Occupational radiation exposure among medical personnel in university and general hospitals in Japan.

OBJECTIVE: This study aimed to compare the occupational radiation exposure of medical workers between general hospitals and university hospitals. METHODS: Radiation exposure data from three hospitals in Hiroshima city, including one university hospital and two general hospitals, were collected using personal dosimeters. Monthly radiation doses were analyzed, and the annual sum of radiation exposure dose was calculated for 538 subjects in general hospitals and 1224 subjects in the university hospital. To assess the impact of locality, additional data from Nagasaki University Hospital and Fukushima Medical University Hospital were included for comparative analysis. Professional affiliations, such as doctors, nurses, and radiological technologists, were considered in the evaluation. RESULTS: The study revealed slight but significant differences in radiation doses between general and university hospitals. In general hospitals, except for radiological technologists, a slightly higher radiation dose was observed compared to university hospitals. Despite the annual increase in the use of medical radiation, the majority of hospital workers in both settings adhered to safety guidelines, with occupational radiation exposure remaining below the limit of detection (LOD). Workers who involved in fluoroscopic procedure, whether at university or general hospitals, had higher radiation doses than those who did not. CONCLUSION: The study's primary conclusion is that workers in general hospitals experience a slight but significantly higher radiation dose and a lower percentage below the LOD compared to university hospitals. The observed difference is attributed to the greater workload at general hospitals than at university hospitals, and also may be due to the different nature of university hospital and general hospital. University hospitals, characterized by greater academic orientation, tend to benefit from comprehensive support systems, specialized expertise, and advanced technology, leading to more structured and regulated radiation control. These findings provide a basis for targeted interventions, improved safety protocols.

Radiation Exposure Characteristics among Healthcare Workers: Before and After Japan's Ordinance Revision.

ABSTRACT: Radioactive materials and ionizing radiation have both medical value and disease risks, necessitating radiation dose measurement and risk reduction strategies. The International Commission on Radiological Protection (ICRP) lowered the lens of the eye exposure limit, leading to Japan's revised "Ionizing Radiation Ordinance." However, the effects on radiation exposure in medical settings and compliance feasibility remain unclear. To examine the impact of the revision to the "Ionizing Radiation Ordinance" and use it for measures to reduce exposure to radiation, a comprehensive analysis was conducted on data collected from Nagasaki University Hospital, Hiroshima University Hospital, and Fukushima Medical University Hospital in 2018, 2020, and April to September 2021. This included information on age, sex, occupation, department, and monthly radiation doses of workers, aiming to assess the impact of the revision to the "Ionizing Radiation Ordinance" on radiation exposure before and after its enforcement. Out of 9,076 cases studied, 7,963 (87.7%) had radiation doses below the measurable limit throughout the year. Only 292 cases (3.2%) exceeded 1 mSv y -1 , with 9 doctors and 2 radiological technologists surpassing 5 mSv y -1 . Radiological technologists showed significantly higher doses compared to doctors, dentists, and nurses (p < 0.01), while male subjects had significantly higher exposure doses than females (p < 0.01). No significant changes in radiation exposure were observed before and after the revision of the Ionizing Radiation Ordinance; however, variations in radiation exposure control were noted, particularly among nurses and radiological technologists, suggesting the impact of the revision and the need for tailored countermeasures to reduce radiation dose in each group.

Temporal variation in environmental radioactivity and radiation exposure doses in the restricted areas around the Fukushima Daiichi Nuclear Power Plant.

Temporal variation and fluctuation in environmental contamination in Futaba town and Okuma town, the location of the Fukushima Daiichi Nuclear Power Plant (FDNPP), were evaluated based on a car-borne survey conducted from October 2021 to November 2022. Although the environmental radioactivity in the interim storage facility area (ISF) was higher than that in open areas (i.e., the evacuation order lifted areas in Futaba town and the Specific Reconstruction and Regeneration Base area [SRRB] in Okuma town), only minor temporal changes were seen in the ambient dose and detection rate of radiocesium (the proportion of radiocesium detected points per all measuring points) in those areas, respectively. These findings suggest that the observed variations may result from physical decay and environmental remediation. Resuspension caused by human activities and weather could also affect the detection rate of radiocesium. The annual external effective doses in Futaba town and Okuma town were estimated to be at a limited level (< 1 mSv/year). Nevertheless, to help ensure the safety and future prosperity of residents and communities in the affected areas around the FDNPP, long-term follow-up monitoring of temporal exposure dose levels during the recovery and reconstruction phases is extremely important.

Profile of Nagasaki Islands Study (NaIS): A Population-Based Prospective Cohort Study on Multi-disease.

In an aging society, it is important to visualize the conditions of people living with diseases or disabilities, such as frailty and sarcopenia, and determine the environmental and genetic factors underlying such conditions. Atherosclerosis and arterial stiffness are key conditions between these factors and noncommunicable diseases. In 2014, we launched a population-based prospective open-cohort study, the Nagasaki Islands Study (NaIS), which was conducted in Goto City, located in the remote islands of Nagasaki Prefecture, Japan, mostly involving middle-aged and older residents. We conducted our own health checkups along with the annual standardized checkups organized by the municipality; recruited study participants; and started to follow-up with them for vital status (death), migration, and occurrence of diseases such as myocardial infarction, stroke, fracture, and human T-cell leukemia virus type 1 (HTLV-1) -associated uveitis. Our checkups were conducted as baseline surveys in different areas of Goto City during the fiscal years 2014-2016, secondary surveys during 2017-2019, and tertiary surveys since 2021, consisting of medical interviews, physical examinations, blood and urine tests, body composition measurements, osteoporosis screening, arterial stiffness measurements, carotid ultrasonography, and dental examination. A total of 4,957 residents participated in either the baseline or secondary surveys and were followed-up; and 3,594 and 3,364 residents (aged 27-96 and 28-98 years) participated in the baseline and secondary surveys, respectively. In conclusion, the NaIS has been undertaken to reveal the influence of aging and risk factors of noncommunicable diseases and disabilities, with an aim to contribute towards better healthcare in the future.

Assessment of Radiation Risk Perception and Interest in Tritiated Water among Returnees to and Evacuees from Tomioka Town within 20 km of the Fukushima Daiichi Nuclear Power Plant.

In this study, we aimed to investigate radiation risk perception, mental health, and interest in tritiated water among evacuees from and returnees to Tomioka town, Japan, as well as to evaluate the intention to return (ITR) among evacuees living inside and outside Fukushima Prefecture. Of the 1728 respondents, 318 (18.4%) and 1203 (69.6%) participants reported living outside and inside Fukushima Prefecture, and 207 (12.0%) reported living in Tomioka. The ITR was not significantly different between those who lived inside and outside the prefecture among the evacuees. Similarly, there were no significant differences in radiation risk perception, mental health, and interest in tritiated water. However, the evacuees were independently associated with a motivation to learn about tritiated water (OR = 1.242, 95%Cl: 1.041-1.438, p = 0.016), reluctance to consume food from Tomioka (OR = 1.635, 95%Cl: 1.372-1.948, p < 0.001), and concern that adverse health effects would occur because of the Fukushima Daiichi Nuclear Power Plant accident (OR = 1.279, 95%Cl: 1.055-1.550, p = 0.012) compared to returnees, according to logistic regression analysis. Interestingly, the returnees were found to have better mental health but lower life satisfaction than the evacuees. These findings suggest the importance of ongoing risk communication about radiation exposure and tritiated water among residents regardless of their place of residency.

Intention to Return and Perception of the Health Risk Due to Radiation Exposure Among Residents in Tomioka Town, Fukushima Prefecture, Stratified by Gender and Generation.

OBJECTIVE: The aim of this study was to clarify residents' intentions to return (ITR) to Tomioka town, Fukushima Prefecture; and their risk perception of the health effects of radiation exposure as stratified by gender and generation. METHODS: Of almost 8000 residents who were 20 years of age or older and who had lived, prior to the accident, in the zones of Tomioka town where residents were permitted to return, 1860 were included in the analysis. For the analysis, the residents were divided into 4 groups which were stratified by gender and age: older males (over 50 years), young males (20-49 years), older females (over 50 years), and young females (20-49 years). RESULTS: ITR was found to be significantly lower in young males, young females, and older females than in older males. Conversely, young and older females had significantly higher levels of anxiety about drinking tap water and consuming food collected in Tomioka town. Young and older females also had greater concerns about adverse health effects on themselves and their offspring due to living in Tomioka town. CONCLUSION: Our results showed that special attention should be paid to younger residents, particularly to young females, with regard to recovery from a nuclear disaster.

Determining Response to Treatment for Drug-Induced Bronchocentric Granulomatosis by the Forced Oscillation Technique.

Anti-tumor necrosis factor alpha (TNFα) therapy is widely used to treat various inflammatory conditions. Paradoxically, there are several case reports describing the development of bronchocentric granulomatosis treated with TNFα inhibitors, and it is difficult to determine the effect of treatment using conventional spirometry because the lesions are located in small airways. However, it has been reported that the forced oscillation technique (FOT) is useful in the evaluation of small airway disease in bronchial asthma or chronic obstructive pulmonary disease. We performed the FOT to determine the effect of treatment on bronchocentric granulomatosis and found it to be useful. We report the case of a 55-year-old female with ulcerative colitis who was treated with golimumab and who developed bronchocentric granulomatosis as a sarcoid-like reaction to golimumab. She was successfully treated with prednisone, and the treatment efficacy was confirmed by the FOT. The FOT may be useful in the evaluation of small airway disease in bronchocentric granulomatosis. This case may help inform clinicians of the usefulness of the FOT to assess small airway disease in various diseases.

Risk Perception of Health Risks Associated with Radiation Exposure among Residents of Okuma, Fukushima Prefecture.

Ten years have passed since the Great East Japan Earthquake and the subsequent Fukushima Daiichi nuclear power plant accident on 11 March 2011. Okuma is a town hosting the Fukushima Daiichi nuclear power plant. The evacuation order for Okuma was partially lifted in April 2019. To clarify factors associated with risk perceptions of radiation among the residents of Okuma, we conducted a questionnaire survey in January 2021. Our results revealed that resident anxieties regarding the health effects of radiation exposure from living in Okuma were independently associated with positive PCL-Specific score, recognition of the consultation services with radiation experts in the municipal government of Okuma, and planned request for consultation service regarding radiation exposure by radiation experts, along with being female and living with a child. It is important for radiation experts to promote periodic communication of risks with individuals on a small scale to provide accurate information about the health effects of radiation and to provide maternal and child healthcare services and support regarding child-rearing and radiation exposure, to reduce concerns about radiation exposure and facilitate healthy living and wellbeing in Okuma.

Risk perception of the pre-distribution of stable iodine to guardians of children living around the Genkai Nuclear Power Plant, Saga Prefecture, Japan.

Iodine thyroid blocking (ITB) is effective for preventing childhood thyroid cancer when radioactive iodine is released into the environment during a nuclear power plant accident. Japan employs the pre-distribution of stable iodine (PDSI) to residents living near nuclear power plants; however, the number of residents who have actually received stable iodine to date remains limited. The aim of this study was to evaluate the profile of guardians of children living around the Genkai Nuclear Power Plant (GNPP) in Japan. We distributed self-administered questionnaires regarding perception of risks associated with administration of stable iodide to approximated 400 guardians of children aged 0-6 in 10 kindergartens located in four municipalities. We obtained responses from 286 guardians, and after excluding invalid responses, 247 were included in the analysis. Logistic regression analysis revealed that living within 5 km of the GNPP (odds ratio [OR] = 4.48, 95% confidence interval [CI]: 2.43-8.24), awareness of preferential implementation of ITB to children (OR = 3.33, 95%CI: 1.78-6.22), and awareness of the prophylaxis booklet published by the local government (OR = 2.53, 95%CI: 1.37-4.68) were independently associated with PDSI for children. The main reasons for not receiving PDSI were "anxiety about the side effects of stable iodine" (40.2%), "distrust of the effectiveness of SI" (23.5%), "complicated procedures for receiving stable iodine" (15.7%) and "missed the date for receiving stable iodine" (8.8%). In the case of ITB implementation during a nuclear emergency, it is necessary to clarify the risk perceptions of guardians and adapt risk communication accordingly.

Experiences of crisis communication during radiation emergency and risk communication for recovery of the community in Fukushima.

Since 2011, Nagasaki University (Nagasaki, Japan) has been assisting the reconstruction efforts of Kawauchi Village (Fukushima Prefecture), which was the first village to decide to return to their home town after the evacuation due to the accident at the Fukushima Daiichi Nuclear Power Station. In April 2013, Nagasaki University and the Kawauchi Government Office concluded an agreement concerning comprehensive cooperation toward the reconstruction of the village. Furthermore, we began comprehensive support for the residents of Tomioka who returned to their hometown in 2017, and of Ohkuma town in 2020. On the basis of the experiences in Kawauchi, Tomioka and Ohkuma, it is clear that the cooperation of residents, local authorities and specialists is essential for the recovery of areas affected by the accident at the Fukushima Daiichi Nuclear Power Station. Accumulated experiences and practices should be carefully evaluated and recorded to prepare for unexpected nuclear disasters in the future.

LOCAL LEVELS OF RADIATION EXPOSURE DOSES DUE TO RADIOCESIUM FOR RETURNED RESIDENTS IN TOMIOKA TOWN, FUKUSHIMA PREFECTURE.

Tomioka Town is located within a 20-km radius of the Fukushima Daiichi Nuclear Power Station. Radiation dose rates due to radiocesium in residents' living spaces were evaluated from the measurements of ambient dose rates and environmental samples after returning home. The mean ambient dose rates were 0.15-0.18-µSv/h indoors and 0.23-0.26-µSv/h outdoors during 2018 and 2019, and the additional radiation dose rates were calculated to be 1.4 mSv/y in 2018 and 1.1 mSv/y in 2019. Ambient dose equivalent from surface soils within housing sites were estimated to be 0.66 mSv/y in 2018 and 0.54 mSv/y in 2019. Moreover, committed effective doses from local foods were calculated in 19-74 µSv/y for children and 39-100 µSv/y for adults during 2018 and 2019. These findings suggest that current radiation exposure doses have been controlled at the levels close to the public dose limit (1 mSv/y) in residents' living spaces.

The Relationship between Dental Findings and Tongue Pressure: A Survey of 745 Community-Dwelling Adults and Elderly Persons in Japan.

INTRODUCTION: Reduced tongue pressure is one of the causes of dysphagia. The purpose of this study was to investigate the relationship between dental findings and tongue pressure, and whether prosthetic treatment prevents reduced tongue pressure. METHODS: This was a cross-sectional study. Participants were 745 community-dwelling adults and elderly persons in the Goto Islands in Nagasaki, who underwent a health checkup for residents in 2015 and 2016. Data were collected on gender; age; grip strength; hemoglobin; Creatinine (Cr); glycated hemoglobin (HbA1c); history of stroke; smoking, drinking, exercise, and walking habits; number of teeth; wearing of removable dentures; functional units of natural teeth (n-FTUs), fixed prostheses (nif-FTUs), and removable dentures (t-FTUs); and tongue pressure. The associations between each variable and tongue pressure were examined using multiple regression analysis. Next, those with 3 or fewer n-FTUs were selected, and differences in tongue pressure were compared between those with 3 or fewer nif-FTUs and those with 4 or more nif-FTUs, using a propensity score matching method. RESULTS: Male gender, weak grip strength, low HbA1c, no drinking, and a low number of teeth were independent factors significantly associated with lower tongue pressure. Among participants with 3 or fewer n-FTUs, the 43 with 4 or more nif-FTUs showed significantly higher tongue pressure than the 43 with 3 or fewer nif-FTUs after propensity score matching, although the number of t-FTUs was not associated with tongue pressure. DISCUSSION/CONCLUSION: Tooth loss was significantly associated with lower tongue pressure. It was suggested that fixed prosthesis treatment might prevent the reduction of tongue pressure, but removable dentures did not have such an effect.

Risk perception regarding implementation of iodine thyroid blocking during a nuclear disaster of mothers living near a nuclear power station in Japan.

Pre-emptive evacuation orders following the accident at the Fukushima Daiichi Nuclear Power Station (FDNPS) in March 2011 and subsequent regulatory limits regarding contaminated food, milk, and water minimized the external and internal radiation exposure doses of nearby residents. However, with regard to implementation of iodine thyroid blocking (ITB), residents were confused because no information on the matter was released by the central and/or local governments. Based on lessons learned from the FDNPS accident, many countries have revised their guidelines regarding ITB during nuclear disasters. To adequately revise such guidelines and ensure effective ITB implementation during a nuclear disaster, however, residents' perceptions of ITB must be clarified. In this study, the perception of risks associated with ITB was investigated in mothers residing near the Sendai Nuclear Power Plant (SNPP) in Kagoshima Prefecture, Japan. Of the 520 mothers surveyed, 467 (89.8%) expressed anxiety regarding the administration of potassium iodine (KI) to their children. Logistic regression analysis revealed that the mothers' anxiety regarding the administration of KI to their children was positively correlated with their wish to consult an expert about KI and their hesitation to let their children eat foods produced in Fukushima, and negatively correlated with having confidence about administering KI to their children. Careful communication of potential risks to mothers residing near nuclear power plants is thus critical for implementing effective ITB in children.

Health-related quality of life in Japanese patients with prostate cancer following proton beam therapy: an institutional cohort study.

OBJECTIVE: Many treatment options have guaranteed long-term survival in patients with localized prostate cancer and health-related quality of life has become a greater concern for those patients. The purpose of this study was to reveal the health-related quality of life after proton beam therapy and to clarify the differences from other treatment modalities for prostate cancer. METHODS: Between January 2011 and April 2016, 583 patients were enrolled in the study and health-related quality of life outcomes using the Expanded Prostate Cancer Index Composite questionnaire were evaluated and compared with previous research targeted at Japanese patients. RESULTS: We found a significant decrease in the least square mean scores for urinary and bowel domains excluding the incontinence subscale after proton beam therapy (P < 0.0001) and recovery at a year following treatment. The scores for sexual function in patients without androgen deprivation therapy decreased each year after proton beam therapy (P < 0.0001). The scores for hormones in patients without androgen deprivation therapy remained high and those of patients with androgen deprivation therapy were lower before treatment but were comparable to those of non-androgen deprivation therapy patients at 2 years post-treatment. We found that the impact of radiotherapy including proton beam therapy on urinary condition and sexual function was lower than that of surgery. CONCLUSIONS: For the first time in Japan, we investigated health-related quality of life using Expanded Prostate Cancer Index Composite questionnaires in patients with prostate cancer after proton beam therapy and compared it with other treatment modalities.

Evaluation of Environmental Contamination and Estimated Radiation Exposure Dose Rates among Residents Immediately after Returning Home to Tomioka Town, Fukushima Prefecture.

On 1 April 2017, six years have passed since the Fukushima Daiichi Nuclear Power Station (FDNPS) accident, and the Japanese government declared that some residents who lived in Tomioka Town, Fukushima Prefecture could return to their homes. We evaluated environmental contamination and radiation exposure dose rates due to artificial radionuclides in the livelihood zone of residents (living space such as housing sites), including a restricted area located within a 10-km radius from the FDNPS, immediately after residents had returned home in Tomioka town. In areas where the evacuation orders had been lifted, the median air dose rates were 0.20 µSv/h indoors and 0.26 µSv/h outdoors, and the radiation exposure dose rate was 1.6 mSv/y. By contrast, in the "difficult-to-return zone," the median air dose rate was 2.3 µSv/h (20 mSv/y) outdoors. Moreover, the dose-forming artificial radionuclides (radiocesium) in the surface soil were 0.018 µSv/h (0.17 mSv/y) in the evacuation order-lifted areas and 0.73 µSv/h (6.4 mSv/y) in the difficult-to-return zone. These findings indicate that current concentrations of artificial radionuclides in soil samples have been decreasing in the evacuation order-lifted areas of Tomioka town; however, a significant external exposure risk still exists in the difficult-to-return zone. The case of Tomioka town is expected to be the first reconstruction model including the difficult-to-return zone.

Risk perceptions regarding radiation exposure among Japanese schoolteachers living around the Sendai Nuclear Power Plant after the Fukushima accident.

In response to the Fukushima Daiichi nuclear power plant disaster, the Nuclear Regulation Authority of Japan issued the new "Nuclear Emergency Response Guideline." However, there is a perception that scientific information about the health impact of radiation exposure has not been adequately shared among the local government staffs, including schoolteachers. We contacted schoolteachers at all 120 schools within the Urgent Protective Action Planning Zone of the Sendai Nuclear Power Plant, Kagoshima prefecture, in 2017. We invited them to take part in a written survey to clarify their concerns and risk perceptions regarding the effects of radiation exposure on health. Five hundred and fifty schoolteachers' replies were included in the analysis. The results revealed that 355 schoolteachers had concerns about the health effects of radiation exposure due to working within the Urgent Protective Action Planning Zone. A logistic regression analysis revealed that sex (OR = 2.26, 95% CI: 1.49-3.45, p < 0.001), age (OR = 3.39, 95% CI: 2.10-5.47, p < 0.001), reluctance to undergo a radiological examination at a hospital (OR = 1.91, 95% CI: 1.23-2.88, p = 0.004), place of work (OR = 2.18, 95% CI: 1.46-3.27, p < 0.001), and anxiety about having to address questions about radiation from students (OR = 4.66, 95% CI: 2.83-7.67, p < 0.001) were independently associated with schoolteachers' concerns about the health effects of radiation exposure due to working in the area around the nuclear power plant. Therefore, it is important to respond to these concerns in order to establish a meaningful education program for school children on radiation and its health effects.