This 3-y retrospective study analyzed 180 paired dosimetry records from five interventional radiologists and five cardiologists, comparing whole-body Hp(10) with eye-lens Hp(3) and extremity Hp(0.07) doses. Moderate-to-strong linear correlations were observed (r = 0.86-0.91, R2 = 0.73-0.83), indicating that chest-level dosemeters may support the estimation of localized exposure. Coefficients of variation were ~30% for k1 and 27% for k2, reflecting heterogeneous exposure conditions. Variance-component analysis showed that inter-operator variability accounted for 20%-25% of total variance, versus 75%-80% residual within-operator variability, likely reflecting differences in workload, case mix, positioning, exposure geometry, shielding, and measurement uncertainty. The eye-lens conversion coefficient was higher in cardiologists (1.8) than in the non-neurointerventional radiology/neurointerventional radiology group (0.68), suggesting that operator-group-specific conversion coefficients may be more appropriate than a single universal coefficient. Empirically derived conversion coefficients provide a valuable complementary approach for the retrospective estimation of localized dose exposure when dedicated dosimetry is unavailable.

This study assessed indoor radon (222Rn) concentrations across 150 dwellings in Obuasi, Ghana, using CR-39 SSNTDs over a 180-day period. The influence of wall construction materials (concrete, sandcrete, clay, and wood), interior finishes (paint and paper plaster), and floor variations (mortar and tile) on radon levels were evaluated alongside soil (226Ra) activity and 222Rn exhalation rates. Indoor 222Rn varied from 15.1 to 64.9 Bq m-3 (AM: 87.9 ± 10.1 Bq/m3), with concrete dwellings recording the highest concentrations and wooden dwellings the lowest. Bedrooms exhibited the highest indoor radon concentrations, consistent with limited ventilation and typically longer occupancy periods. Paper-plastered walls and tiled floors were associated with lower radon levels compared to painted walls and mortar floors. Strong positive correlations were observed between soil 226Ra, 222Rn exhalation rate (r = 0.87), and indoor radon (r = 0.61), confirming geogenic sources as primary contributors to indoor radon variability. Annual effective doses ranged from 0.3 to 9.2 mSv/yr, with 13% of locations exceeding International Commission on Radiological Protection (ICRP) reference limits. These findings offer evidence-based guidance for safer construction practices and support the development of national radon reference levels in Ghana.

Radiation dose monitoring software (DMS) tools are increasingly used to support automated monitoring of radiation dose in medical imaging. This study evaluated the frequency and causes of high-dose events detected by a DMS in computed tomography (CT). All CT examinations performed at one hospital across three CT scanners over a one-year period were retrospectively analysed to establish the frequency and causes of high-dose alerts. Descriptive statistics summarized alert frequency and distribution, and multivariable logistic regression identified factors independently associated with high-dose alerts. Of 11,865 CT examinations, 851 (7%) exceeded predefined dose thresholds. High-dose alerts occurred most frequently in spine (17%), musculoskeletal joint (14%), abdomen/pelvis (8%), vascular angiography (8%), chest/lung (5%), and head/face (4%) examinations. Reasons for high-dose alerts included high body mass index (29%), scan repetition (25%), additional scans (15%), patient malpositioning (12%), excess scan range (11%), and orthopaedic hardware (6%). Multivariable analysis showed that overweight status, scanner model, spine and joint examinations, and patients aged 45-74 years were independently associated with high-dose alert occurrence (P < .05). DMS is an effective tool that enables imaging facilities to automatically identify high-dose events, facilitating investigation of their causes, protocol review, and identification of opportunities for dose optimisation.

This study compared external dose rates and radiation protection metrics between the conventional whole-gland technique (CWT) and sparse implantation technique (SIT) in 100 patients (50 each with CWT and SIT) undergoing permanent 125I prostate brachytherapy. External dose rates were measured at various distances from the anterior body surface at 1 and 30 days post-procedure. Time-dependent dose rates were estimated using an exponential decay model based on the physical half-life and compared with measured values. Lifetime cumulative effective dose, cumulative effective dose during the first 60 days, and distance-specific precaution periods were also evaluated using occupancy factors. SIT reduced external radiation exposure and shortened the precaution period compared with CWT. The precaution period increased nonlinearly at closer ranges and was consistently shorter in the SIT group compared with the CWT group. Utilizing cumulative effective dose assessments during the initial 60 days post-procedure provides a practical radiation protection indicator for real-world environments.

This study evaluated fetal-region doses and dose distributions for X-ray pelvimetry (Guthmann and Martius methods) using exposure conditions from a nationwide survey in Japan and compared them with those of a low-dose computed tomography (CT) protocol using a realistic late-pregnancy phantom. A pregnancy model phantom combining an anthropomorphic phantom with a custom-made abdominal phantom was used. Real-time dosimeters were placed at 18 sites across three abdominal levels. The low-dose CT protocol showed a nearly uniform fetal-region dose distribution, whereas the X-ray methods showed heterogeneous distributions depending on beam direction and irradiation field. The reported mean fetal-region doses were 1.16 mGy for Guthmann, 4.05 mGy for Martius, 5.21 mGy for the combined X-ray examinations, and 0.69 mGy for low-dose CT. These results indicate that the low-dose CT protocol evaluated in this study produced a lower fetal-region dose than the Guthmann and Martius methods evaluated in this study.

Forest floor humus is a long-term reservoir of radiocaesium, but its behaviour decades after the Chernobyl accident remains incompletely understood. In 2020, 283 humus samples from Czech coniferous forests were analysed for 137Cs, 40K, and 210Pb activities, element contents and site characteristics. 137Cs activity ranged from 6.26 to 931 Bq kg-1, with a geometric mean (GM) of 90.5 Bq kg-1. At 157 corresponding monitoring locations, GM 137Cs activity decreased from 342 Bq kg-1 in 1995 to 195 Bq kg-1 in 2005 and 99 Bq kg-1 in 2020. Effective half-lives increased from 12.3 to 15.4 years, while environmental half-lives increased from 20.8 to 31.5 years, indicating a slowing of 137Cs removal or redistribution. Present-day variability was associated mainly with post-Chernobyl deposition and modified by 40K, 210Pb, Pb, acidity, and humus type.

Chronic myeloid leukaemia (CML) is a clonal myeloproliferative neoplasm associated with the Philadelphia chromosome, and ionizing radiation is a well-established leukemogenic factor. Despite regulated dose limits, occupationally related CML remains rare and under-recognized. We present the case of a 53-year-old male radiology technician diagnosed with CML following the detection of leukocytosis during routine periodic fitness-for-work surveillance. The patient had 29 years of documented occupational exposure with a cumulative effective dose of 150 mSv, without acute incidents. While International Commission on Radiological Protection recommendations primarily focus on fitness-for-work rather than malignancy screening, this case-the first officially recognized and institutionally attributed occupational CML in our country-demonstrates how systematic surveillance can facilitate the identification of serious haematological conditions in high-exposure (Class A) workers. It provides a structured Probability of Causation assessment to support occupational attribution and statutory recognition within a regulated low-dose environment on a probabilistic basis.

To quantify and compare breast radiation dose across CT protocols using shielding and automatic tube current modulation (ATCM) in single- and dual-energy scanning modes. Surface breast dose was measured using a calibrated pencil ionization chamber placed in a female anthropomorphic phantom. Scans were performed on a 128-slice CT system across multiple anatomical regions using manual mA, ATCM, lead shielding, and single- and dual-energy modes. In single-energy abdominal CT, shielding reduced measured surface breast dose by 12.2%, and ATCM provided an additional 38.2% reduction. Dual-energy CT resulted in higher measured surface breast doses than single-energy, but shielding reduced dose by approximately 62%. The greatest reductions were observed in head and neck (63.7%) and facial bone scans (89.5%). Lead shielding and ATCM effectively reduced surface breast radiation dose, particularly in regions dominated by scatter. Dual-energy imaging increased dose, while combining shielding with ATCM provided the greatest reduction.

This study presents the application of an analytical model, PARMA, to estimate the population-weighted annual absorbed dose to the lens of the eye due to cosmic rays. Cosmic ray flux data incorporating geographical altitude, together with the global population data from 2020, were used to estimate the global population-weighted annual eye lens dose. The resulting value was 0.267 mGy, ~11% lower than the annual effective dose due to cosmic rays evaluated in the latest UNSCEAR reports. This population-weighted estimate provides a more accurate assessment of background eye lens dose levels and facilitates comparison among the public, aircrew, and astronauts. This estimate also provides a refined baseline for epidemiological studies of lens cataracts.

Monte Carlo (MC) methods are generally recognized as the gold standard for dose calculations. However, achieving high statistical confidence is computationally expensive, particularly when complex secondary particles are involved. Kinetic Energy Released in Matter (KERMA) approximation method is a variance reduction technique widely used in MC simulations. This study evaluated the accuracy and efficiency of the KERMA approximation for Boron Neutron Capture Therapy (BNCT) dose calculations using the TOol for PArticle Simulation MC code. Simulations were performed on a CT phantom of a glioblastoma patient using an accelerator-based BNCT source. It was found that neutron KERMA results agreed with Analog MC results within 2%, while providing a 157-fold computational speed-up. However, the photon KERMA approximation overestimated skin photon dose by ~12%. The results suggest that the KERMA approximation for BNCT offers clinically acceptable accuracy and efficiency, while using Analog MC method for skin photon dose evaluation can further improve overall accuracy.

Detection and management of alpha (α)-emitting radioactive sources in scrap metal present a significant challenge for radiological safety, particularly in countries lacking infrastructure for the final disposal of radioactive waste. This paper presents a case study from Kosovo addressing the detection, identification, dose measurement, and isolation of an alpha-emitting radioactive source discovered in scrap metal. Identification was performed using portable radiation survey instruments and gamma spectrometry, confirming the presence of thorium-232 and uranium-232. Measurements indicated a count rate of ~2000 cps and a maximum ambient dose rate of 6.51 μSv/h measured at an approximate distance of 5 cm from the radioactive source prior to isolation and concrete filling. To reduce exposure and contamination risks, the source was isolated in a 200-L metal drum filled with reinforced concrete. Dose rate mapping performed before and after isolation demonstrated a significant reduction in radiation levels, with a maximum reduction factor of 4.86, indicating a measurable reduction in ambient dose rate following temporary isolation.

The increasing exposure to low-frequency electromagnetic fields has raised significant concerns regarding its potential effects on human health and the environment. At the same time, it has spurred growing interest in identifying low-exposure scenarios to support green and sustainable objectives. This study presents the results of in situ measurements of magnetic flux density across various exposure scenarios. Measurements were also conducted at close distances from different photovoltaic panels to summarize magnetic flux density exposure levels. Additionally, the study includes the measurement of magnetic flux density at various locations within electric, mild hybrid, and hybrid vehicles. To our knowledge, this is the first time such measurements have been reported for the region of Kosovo, providing initial valuable data for assessing exposure levels for both the general population and workers. The results offer a basis for comparative studies with other countries, contributing to the global understanding of electromagnetic field exposure.

The aim was to assess the impact of collimation on the field of view, dose-area product, effective dose, and absorbed dose to organs located in or near the primary beam. Data were collected using two Siemens radiography units. Imaging was performed under standard clinical protocols in posteroanterior (PA) and lateral projections. Images from 372 patients aged 18 years or older were randomly selected for analysis. For each image, exposure parameters, dose-area product, and field of view were recorded. Based on the field of view, images were classified as optimally or non-optimally collimated. Effective dose and absorbed organ doses were calculated using PCXMC 2.0. With optimal collimation, the field of view was reduced by up to 14.5%, and the dose-area product decreased by 26.6% in the PA projection and 48.4% in the lateral projection. Correspondingly, the effective dose was reduced by 18.3% in PA and 49.1% in lateral projections. Absorbed doses to selected organs decreased by 10%-55.5% in PA and 31.8%-60.9% in lateral projections. The results indicate that collimation is an essential optimization tool that can significantly reduce the patient's dose, thereby lowering the risk of radiation-induced complications.

The deployment of baggage scanners in airports and public facilities requires periodic radiation surveys to ensure occupational safety and regulatory compliance. This study assessed ambient dose equivalent rates (H* (10)) around baggage scanners at selected airports, ports, and commercial facilities. Measurements were taken at: 1 m from the entry and exit points, 2 m from the scanner, and the control panel. Measured dose rates ranged from 0.02 to 0.55 μSv/h, with the highest values near the entry and exit openings. Dose rates at operator positions were generally ≤0.10 μSv/h, comparable to background levels. Conservative annual effective dose ranged from 0.28 to 4.22 mSv/year. Realistic occupancy scenarios indicated that most operators received <1 mSv/year. Estimated doses were below the 20 mSv/year recommended by international standards. These results confirm adequate radiation safety margins in Tanzanian facilities. Continued routine monitoring and personal dosimetry are recommended to maintain compliance and protect workers.

Occupational radiation exposure remains a critical concern in interventional cardiology, particularly regarding brain and ocular protection. This study evaluates the protective efficacy of a 0.12 mmPb leaded acrylic full-face shield through a series of comprehensive in vivo dose measurements conducted on a primary cardiologist during real-time fluoroscopy procedures. The cardiologist was equipped with a tight-fitting elastic mask where 29 small pockets were distributed across the head, housing 29 thermoluminescent dosemeters (TLD) calibrated in Hp(0.07). Two series of measurements were conducted: the first using the leaded acrylic face shield without protective glasses, and the second without the leaded face shield and with protective glasses. The Dose Reduction Factors (DRFs) for the different superficial head areas, calculated as the ratio of Hp(0.07) with and without the leaded face shield, depended on the measurement point as expected and ranged between 0.32 and 0.57, where the lower value was for the frontal lobe. Regarding dose reduction measured around the eye orbit, a DRF of 0.10 and 0.35 was achieved for the right and left sides, respectively, indicating a significant level of protection of the ocular area.