International Journal of Nanomedicine

Abstract The aim of this comprehensive study was to analyze the annual effective doses to the public due to radioactive effluents discharged from the Hanbit nuclear power plants (NPPs) in Korea and identify potential improvements for the current environmental radiation monitoring system. We meticulously analyzed the amount of radioactive effluents discharged from the Hanbit NPPs and their resulting doses to the public for a decade (2014–23). Carbon-14, which accounted for only 1.90% of the total activity in radioactive effluents, contributed 88.53% of the annual effective doses to the public. This impact was significantly larger than that of tritium, which constituted most of the radioactive effluents. We propose potential improvements for the environmental monitoring system, including an increase in monitoring points and cycles of the seawater and seabed sediments to consider the characteristics of oceanic dispersion and the implementation of a radioactivity analysis of carbon-14 in ingestion and respiration-related environmental samples.

Abstract With the increase in the distribution of sources of electromagnetic fields in the environment, public exposure to non-ionizing radiation emitted from these sources will increase and change with time. This work aims at the evaluation of public exposure to radiofrequency electromagnetic fields in the West Bank and compares this exposure with previous studies with a time interval difference of 11 years. Measurements of exposure were conducted in the outdoor environment in 149 locations using tri-axial E-field frequency-selective personal exposure meter EME SPY 140 enabling measurements of electric field strength in 14 predefined frequency bands in the range from 80 to 6 GHz. The average field strength from all sources in all investigated locations was 1.4 Vm−1. The maximum exposure measured at any location in the country was 7.43 Vm−1 and was found in Ramallah City center. The exposure quotient corresponding to this value was about 19 times below unity. The total exposure quotient for all locations was 0.001 with FM broadcasting being the main contributor by about 36%, UMTS2100 downlink by 24%, GSM 900 downlink contributing by 17%, WiFi 5GHz by 9% GSM 1800 downlink by 5%. Seven other RF sources contributed together by only 9% including WiMax, TV, WiFi 2 GHz, and others. More than 90% of the electric field strength values were below the level of 3 Vm−1. Within 11 years the average total exposure coefficient increased by a factor of about 2.

Abstract Due to the increasing cases of cancer in Babylon and the neighboring Governorates according to the annual reports of the Iraqi Cancer Registry, this study was conducted on thirteen brick factories south of Babylon Governorate, by using a NaI (Tl) gamma-ray detector (3″ × 3″). Brick samples (S) taken from surface soil production line (5–50 cm) and (D) taken from deep soil production line (50–300 cm) were collected from those factories. The average values of the activity concentrations of 238U, 232Th, and 40K for the brick samples obtained from the surface soil are (19.9 ± 1.5), (47 ± 2.8), and (365.8 ± 6.7) Bq/kg respectively, while the average values of the deep soil reached 18 ± 1.5, 41.7 ± 2.7, and 352.4 ± 6.61 respectively. Also, radiological hazards including Radium equivalent activity (Raeq), absorbed dose rate (DR), indoor and outdoor annual effective dose (AEDEindoor and AEDEoutdoor), and excess lifetime cancer risk (ELCRindoor) were calculated. The results of activity concentrations were within the permissible limits, except for the concentrations of 232Th, also there was a variation in the measurements between the brick production lines using surface and deep soil. The results of radiological hazards were within the limits allowed by the United Nations Scientific Committee on the effects of atomic radiation, except for the DR and ELCRindoor, for some samples, which pose a risk to users because high concentrations of 232Th in certain samples lead to elevated corresponding radiological indices, further research is needed to link these levels to cancer incidence conclusively. Therefore, it is recommended to adopt precautionary measures in factories with increased values to mitigate potential risks.

Abstract The market share of pure electric vehicle (PEV) as a green transportation steadily increases as the global demand for renewable energy sources and environmentally friendly mobility continues to increase. However, during PEV operation, the inverter system, as the key power conversion device, generates strong electromagnetic field in the local space. Long-term exposure to such electromagnetic environments may have potential effects on human body. In this study, the electromagnetic environment model of the PEV body, human body and simplified inverter is established. The finite element software, COMSOL Multiphysics, is used to calculate and analyse the variations in the induction field in different tissues of the driver and rear passenger, caused by the electromagnetic field generated by the inverter system operating at maximum power. The electromagnetic exposure level of the driver and rear passenger is assessed. Results show significant differences in the electromagnetic exposure levels of different seating positions in the vehicles. The electromagnetic exposure level in the driver’s body is higher than that of the rear passenger, but it does not exceed the exposure limits defined by the International Commission for Non-ionizing Radiation Protection. This finding effectively complements the study on evaluating the safety of the electromagnetic environment of PEV and improves public awareness.

Abstract Activity concentration of 238 U and 232Th and their decay products are assessed in soil at three hydrocarbon zones to determine the baseline before further fracking studies. The range of activity concentration for the three zones was 238U (from 9.2 ± 0.5 to 115.8 ± 7.5) Bq kg−1, 228Ra (from 8.3 ± 2.0 to 50.0 ± 4.4) Bq kg−1 and 226Ra (from 24.1 ± 2.3 to 86.8 ± 4.7) Bq kg−1; which are comparable to the global average values reported by UNSCEAR in soil. Similar activity-concentration patterns for 238U decay series and 232Th decay series for the three zones indicate no previous industrial action. This baseline is useful to assess a possible enrichment of Naturally Occurring Radioactive Materials if industrial activities take place in the future.

Abstract The UKHSA radon detectors with polyallyldiglycol carbonate sensing material produced from 2010 onward were used to confirm that they are purely radon detectors only with negligible interference from thoron presence. The statistical analysis of results, after following standard detector processing procedures, showed that such devices can only detect 2.4% ± 0.3% of the total thoron activity concentration compared to the calibrated reference device. It was also demonstrated that thoron, unlike radon, can only travel a very short distance from the source to be effectively measured. Based on the above, it has been concluded that interference of thoron in radon measurement is negligible (within the statistical measurement error), and hence can be ignored in standard indoor and outdoor measurements.

Abstract Naturally Occurring Radioactive Material (NORM) may pose radiological risks across various industrial processes. Characterizing NORM is challenging due to radionuclide diversity, complex material matrices, and the multiple analytical techniques required. This study documents an Intercomparison Exercise (ICE) on the radioanalytical characterization of NORM, organized by International Atomic Energy Agency and EEAE to evaluate participants’ abilities to implement appropriate radioanalytical techniques and promote harmonization, thus contributing to ongoing optimization efforts into radiation protection of workers and the public. Thirty-one laboratories from 21 countries participated and determined the activity concentrations of long-lived radionuclides such as 40K, 238U, 226Ra, and 232Th in two ICE items, most through gamma spectrometry. Improper handling and insufficient testing of equilibria status within uranium and thorium series were key sources of unsatisfactory results. Notably, laboratories’ accreditation status did not correlate with analytical accuracy. Overall, study findings highlight improvements are needed in sample preparation, assumptions’ validation and measurement uncertainty budget estimation procedures.

Abstract During the school year, radon (222Rn) was continuously measured with passive detectors in all public schools in Montenegro—345 primary and 47 secondary schools. Measurements were taken in all ground-floor classrooms and offices (2336 rooms in total), as well as in 182 first-floor rooms across 91 schools. On the first floor, the arithmetic mean (AM) of radon concentrations was 100 Bq/m3, and the median (MED) was 65 Bq/m3, with only five schools having rooms where radon levels exceeded 300 Bq/m3. On the ground floor of all 392 schools, the AM was 276 Bq/m3, and the MED was 146 Bq/m3. In 188 schools, some rooms had radon levels above 300 Bq/m3, and in 43 schools, certain rooms exceeded 1000 Bq/m3. An assessment of the effective annual doses from radon inhalation for pupils was also conducted. On average, the dose was 0.66 mSv per school year, although in some classrooms it reached up to 11 mSv.

Abstract The design of Bonner Sphere Spectrometer (BSS) was optimized using Bayesian approach for two different measurement purposes in the ISO 8529 neutron standard field of 241Am-Be source as follows: (i) for the best estimation of neutron fluence spectrum and (ii) for the best estimation of neutron ambient dose equivalent, H*(10). As results, two optimal sets of BSS system (with sequential specific diameters) were proposed: (i) for the first problem, an optimal BSS system with a maximum of six different diameters is needed to obtain neutron fluence spectrum with the standard uncertainties in each energy bin as low as reasonably achievable and (ii) for the second problem, if one would just like to achieve the output H*(10) with a standard uncertainty <10%, only two optimal BSS measurements are needed.

Abstract Purpose The aim of this study was to evaluate the radiation level of a ZAP-X self-shielding system by comparing it with the requirements of the Chinese radiation protection standards and to provide a practical solution for the operation of ZAP-X in China. Methods Under the maximum workload of the ZAP-X system, the weekly radiation dose and the instantaneous dose rate (IDR) outside the safety perimeter of the ZAP-X system were compared to the requirements of relevant standards. Results The maximum weekly and annual dose equivalents, derived from the IDRs and accumulative doses, were as follows:1.99 μSv/week and 0.10 mSv/year, and 3.47 μSv/week and 0.17 mSv/year, respectively. Conclusion The radiation levels around the ZAP-X system meet the requirements of the weekly and annual dose constraints in relevant Chinese standards. The IDRs generated by the ZAP-X system do not meet the requirements of the existing radiation protection standards. A viable solution is to adjust the safety perimeter to comply with existing standards.

Abstract Monazite is used as a raw material for the production of rare earth elements. The workers in the monazite industry are exposed to radiation from the raw material. Therefore, internal radiation dose should be assessed for radiological safety assessment of the workers. The objective of this study is to assess the internal radiation dose to workers of the monazite industry in Korea by means of measured particulate. Particulate properties, including size distribution, density, shape, and radioactivity concentration were analyzed. Then, the internal radiation dose coefficients were derived using the IMBA software. Work scenarios were derived by identifying the work time. Finally, internal radiation doses were calculated with the collected and calculated data. The internal radiation dose ranged from 7.48 × 10−3 to 3.25 × 10−1 mSv y−1 with dose difference by orders of magnitude. It is highlighted why such data should be directly collected at sites to realistically assess radiation dose to workers.

Abstract This study assesses the activity concentrations of the radionuclides 238U, 232Th, and 40K in soil samples collected from Wolaita Sodo town, located in the Southern Nations, Nationalities, and Peoples' (SNNP) Region, Ethiopia. A gamma-ray spectrometer equipped with a NaI(Tl) detector was used for the measurements. The concentrations of 238U, 232Th, and 40K varied from 3.25 ± 1.5 to 13.84 ± 2.2 Bq.kg−1, 0.4 ± 0.9 to 85.12 ± 3.4 Bq.kg−1, and 34.43 ± 2.7 to 748.07 ± 5.9 Bq.kg−1, respectively. The average activity concentrations were 7.83 ± 1.9 Bq.kg−1, 40.74 ± 2.7 Bq.kg−1, and 161.63 ± 3.9 Bq.kg−1 for 238U, 232Th, and 40K, respectively. The average radium equivalent activity was 192.25 Bq.kg−1, well below the recommended safety limit of 370 Bq.kg−1. The average gamma dose rate, and annual effective dose rate were 35.68 nGy.h−1, and 0.18 mSv.y−1, respectively. The internal and external indexes are below the recommended limit set by UNSCEAR and ICRP. However, the estimated excess lifetime cancer risk and indoor radon concentrations are slightly higher. Despite this, the overall radiological impact on the environment and public health in the study area remains negligible. This study provides valuable baseline data for radiation protection and informs urban and environmental policy in the region.

Abstract The present work is the first and foremost radiological study of soil samples collected from industrial estates in Tamil Nadu. The magnetic susceptibility measurement revealed that 74.19% of the samples have medium %χFD, which denotes a commixture of coarser grains or the SP grains with a size of <0.005 μm. The range of measured activities of 210Po and 210Pb were 3 ± 0.3–38 ± 2.6 Bq kg−1 and 16 ± 1.5–48 ± 2.9 Bq kg−1. The mean activity concentrations of 238U (33 Bq kg−1) and 40K (467 Bq kg−1) marginally exceeded the Indian recommended values of 28.67 and 400 Bq kg−1, respectively, whereas 232Th (47 Bq kg−1) did not exceed 63.83 Bq kg−1. The 238U and 232Th are the significant contributors to the production of radiogenic heat in the study area. Pearson correlation analysis confirmed the prime role of 232Th in radiation hazards and the insignificant relation between magnetic minerals and natural radioactivity.

Abstract Quality control (QC) of personal radiation protective equipment (PRPE) is essential to detect tears and holes in the attenuating layers. Routinely, this QC is performed using fluoroscopy on a conventional X-ray table. However, such a QC procedure is laborious and time consuming. This study aims to establish faster PRPE QC using CT scout or a biplanar radiography device. A reproducible 0.25 mm lead-equivalent phantom of ten holes (diameter 10 mm – 1 mm) and two incisions (length 50 mm and 25 mm with a width of 0.63 mm) was created to assess the defect detection performance using fluoroscopy, CT scout (Siemens Somatom Definition Flash and GE Revolution) and a biplanar radiography device (EOS). Additionally, three pieces of PRPE were imaged on all modalities and compared in terms of speed and defect detection performance. Defect quantification was performed with an X-ray opaque grid, the modality’s line tool and the built-in wand tool in ImageJ software. All modalities could visualize the smallest defects (1 mm). However, for the Siemens Flash, the smallest defect was only visible when the scout length was at most 50 cm. Fluoroscopy was the most time consuming (>1 min/piece). Both CT scout and the EOS allowed faster analysis (<10 s). The EOS system had the highest resolution of 5.19 pixels/mm for all set scan speeds. However, to image the reference pieces, a seamstress doll was needed. The wand tool was found to be the most accurate for defect estimation. Both the EOS and a CT scout allowed faster QC of PRPE with equivalent defect detection performance. However, specific positioning and scan length must be considered.