Radiation Exposure Management Research Articles

Clinical diagnostic reference levels in neuroradiology based on clinical indication.

This study focuses on patient radiation exposure in interventional neuroradiology (INR) procedures, a field that has advanced significantly since its inception in the 1980s. INR employs minimally invasive techniques to treat complex cerebrovascular diseases in the head, neck, and spine. The study establishes diagnostic reference levels (DRLs) for three clinical indications (CIs): stroke (S), brain aneurysms (ANs), and brain arteriovenous malformation (AVM). Data from 209 adult patients were analyzed, and DRLs were determined in terms of various dosimetric and technical quantities. For stroke, the established DRLs median values were found to be 78Gycm2, 378mGy, 118mGy, 12min, 442 images, and 15 runs. Similarly, DRLs for brain AN are 85Gycm2, 611mGy, 95.5mGy, 19.5, 717 images, and 26 runs. For brain AVM, the DRL's are 180Gycm2, 1144mGy, 537mGy, 36min, 1375 images, and 31 runs. Notably, this study is unique in reporting DRLs for specific CIs within INR procedures, providing valuable insights for optimizing patient safety and radiation exposure management.

Proposing national diagnostic reference levels for electrophysiology studies and catheter ablation procedures in Bulgaria

IntroductionThe implementation of diagnostic reference levels (DRLs) is an essential tool for optimisation of the routine practice, better management of patient exposure while maintaining sufficient image quality. National DRLs for electrophysiology (EP) procedures are not available in our country. PurposeThe main purpose of the study was to propose, for first time in Bulgaria, national DRLs (NDRLs) for EP studies and ablation procedures of two different levels of complexity. The proposed DRLs can be later used to establish NDRLs by the national authority with regulatory functions related to medical exposure. MethodA retrospective study was done with the three highest volume Bulgarian EP centers, where over 95% of all cardiac ablations were performed. Data were extracted from the electronic registry for invasive electrophysiology BG-EPHY. Independently of the proposed NDRLs, we also compared the air kerma-area product (KAP) between the participating centers for procedures of the same level of complexity. ResultsThe proposed NDRL in terms of KAP were: 5.2 Gy.cm2 for diagnostic EP studies, 25.5 Gy.cm2 for simple ablations, and 52.1 Gy.cm2 for complex ablations. There was a significant variation in KAP for procedures with the same degree of complexity within each center. ConclusionThis study is the first to propose NDLRs for EP studies and ablation procedures of two levels of complexity in Bulgaria. The results identified EP procedures requiring further optimization of patient protection and provided a basis for future comparisons and standardization with further investigations on the topic. The proposed NDRLs are recommended to be used for better management of radiation exposure during EP procedures of different levels of complexity.

High throughput screen of small molecules as potential countermeasures to galactic cosmic radiation induced cellular dysfunction

Space travel increases galactic cosmic ray exposure to flight crews and this is significantly elevated once travel moves beyond low Earth orbit. This includes combinations of high energy protons and heavy ions such as 56Fe or 16O. There are distinct differences in the biological response to low-energy transfer (x-rays) or high-energy transfer (High-LET). However, given the relatively low fluence rate of exposure during flight operations, it might be possible to manage these deleterious effects using small molecules currently available. Virtually all reports to date examining small molecule management of radiation exposure are based on low-LET challenges. To that end an FDA approved drug library (725 drugs) was used to perform a high throughput screen of cultured cells following exposure to galactic cosmic radiation. The H9c2 myoblasts, ES-D3 pluripotent cells, and Hy926 endothelial cell lines were exposed to a single exposure (75 cGy) using the 5-ion GCRsim protocol developed at the NASA Space Radiation Laboratory (NSRL). Following GCR exposure cells were maintained for up to two weeks. For each drug (@10µM), a hierarchical cumulative score was developed incorporating measures of mitochondrial and cellular function, oxidant stress and cell senescence. The top 160 scores were retested following a similar protocol using 1µM of each drug. Within the 160 drugs, 33 are considered to have an anti-inflammatory capacity, while others also indirectly suppressed pro-inflammatory pathways or had noted antioxidant capacity. Lead candidates came from different drug classes that included angiotensin converting enzyme inhibitors or AT1 antagonists, COX2 inhibitors, as well as drugs mediated by histamine receptors. Surprisingly, different classes of anti-diabetic medications were observed to be useful including sulfonylureas and metformin. Using a hierarchical decision structure, we have identified several lead candidates. That no one drug or even drug class was completely successful across all parameters tested suggests the complexity of managing the consequences of galactic cosmic radiation exposure.

The Importance of Radiation Protection Education and Training for Medical Professionals of All Specialties.

The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. Lately, more advanced techniques have been introduced in medical imaging expanding the diagnostic and therapeutic applications of ionizing radiation. Among the various strategies that have been proposed for the management of radiation exposure, education and training seem to have a strong impact on radiation protection and dose reduction. However, according to several studies, medical professionals appear to lack knowledge on basic radiation protection aspects. Therefore, the establishment of an accreditation and certification system in radiation protection for all medical professionals employing ionizing radiation is considered as high priority. The purpose of this review article is to highlight the importance of education and training in radiation protection, provide recommendations for an effective educational program and propose an educational program structure for the different medical specialties.

A Personalized Radiation Exposure Management System Based on Wireless Sensor Network

A Personalized Radiation Exposure Management System Based on Wireless Sensor Network

Управление личным составом пожарно-спасательных гарнизонов с учётом радиационного воздействия

Introduction. At present, despite the efforts made by the state, the state of radiation protection does not reach the level at which there is no unacceptable risk of harm to the life or health of people, the environment, the property of individuals and legal entities, state and municipal property on the territory of the Russian Federation in the event of implementation of radiation treats. The readiness of management bodies, forces and means of fire and rescue garrisons to eliminate the consequences of radiation accidents is a very urgent problem. Goals and objectives. The aim of the work is to improve the management of the personnel of fire and rescue garrisons, taking into account the radiation exposure in preparation for liquidation and during the elimination of radiation accidents. Tasks include the creation and justification of a model that allows you to convert the exit risks of the deterministic effects into the risks of stochastic effects. Methods. To create a model for the management of fire and rescue garrisons’ personnel, taking into account the radiation exposure, we used the literature experimental data and used the probabilistic-statistical method and the method of least squares. Results and discussion. The calculated model of management of the fire and rescue garrisons’ personnel, taking into account radiation exposure in preparation for liquidation and in the course of liquidation of radiation accidents, is developed. The probabilistic mathematical model allows us to estimate the exit of stochastic and deterministic effects depending on the effective radiation dose. The excellent convergence of the predicted (calculated) value EAR1 = 0,000607 and the statistical value EAR0 = 0,000724 is due to the fact that the reference points LD10 = 2 Gy , LD50/60 = 4 Gy , LD90 = 6 Gy are based on repeatedly verified statistical data on radiation accidents and deaths of more than 1000 people in radiation accidents [1]. This indicates that the mathematical model adequately reflects the exit of stochastic and deterministic effects observed during the operation of nuclear facilities both in normal mode and in radiation accidents. Conclusions. The probability of exit of stochastic and deterministic effects depending on the radiation dose received by the personnel of fire and rescue garrisons is presented. The threshold of the stochastic effect for humans is in the vicinity of the equivalent dose of 10 mSv for radiation with low linear energy transfer. At the same time, the probability of a stochastic effect is 3 · 10-6 on average after 15 years. This model of radiation exposure management for the personnel of fire and rescue garrisons could be a good tool for the emergency response manager (fire extinguishing manager) during preparation for the elimination and during the elimination of radiation accidents. Keywords: management, personnel, fire and rescue garrison, radiation exposure, effective radiation dose, risk of death

Radionuclide-Specific Exposure Pathway Analysis of Kori Unit 1 Containment Building Surface

Site characterization for decommissioning Kori Unit 1 is ongoing in South Korea after 40 years of successful operation. Kori Unit 1’s containment building is assumed to be mostly radioactively contaminated, and therefore radiation exposure management and detailed contamination investigation are required for decommissioning and dismantling it safely. In this study, site-specific Derived Concentration Guideline Levels (DCGLs) were derived using the residual radioactivity risk evaluation tool, RESRAD-BUILD code. A conceptual model of containment building for Kori Unit 1 was set up and limited occupational worker building inspection scenario was applied. Depending on the source location, the maximum contribution source and exposure pathway of each radionuclide were analyzed. The contribution of radionuclides to dose and exposure pathways, by source location, is expected to serve as basic data in the assessment criteria of survey areas and classification of impact areas during further decommissioning and decontamination of sites.

Practicalities of dose management for Japanese astronauts staying at the International Space Station.

Japanese astronauts started staying at the International Space Station (ISS) in 2009, with each stay lasting for approximately 6 months. In total, seven Japanese astronauts have stayed at the ISS eight times. As there is no law for protection against space radiation exposure of astronauts in Japan, the Japan Aerospace Exploration Agency (JAXA) created its own rules and has applied them successfully to radiation exposure management for Japanese ISS astronauts, collaborating with ISS international partners. Regarding dose management, JAXA has implemented several dose limits to protect against both the stochastic effects of radiation and dose-dependent tissue reactions. The scope of the rules includes limiting exposure during spaceflight, exposure during several types of training, and exposure from astronaut-specific medical examinations. We, therefore, are tasked with calculating the dose from all exposure types applied to the dose limits annually for each astronaut. Whenever a Japanese astronaut is at the ISS, we monitor readings of an instrument in real-time to confirm that the exposed dose is below the set limits, as the space radiation environment can fluctuate in relation to solar activity.

Internal Dose Assessment of Worker by Radioactive Aerosol Generated During Mechanical Cutting of Radioactive Concrete

Removing radioactive concrete is crucial in the decommissioning of nuclear power plants. However, this process generates radioactive aerosols, exposing workers to radiation. Although large amounts of radioactive concrete are generated during decommissioning, studies on the internal exposure of workers to radioactive aerosols generated from the cutting of radioactive concrete are very limited. In this study, therefore, we calculate the internal radiation doses of workers exposed to radioactive aerosols during activities such as drilling and cutting of radioactive concrete, using previous research data. The electrical-mobility-equivalent diameter measured in a previous study was converted to aerodynamic diameter using the Newton–Raphson method. Furthermore, the specific activity of each nuclide in radioactive concrete 10 years after nuclear power plants are shut down was calculated using the ORIGEN code. Eventually, we calculated the committed effective dose for each nuclide using the IMBA software. The maximum effective dose of 152Eu constituted 83.09% of the total dose; moreover, the five highest-ranked elements (152Eu, 154Eu, 60Co, 239Pu, 55Fe) constituted 99.63%. Therefore, we postulate that these major elements could be measured first for rapid radiation exposure management of workers involved in decommissioning of nuclear power plants, even if all radioactive elements in concrete are not considered.

Activation of FLiBe coolant in the molten salt reactor

As an excellent material for candidate coolant of the molten salt reactor, the activation of 2LiF-BeF2 is an important issue and should be concerned. In this paper, the activation of 2LiF-BeF2 has been analyzed based on a specific Molten Salt Reactor. And combined approaches, Monte Carlo method for neutron transport and extension of the Euler for inventory calculation, have been adopted. The short life nuclides for shielding design, the long-life nuclides for occupational radiation exposure management and 3H, 14C production for environment protection have been studied.

SU‐D‐209‐03: Radiation Dose Reduction Using Real‐Time Image Processing in Interventional Radiology

Purpose:To characterize changes in radiation dose after introducing a new real‐time image processing technology in interventional radiology systems.Methods:Interventional radiology (IR) procedures are increasingly complex, at times requiring substantial time and radiation dose. The risk of inducing tissue reactions as well as long‐term stochastic effects such as radiation‐induced cancer is not trivial. To reduce this risk, IR systems are increasingly equipped with dose reduction technologies.Recently, ClarityIQ (Philips Healthcare) technology was installed in our existing neuroradiology IR (NIR) and vascular IR (VIR) suites respectively. ClarityIQ includes real‐time image processing that reduces noise/artifacts, enhances images, and sharpens edges while also reducing radiation dose rates. We reviewed 412 NIR (175 pre‐ and 237 post‐ClarityIQ) procedures and 329 VIR (156 preand 173 post‐ClarityIQ) procedures performed at our institution pre‐ and post‐ClarityIQ implementation. NIR procedures were primarily classified as interventional or diagnostic. VIR procedures included drain port, drain placement, tube change, mesenteric, and implanted venous procedures. Air Kerma (AK in units of mGy) was documented for all the cases using a commercial radiation exposure management system.Results:When considering all NIR procedures, median AK decreased from 1194 mGy to 561 mGy. When considering all VIR procedures, median AK decreased from 49 to 14 mGy. Both NIR and VIR exhibited a decrease in AK exceeding 50% after ClarityIQ implementation, a statistically significant (p<0.05) difference. Of the 5 most common VIR procedures, all median AK values decreased, but significance (p<0.05) was only reached in venous access (N=53), angio mesenteric (N=41), and drain placement procedures (N=31).Conclusion:ClarityIQ can reduce dose significantly for both NIR and VIR procedures. Image quality was not assessed in conjunction with the dose reduction.

방사선과 대학생이 방사선피폭관리에 대한 지식, 태도, 행위에 관한 연구

본 연구의 조사대상은 대구, 경북지역에 소재한 대학교에 재학 중인 방사선과를 전공하는 대학생을 조사대상으로 2014년 2월 3일부터 2월21일까지 설문조사를 실시하여 다음과 같은 결과를 얻었다. 1. 방사선피폭관리에 대한 지식에 대해서는 'X선의 차폐는 납이나 콘크리트로 된 물질이 가능 하다', '인체에서 생식선은 방사선에 매우 민감한 부분이다' 문항에서 가장 높은 점수를 보였고, '직업상 피폭선량은 규정된 5년간에 대해 평균하여 연간 20 mSv를 넘을 수 없다'는 방사선피폭관리에 대한 지식이 가장 낮은 점수를 보였다. 2. 방사선피폭관리에 대한 태도에 대해서는 '방사선피폭과 관련하여 정기적인 건강진단을 받아야한다'. '방사선 조사지역에서 작업 시 방호복을 착용해야한다'는 문항에서 가장 높은 태도 수준을 보였고, '방사선장치의 선량보정 (Calibration)을 위한 선량측정을 정기적으로 해야 한다'는 방사선피폭관리에 대한 태도에서 가장 낮은 태도수준을 보였다. 3. 방사선피폭관리에 대한 행위에 대해서는 '방사선 조사 시 방어벽(판) 뒤에서 작업을 한 다'. '방사선피폭관리에 관한 교육을 정기적으로 받는 다'는 문항에서 가장 높은 행위 수준을 보였고, '근무지의 방사선 관련 장비가 순조로운 작업 상태로 되어 있는가를 사용 전 점점(Check)한다'는 가장 낮은 행위 수준을 보였다. Participants of this study were students of radiology who were attending colleges or universities located in Daegu and Gyeongbuk. This researcher conducted a questionnaire survey of those students from Feb. 3rd to 21st, 2014. The findings of the study can be summarized as follows. 1. Concerning the knowledge of radiation exposure management, the respondents' scores were highest in two items, or 'Materials based on lead or concrete may shield X-rays' and 'The sexual gland is very sensitive to radiation' and lowest in the item which says' 'Occupational radiation exposure dose should not exceed 20mSv a year in average on a 5-year period basis'. 2. The participants' scores for the attitudes of radiation exposure management were higher in two items, or 'Health examination should be made regularly in relation to radiation exposure' and 'Those who work within the area of irradiation should wear protective clothes' and lowest in the item which says 'Radiation exposure dose should be regularly measured for the calibration of the radiation system'. 3. For the behaviors of radiation exposure management, the surveyed students showed highest scores in two items, or 'When irradiating the patient, the radiator should be behind the protective barrier(plate)' and 'It is needed to receive the education of radiation exposure management regularly' While, their score for a behavior described in the item saying 'Before using the radiation system, it is needed to check whether the machine works normally.

Contemporary management of radiation exposure and injury.

Contemporary management of radiation exposure and injury.

Establishing diagnostic reference levels for interventional procedures in Kenya

PurposeTo quantify ionizing radiation exposure to patients during interventional procedures and establish national diagnostic reference levels (NDRLs) for clinical radiation exposure management. MethodsThe cumulative reference point air kerma, kerma area product, fluoroscopy time and other operational parameters were monitored for 50 children and 261 adult patient procedures in five catheterization medical laboratories in Kenya. To estimate the risk associated with the exposure, effective doses were derived from the kerma area product using conversion factors from Monte Carlo models. ResultsAbout 3% of the measured cumulative reference point air kerma for the interventional procedures approached the threshold dose limit with the potential to cause deterministic effects such as skin injuries. In interventional cardiology, the results obtained for both children and adults indicated 33% were below the diagnostic reference levels (DRLs). In adult interventional radiology, 29% for cumulative reference point air kerma, and 43% for kerma area product and fluoroscopy time respectively were below the diagnostic reference levels. NDRLs were proposed for routine use in the procedures considered and for the non-existent DRLs situations in paediatric interventional cardiology. ConclusionThe measured patient doses were above the DRLs available in the literature indicating a need for radiation optimization through, continuous monitoring and recording of patient dose. To promote radiation safety, facilities performing interventional procedures need to establish a radiation monitoring notification threshold for possible deterministic effects, in addition to the use of the newly established national diagnostic reference levels, as a quality assurance measure.

Risk perception and feeling of worry of radiation exposure at work : A case of radiologic technologists in South Korea

Background:Despite increasing concerns about radiologic technologists (RT), the occupational group exposed to the highest dose of radiation worldwide, little is known about the factors affecting their thoughts and feelings of risk at work. Aims: To fill this gap, this study attempted to (1) identify key variables predicting perceived risk and worry among RT, and (2) provide implications for improving organizational communications between health experts including RT and managers. Methods: A nationwide representative survey of RT (N=585) was conducted in 2012 using a stratified multistage random sampling design. Both qualitative and quantitative data were collected by face to face interviews. Questionnaires consisted of (1) risk ratings, (2) risk perception of radiation exposure at work (3) affect, value, trust(e.g. toward experts), worry and intention to quit RT work, and (4) job related factors(e.g. tenure) as well as demographic variables Results:For RT that routinely working with radiation technologies and equipment, neutral (53.7%) or positive (31.7%) rather than negative (14.6%) affective image of radiation risk was dominant. Risk of radiation exposure was differently perceived: it was the second-lowest as a general risk, but ranked in the top three when it was considered as ‘my risk’. Results of multiple regressions showed that ‘organizational trust’, the extent to which RTs believe in their hospital’s efforts for timely and effective risk management of radiation exposure, was the strongest predictors of both risk perception and worry of radiation exposure at work. Conclusions: Consistent with the literature on risk perception, findings of this study suggested that the same risk can mean different things in different contexts. In particular, this study highlighted the importance of organizational trust in risk perception and job related worry. For a healthier occupational environment, hospital managers need to be aware that trust can play a role in work safety and psychological well-being among health experts.

Risks and Management of Radiation Exposure

Risks and Management of Radiation Exposure

Risks and Management of Radiation Exposure

High-energy ionizing radiation is harmful. Low-level exposure sources include background, occupational, and medical diagnostics. Radiation disaster incidents include radioactive substance accidents and nuclear power plant accidents. Terrorism and international conflict could trigger intentional radiation disasters that include radiation dispersion devices (RDD) (a radioactive dirty bomb), deliberate exposure to industrial radioactive substances, nuclear power plant sabotage, and nuclear weapon detonation. Nuclear fissioning events such as nuclear power plant incidents and nuclear weapon detonation release radioactive fallout that include radioactive iodine 131, cesium 137, strontium 90, uranium, plutonium, and many other radioactive isotopes. An RDD dirty bomb is likely to spread only one radioactive substance, with the most likely substance being cesium 137. Cobalt 60 and strontium 90 are other RDD dirty bomb possibilities. In a radiation disaster, stable patients should be decontaminated to minimize further radiation exposure. Potassium iodide (KI) is useful for iodine 131 exposure. Prussian blue (ferric hexacyanoferrate) enhances the fecal excretion of cesium via ion exchange. Ca-DTPA (diethylenetriaminepentaacetic acid) and Zn-DTPA form stable ionic complexes with plutonium, americium, and curium, which are excreted in the urine. Amifostine enhances chemical and enzymatic repair of damaged DNA. Acute radiation sickness ranges in severity from mild to lethal, which can be assessed by the nausea/vomiting onset/duration, complete blood cell count findings, and neurologic symptoms.

Radiation exposure among emergency healthcare providers by portable radiograph

Purpose: The healthcare providers in emergency department(ED) are vulnerable to radiation exposure by portableradiographs. But there are few studies that showed the difference between professions and the radiologic technicians. Thisstudy was conducted to measure radiation exposure level to portable radiography equipment, for the healthcare providers, inED.Methods: A prospective study was conducted from July 1, 2010 to December 31, 2010 at the ED. Each worethermoluminescent personal radiation dosimetry monitors at near the heart while working in the ED. We estimated the radiationexposure dose of these healthcare providers in ED for six months and compared the results with those obtained for theworkers in the radiology department.Results: The radiation exposure of three types of portable radiographs(Chest, C-spine, Pelvis) was rapidly decreased bydiameter from the beam. The total radiation exposure of over 6 months goes as follows; nurse(0.022±0.008 mSv), emergencyphysicians(0.388±0.735 mSv), emergency medical technicians(0.320±0.217 mSv), intern(0.267±0.478 mSv), resident(0.20±0mSv). The average exposure does of the healthcare providers in the ED was lower than that of radiologic technicians(0.122±0.339 vs 0.455±0.654 mSv, p=0.007) but the difference of radiation exposure among interns, emergency physicians,and radiologic technician was not statistically significant(0.267±0.47 vs 0.388±0.735 vs 0.513±0.692 mSv, p=0.101).Conclusion: The average of radiation exposure among emergency healthcare providers by portable radiography equipmentwas 0.1222mSv, and there was no interprofessional difference between the physicians and the other groups. But managementof radiation exposure in healthcare providers is important because total radiation exposure of the emergency physicians and theintern shows exposure to a lot of radiation as observed in the radiologic technologists.

DAP(Dose Area Product)를 이용한 TLD와 PLD의 선량 측정 비교

본 연구는 현재 법령 개인선량계인 PLD와 TLD의 선량 분석을 통해 성능 차이를 알아보고자 하였다. 자동판독장치를 이용해 PLD와 TLD의 적산선량을 판독 후 선량 교정 과정을 거친 두 소자의 값은 70kVp, 200mA, 0.012sec와 42kVp, 100mA, 0.012sec의 각각의 촬영조건에서 TLD는 PLD 측정 시와 통계적 차이를 나타냈다(각각 p<0.001, p<0.001). DAP와 두 소자의 측정값 차이는 70kVp, 200mA, 0.012sec 촬영조건에서 TLD는 DAP 평균값보다 <TEX>$44.2mGy{\cdot}cm^2$</TEX>이 낮은 값이 나타났고, PLD는 DAP 평균값에 <TEX>$15.5mGy{\cdot}cm^2$</TEX>이 낮은 <TEX>$246.8mGy{\cdot}cm^2$</TEX>으로 나타났다. 42kVp, 100mA, 0.012sec 촬영조건에서는 TLD는 DAP 평균 값의 <TEX>$17.9mGy{\cdot}cm^2$</TEX>이 낮은 값을 보였으며, PLD는 DAP 평균값에 <TEX>$7.6mGy{\cdot}cm^2$</TEX>이 낮은 <TEX>$82.6mGy{\cdot}cm^2$</TEX>으로 나타나 PLD가 DAP에 더 근접한 값을 보였다. 또한 PLD에 비해 TLD는 10개의 각 소자마다 측정된 선량 값에서 소자 상호간의 편차가 크게 나타났고, 1개의 소자를 반복 측정한 재현성 실험에서 PLD는 <TEX>${\pm}1%$</TEX> 이내로 TLD <TEX>${\pm}2%$</TEX> 보다 낮게 나타났다. 따라서 PLD가 TLD에 비해 선량 측정 능력면에서 더 우수한 결과가 나타났고, 진단용 방사선영역에서 방사선작업종사자의 개인피폭 관리에 PLD가 더욱 적합하고 유리함을 확인할 수 있었다. The results of analyzing the difference between performances of individual dosimeters on this research subjecting the PLD and TLD, which are the official personal dosimeters, through dosimetry are as follows. After scanning the integral dose using an automatic scanner, the values of two devices that went through dose adjustment process had a statistical difference in TLD and PLD measurements under each filming conditions which were 70kVp, 200mA, 0.012sec and 42kVp, 100mA, and 0.012sec (p<0.001 and p<0.001 respectively). As for the difference of measurement value between DAP and the two particles under 70kVp, 200mA, 0.012sec filming condition, TLD had a value lower than DAP average value by <TEX>$44.2mGy{\cdot}cm^2$</TEX> and PLD had a value of <TEX>$246.8mGy{\cdot}cm^2$</TEX> which was lower than DAP average value by <TEX>$15.5mGy{\cdot}cm^2$</TEX>, while under 42kVp, 100mA, 0.012sec filming condition, TLD had a value lower than DAP average value by <TEX>$17.9mGy{\cdot}cm^2$</TEX> and PLD had a value of <TEX>$82.6mGy{\cdot}cm^2$</TEX> which was lower than DAP average value by 7.6<TEX>$mGy{\cdot}cm^2$</TEX>. Also, compared to PLD, each of 10 devices measured dose value in TLD had a larger deviation between the particles, and for a reproducibility test which repeatedly measured one particle, PLD had <TEX>${\pm}1%$</TEX> which was lower than TLD's <TEX>${\pm}2%$</TEX>. As such, PLD had a superior performance result in dose measurement capacities aspect compared to TLD, and therefore we could verify that PLD is more appropriate and advantageous in managing radiation-related task performing worker's personal radiation exposure management in the diagnostic radiation field.

Radiation Environment in Space

Japanese Experiment Module (Kibo) had been build into the International Space Station (ISS), which is a multipurpose manned facility and laboratory and is operated in orbit at about 400 km in altitude. Two Japanese astronauts stayed in the ISS for long time (4.5 and 5.5 months) for the first time. Space radiation exposure is one of the biggest safety issues for astronauts to stay for such a long duration in space. This special paper is presenting commentary on space radiation environment in ISS, neutrons measurements and light particles (protons and electrons) measurements, the instruments, radiation exposure management for Japanese astronauts and some comments in view of health physics.