This paper presents findings on groundwater physiochemical composition and radioactivity levels in households in Bac Lieu province, Vietnam. Through discriminant analysis, it was observed that groundwater quality exhibits spatial variations corresponding to saline intrusion zones. The paired-samples T-tests revealed significantly different ratios of Ra-224, Ra-226, and Ra-228 isotopes between Na-Cl and Ca-Na-HCO3 water types. All three water types had a ratio of Ra-226/Ra-228 of approximately one, indicating the presence of groundwater aquifers beneath the crust and fluvial marine sediment. Furthermore, strong associations between sulfate and calcium suggest that CO2 enrichment in groundwater aquifers indicates anoxic aquatic environments. Twenty-five of the thirty-three evaluated samples exceeded the national technical regulations for domestic water quality with parameters such as chloride, sulfate, sodium, gross alpha, or total dissolved solids. Fifteen samples exceeded gross alpha\'s allowable contamination threshold of 0.1 Bq/L. The combination of Ra-226 and Ra-228 did not surpass the U.S. Environmental Protection Agency\'s recommended limit of 0.185 Bq/L. However, nineteen samples exhibited annual committed effective doses of radium isotopes for infants that exceeded the WHO recommendation of 0.1 mSv/year.

Radiation-induced acoustics (RIA) shows promise in advancing radiological imaging and radiotherapy dosimetry methods. However, RIA signals often require extensive averaging to achieve reasonable signal-to-noise ratios, which increases patient radiation exposure and limits real-time applications. Therefore, this paper proposes a discrete wavelet transform (DWT) based filtering approach to denoise the RIA signals and avoid extensive averaging. The algorithm was benchmarked against low-pass filters and tested on various types of RIA sources, including low-energy X-rays, high-energy X-rays, and protons. The proposed method significantly reduced the required averages (1000 times less averaging for low-energy X-ray RIA, 32 times less averaging for high-energy X-ray RIA, and 4 times less averaging for proton RIA) and demonstrated robustness in filtering signals from different sources of radiation. The coif5 wavelet in conjunction with the sqtwolog threshold selection algorithm yielded the best results. The proposed DWT filtering method enables high-quality, automated, and robust filtering of RIA signals, with a performance similar to low-pass filtering, aiding in the clinical translation of radiation-based acoustic imaging for radiology and radiation oncology.

The neutron activation of stable isotopes in environmental matrices, such as soil and groundwater, is a critical aspect of assessing the impact of radionuclide production facilities on the surrounding ecosystem. The envisioned Low-Energy Radioactive Ion Beams (LERIB) facility at the iThemba LABS, South Africa is anticipated to generate significant sources of ionising radiation. The study investigated the possible repercussions of neutron irradiation stemming from the facility, focusing on the activation of stable isotopic compositions in the environment. The investigation employed a combination of experimental and analytical techniques to characterize the neutron activation products in soil and groundwater samples collected from the vicinity. Samples were collected from designated areas for background radiological measurements and were irradiated with neutrons for a period of 1 h. The induced radioactivity measured by the High Purity Germanium detector included 24Na, 22Na, 54Mn, 52Mn, and 46Sc. The application of Darcy\'s law for groundwater velocity suggests that radionuclides in groundwater will migrate at an average flow velocity of 0.8 m/day. The isotopes with longer half-lives have count rates at background concentrations; therefore, environmental impacts on the site and surrounding communities might be minimal.

The maturation of robotic and remote systems presents opportunities to expand the use of technologies that have typically been restricted to high-dose/high-risk nuclear work for moderate- or low-risk work to further reduce radiation exposure to workers. This study quantifies the potential dose savings achieved through the use of robotic techniques for characterizing transuranic-contaminated waste items and compares dose estimates from a simplistic, user-friendly deterministic radiation transport code and a more robust, complex Monte Carlo code. Three scenarios of transuranic-contaminated waste items described in published reports are modeled using representative source geometries in MicroShield and MCNP radiation transport codes. Estimated dose rates are determined at points ranging from 30 cm to 300 cm from the face of the waste item to represent the increase in distance allowed by robotic or remote system implementation for characterization activities. The dose rate savings are then converted to detriment cost savings using a dollar-per-person-dose conversion factor to provide a financial context. The radiation transport simulations show no consistent bias in estimated dose rate by varying simulation methodology or using geometrical simplifications-in some cases, MicroShield produces higher dose rate estimates while MCNP estimates are higher in other cases. In the MCNP simulations, the volume source geometry consistently produces a higher dose rate than the slab source geometry, but the MicroShield dose rate estimates do not display the same trend. Dose savings range from 1.60 × 10-5 μSv h-1 to 1.75 × 101 μSv h-1 with associated detriment cost savings from < 0.010 USD/person-h to 14 USD/person-h.

All humans are exposed to radon, the primary source of natural radiation, which can harm people due to natural processes rather than human activity. Thus, it is of significant importance to determine the levels of radon in indoor, soil gas, water, and outdoors. Radon concentration (CRn) was measured in Kiraz district, İzmir, and the correlation between the indoor and soil gas CRn values was investigated. The indoor CRn values measured in 40 randomly selected dwellings in Kiraz exhibited a wide range from 19.50 ± 2.50 to 204.70 ± 8.00 Bq m-3 with an average value of 61.11 ± 4.23 Bq m-3. The measured indoor CRn values were compared to the reference levels in the world to help control radon in the dwellings. Indoor CRn values were lower than the ICRP reference level of 300 Bq m-3 in all of the dwellings studied. Furthermore, in 34 dwellings (representing 85% of the total number of dwellings studied), indoor CRn values were lower than the WHO reference level of 100 Bq m-3. Health hazard indices, namely annual effective dose (AED) and excess lifetime cancer risk (ELCR), were also calculated for each dwelling and compared with internationally acceptable levels to estimate the risk to human health. The AED values varied from 0.49 ± 0.06 to 5.16 ± 0.20 mSv y-1 with an average value of 1.54 ± 0.11 mSv y-1, which exceeds the world average of 1.15 mSv y-1 as reported by UNSCEAR. The ELCR values ranged from 2.05 ± 0.26 × 10-3 to 21.55 ± 0.84 × 10-3 with an average value of 6.43 ± 0.44 × 10-3, exceeding the world average of 0.29 × 10-3 as reported by UNSCEAR. The soil gas CRn values measured exhibited a wide variation ranging from 129.25 ± 6.38 Bq m-3 to 6172.64 ± 44.06 Bq m-3 with an average value of 1291.79 ± 18.70 Bq m-3. The soil gas CRn values were less than 10,000 Bq m-3; hence, the research area is categorized as \"low radon risk areas\" according to Sweden Criteria, and so no special constructions are required in the studied area. When soil gas CRn values were compared to indoor CRn values, no linear relationship was found between the CRn values. However, a strong positive linear correlation was found between indoor and soil gas CRn values less than 200 Bq m-3 and 2500 Bq m-3, respectively.

This investigation quantifies the activity concentrations of natural radionuclides (226Ra, 232Th, and 40K) in the soils and certain rocks of the Koytash-Ugam Range, Uzbekistan, and assesses their radiological risks. Gamma-spectrometric analysis of soil and rock samples revealed activity concentrations ranging from 456.2 ± 56.0 to 813.9 ± 76.0 Bq kg-1 for 40K, 18.2 ± 6.3 to 70.0 ± 12.0 Bq kg-1 for 226Ra, and 30.1 ± 2.9 to 57.9 ± 10 Bq kg-1 for 232Th. This data indicates a heterogeneous distribution of radionuclides, informing radiation safety and health risk assessments on a global scale. The calculation of radiological hazard indices, including the alpha-index (ranging from 0.09 to 0.35), gamma-index (ranging from 0.40 to 0.73), and both internal (ranging from 0.40 to 0.54) and external (ranging from 0.36 to 0.54) hazard indices, was undertaken to ascertain potential health risks. The radium equivalent activity ranged from 108.4 to 199.3 Bq kg-1, and the absorbed dose rates were 51.0-93.3 nGy h-1 indoors and 96.6-178.2 nGy h-1 outdoors. These metrics underlie the estimated annual effective dose of 536.5-988.5 × 10-3 mSv y-1, highlighting the variability in radiation exposure. Additionally, the potential lifetime cancer risk was projected at 1770.4 to 3262.0 per million, with an annual gonadal dose equivalent of 361.9 to 655.5 μSv y-1, reflecting natural background radiation influence. The results underscore the importance of safe material use in construction and the necessity for routine natural radioactivity monitoring. Radon flux density (RFD) values within acceptable construction limits (26-176 mBq m-2 s-1) suggest the area\'s suitability for development, considering recommended safety guidelines. This study not only aids local environmental and public health frameworks but also enriches the international knowledge base, facilitating comparative studies for the advancement of global radiation protection standards. Through a detailed examination of radionuclide distribution in an under-researched area, our research highlights the critical need for integrated international approaches to natural radiological hazard assessment.

The natural radioactive decay of uranium in rocks and soils gives rise to the presence of radon in groundwater. The existence of radon in groundwater at activity levels way higher than the reference limits set by US-EPA and WHO was widely covered in literature. The exposure to elevated levels of radon in ground and drinking water have been reported in literature to cause adverse health impacts. The aim of the present paper is to give an overview of radon gas in groundwater followed by the safe limits suggested by international organizations and agencies such as US-EPA and WHO. The paper also discusses the health effects associated with the exposure to radon levels and the estimation of the annual effective dose through ingestion and inhalation. This is followed by the radon levels around the world as well as the corresponding annual effective doses reported in literature. The determination techniques of radon levels in water covered in literature such as liquid scintillation counting, gamma-ray spectrometry and emanometry were also discussed and reviewed in the present work. Next, the paper sheds light on the most frequently used treatment techniques such as aeration, adsorption, filtration as well as biological techniques and evaluates their efficiency in mitigating radon levels in water. The paper also highlights the main precautions and future mitigation plans for radon in groundwater as well as delved onto future research perspectives of radon. It was found out that the type of rock played a key role in determining the radon levels. For instance, granitic rock types were reported to contribute to the elevation in the groundwater radon levels due to their characteristic permeability as a result of the formed fractures as well as their natural incorporation of high levels of uranium. Some of the reported radon levels in groundwater in literature were way higher than the guidelines set by the World Health Organization (WHO) for drinking water and US-EPA alternative higher maximum contaminant level. This review paper could be of importance to researchers working on the evaluation as well as the treatment of radon gas in water as it will provide a critical and state of the art review on radon gas in groundwater.

Radiopharmacy staff members are subject to extremity radiation doses, particularly to the fingertips. Dosemeters, such as, thermoluminescent detectors (TLDs) are currently used for monitoring fingertip doses. This study aimed to use real-time dosemeters to monitor radiopharmacy extremity doses to identify specific procedural steps associated with higher fingertip doses and, subsequently, reduce dose through promotion of optimised radiation protection practises. Five radiopharmacy operators were monitored using an ED3 active extremity dosemeter with a detector attached to each tip of the index fingers. Dose rate and accumulated dose data were matched to the handled radioactivity data, of99mTc-labelled radiopharmaceuticals only, with the dose per activity (μSv MBq-1) calculated for each step. Once baseline dose data was established, an educational session identified technique adjustments toward improved radiation protection. A subsequent monitored session was undertaken with the dose data compared to quantify changes in operator doses. Radiopharmacy steps which significantly contributed to extremity doses were identified. The average accumulated dose per activity across all procedural steps for the99mTc-labelled radiopharmaceuticals for all operators before the educational session was 0.042 ± 0.045μSv MBq-1and 0.042 ± 0.041μSv MBq-1(n= 89) for non-dominant and dominant index fingertips, respectively, and 0.030 ± 0.044μSv MBq-1and 0.031 ± 0.032μSv MBq-1(n= 97), respectively, afterwards. Overall, there was an average 40.7% reduction in the total extremity dose received after the educational session. Real-time electronic extremity dosemeters for monitoring radiopharmacy extremity dose presented as a useful tool for incorporation into radiation protection education and training, towards optimised radiopharmacy technique.

This study aimed to estimate radon concentrations in groundwater and surface water to evaluate radon (222Rn) contamination in drinking water within the Amreli region of Saurashtra, Gujarat, India. Water samples from 84 sites, covering about 3000 km2, were analyzed using the RAD7 device from Durridge Instruments. Samples were collected in 250 ml radon-tight bottles. Radon concentrations ranged from 0.1 to 13.6 Bq/L, averaging 4.52 Bq/L. At three sites (P9, P29, P35), radon levels exceeded the USEPA limit of 11.1 Bq/L. P9 and P29 are near the Tulsishyam geothermal area, while P35 is close to the Savarkundla fault. Geothermal fluids in Tulsishyam may facilitate radon migration, and swarm-type earthquakes near Savarkundla could also contribute to radon migration. Concurrently, physicochemical parameters like Potential of Hydrogen (pH) and Total Dissolved Solid (TDS) were measured, with no significant correlation found between radon levels and these parameters. Samples were taken from tube wells with depths ranging from 105 to 750 feet, averaging 359 feet. A strong and significant correlation (0.83) was observed between radon concentration and water depth. Health risks from radon exposure were assessed by estimating annual effective dose rates for different age groups through ingestion and inhalation. In some instances, the annual effective dose rate surpassed the WHO-recommended value of 100 µSv/year. However, in most instances, the presence of radon in the water does not indicate a significant radiological risk.

The use of a Monte Carlo code in the assessment of residual radioactivity for decommissioning of a medical cyclotron facility requires a reasonable approximation to the facility\'s history of operations. A periodic irradiation scenario simulating the cyclotron\'s daily operation for radioisotope production is generally considered reasonable, but its implementation in the code\'s input file can be cumbersome because more than thousands of irradiation cycles must be modeled. In practice, two simplified scenarios with continuous irradiation are commonly used instead: (i) omitting the downtime between two irradiation periods and (ii) extending the irradiation duration across the entire operational lifespan of the facility, albeit with a reduced beam current to maintain workload consistency. A systematic comparison of residual radionuclide productions across various half-lives under these three scenarios was performed. This technical note presents the resulting correction factors for the two simplified continuous irradiation models, enhancing their applicability in estimating radioactive inventories under a range of circumstances.