Comprehensive elucidation of resting-state functional connectivity in anorexia nervosa by a multicenter cross-sectional study.

BACKGROUND: Previous research on the changes in resting-state functional connectivity (rsFC) in anorexia nervosa (AN) has been limited by an insufficient sample size, which reduced the reliability of the results and made it difficult to set the whole brain as regions of interest (ROIs). METHODS: We analyzed functional magnetic resonance imaging data from 114 female AN patients and 135 healthy controls (HC) and obtained self-reported psychological scales, including eating disorder examination questionnaire 6.0. One hundred sixty-four cortical, subcortical, cerebellar, and network parcellation regions were considered as ROIs. We calculated the ROI-to-ROI rsFCs and performed group comparisons. RESULTS: Compared to HC, AN patients showed 12 stronger rsFCs mainly in regions containing dorsolateral prefrontal cortex (DLPFC), and 33 weaker rsFCs primarily in regions containing cerebellum, within temporal lobe, between posterior fusiform cortex and lateral part of visual network, and between anterior cingulate cortex (ACC) and thalamus (p < 0.01, false discovery rate [FDR] correction). Comparisons between AN subtypes showed that there were stronger rsFCs between right lingual gyrus and right supracalcarine cortex and between left temporal occipital fusiform cortex and medial part of visual network in the restricting type compared to the binge/purging type (p < 0.01, FDR correction). CONCLUSION: Stronger rsFCs in regions containing mainly DLPFC, and weaker rsFCs in regions containing primarily cerebellum, within temporal lobe, between posterior fusiform cortex and lateral part of visual network, and between ACC and thalamus, may represent categorical diagnostic markers discriminating AN patients from HC.

Internal radiation exposure from 137Cs and its association with the dietary habits of residents from areas affected by the Chernobyl nuclear accident, Ukraine: 2016-2018.

The total annual effective dose has steadily decreased since the fallout of the Chernobyl Nuclear Power Plant. However, chronic internal exposure to 137Cs still persists and fluctuates in a complex and unpredictable manner. Recently, body contamination was found to primarily occur owing to the intake of forest foodstuffs that contain long-lived 137Cs. Forest foodstuffs may have up to 100 times higher concentration of cesium than does local milk and meat. The present study aimed to investigate the recent dietary habits of residents in the Zhytomyr region of Ukraine, and assess the effect of the intake of forest foodstuffs on the increase in internal radioactivity from 137Cs. We screened 1,612 participants, from July 2016 to February 2018 for internal radioactivity, using whole-body counter at Korosten Medical Center and surveyed their background and intake habits. We analyzed the association among food type, intake frequency, and internal exposure dose. The analysis revealed that nearly 90% of the participants regularly consumed one of the forest foodstuffs (mushrooms, berries, fish) or milk. Nearly 80% of the participants indicated that they consumed mushrooms or berries or both. Internal radioactivity was detected in 30% of the participants. The diet that included mushrooms exhibited the highest internal radioactivity. The lowest Bq/kg concentration was observed in the only-berry group, following the no-intake group. There was a significant correlation between the intake frequency and the magnitude of Bq/kg. Radioactivity detected in the mushroom-berry and only-mushroom group were 8.6 and 9.2 Bq/kg, respectively. The lowest and highest intake frequency showed a radioactivity of 2.4 and 7.5 Bq/kg, respectively. Radioactivity in the winter season was significantly higher than that in other seasons. In conclusion, our study revealed that internal radioactivity varies depending on the type of food, intake frequency, and season.

The association between upper gastrointestinal endoscopic findings and internal radiation exposure in residents living in areas affected by the Chernobyl nuclear accident.

Many people living around the Chernobyl Nuclear Power Plant (CNPP) have been exposed to 137Cs for several decades after the CNPP accident. Although half-life of 137Cs is about 30 years, some wild forest foodstuffs are contaminated by 137Cs even now. We pointed out in a previous report that low-dose internal radiation has been occasionally detected in people's body. Moreover, some doctors in local hospitals have claimed that internal exposure from contaminated foodstuffs may affect the digestive organs and possibly cause gastrointestinal (GI) diseases. Thus, we attempt to assess whether internal radiation exposure affects digestive organs or not, and the possible factors that influence digestive organs. Overall, 1,612 residents were assessed for internal 137Cs concentration using Whole-Body Counter and their digestive organs were screened with upper GI endoscopy from 2016-2018 in the Zhytomyr region, Ukraine. All participants answered to the questionnaire including their background, intake of wild forest foodstuff, intake frequency, smoking habits, and alcohol consumption. We checked the number of upper GI endoscopic diagnosis per person to assess the extent of damage to the upper digestive organs. Next, we statistically analyzed associations between this number and age, sex, level of internal exposure dose, alcohol consumption, wild forest foodstuff intake, and smoking. Consequently, we revealed that the number of GI diagnosis is significantly increased by factors such as sex, intake of wild forest foodstuff, and alcohol consumption. However, the average level of internal exposure of 137Cs and smoking did not relate to the number of GI diagnosis. Thus, the results of multiple regression revealed that alcohol consumption is independently related to the number of GI diagnosis that is most likely accompanied by the intake of wild forest foodstuff. In conclusion, the low-dose internal exposure may not affect the digestive organs of residents living around CNPP.

Guided internet-based cognitive behavioral therapy for obsessive-compulsive disorder: A multicenter randomized controlled trial in Japan.

Few studies have compared the effectiveness of internet-based cognitive behavior therapy (ICBT) for obsessive-compulsive disorder (OCD) with treatment as usual (TAU). We investigated the effectiveness of guided ICBT for patients with OCD. This prospective, randomized, controlled, assessor-blinded, multicenter clinical trial was conducted at three facilities in Japan from January 2020 to March 2021. Thirty-one patients with OCD as the primary diagnosis participated in the trial and were randomly assigned to either the intervention group or the control group. The primary outcome was the Yale-Brown obsessive-compulsive scale score; the assessors were blinded. Results of the analysis of covariance among the groups were significantly different between the groups (p < 0.01, effect size Cohen's d = 1.05), indicating the superiority of guided ICBT. The results suggest that guided ICBT is more effective than TAU for treating OCD. RCT REGISTRATION: UMIN Clinical Trials Registry (UMIN000039375).

Feasibility of guided internet-based cognitive behavioral therapy for patients with anorexia nervosa.

Objective: The objective of the present study was to investigate the feasibility of guided internet cognitive behavioral therapy (ICBT) for anorexia nervosa. Methods: We conducted a prospective single-arm study between January 2020 and March 2021. The intervention was built using videos, web programs, and chat tools. The intervention program was largely based on metacognitive training. Participants performed the self-help program once a week for 12 consecutive weeks. The primary outcome was the global Eating Disorder Examination Questionnaire (EDE-Q) score. Secondary outcomes included clinical symptoms of eating disorders, metacognitive function, body mass index, depression, and generalized anxiety. The main statistical analysis examined whether the EDE-Q score and other outcomes at the end of the intervention differed from the baseline. Results: Fourteen participants underwent the trial treatment, and 13 completed the intervention. There was a significant reduction in the global EDE-Q score from 3.48 (SD = 1.4) to 2.54 (SD = 1.5, p = 0.02, Cohen's d = 0.75) from baseline to post-intervention. Some EDE-Q subscales and body checking questionnaire scale demonstrated statistically significant improvements, with moderate to large effect sizes. Although there was no significant improvement in body mass index, metacognitive function, or depressive symptoms, there was a significant improvement in the severity of generalized anxiety (M = -4.0, p = 0.01, Cohen's d = 0.95). No adverse events were observed. Discussion: Our findings suggest that guided ICBT for anorexia nervosa is well accepted by female patients and practical as a telemedicine approach that improves symptoms. In the future, tightly controlled randomized controlled trials should be conducted for efficacy verification.

White matter microstructure and its relation to clinical features of obsessive-compulsive disorder: findings from the ENIGMA OCD Working Group.

Microstructural alterations in cortico-subcortical connections are thought to be present in obsessive-compulsive disorder (OCD). However, prior studies have yielded inconsistent findings, perhaps because small sample sizes provided insufficient power to detect subtle abnormalities. Here we investigated microstructural white matter alterations and their relation to clinical features in the largest dataset of adult and pediatric OCD to date. We analyzed diffusion tensor imaging metrics from 700 adult patients and 645 adult controls, as well as 174 pediatric patients and 144 pediatric controls across 19 sites participating in the ENIGMA OCD Working Group, in a cross-sectional case-control magnetic resonance study. We extracted measures of fractional anisotropy (FA) as main outcome, and mean diffusivity, radial diffusivity, and axial diffusivity as secondary outcomes for 25 white matter regions. We meta-analyzed patient-control group differences (Cohen's d) across sites, after adjusting for age and sex, and investigated associations with clinical characteristics. Adult OCD patients showed significant FA reduction in the sagittal stratum (d = -0.21, z = -3.21, p = 0.001) and posterior thalamic radiation (d = -0.26, z = -4.57, p < 0.0001). In the sagittal stratum, lower FA was associated with a younger age of onset (z = 2.71, p = 0.006), longer duration of illness (z = -2.086, p = 0.036), and a higher percentage of medicated patients in the cohorts studied (z = -1.98, p = 0.047). No significant association with symptom severity was found. Pediatric OCD patients did not show any detectable microstructural abnormalities compared to controls. Our findings of microstructural alterations in projection and association fibers to posterior brain regions in OCD are consistent with models emphasizing deficits in connectivity as an important feature of this disorder.

Screening for the 137Cs body burden owing to the Chernobyl accident in Zhytomyr region, Ukraine: 2009-2018.

The Chernobyl Nuclear Power Plant accident released vast amounts of various fission products, of which 131I and 137Cs are considered the most important because they are a major source of radiation exposure to the general public. 137Cs, unlike 131I, has a 30-year half-life that continues to expose people internally and externally for several decades after being deposited into the ground. 137Cs can be easily transmitted to the body through the intake of products and wild forest foodstuffs produced in contaminated areas. In the early phase, external exposure to 137Cs was predominant; however, it gradually diminished, mostly owing to horizontal and vertical distribution, and internal exposure started gaining dominance. Prior studies have shown that people in the affected areas have been constantly subjected to the inevitable low-grade internal exposure, which in turn has led to high anxiety and concern regarding the potential health effects. The present 10-year study assessed the latest status of the body burden among residents of the contaminated parts of the Zhytomyr region of Ukraine by measuring the internal concentration of 137Cs using the whole-body counter installed at the Medical Center of Korosten city. Almost 110 000 examinees from eight different districts were screened between 2009 and 2018. The study area was situated to the west of Chernobyl, which experienced a significant fallout of 137Cs and 131I from the Chernobyl Nuclear Power Plant. We analyzed the data for internal exposure to 137Cs by obtaining the actual magnitude, pace, and pattern of change for each year. During the study, the average 137Cs concentration in residents fell from 21.6 Bq/kg at the beginning of the study to 3.0 Bq/kg at the end of the study. The proportion of examinees with detectable levels had also fallen rapidly, from 45% to 11%. We found a weaker seasonal effect and a significantly higher Bq/kg concentration in adolescents than in other age groups.

Eating Disorder Neuroimaging Initiative (EDNI): a multicentre prospective cohort study protocol for elucidating the neural effects of cognitive-behavioural therapy for eating disorders.

INTRODUCTION: Anorexia nervosa is a refractory psychiatric disorder with a mortality rate of 5.9% and standardised mortality ratio of 5.35, which is much higher than other psychiatric disorders. The standardised mortality ratio of bulimia nervosa is 1.49; however, it is characterised by suicidality resulting in a shorter time to death. While there is no current validated drug treatment for eating disorders in Japan, cognitive-behavioural therapy (CBT) is a well-established and commonly used treatment. CBT is also recommended in the Japanese Guidelines for the Treatment of Eating Disorders (2012) and has been covered by insurance since 2018. However, the neural mechanisms responsible for the effect of CBT have not been elucidated, and the use of biomarkers such as neuroimaging data would be beneficial. METHODS AND ANALYSIS: The Eating Disorder Neuroimaging Initiative is a multisite prospective cohort study. We will longitudinally collect data from 72 patients with eating disorders (anorexia nervosa and bulimia nervosa) and 70 controls. Data will be collected at baseline, after 21-41 sessions of CBT and 12 months later. We will assess longitudinal changes in neural circuit function, clinical data, gene expression and psychological measures by therapeutic intervention and analyse the relationship among them using machine learning methods. ETHICS AND DISSEMINATION: The study was approved by The Ethical Committee of the National Center of Neurology and Psychiatry (A2019-072). We will obtain written informed consent from all patients who participate in the study after they had been fully informed about the study protocol. All imaging, demographic and clinical data are shared between the participating sites and will be made publicly available in 2024. TRIAL REGISTRATION NUMBER: UMIN000039841.

Barriers to Prevention and Treatment of Type 2 Diabetes Mellitus Among Outpatients in Belarus.

Objectives: This study aimed to determine the main barriers and reasons for non-adherence to preventive measures and treatment for type 2 diabetes mellitus among outpatients in Belarus. Methods: An anonymous questionnaire survey was conducted with 814 adults aged 18 years and over who visited outpatient health care units and hospitals in Belarus. The questionnaire was developed to analyze the perceived barriers that limit adherence to preventive measures and treatment for type 2 diabetes. Results: The proportion of respondents who reported doing daily physical activity was 53.2%, and 46.6% consumed at least 400 grams of fruit and vegetables per day. Among the 42.8% of respondents with a prescribed treatment for type 2 diabetes mellitus, 50.1% sometimes forgot to take their medicine. The specific barriers to treatment most frequently identified by survey respondents were "Financial situation" (23.5% of respondents), and "Fear of side effects" (25.2%). Those for lifestyle instructions were "Insufficient knowledge" (29.3%), "Financial situation" (27.9%), and "Lack of motivation" (21.7%). Conclusions: The study revealed that the main barriers to adherence were insufficient knowledge of diabetes and its treatment and an underestimation of the role of behavioral risk factors in health, combined with financial difficulties. We recommend that physicians should take a patient-centered approach to raising awareness of behavioral risk factors for type 2 diabetes mellitus, and suggest that the importance of adhering to preventative measures and treatment should be promoted in consultations in Belarus.

Relationship between the ability to stand and physical function in stroke survivors with hemiplegia: a pilot study.

Takahashi J. Relationship between the ability to stand and physical function in stroke survivors with hemiplegia: a pilot study. Jpn J Compr Rehabil Sci 2021; 12: 4-8. Objective: This study aimed to identify the physical functions necessary to enable stroke survivors with hemiplegia to stand from a chair. Methods: Fifteen patients who had suffered a hemiplegic stroke were divided into two groups, the pull and unable groups, based on their ability to stand by pulling a handrail. Their motor palsy, Stroke Impairment Assessment Set, and unaffected muscle strength were assessed. Results: Patients in the pull group had less motor palsy, higher muscle strength of the upper extremity on the unaffected side, and greater angle of ankle dorsiflexion on the affected side, compared to the patients in the unable group. Conclusion: The function of the affected lower limb and the unaffected upper limb's muscle strength determines the ability of patients who have suffered a hemiplegic stroke to lift their body upwards while standing from a chair.

Neuropsychological Comparison Between Patients with Social Anxiety and Healthy Controls: Weak Central Coherence and Visual Scanning Deficit.

INTRODUCTION: Although deficits in neuropsychological functioning have been reported in social anxiety disorder (SAD), studies focusing on neuropsychological dysfunction in SAD are limited, and the evidence is still lacking. The purpose of this study was to examine the deficits in neuropsychological functioning in patients with SAD by comparing SAD patients and a healthy control (HC) group. MATERIALS AND METHODS: A total of 72 participants (20 in the SAD group and 52 in the HC group) were assessed with neuropsychological tests, consisting of the Rey Complex Figure Test (RCFT) to measure central coherence and the Trail Making Test A and B (TMT-A; TMT-B) to measure visual scanning and executive functioning. RESULTS: Analysis of covariance with depressive symptoms as a covariate revealed that central coherence (RCFT) and visual scanning (TMT-A) were significantly lower in the SAD group than in the HC group. No difference was found in executive functioning (TMT-B) when the effect of visual scanning was considered. DISCUSSION: Our findings suggest that SAD patients have weak central coherence and deficits in visual scanning compared to healthy controls. The clinical implications of these neuropsychological functioning deficits in SAD patients are discussed.

Cognitive-behavioral family therapy as psychoeducation for adolescents with high-functioning autism spectrum disorders: Aware and Care for my Autistic Traits (ACAT) program study protocol for a pragmatic multisite randomized controlled trial.

BACKGROUND: One aim of an autism spectrum disorder (ASD) diagnosis is to obtain special support for the disorder, though this does not guarantee practical support. We developed a psychoeducational program using cognitive-behavioral therapy (CBT) and Aware and Care for my Autistic Traits (ACAT) for Japanese adolescents with high-functioning ASD and their parents. METHODS: This multisite study is a randomized controlled trial. In total, 24 participants will be assigned to the ACAT group and 24 to the treatment-as-usual (TAU) group. The ACAT group will receive a weekly 100-min session for 6 weeks, regular medical care, and one follow-up session. In this ongoing clinical trial, we will compare the scores of the measures recorded in the pre- and post-intervention stages between the ACAT and TAU groups. A total of 41 patients out of a target of 48 have participated in the trial to date. The primary outcome measure is the Autism Knowledge Questionnaire. Secondary outcome measures include Barriers to Access to Care Evaluation 3rd Edition, the Strengths and Difficulties Questionnaire, the Vineland Adaptive Behavior Scales second edition, the Parenting Resilience Elements Questionnaire, the General Health Questionnaire 12, and the Depression Self-Rating Scale for Children assessments, as well as an electroencephalographic recording. DISCUSSION: It is expected that participants in the ACAT group will significantly increase their self-understanding and awareness of ASD symptoms compared to those in the TAU group. Additionally, the ACAT group is expected to exhibit improved social adaptation and mental health if children and parents are able to better understand the ASD characteristics through sessions. This intervention will contribute to the establishment of an effective evidence-based treatment strategy for adolescents with ASD. TRIAL REGISTRATION: UMIN Register 000029851 . Registered on January 06, 2018.

Predictors of response to exposure and response prevention-based cognitive behavioral therapy for obsessive-compulsive disorder.

BACKGROUND: Cognitive behavioral therapy (CBT), which includes exposure and response prevention (ERP), is effective in improving symptoms of obsessive-compulsive disorder (OCD). However, whether poor cognitive functions and autism spectrum disorder (ASD) traits affect the therapeutic response of patients with OCD to ERP-based CBT remains unclear. This study aimed to identify factors predictive of the therapeutic response of Japanese patients with OCD to ERP-based CBT. METHODS: Forty-two Japanese outpatients with OCD were assessed using the Wechsler Adult Intelligence Scale-III (WAIS-III), Yale-Brown Obsessive-Compulsive Scale, Patient Health Questionnaire 9-item scale, and Autism Spectrum Quotient (AQ) at pre- and post-treatment. We used multiple regression analyses to estimate the effect on therapeutic response change. The treatment response change was set as a dependent variable in multiple regression analyses. RESULTS: Multiple regression analyses showed that among independent variables, communication as an AQ sub-scale and Letter Number Sequencing as a WAIS-III sub-test predict the therapeutic response to ERP-based CBT . CONCLUSIONS: Our results suggest that diminished working memory (Letter Number Sequencing), poor communication skill (AQ sub-scale) may undermine responsiveness to ERP-based CBT among patients with OCD. TRIAL REGISTRATION: UMIN, UMIN00024087 . Registered 20 September 2016 - Retrospectively registered (including retrospective data).

Activities concentration of radiocesium in wild mushroom collected in Ukraine 30 years after the Chernobyl power plant accident.

Mushrooms are recognized as one of the main contributors to internal radiation exposure from the activity concentration of radiocesium released by the accident at the Chernobyl nuclear power plant (CNNP). We evaluated the activity concentrations of the artificial radionuclides (radiocesium) in wild mushrooms collected in 2015 from Korosten and Lugine, Zhitomir region, Ukraine, located 120 km away from the CNPP. Cesium-137 was detected in 110 of 127 mushroom samples (86.6%). Based on the average mushroom consumption (5 kg per year), we calculated committed effective doses ranging from 0.001-0.12 mSv. Cesium-137 remains in the wild mushrooms even 30 years after the accident, but the committed effective doses are limited by the amount of contaminated mushrooms consumed. However, evaluation of internal radiation exposure and assessment of environmental radioactivity in the surrounding area affected by the nuclear accident are still necessary in order to relieve anxiety about internal radiation exposure, as long as the possibility of consumption of contaminated mushrooms remains.

Does grip strength on the unaffected side of patients with hemiparetic stroke reflect the strength of other ipsilateral muscles?

[Purpose] Grip strength is used as an indicator of overall body muscular strength. However, most studies on grip strength have been performed in healthy people, and no study has evaluated it in the unaffected side of patients with hemiparetic stroke. The purpose of this study was to determine if grip strength on the unaffected side of patients with hemiparetic stroke correlates with the strength of other ipsilateral musculature. [Subjects and Methods] The maximal strengths of the muscles on the unaffected side of 31 patients with hemiparetic stroke were measured, and correlation coefficients were calculated. [Results] The results revealed significant positive correlations between grip strength on the unaffected side and the strength of the other ipsilateral muscle groups, with relatively high correlations being observed for the upper extremity muscle groups. [Conclusion] This suggests that grip strength on the unaffected side of patients with hemiparetic stroke can be used as a simple way to estimate overall strength on that side.

Increased Serum Levels of Oxytocin in 'Treatment Resistant Depression in Adolescents (TRDIA)' Group.

OBJECTIVE: 'Treatment-resistant depression' is depression that does not respond to an adequate regimen of evidence-based treatment. Treatment-resistant depression frequently becomes chronic. Children with treatment-resistant depression might also develop bipolar disorder (BD). The objective of this study was to determine whether serum levels of oxytocin (OXT) in treatment-resistant depression in adolescents (TRDIA) differ from non-treatment-resistant depression in adolescents (non-TRDIA) or controls. We also investigated the relationships between serum OXT levels and the clinical symptoms, severity, and familial histories of adolescent depressive patients. METHODS: We measured serum OXT levels: TRDIA (n = 10), non-TRDIA (n = 27), and age- and sex- matched, neurotypical controls (n = 25). Patients were evaluated using the Children's Depression Rating Scale-Revised (CDRS-R) and the Depression Self-Rating Scale for Children-Japanese Version (DSRS-C-J). The patients were also assessed retrospectively using the following variables: familial history of major depressive disorder and BD (1st degree or 2nd degree), history of disruptive mood dysregulation disorder, recurrent depressive disorder (RDD), history of antidepressant activation. RESULTS: Serum levels of OXT among the TRDIA and non-TRDIA patients and controls differed significantly. Interestingly, the rates of a family history of BD (1st or 2nd degree), RDD and a history of antidepressant activation in our TRDIA group were significantly higher than those of the non-TRDIA group. CONCLUSIONS: Serum levels of OXT may play a role in the pathophysiology of TRDIA.

Evaluation of thyroid antibodies and benign disease prevalence among young adults exposed to (131)I more than 25 years after the accident at the Chernobyl Nuclear Power Plant.

Background. The Chernobyl Nuclear Power Plant (CNPP) accident exposed a large number of inhabitants to internal (131)I radiation. The associations between internal (131)I exposure and thyroid autoimmunity and benign thyroid diseases remain controversial in the population living in the contaminated area around the CNNP. In this study, we evaluate the association of (131)I with benign thyroid diseases. Methods. We compared the prevalence of Anti-Thyroid Autoantibodies (ATAs), thyroid function, and prevalence of thyroid ultrasound finding outcomes in 300 residents of the contaminated area of Ukraine who were 0-5 years of age at the time of the CNPP accident (group 1) and 300 sex-matched residents who were born after the accident (group 2). Results. We did not find any differences of the prevalence of Antithyroglobulin Antibodies (TGAb) positive, Antithyroid Peroxidase Antibodies (TPOAb) positive, and TGAb and/or TPOAb positive between the study groups. (11.7% vs 10.3%; p = 0.602, 17.3% vs 13.0%; p = 0.136, 21.0% vs 17.3%; p = 0.254, respectively); after adjusting for age and sex, the prevalence was not associated with the (131)I exposure status in the study groups. The prevalence of subclinical and overt hypothyroidism cases was not significantly different (p = 0.093 and p = 0.320) in the two groups, nor was the prevalence of goiter (p = 0.482). On the other hand, the prevalence of nodules was significantly higher in group 1 (p = 0.003), though not significantly so after adjustment for age and sex. Discussion. Working 26-27 years after the CNNP accident, we found no increased prevalence of ATAs or benign thyroid diseases in young adults exposed to (131)I fallout during early childhood in the contaminated area of Ukraine. Long-term follow-up is needed to clarify the effects of radiation exposure on autoimmunity reaction in the thyroid.

Evaluation of the Relationship between Current Internal 137Cs Exposure in Residents and Soil Contamination West of Chernobyl in Northern Ukraine.

After the Chernobyl Nuclear Power Plant accident, the residents living around the Chernobyl were revealed to have been internally exposed to 137Cs through the intake of contaminated local foods. To evaluate the current situation of internal 137Cs exposure and the relationship between the 137Cs soil contamination and internal exposure in residents, we investigated the 137Cs body burden in residents who were living in 10 selected cities from the northern part of the Zhitomir region, Ukraine, and collected soil samples from three family farms and wild forests of each city to measured 137Cs concentrations. The total number of study participants was 36,862, of which 68.9% of them were female. After 2010, the annual effective doses were less than 0.1 mSv in over 90% of the residents. The 137Cs body burden was significantly higher in autumn than other seasons (p < 0.001) and in residents living in more contaminated areas (p < 0.001). We also found a significant correlation between the proportion of residents in each city with an estimated annual exposure dose exceeding 0.1 mSv and 137Cs concentration of soil samples from family farms (r = 0.828, p = 0.003). In conclusion, more than 25 years after the Chernobyl accident, the internal exposure doses to residents living in contaminated areas of northern Ukraine is limited but still related to 137Cs soil contamination. Furthermore, the consumption of local foods is considered to be the cause of internal exposure.

Vertical distribution and estimated doses from artificial radionuclides in soil samples around the Chernobyl nuclear power plant and the Semipalatinsk nuclear testing site.

For the current on-site evaluation of the environmental contamination and contributory external exposure after the accident at the Chernobyl Nuclear Power Plant (CNPP) and the nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS), the concentrations of artificial radionuclides in soil samples from each area were analyzed by gamma spectrometry. Four artificial radionuclides ((241)Am, (134)Cs, (137)Cs, and (60)Co) were detected in surface soil around CNPP, whereas seven artificial radionuclides ((241)Am, (57)Co, (137)Cs, (95)Zr, (95)Nb, (58)Co, and (60)Co) were detected in surface soil around SNTS. Effective doses around CNPP were over the public dose limit of 1 mSv/y (International Commission on Radiological Protection, 1991). These levels in a contaminated area 12 km from Unit 4 were high, whereas levels in a decontaminated area 12 km from Unit 4 and another contaminated area 15 km from Unit 4 were comparatively low. On the other hand, the effective doses around SNTS were below the public dose limit. These findings suggest that the environmental contamination and effective doses on the ground definitely decrease with decontamination such as removing surface soil, although the effective doses of the sampling points around CNPP in the present study were all over the public dose limit. Thus, the remediation of soil as a countermeasure could be an extremely effective method not only for areas around CNPP and SNTS but also for areas around the Fukushima Dai-ichi Nuclear Power Plant (FNPP), and external exposure levels will be certainly reduced. Long-term follow-up of environmental monitoring around CNPP, SNTS, and FNPP, as well as evaluation of the health effects in the population residing around these areas, could contribute to radiation safety and reduce unnecessary exposure to the public.