risk of lung cancer. To minimise the health risk, indoor radon concentrations can be reduced using well-established mitigation methods. The performance of various radon reduction methods, their combination as well as other factors that can impact the efficiency of radon mitigation, were analysed using data collected from approximately 2800 dwellings that had installed radon mitigation techniques during the period 2007-2017. As demonstrated previously (Hodgson 2011), active methods are the most effective at reducing high concentrations of radon to below the Action and Target Levels (200 Bq m-3and 100 Bq m-3respectively). Reduction factors of up to 5.5 using single active methods and 8.3 using a combination of active methods were estimated in this study. For indoor radon levels greater than 1 000 Bq m-3, the Active Sump remained the most efficient technique, with the Active Underfloor Ventilation being the second most effective method. Passive methods alone or in combination with other passive methods offered moderate reductions at high radon concentration. Of the passive methods, Underfloor Ventilation was found to have the highest performance with a reduction factor of 1.8. The conclusions of this study should be used to update guidance for stakeholders including householders, contractors, radon awareness campaigns and the UKradon.org website.

Assessment of Occupational Radiation Exposures at Ghana Research Reactor-1 Facility.

The annual occupational doses for workers at the Ghana Research Reactor-1 facility were assessed for the period 2018-2021. The dose records of monitored staff were retrieved and analysis done for dose distribution and collective effective doses. Thermoluminiscent dosimeters were used to monitor the occupational exposures. The dosimeters were evaluated for the cumulative radiation dose levels using the Harshaw 6600 TLD reader system. Annual dose of 1.52 mSv/year was the maximum acquired by an individual. An annual average effective dose range of 0.20-1.36 mSv was determined for all workers. The annual total collective effective dose was established to be in the range of 0.40-10.08 man-Sv. The 20 mSv annual limit for occupational exposure was not exceeded for monitored workers. The assessment shows that the GHARR-1 facility, in terms of radiation health effects, is a favorable environment for workers since exposures are mostly below occupational exposure limit.

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.

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.