Radiation Protection

Catheter angiography and interventional radiologic procedures are the medical applications with the highest exposure to radiation. The projection used, in other words the irradiated region of the patient, constantly changes and the change in irradiation geometry due to the movements of the image amplifier is another important factor. Irradiation can be achieved in the form of continuous (fluoroscopic) or sequential static images (filming). In these irradiations the kVp, mA and irradiation time of the system change continuously depending on the patient thickness. The aim of this study was to determine the dose of radiation the staff working in Angiography and Interventional Radiology unit and the patients undergoing intervention were exposed to and to discuss the measures to decrease the dose of radiation. In this study, the dose values of 129 patients and three physicians and two radiotechnologists working in the unit were determined. In order to evaluate the radiation doses of the ...

The current system of dosimetric quantities has been defined by the International Commission on Radiological Protection (ICRP) and the International Commission on Radiation Units and Measurements (ICRU). Complexity of the system implies the physical nature of ionizing radiation, resulting from the presence of different types of radiation of different ionization capabilities, as well as the individual radiation sensitivity of biological material exposed. According to the latest recommendations, there are three types of dosimeter quantities relevant to radiation protection and radiological assessment of occupational exposure. These are the basic quantities, safety quantities and operational quantities. Dose limits for occupational exposure relate directly to the protection quantities, i.e. the equivalent dose and effective dose, while these quantities are practically unmeasurable in real measurement conditions. For this reason, in the system of dosimetric quantities directly measurabl...

The adequate management of water resources is of national strategic interest to guarantee access, equitable and sustainable distribution of the water resource as a key component for national socio-economic development and the preservation of the environment. In general, agriculture consume the largest volume of water available for consumptive use. Amongst the factors that contribute to irrigation water wastage is the lack of knowledge of the soil hydraulic conductivity properties. Therefore, there are incentives to propose new methods and techniques, in coherence with current trends in agri-instrumentation and information technology systems, to assess the hydraulic conductivity properties of soils, in order to provide hard data that can in turn be used to optimize water resources planning and allocation for irrigation purposes. Here, the authors present an IoT Electrical Impedance Tomography sensor (Electrical impedance Tomography - Wetting Front Detector: EIT-WFD) for in situ monitoring the change of water content in crop soils as irrigation is applied. The distributed computing architecture on the edge allows obtaining data for imaging the soil wetting front propagating down the soil sample, and facilitates the integration of hydraulic conductivity data with other agriculture sensing systems and have important implications for evaluating the effects of irrigation and agricultural management.

Mammography is the best tool for early detection of Breast Cancer. In this diagnostic radiology modality it is necessary to establish the criteria to ensure the proper use and operation of the equipment used to obtain mammographic images in order to contribute to the safe use of ionizing radiation. The aim of the work was to implement at FUCAM-AC the radiation protection program which must be established for patients and radiation workers according to Mexican standards . To achieve this goal, radiation protection and quality control manuals were elaborated . Furthermore, a quality control program (QCP) in the mammography systems (analog/digital), darkroom included, has been implemented. Daily sensitometry, non-variability of the image quality, visualizing artifacts, revision of the equipment mechanical stability, compression force and analysis of repetition studies are some of the QCP routine tests that must be performed by radiological technicians of this institution as a set of actions to ensure the protection of patients. Image quality and patients dose assessment were performed on 4 analog equipment installed in 2 mobile units. In relation to dose assessment, all equipment passed the acceptance criteria (<3 mGy per projection). The image quality test showed that most images (70%) presented artifacts. A brief summary of the results of quality control tests applied to the equipment and film processor are presented. To maintain an adequate level of quality and safety at FUCAM-AC is necessary that the proposed radiation protection program in this work is applied.

Objective: Evaluate the level of compliance with radiation protection rules in the medical imaging department of the University Hospital Center (CHU) of Kati. Methodology: This was a cross-sectional and descriptive study carried out in the medical imaging department of Pr Bocar Sidy Sall (BSS) Hospital of Kati. A questionnaire was developed and sent to the staff of the medical imaging department. The assessment focused on the radiation protection of personnel, radiation protection measures for patients, the delimitation and signage of zoning as well as the application of radiation protection principles. Results: Twenty-one people participated in the study, 90% of whom were men. The 30 -39 age group was predominant with 61.90%. 33.33% of the staff knew the principles of radiation protection; 86% of our sample knew the basic rules of radiation protection. The majority of the staff in the imaging department (61.90%) had a perfect knowledge of protective equipment. For 76% of our workforce, the limits of the radiation doses received are regulated in Mali. 76% of those surveyed have not taken any additional training in radiation protection. The doors are closed during the X-ray examination for 76.19% of the respondents and 95% of the staff put themselves behind the sealed screen during the examination. For 81% of the respondents, the design of the premises met radiation protection standards. 62% of practitioners have a dosimeter and 80% of them wear it during their shift. For 62% of our sample, the

Conclusions: Radiation protection eyewear contains detectable lead on the external surface of the lenses and is not encapsulated with any protective material. Caution and handwashing should be performed after direct contact is made with lead containing lenses.

The examination of nasopharynx CT Scan for the diagnosis tumors, was performed by two phase, plain phase and contrast medium phase, so will result in a very high radiation dose to the organs in the head especially the eyes. This study aimed to obtain the value of the radiation dose was received organ in the eye in patient who underwent nasopharynx CT Scan. The study was begun by measuring the consistency of the output X-ray tube voltage (kVp Output). Furthermore, measurement of the radiation dose to the organ eye using TLD-100 chips were placed on the surface of the eye organ of the 22 different patients with sequences and spiral scan mode, and using the slice number between 24 to 39. Measurement technique was done by using a tube voltage and tube current time fixed at 130 kVp, 250 mAs, slice thickness and slice collimation of 4 mm and 6x2 mm. The result on the eye organ doses of nasopharynx CT Scan two phase with sequence mode to obtain eye organ dose value between 83.291 mGy to 101.571 mGy, whereas the spiral mode to obtain eye organ dose values varied between 89.536 mGy to 109.359 mGy, showing that the value of the eye organ dose spiral modes greater than mode sequence. The results also showed that the value of the eye organ dose received about one fifth of the value of the damage threshold of the eye lens dose of 500 mGy.

Background: Radiation protection is very important for patient and personnel safety in radiology services. It has been given in the college through classical lectures, including in Radiodiagnostic and Radiotherapy Department Poltekkes Kemenkes Semarang. The student's knowledge is routinely evaluated but their compliance in the clinical activities has never been specifically observed. This study aims to find out the relationship between knowledge toward compliance of the application of radiation protection on clinical practice students. Methods: This is quantitative research with a cross-sectional design. Research was conducted on 90 second-year clinical internship students of the Radiodiagnostic and Radiotherapy Department. The level of knowledge was measured by written test, while the level of compliance was observed by clinical observation. The affecting factors are investigated through indepth interview. Data were analyzed by Spearman Rank Correlation. The knowledge levels among the students were "excellent" (18%), "good" (68%), and "fair" (14%). The radiation protection compliance levels were "good" (73%) and "very good" (27%). There was a significant relationship between radiation protection knowledge level toward radiation protection compliance (p value <0.05). The strength of the relationship was low (coefficient interval = 0.257). Conclusions: There was a relationship between knowledge and the level of compliance, but it was not the only influencing factor. The environment tends to have an effect on the level of compliance. Radiographers and clinical instructors should be good role model in applying radiation protection.

Background: Radiation protection is crucial in various fields due to the harmful effects of radiation. Shielding is used to reduce radiation exposure, but gamma radiation poses challenges due to its high energy and penetration capabilities. This work investigates the radiation shielding properties of polyvinylidene fluoride (PVDF) samples containing different weight fraction of tungsten carbide (WC), tungsten trioxide (WO3), and tungsten disulfide (WS2). Parameters such as the mass attenuation coefficient (MAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), and macroscopic effective removal cross-section for fast neutrons (ΣR) were calculated using the Phy-X/PSD software. EpiXS simulations were conducted for MAC validation. : Increasing the weight fraction of the additives resulted in higher MAC values, indicating improved radiation shielding. PVDF-xWC showed the highest percentage increase in MAC values. MFP results indicated that PVDF-0.20WC has the lowest values, suggesting superior shielding properties compared to PVDF-0.20WO3 and PVDF-0.20WS2. PVDF-0.20WC also exhibited the highest Zeff values, while PVDF-0.20WS2 showed a slightly higher increase in Zeff at energies of 0.662 and 1.333 MeV. PVDF-0.20WC has demonstrated the highest ΣR value, indicating effective shielding against fast neutrons, while PVDF-0.20WS2 had the lowest ΣR value. The Monte Carlo N-Particle Transport version 5 (MCNP5) simulations showed that PVDF-xWC attenuates gamma radiation more than pure PVDF, significantly decreasing the dose equivalent rate. Conclusion: Overall, this research provides insights into the radiation shielding properties of PVDF mixtures, with PVDF-xWC showing the most promising results.

A number of mobile plants for the liquid low and intermediate level radioactive waste (LLILW) reprocessing was developed and assembled at Moscow SIA “Radon”. These plants can be used at places where LLILW is generated. During the utilisation and repairing of atomic submarines at FGUP «Zvezdochka» of Russian centre for atomic shipbuilding in Severodvinsk, Arkhangelsk region saline liquid radioactive wastes are formed. The mobile plant of SIA “Radon” «ECO-3» was applied for the purification such waste [1]. About 820 m 3 of low salinity LLILW from the tanker «Osetia» was purified in the plant «ECO-3» within the first half of 1999. The plant «ECO-3» operation was based on sorption and electromembrane technology of low level salted LLILW purifying and concentrating with the use of selective sorbents and electrodialysis apparatus. Also the conditioning of formed secondary waste was carried out. The report contains an apparatus technological flow sheet, results of radiometric, spectrometri...

Regulatory entities require that for any radiation facility the surrounding areas must be restricted unless the dose equivalent is less than 0.02 mSv in any one hour. Two Monte Carlo radiation transport simulation codes, MCNP5 and Mercurad, were used to design a facility to shield a 3.48 ϫ 10 5 MBq 137 Cs irradiator that meets these requirements. Simulations showed that the dose equivalent rates were below the legal limit for unrestricted access and the facility was constructed using available concrete block and student labor to minimize costs. To verify the accuracy of the Monte Carlo radiation transport codes, an ion chamber was used to characterize the facility. Ion chamber measurements in the actual, as-built irradiation facility showed that the Monte Carlo codes, MCNP5 and Mercurad, agreed by a factor of better than 6% and better than 11%,

Conducting a hospital-based radiution safety training class may lead to temporaiy technologist stamng shortages resulting in a reduction ofpatient services or even the cessation of all routine patient services. Use of an interactive computer-based radiation safety training sofhvare program may provide a practical alternative for hospital diagnostic and therappeutic radiation departments, as well as other hospital departments irtilizing radiation sources, in meeting annual radiation safety training requirements for radiation workers. Medical radiation workers' participation in computerbased radiation safety training can make a positive impact on radiation .saf&y awareness in the hospital, ~zssist license holders in satis/jh,y regulatory training requirements, ensitre maximum participation of staff technologists, and reduce the burden of technologist stamng .shortages caused by traditional methods of training.

The risk index Lost Life Expectancy Rate (LLER) provides a unitless number (time of life expectancy lost per time exposed) describing the risk from exposure to a given hazard or from partaking in a given activity. Simple equations to calculate the LLER from radiation-induced cancers caused by an exposure to low-level radiation were derived using the relative risk models developed by the Nuclear Regulatory Commission (upper bound estimate), the United Nations Scientific Committee on the Effects of Atomic Radiation-1988, and the National Academy of Science's Committee on the Biological Effects of Ionizing Radiation (BEIR V). Estimates of the LLER to an average person from a continuous exposure to 0.1 pSv h-' based on these models, respectively, are 5.5 x lo-", 9.5 X and 9.4 X lo-". These values compare to LLERs of 0.015 from occupational accidents, 0.25 from being an automobile passenger, and 2.0 from cigarette smoking. Factors effecting LLER from radiation exposures examined in this work include dose rate, age, sex, race and smoking status.

The left kidney of 9 dogs was irradiated daily for three days with 300 kVp X-rays. Radioprotection was attempted in 5 of the kidneys by administration of degradable microspheres in the renal artery, immediately before irradiation. Protected kidneys received 3 x 8 or 3 x 12 Gy in midplane dose, unprotected kidneys 3 x 5.2 o r 3 x 8 Gy. A protective effect due to induced hypoxia could be demonstrated in creatinine clearance, which was significantly higher in protected than in unprotected kidneys at 7 -13 weeks after irradiation.

An Airtight room was installed to prevent the diffusion of tritium from the instrument room to other areas in HANARO. It was isolated by a robust structure and the inside was closed tightly. A Tritium removal system located outside the instrument room was connected to the airtight room to lower the tritium concentration when the workers enter the room for maintenance of the instruments. The tritium concentration and the dew point in the airtight room were continuously measured during the operation of the tritium removal system. The data were analyzed by using a model. There was a difference between the measured tritium concentration and the one obtained by the model. It is believed that the difference is due to the change of the generation rate of tritium which would increase as the dew point becomes lower. Based on this assumption, the previous equation was revised to better express the performance of the tritium removal system. It was re-estimated that the change of tritium concen...

Most of the Japanese-to-JSL (Japanese Sign Language) translators utilize CG (Computer Graphics) animation to present translation results. However, foregoing systems cannot produce natural and legible sign expressions for the Deaf, because they are based on word-for-word translation. Our research aims to produce animation including proper modifier representation, which can express nuances of original sentences. This paper proposes a method to include modifier representation into animations automatically.

A series of concrete maxis were designed and prepared by replacement percentages (0, 5, 10, and 20 wt%) of their fine aggregates by blast furnace slag. Mechanical properties, corrosion in the steel reinforcement, and different types of Nuclear radiation parameters of four concrete maxis were studied. The corrosion behavior was investigated using different electrochemical techniques and optical microscope. Also, three types of neutron energies as well as nine gamma ray energy lines (121.78 – 1407.92 keV) were used to evaluate the macroscopic neutron cross-sections (Σ, cm) and mass attenuation coefficients (σ, cm/g) of gamma ray, respectively, in investigated concrete samples. The results showed that, the mechanical properties of concrete and the corrosion resistance of steel imbedded in concrete were increased with increasing blast furnace slag up to 10 wt. %. While, 20 wt % was the optimum percentage for the values of mass attenuation coefficients of most investigated γ-ray energy l...

Context: Essiac tea is been used widely in the homeopathy market for cancer treatment. Aims: We hypothesized its use for DNA-damaged mitigation under very low ionizing radiation (IR) on BALB/c mice (10-40 mSv). Settings and Design: The radioprotection of Essiac tea formulae was evidenced by comet assay (CA) and micronucleus (MN) acridine orange staining. We also reported complete blood count, animal weight, and fasting glucose levels to control for tea toxicity. Materials and Methods: Fifty BALB/c male mice of 6-7 week old and pathogen free mice were randomly divided in to control group, control irradiated mice, irradiated and tea or ascorbic acid treated mice, tea treated mice and ascorbic acid treated mice. Genuine Essiac tea treatment was given ad libitum for 7 weeks and ascorbic for no >13 days. The animals were exposed to three different X-ray doses (10 mSv, 20 mSv, and 40 mSv). Statistical Analysis Used: An independent one-tailed t-test or Dunnett's test was used to compare animal weight, fasting glucose levels, white blood count, comet percentage, and MN percentage, between doses, treatment, and controls, after a Welch's ANOVA and Mann-Whitney U-test using Excel worksheets from Biostathandbook.com website. Results: The tea formula resulted in a significant reduction of DNA damaged evidenced by CA (P < 0.01 for dose 3-40 mSv). By MN staining, the peak of significant induction of MNs was by the lower doses, D1 and D2, with a P value = 0.001 and P value = 0.014, respectively; however those irradiated animals when were treated with tea showed reduction of MNs and no significant difference from controls. Conclusions: Using an optimized murine model, we demonstrated that Genuine Essiac tea is not toxic and that it acts as a radioprotector against very low doses of IR.

Exposure to the IR is common to certain people like professionals handling radioactive materials or to the patients undergoing radio-diagnostics and radiotherapy or as millions of people who travel by air are exposed by X-rays scanning every day. Though it is indirect cause, IR may trigger mutation in healthy cells which further induces molecular alterations. It´s known that ionizing radiation generates free radicals from cytoplasmic water and ultimately induces biomolecules lesions such as DNA damage. These damages may lead to neoplasm in normal and healthy cells however IR is not by itself a recognized and indisputable carcinogen present in the environment. In order to develop some type of cancer, they have to interact within the organisms and cells with other multiple factors of high complexity from physiological to environmental components (genetics of the living being, cellular microenvironment, epigenetic factors, environmental conditions, and others, perhaps still unknown). Here we discuss and present IR effect on living cells, ways of damage determination and compounds reported as radioprotectors.

Xeroderma pigmentosum (XP) is a rare genetic condition caused by defective nucleotide excision repair and characterised by skin cancer, ocular and neurological involvement. Stringent ultraviolet protection is the only way to prevent skin cancer. Despite the risks, some patients&#39; photoprotection is poor, with a potentially devastating impact on their prognosis. The aim of this research is to identify disease-specific and psychosocial predictors of photoprotection behaviour and ultraviolet radiation (UVR) dose to the face. Mixed methods research based on 45 UK patients will involve qualitative interviews to identify individuals&#39; experience of XP and the influences on their photoprotection behaviours and a cross-sectional quantitative survey to assess biopsychosocial correlates of these behaviours at baseline. This will be followed by objective measurement of UVR exposure for 21 days by wrist-worn dosimeter and daily recording of photoprotection behaviours and psychological var...

At its 10th plenary meeting, on 1 December 2023, the second Meeting of States Parties to the Treaty on the Prohibition of Nuclear Weapons decided that the third Meeting of States Parties to the Treaty would be held from 3 to 7 March 2025. By its resolution 79/38, the General Assembly also confirmed that the third Meeting of States Parties to the Treaty would be held at United Nations Headquarters in New York from 3 to 7 March 2025.
2. Accordingly, in a note verbale dated 4 October 2024, the Secretary-General convened the third Meeting of States Parties to the Treaty from 3 to 7 March 2025 at United Nations Headquarters in New York.

Lead is a hazardous material, and the U.S. Congress has mandated the rapid reduction of all hazardous waste generation as a matter of national policy. With the large amount of plutonium handling in numerous projects including the development of mixed oxide (MOX) fuel, 238 Pu power sources, etc., hand glove protection for the emitted alpha, beta, and low energy photons is an important issue. Leaded gloves are the prime shields used for radiological hand protection. U.S. Department of Energy laboratories require a substitute material for the lead oxide in the gloves as a way to reduce mixed waste. To solve this problem, a new blend of non-hazardous materials that have the same radiological properties and approximately the same cost of production have been investigated. The investigations have produced alternative materials using calculations and experiments. The selection of the constituent compounds for the new composite materials was based on the k-absorption edge energy of the main constituent element(s) in the compounds. The formulations of these composites were fashioned on the principle of blending Neoprene rubber formulation with several constituent compounds. Calculations based on the Lambert-Beer attenuation law together with the mass attenuation coefficient values from the XCOM cross section database program were used to determine the transmission fractions of these proposed composite materials. Selected composite materials that compared favorably with the leaded-Neoprene were fabricated. These fabricated composite materials were tested with attenuation experiments and the results were in excellent agreement with the calculations using the Lambert-Beer attenuation law.

The nuclear power industry work ethic and culture is founded on learning from experience and continuously finding ways to improve performance-especially in regard to radiation safety. Over the past 25 y, this process of continuous improvement has yielded exceptional results in regard to radiation protection of workers, the public and the environment. In light of the resurgence of nuclear energy in the United States, the nuclear power industry is developing strategies to achieve continuous improvements to performance and address emerging challenges in the area of radiation protection.

The German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) on behalf of the Government of the Federal Republic of Germany supports the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU) in enhancement of nuclear safety and radiation protection and strengthening of the physical protection. One of the main objectives of the agreement concluded by these parties in 2008 was the retrieval and safe interim storage of disused orphan high radioactive sealed sources in Ukraine. At present, the Ukrainian National Registry does not account all high active radiation sources but only for about 70 -80 %. GRS in charge of BMU to execute the program since 2008 concluded subcontracts with the waste management and interim storage facilities RADON at different regions in Ukraine as well with the waste management and interim storage facility IZOTOP at Kiev. Below selected examples of removal of high active Co-60 and Cs-137 sources from irradiation facilities at research institutes are described. By end of 2012 removal and safe interim storage of 12.000 disused radioactive sealed sources with a total activity of more than 5,7⋅10 14 Bq was achieved within the frame of this program. The German support program will be continued up to the end of 2013 with the aim to remove and safely store almost all disused radioactive sealed sources in Ukraine.

The present study was conducted to investigate the effect of selenium toxicity on some blood, cellular and biochemical parameters in adult Awasiy ewes. The first group (DW) included ten ewes pumped with distilled water daily for ten weeks, the second group (SS+RX) included ten ewes pumped with salt sodium selenite (1.2 mg / kg BW) daily and orally for eight weeks and then treated with N-Acetyl Lcysteine (70 mg / kg BW) daily and orally from week 9 to week 10. The third group (SS) also included ten ewes that were injected with sodium selenite (1.2 mg / kg BW) orally daily for 10 weeks. The results of this study also showed a significant increase (P0.05) in the second group (SS+RX) and SS (SS), which was injected with sodium selenite on serum selenium concentration starting from the first week to At the end of the experiment, selenium concentration showed a decrease starting from the ninth week in the second group (SS+RX) after treatment with N-Acetyl L-cysteine until the end of the experiment compared with the control group. The results of these study also showed a significant (P≤0.05) increase of glutathione peroxidase concentration in groups (G2, G3) start in week one (W1) till the fifth week which reach the peak, then its start to decline and continue until the end of experiment in (G3), while it was returned to normal level in the ninth week and remain steady until the end of the experiment in (G2) compared with control group. The cellular tests performed on the blood lymphocytes included chromosomal aberration, which showed significant results of P0.05 in the two groups that were injected with sodium selenite, the second group (SS+RX) and (SS) compared to the control group (DW). These abnormalities began from the end of the first week of the experiment until the end of the tenth week in both groups even after treatment with N-Acetyl L-cysteine for the second group (RX + SS) which starts from the ninth week until the end of the tenth week. The second cytological examination included micronucleus, which showed a significant change (P0.05) in both the (SS+RX) and (SS) and the (SS) compared to the control group (DW), which began from the end of the third week until the end (N-Acetyl L-cysteine) in the second group (RX + SS), starting from the ninth week and ending with the experiment. The current study indicates that changes in the genetic level of the cells remain constant despite the given treatment and the return of cases to normal bed and laboratory, which confirms that the poisoning of the element of selenium is dangerous and permanent effects.

A metrologia desempenha um papel crucial na padronização das unidades de medida, sempre considerando uma incerteza nos seus resultados, o que é importante em todos os níveis de comparação. O presente estudo buscou apresentar e implementar um framework para a calibração de sensores de temperatura, através da construção de dois protótipos com dois sensores de temperatura, e um termohigrômetro de referência. O método de pesquisa foi executado em quatro fases: seleção dos materiais (Fase I), montagem e validação dos protótipos (Fases II e III), análise dos dados coletados e proposta de framework (Fase IV). Para este estudo 60 amostras foram coletadas em intervalos de 1 minuto para comparação com o termohigrômetro. Os resultados demonstraram que ambos os sensores apresentaram diferenças em relação ao termohigrômetro, com médias de 1,7383°C para o DHT11 e 0,8253°C para o GY-906 BCC. O processo de calibração foi conduzido por meio de cálculos de ajustes a fim de alinhar as medições dos sensores aos valores de referência. Após implementar esses ajustes, os protótipos calibrados foram capazes de realizar medições mais precisas e consistentes. Portanto, a calibração dos sensores supracitados por meio do framework proposto reduziu a incerteza das medições de temperatura.

Intimacy of textiles to human skin and consequent upsurge in global skin disorders because of elevated exposure to UV radiations has provided thrust to develop UV protective clothing. Vulnerability of cotton against UV radiations necessitates introduction of various approaches to elevate its UV protection. In this study, performance of two conventional UV absorbers, viz. benzophenone and its derivative 2,4 dihydroxybenzophenone was studied in terms of 'ultraviolet protection factor' (UPF) as well as color fastness, tensile strength, handle, etc. Performance of two novel UV absorbers, viz. avobenzone alone and in combination with octocrylene, was also evaluated for their ability to absorb UV radiation over a broader spectrum. The effect of UV finish with 2,4 dihydroxybenzophenone was found to be more pronounced compared to that with benzophenone; the UPF ratings increased up to 200 with avobenzone alone and in combination with octocrylene. The combination of the novel UV absorbers reduced the UV transmission considerably well below 1% in the UV-A and UV-B range along with good color fastness and marginal reduction in air permeability, handle and tensile strength.

This work reports the results of a study comparing computer controlled and manual shielding block cutting. The general problems inherent in automated block cutting have been identified and minimized. A system whose accuracy is sufficient for clinical applications has been developed. The relative accuracy of our automated system versus experienced technician controlled cutting was investigaed. In gene* it is found that automated cutting is somewhat faster and more accurate than manual cutting for very huge fields, but that the reverse is true for most smaller fields. The relative cost effectiveness of automated cutting is dependent on the percentage of computer designed blocks which are generated in the clinical setting. At the present time, the traditional manual method is still favored.

The examination of nasopharynx CT Scan for the diagnosis tumors, was performed by two phase, plain phase and contrast medium phase, so will result in a very high radiation dose to the organs in the head especially the eyes. This study aimed to obtain the value of the radiation dose was received organ in the eye in patient who underwent nasopharynx CT Scan. The study was begun by measuring the consistency of the output X-ray tube voltage (kVp Output). Furthermore, measurement of the radiation dose to the organ eye using TLD-100 chips were placed on the surface of the eye organ of the 22 different patients with sequences and spiral scan mode, and using the slice number between 24 to 39. Measurement technique was done by using a tube voltage and tube current time fixed at 130 kVp, 250 mAs, slice thickness and slice collimation of 4 mm and 6x2 mm. The result on the eye organ doses of nasopharynx CT Scan two phase with sequence mode to obtain eye organ dose value between 83.291 mGy to 101.571 mGy, whereas the spiral mode to obtain eye organ dose values varied between 89.536 mGy to 109.359 mGy, showing that the value of the eye organ dose spiral modes greater than mode sequence. The results also showed that the value of the eye organ dose received about one fifth of the value of the damage threshold of the eye lens dose of 500 mGy.

In this study, which is the first of its kind in the gulf region, eye doses of interventional cardiologists and nurses were measured using active dosimeters for left and right eyes, in 60 percutaneous coronary interventions in three main hospitals in Kuwait. The dose given in terms of H p (0.07) per procedure when ceiling suspended screens were used by main operators ranged from 18.5 to 30.3 µSv for the left eye and from 12.6 to 23.6 µSv for the right eye. Taking into account typical staff workload, the results show that the dose limit of 20 mSv/year to the eyes can be exceeded for interventional cardiologists in some situations, which demonstrates the need of using additional effective radiation protection tools, e.g. protective eye spectacles, in addition to the regular and proper use of ceiling suspended screens. With indications of increase in workload, the need for availability of a dedicated active dosimeter for the regular monitoring of eye doses is emphasized.

Life has evolved on Earth for about 4 billion years in the presence of the natural background of ionizing radiation. It is extremely likely that it contributed, and still contributes, to shaping present form of life. Today the natural background radiation is extremely small (few mSv/y), however it may be significant enough for living organisms to respond to it, perhaps keeping memory of this exposure. A better understanding of this response is relevant not only for improving our knowledge on life evolution, but also for assessing the robustness of the present radiation protection system at low doses, such as those typically encountered in everyday life. Given the large uncertainties in epidemiological data below 100 mSv, quantitative evaluation of these health risk is currently obtained with the aid of radiobiological models. These predict a health detriment, caused by radiation-induced genetic mutations, linearly related to the dose. However a number of studies challenged this para...

In the framework of a collaborative project on the influence of the shielding on the biological effectiveness of space radiation, we studied DNA fragmentation induced by 1 GeV/nucleon iron ions and titanium ions with and without a 197-mmthick polymethylmethacrylate (PMMA) shield in AG1522 human fibroblasts. Pulsed-and constant-field gel electrophoresis were used to analyze DNA fragmentation in the size range 1-5700 kbp. The results show that, mainly owing to a higher production of small fragments (1-23 kbp), titanium ions are more effective than iron ions at inducing DNA double-strand breaks (DSBs), their RBE being 2.4 and 1.5, respectively. The insertion of a PMMA shield decreases DNA breakage, with shielding protection factors (ratio of the unshielded/shielded cross sections for DSB production) of about 1.6 for iron ions and 2.1 for titanium ions. However, the DSB yield (no. of DSBs per unit mass per unit dose) is almost unaffected by the presence of the shield, and the relative contributions of the fragments in the different size ranges are almost the same with or without shielding. This indicates that, under our conditions, the effect of shielding is mainly to reduce the dose per unit incident fluence, leaving radiation quality practically unaffected.

DNA double strand breaks / DNA repair / Cell cycle checkpoints / Ionizing radiation / Space radiation DNA repair systems and cell cycle checkpoints closely co-operate in the attempt of maintaining the genomic integrity of cells damaged by ionizing radiation. DNA double-strand breaks (DSB) are considered as the most biologically important radiation-induced damage. Their spatial distribution and association with other types of damage depend on radiation quality. It is believed these features affect damage reparability, thus explaining the higher efficiency for cellular effects of densely ionizing radiation with respect to γ-rays. DSB repair systems identified in mammalian cells are homologous recombination (HR), single-strand annealing (SSA) and non-homologous end-joining (NHEJ). Some enzymes may participate in more than one of these repair systems. DNA damage also triggers biochemical signals activating checkpoints responsible for delay in cell cycle progression that allows more time for repair. Those at G1/S and S phases prevent replication of damaged DNA and those at G2/M phase prevent segregation of changed chromosomes. Individuals with lack or alterations of genes involved in DNA DSB repair and cell cycle checkpoints exhibit syndromes characterized by genome instability and predisposition to cancer. Information reviewed in this paper on the basic mechanisms of cellular response to ionizing radiation indicates their importance for a number of issues relevant to protection of astronauts from space radiation.

Abstract:-A suitable modelling of the radiation-induced DNA fragmentation may greatly help in developing a clearer biophysical description of radiation action in mammalian cells. We have developed a model aimed at describing the DNA fragment distribution induced by ...

In this work we have compared the pattern of DNA fragmentation (in the size range 1-5700 kbp) induced in human fibroblasts by c-rays with that induced by Fe ions with an energy of 115 MeV/u; Fe ions are considered of biological significance for radiation protection issues during long term astronauts' travels. The study has taken into account the comparison of the experimental fragmentation spectra, their analysis performed through the implementation of a phenomenological model, and Monte Carlo simulations performed with the PARTRAC code. The phenomenological method characterizes in an approximate but simple way the nonrandom nature of the experimental fragment distribution caused by high LET radiation; it has the advantage to take into account in a detailed way the background fragmentation. The PARTRAC simulations, on the other hand, thanks to the accurate representation of the chromatin geometry and of the physical and physico-chemical processes associated with the energy deposition by radiation, offer the possibility to compute the spectra and to compare them with the experimental data. We found a satisfactory agreement between the experimental data and the results obtained with PARTRAC, recently upgraded with the implementation of ions heavier than alpha particles; this agreement represents a first validation of the code. A relevant result is represented by the very high number of fragments that, according to the Monte Carlo simulations, are produced by iron ions in the size range <1 kbp: half of the total number of radiation induced fragments is given by fragments in this size range. This is consistent with another important result, i.e., the very high DSB correlation that is found through the GBS model in the lower part of the experimental size range (1-9 kbp) for iron ions. The consequence of this large production of fragments smaller than 1 kbp, undetected experimentally, is the large difference between the experimental and theoretical values of the RBE for DSB production, given respectively by 1.34 and 2.39.

Indoor radon exposure is a significant public health concern, as it is the second leading cause of lung cancer
globally. This systematic review evaluated radon concentrations and associated health risks in Nigerian buildings, including homes, schools, and workplaces, through various monitoring techniques such as CR-39 detectors
and RAD7 monitors. A total of 47 eligible studies were included following PRISMA guidelines that covered the spatial variations of radon exposure across Nigeria, revealed a weighted mean indoor radon concentration of 104
Bq/m3
, exceeding the WHO reference level of 100 Bq/m3 but below the USEPA action level of 148 Bq/m3
.
Certain locations such as Odo-Ona, Ibadan, recorded 531.85 Bq/m3
, corresponding to an annual effective dose of
13.42 mSv/yr, an excess lifetime cancer risk of 51.66 × 10− 3
, and an estimated lung cancer burden of 242 cases/
year per million people. Other regions, including Sokoto Metropolis and Oke-Ogun, also exceeded safety limits,
while coastal areas like Lagos showed the lowest concentrations (7.52 Bq/m3
). Geographic disparities were
evident, with southwestern Nigeria showing the highest risk and accounting for 63 % of studies, while northern
and southeastern regions remain underrepresented. Comparative analysis revealed that Nigerian hotspots surpass radon levels reported in several radon-prone countries, including Bulgaria and Northwest Spain, highlighting a significant health risk. This review presents Nigeria's first indoor radon exposure map in residential and
occupational settings nationwide that clearly identified critical hotspots and emphasizing the urgent need for
targeted interventions. Awareness of the presence of radon and its potential health effects is very low in Nigeria.
Radon mitigation should integrate geological assessments with radon-resistant construction materials, proper
ventilation, and sealed entry points, especially in uranium-rich and permeable soils. Public awareness, routine
monitoring, and regulatory policies are essential, while future research should focus on underrepresented regions
and uncover long-term exposure patterns

This paper examines how an International Atomic Energy Agency (IAEA) expert mission for technical assistance in the late 1950s to Greece was effectively transformed into a mission to achieve the IAEA′s central objective: to consolidate its position as the leading global authority on radiation protection. The study focuses on the work of Alfred Maddock, a professor at the University of Cambridge. In 1959, Maddock arrived in Greece as part of one of the IAEA's original missions, contributing to an educational program on radioisotopes. Beyond providing educational services, Maddock accomplished something more significant. As the Agency's facilitator, he introduced radiation protection materials and concepts to the country in accordance with the IAEA protocols. He introduced dosimetry devices (film badges) and, at the same time, reviewed, modified, and created architectural plans for the laboratories of the Greek Nuclear Centre to meet the IAEA safety standards. It is argued that Maddock's visit to Greece transcended a mere one-sided enforcement process. Rather, it catalyzed a dynamic interaction between Greece and the IAEA, characterized by robust elements of mutual cooperation. This mission stands as a prime example of the gradual integration of IAEA culture within a member state, tailored to local needs and conditions.

The paper gives a cross examination of Meta AI on the question of Google's choice of Chris Busby the referee over Chris Busby the scientist. The conclusion points to significant bias in the choice of the refereee over the scientist for the top Google page over the scientist when AI was foreced to concede a 10-fold excess ratio of the scientist relative to the referee.

The current Boron Neutron Capture Therapy (BNCT) experiments performed at the University of Pavia, Italy, are focusing on the in vivo irradiations of small animals (rats and mice) in order to evaluate the effectiveness of BNCT in the treatment of diffused lung tumors. After the irradiation, the animals are manipulated, which requires an evaluation of the residual radioactivity induced by neutron activation and the relative radiological risk assessment to guarantee the radiation protection of the workers. The induced activity in the irradiated animals was measured by high-resolution open geometry gamma spectroscopy and compared with values obtained by Monte Carlo simulation. After an irradiation time of 15 min in a position where the in-air thermal flux is about 1.2 Â 10 10 cm -2 s -1 , the specific activity induced in the body of the animal is mainly due to 24 Na, 38 Cl, 42 K, 56 Mn, 27 Mg and 49 Ca; it is approximately 540 Bq g -1 in the rat and around 2,050 Bq g -1 in the mouse. During the irradiation, the animal body (except the lung region) is housed in a 95% enriched 6 Li shield; the primary radioisotopes produced inside the shield by the neutron irradiation are 3 H by the 6 Li capture reaction and 18 F by the reaction sequence 6 Li(n,α) 3 H → 16 O(t,n) 18 F. The specific activities of these products are 3.3 kBq g -1 and 880 Bq g -1 , respectively.

Background radiation is everywhere and investigating the amount present in the background, surroundings and environment is essential to research and public health concerns. Humans experience it daily due to both natural and artificial incidents. These incidents include cosmic radiation, internal radiation, terrestrial radiation, nuclear events and medical operations. This research covered the investigation of two area councils, Gwagwalada and Kwali Area Councils in Abuja, Federal Capital Territory, Nigeria. Field exploration and data sampling dose rate were conducted at 11 locations which are the University of Abuja Mini Campus (8.9530N, 7.0730E),

The Convention on Assistance in the Case of a Nuclear Accident or Radiological Emergency (1986) introduced crucial environmental legislation in the nuclear sector, focusing on protecting lives, property, and the environment from radioactive emissions. Later accords like the 1994 Convention on Nuclear Safety and the 1997 Joint Convention on the Safety of Spent Fuel and Radioactive Waste Management reinforced this environmental safeguard. These frameworks are examined in the context of public access to nuclear information, with notable gaps in laws granting the public rights to information and participation in nuclear decision-making. The Aarhus Convention (1998) is significant here, providing the public with rights to obtain environmental information, participate in decision-making, and seek legal remedies. The Espoo Convention and its 2003 Kiev Protocol further enhance public involvement, introducing the Strategic Environmental Assessment (SEA), which mandates environmental impact assessments for nuclear plans and ensures stakeholder consultation. The study also explores compensation for environmental harm caused by nuclear disasters, referencing various conventions like the EU Environmental Liability Directive and the Civil Liability Convention. It advocates for stronger implementation of international treaties, social responsibility in nuclear policies, and effective national regulations. The Indian regulatory landscape, particularly the Atomic Energy Regulatory Board (AERB) and the proposed Nuclear Regulatory Authority of India, is scrutinized. The paper underscores the importance of global collaboration to strengthen international laws on nuclear safety, waste management, liability, and compensation, promoting sustainable development while protecting the environment for future generations.

ources of radiation exposure to the U.S. population are derived from five broad categories: (a) ubiquitous background radiation (including radon); (b) medical procedures in patients; (c) consumer products or activities involving radiation sources; (d) industrial, security, medical, educational, and research radiation sources; and (e) occupational sources in specific categories of workers. Comprehensive assessments of the frequency and associated doses from radiologic and nuclear medicine procedures are conducted only rarely. In the United States, assessments of diagnostic radiologic procedures were conducted in 1964 (1), 1970 (2), and 1980 (3) by the U.S. Food and Drug Administration and Mettler et al (4). Beginning about 1980, the Center for Devices and Radiological Health of the Food and Drug Administration conducted more focused surveys, which included dosimetry data for selected radiologic procedures. The last comprehensive estimates of uses of medical radiation in the United States were performed more than 10 years ago and were published in 2009 by Mettler et al (5) and the National Council on Radiation Protection and Measurements (NCRP) in its Report 160 (6) using data

The detonation of a radiological dispersion device may result in a situation where individuals inhale radioactive materials and require rapid assessment of internal contamination. The feasibility of using a 2×2-inch sodium-iodide detector to determine the committed effective dose to an individual following acute inhalation of gamma-emitting radionuclides was investigated. Experimental configurations of point sources with a polymethyl methacrylate slab phantom were used to validate Monte Carlo simulations. The validated detector model was used to simulate the responses for four detector positions on six different anthropomorphic phantoms. The nuclides examined included 241 Am, 60 Co, 137 Cs, 131 I and 192 Ir. Biokinetic modelling was employed to determine the distributed activity in the body as a function of post-inhalation time. The simulation and biokinetic data were used to determine time-dependent count-rate values at optimal detector locations on the body for each radionuclide corresponding to a target committed effective dose (E50) value of 250 mSv.