An influential factor for external radiation dose estimation for residents after the Fukushima Daiichi Nuclear Power Plant accident-time spent outdoors for residents in Iitate Village

Many studies have been conducted on radiation doses to residents after the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Time spent outdoors is an influential factor for external dose estimation. Since little information was available on actual time spent outdoors for residents, different values of average time spent outdoors per day have been used in dose estimation studies on the FDNPP accident. The most conservative value of 24 h was sometimes used, while 2.4 h was adopted for indoor workers in the UNSCEAR 2013 report. Fukushima Medical University has been estimating individual external doses received by residents as a part of the Fukushima Health Management Survey by collecting information on the records of moves and activities (the Basic Survey) after the accident from each resident. In the present study, these records were analyzed to estimate an average time spent outdoors per day. As an example, in Iitate Village, its arithmetic mean was 2.08 h (95% CI: 1.64-2.51) for a total of 170 persons selected from respondents to the Basic Survey. This is a much smaller value than commonly assumed. When 2.08 h is used for the external dose estimation, the dose is about 25% (23-26% when using the above 95% CI) less compared with the dose estimated for the commonly used value of 8 h.

Comprehensive Survey Results of Childhood Thyroid Ultrasound Examinations in Fukushima in the First Four Years After the Fukushima Daiichi Nuclear Power Plant Accident

BACKGROUND

Thyroid nodules and cancers are rare in children compared with adults. However, after the 1986 Chernobyl Nuclear Power Plant accident, a rapid increase in childhood thyroid cancer was observed. To avoid any confusion and misunderstanding of data obtained in Fukushima after the 2011 nuclear accident, baseline prevalence of thyroid nodules and cancers should be carefully assessed with standardized criteria systematically, and comprehensively applied to the population perceived to be at risk.

AIMS

Under the official framework of the Fukushima Health Management Survey, the thyroids of children in Fukushima were examined using ultrasound, and the results collected in the first four years after the nuclear accident were analyzed in order to establish a baseline prevalence of childhood thyroid abnormalities, especially cancer.

SUBJECTS AND METHODS

Of 367,685 people aged 18 years or younger as of April 1, 2011, who were living in Fukushima Prefecture at the time of the accident, 300,476 underwent thyroid ultrasound screening. Of those, 2108 subjects with thyroid nodules were further examined using an advanced ultrasound instrument, with standardized criteria applied to determine the need for fine-needle aspiration cytology (FNAC). FNAC results determined the need for surgery and histological confirmation of the cytological diagnosis.

RESULTS

Of the 2108 rescreened subjects, 543 underwent FNAC, of whom 113 were diagnosed with malignancy or suspected malignancy. Subsequently, 99 patients underwent surgical resection, revealing 95 cases of papillary thyroid cancer, three poorly differentiated cancers, and one benign nodule. The overall prevalence of childhood thyroid cancer in Fukushima was determined to be 37.3 per 100,000 with no significant differences between evacuated and non-evacuated areas. Thyroid cancer patients had external exposure estimates of <2.2 mSv during the first four months.

CONCLUSIONS

The high prevalence of childhood thyroid cancer detected in this four-year study in Fukushima can be attributed to mass screening. It clearly exceeds what is found incidentally anywhere else. Direct comparisons with any other results, even those from cancer registries, are not meaningful because of differences in methodology.

Three-year trend survey of psychological distress, post-traumatic stress, and problem drinking among residents in the evacuation zone after the Fukushima Daiichi Nuclear Power Plant accident [The Fukushima Health Management Survey]

AIM

Prolonged periods of instability in terms of living environment can lead to a serious increase in mental health issues among disaster-affected individuals. The aim of this study was to assess long-term trends in mental health among adult residents in a nuclear-disaster-affected area.

METHODS

Mail-based, self-administered questionnaire surveys were conducted three times (T1-T3), targeting all residents registered with the municipalities in the evacuation zone in Fukushima prefecture at the time of the disaster. Age-adjusted prevalences of the following were analyzed by sex: risk of psychological distress by the Kessler 6-item Scale, post-traumatic stress by the Post-traumatic Stress Disorder Checklist, and problem drinking by CAGE.

RESULTS

The numbers of respondents and response rates were: 73 568, 40.7% (T1); 55 076, 29.9% (T2); and 46 386, 25.0% (T3). Compared with normal Japanese levels in non-disaster settings (4.7%), the prevalence of general psychological distress by Kessler 6-item Scale ≥ 13 was still high 3 years after the event in both men (11.4%) and women (15.8%). Although the age-adjusted prevalence of psychological distress and post-traumatic stress (Post-traumatic Stress Disorder Checklist ≥ 44) had decreased over time (from 19.0% [T1] to 17.8% [T3] for men, and from 25.3% [T1] to 23.3% [T3] for women), the age-adjusted prevalence of problem drinking (CAGE ≥ 2) remained steady in both men (20.7% [T2] and 20.4% [T3]; P = 0.18) and women (10.5% [T2] and 10.5% [T3]; P = 0.91).

CONCLUSION

Our results suggest that long-term interventions focused on post-traumatic stress as well as other mental health problems are strongly needed for disaster-affected individuals.

Effect of Evacuation on Body Weight After the Great East Japan Earthquake

INTRODUCTION

The Great East Japan Earthquake occurred on March 11, 2011, with a nuclear accident subsequently occurring at the Fukushima Daiichi Nuclear Power Plant. The government ordered a mandatory evacuation from the high radioactive concentration area in Fukushima, which might have forced many evacuees to change particular aspects of their lifestyles. This study assessed the hypothesis that mean body weight and the proportion of overweight/obese individuals would increase among evacuees after versus before the disaster.

METHODS

A longitudinal study examined data collected from 41,633 Japanese participants (mean age, 67 years) sourced from general health checkups conducted in 13 communities between 2008 and 2010. Follow-up examinations were conducted from June 2011 through March 2013.

RESULTS

A total of 27,486 participants (12,432 men and 15,054 women; follow-up proportion, 66%) received follow-up examinations after the disaster, with an average follow-up of 1.6 years. Mean body weight significantly increased in both evacuees (n=9,671) and non-evacuees (n=17,815) after the disaster, with greater changes in body weight among evacuees than non-evacuees (+1.2 kg vs +0.3 kg, p<0.001). The proportion of overweight/obese people also increased among evacuees after the disaster, and evacuation was associated with an increased risk of being overweight, despite adjustments for confounding variables. The proportions of overweight evacuees before and after the disaster were 31.8% and 39.4%, respectively, whereas proportions among non-evacuees were 28.3% and 30.3%, respectively.

CONCLUSIONS

Body weight and the proportion of overweight/obese people increased among residents, especially evacuees, in the evacuation zone of Fukushima prefecture after the Great East Japan Earthquake.

Impact of the Great East Japan Earthquake on feeding methods and newborn growth at 1 month postpartum: results from the Fukushima Health Management Survey

This study examined the effects of three disasters (the Great East Japan Earthquake of March 11, 2011, followed by a tsunami and the Fukushima Daiichi Nuclear Power Plant accident) on feeding methods and growth in infants born after the disasters. Using results from the Fukushima Health Management Survey, Soso District (the affected area where the damaged nuclear power plant is located) and Aizu District (a less-affected area located farthest from the plant) were compared. In this study, newborn and maternal background characteristics were examined, as well as feeding methods, and other factors for newborn growth at the first postpartum examination for 1706 newborns born after the disaster in the affected (n = 836) and less-affected (n = 870) areas. Postpartum examinations took place 1 month after birth. Feeding method trends were examined, and multivariate regression analyses were used to investigate effects on newborn mass gain. There were no significant differences in background characteristics among newborns in these areas. When birth dates were divided into four periods to assess trends, no significant change in the exclusive breastfeeding rate was found, while the exclusive formula-feeding rate was significantly different across time periods in the affected area (p = 0.02). Multivariate analyses revealed no significant independent associations of maternal depression and change in medical facilities (possible disaster effects) with other newborn growth factors in either area. No area differences in newborn growth at the first postpartum examination or in exclusive breastfeeding rates were found during any period. Exclusive formula-feeding rates varied across time periods in the affected, but not in the less-affected area. It is concluded that effective guidance to promote breast-feeding and prevent exclusive use of formula is important for women in post-disaster circumstances.

Drinking Behavior and Mental Illness Among Evacuees in Fukushima Following the Great East Japan Earthquake: The Fukushima Health Management Survey

Background

Recent evidence from alcohol and trauma studies suggests that disasters are associated with increases in the consumption of alcohol. The Great East Japan Earthquake and the associated nuclear disaster have continued to affect the mental health of evacuees from Fukushima. This study aimed to extend these findings by examining the relationship between drinking behaviors and the risk of mental illness after the compound disaster.

Methods

We conducted the Mental Health and Lifestyle Survey with 56,543 evacuees. Kessler's K6 was used to assess the risk of mental illness, and logistic regression models were applied to analyze how drinking behavior patterns influence the risk of serious mental illness after adjustment for confounding variables.

Results

Logistic regression analysis evidenced that beginning heavy and light drinkers had the highest and a higher risk of serious mental illness, respectively. Individuals who were nondrinkers pre‐ and postdisaster had the lowest proportional risk of mental illness. Abstainers also had some risk to their mental health after the compound disaster.

Conclusions

The results of this study highlight that beginning drinkers have a high risk of serious mental illness. Thus, mental health professionals should pay attention to the drinking behaviors of evacuees, which might predict increased risk of serious mental illness and consequently indicate a need for psychological intervention.

Emergency Responses and Health Consequences after the Fukushima Accident; Evacuation and Relocation

The Fukushima accident was a compounding disaster following the strong earthquake and huge tsunami. The direct health effects of radiation were relatively well controlled considering the severity of the accident, not only among emergency workers but also residents. Other serious health issues include deaths during evacuation, collapse of the radiation emergency medical system, increased mortality among displaced elderly people and public healthcare issues in Fukushima residents. The Fukushima mental health and lifestyle survey disclosed that the Fukushima accident caused severe psychological distress in the residents from evacuation zones. In addition to psychiatric and mental health problems, there are lifestyle-related problems such as an increase proportion of those overweight, an increased prevalence of hypertension, diabetes mellitus and dyslipidaemia and changes in health-related behaviours among evacuees; all of which may lead to an increased cardiovascular disease risk in the future. The effects of a major nuclear accident on societies are diverse and enduring. The countermeasures should include disaster management, long-term general public health services, mental and psychological care, behavioural and societal support, in addition to efforts to mitigate the health effects attributable to radiation.

[Association between evacuation condition and habitual physical activity in Great East Japan Earthquake evacuees: The Fukushima Health Management Survey]

Objectives: Prevalence of life-style disease has increased dramatically in evacuees due to the Great East Japan Earthquake. One reason may be that physical activity level decreased from life environment changes due to evacuation. However, associations between evacuation condition and habitual physical activity have not been studied. We examined this association in Fukushima residents who participated in the Fukushima Health Management Survey. Methods: In this study, 37,843 evacuees from 13 municipal evacuation zones from the nuclear-power accident caused by the Great East Japan Earthquake, born before April 1, 1995, were included in the analysis. Evacuation condition was defined by disaster living place (13 zones), evacuation place (inside or outside the prefecture), and current living status (evacuation shelter or temporary housing, rental housing/ apartment, and relative's home or own home). Habitual physical activity was defined from self-administered questionnaires as participants who responded "almost every day" and "2-4 times/week" of regular exercise. In the analysis, habitual physical activity prevalence was aggregated by gender and variables (living place in the disaster, evacuation place, and current living status). Prevalence was adjusted for age, disaster living place, evacuation place, and current living status by standard analysis of covariance methods. Results: Adjusted prevalences of habitual physical activity were: men, 27.9-46.5%; women, 27.0-43.7% in each disaster living place. The differences were 18.6% point in men and 16.7% point in women. For evacuation place, physical activity outside the prefecture for men (37.7%) and inside the prefecture for women (32.1%) were higher, but those differences were only 2.2% point and 1.8% point in men and women, respectively. For current living status, physical activity of those in rental housing/ apartment was the lowest; evacuation shelter or temporary housing was the highest in both genders (men: 38.9%, women: 36.7%). Compared with residents in evacuation shelter or temporary housing, those in rental housing/apartment were 5.4% point and 7.1% point lower and those in relative's home or own home were 2.0% point and 4.2% point lower in men and women. Conclusion: Habitual physical activity in residents who lived in 13 municipal evacuation zone differed by disaster living place and current living status, while it was similar regardless of placement in the prefecture. In particular, prevalence was the lowest in participants who lived in rental housing/ apartment. We need to plan and perform additional life-style disease prevention strategies for participants who become isolated.

Hypo-high-density Lipoprotein Cholesterolemia Caused by Evacuation after the Fukushima Daiichi Nuclear Power Plant Accident: Results from the Fukushima Health Management Survey

Objective The Great East Japan Earthquake and the Fukushima Daiichi nuclear disaster forced the evacuation of residents and led to many changes in the lifestyle of the evacuees. A comprehensive health check was implemented to support the prevention of lifestyle-related disease, and we analyzed changes in lipid metabolism before and after these disasters. Methods Subjects included Japanese men and women living near the Fukushima Daiichi nuclear power plant in Fukushima Prefecture. Annual health checkups, focusing on metabolic syndromes, were conducted for persons ≥40 years of age by the Heath Care Insures. Results A total of 27,486 subjects underwent a follow-up examination after the disaster, with a mean follow-up of 1.6 years. Following the disaster, the prevalence of hypo-high-density lipoprotein (HDL) cholesterolemia increased significantly from 6.0% to 7.2%. In the hypo-HDL cholesterolemia group, the body mass index (BMI), blood pressure, and LDL-C level increased significantly in men after the disaster. On the other hand, in the normal HDL-C level group, the BMI, blood pressure, glucose and lipid metabolism, and liver function were adversely affected. The decrease in HDL-C was significantly greater in evacuees than non-evacuees in the normal HDL-C level group. Furthermore, a multivariate logistic regression analysis showed that the evacuation was significantly associated with the incidence of hypo-HDL cholesterolemia. Conclusion This is the first study to evaluate how the evacuation affected the incidence of hypo-HDL cholesterolemia and led to an increase in cardiovascular disease. This information may be important in the follow-up and lifestyle change recommendations for evacuees.

Prevalence of Renal Dysfunction among Evacuees and Non-evacuees after the Great East Earthquake: Results from the Fukushima Health Management Survey

Objective We conducted the present study to evaluate the prevalence of chronic kidney disease (CKD) and CKD complications among evacuees and non-evacuees after the Great East Japan Earthquake and Fukushima Daiichi nuclear disaster. Methods Twenty-seven thousand and eighty-eight subjects who were living near the Fukushima Daiichi Nuclear Power Plant in Fukushima Prefecture in Japan, aged ≥40 years by the Heath Care Insures, were included in the analyses. Metabolic factors were compared between the evacuees and non-evacuees stratified by the eGFR and proteinuria grades. Results The prevalence of CKD with a low eGFR (<60 mL/min/1.73 m(2)) and proteinuria were 21.59% and 1.85%, respectively. The risk of CKD complications was classified into four grades according to the eGFR and proteinuria grades. The prevalence of diabetes, hypertension, and dyslipidemia were significantly higher in the very high risk group than in the low risk group. The prevalence of diabetes and dyslipidemia were significantly higher in evacuees than in non-evacuees in only the low risk group. However, a multivariate logistic regression analysis showed that evacuation was not significantly associated with the risk of a low eGFR or proteinuria. Conclusion This study did not reach the definitive conclusion that evacuation elevated the risk of CKD complication, although evacuation might lead to increased CKD complications in the future. We believe that this information is important for follow-up and lifestyle change recommendations for evacuees.

The protocol and preliminary baseline survey results of the thyroid ultrasound examination in Fukushima [Rapid Communication]

After the Fukushima nuclear power plant accident on March 11, 2011, the public of Japan became particularly concerned about the possibility of an increased risk of childhood thyroid cancer, similar to what was observed after the Chernobyl's accident. Due to serious public health perception, there was an urgency to evaluate the baseline levels of childhood thyroid status in Fukushima prefecture. Therefore we have commenced a thyroid ultrasound examination (TUE) survey of the approximately 360,000 pediatric inhabitants (0 to 18 years of age) who lived in Fukushima at the time of the accident in October 2011. The subjects were divided into three categories according to the standardized diagnostic criteria of ultrasound findings. Category A contained the subjects whose TUE findings were intact or benign. Category B were recommended a confirmatory TUE. Category C was recommended an immediate confirmatory TUE.

RESULTS

The survey of 40,302 subjects in the first year was completed in March, 2013. There were 40,097 (99.5%), 205 (0.50%) and 0 subjects in categories A, B and C, respectively. Of the 82 category B subjects who underwent fine needle aspiration cytology (FNAC), 12 were diagnosed with a malignant tumor or were suspected to have malignancy. The 12 subjects received thyroid surgery and 11 thyroid cancers and one benign nodule were confirmed histologically after surgery. This is the first large-scaled TUE survey to employ sophisticated ultrasound screening and aim to evaluate the baseline frequency of childhood thyroid nodules and cysts. The results will become the golden standard of future comparative TUE in Fukushima, Japan.

Effectiveness of locomotion training in a home visit preventive care project: one-group pre-intervention versus post-intervention design study

BACKGROUND

Locomotion training in a home visit-type preventive-care program has been reported elsewhere. However, continuation of appropriate exercises in a home setting is difficult, and few reports are available on locomotion training in a home setting. The objective of this study was to evaluate the effectiveness of locomotion training over 3 months in a home visit-type preventive-care program for improvement of motor function among elderly people.

METHODS

Nine hundred and fifty-eight elderly people in Tendo City in Japan who were not currently attending any preventive-care program were invited to participate in the study, and 87 were enrolled. In the pre-intervention and post-intervention assessments, we administered an interview survey (the Kihon Checklist), the timed one-leg standing test with eyes open and the sit-to-stand test, at the participants' homes. The intervention involved one set of training exercises with the participants standing on each leg for 1 min and squatting five or six times. The participants were asked to repeat one set of the exercises three times a day at home. In addition, the participants were regularly asked over the telephone about their performance of the exercises.

RESULTS

Physical strength, cognitive function, and total scores of the Kihon Checklist were significantly lower after the intervention than before. In addition, the one-leg standing test time was significantly longer after the intervention (mean ± SD, 23.9 ± 35.4) than before (15.7 ± 20.5), and the sit-to-stand test time was significantly shorter after the intervention (13.0 ± 6.2) than before (14.8 ± 8.3).

CONCLUSION

Locomotion training in a home-visit preventive-care program with telephone support effectively improved the motor function of elderly people who were not currently attending any preventive-care program organized by the long-term care insurance system.

THE BASIC DATA FOR RESIDENTS AGED 15 YEARS OR YOUNGER WHO RECEIVED A COMPREHENSIVE HEALTH CHECK IN 2011-2012 AS A PART OF THE FUKUSHIMA HEALTH MANAGEMENT SURVEY AFTER THE GREAT EAST JAPAN EARTHQUAKE

AIM

To assist in the long-term health management of residents and evaluate the health impacts after the Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Plant accident in Fukushima Prefecture, the Fukushima prefectural government decided to implement the Fukushima Health Management Survey. This report describes the results for residents aged 15 years or younger who received health checks and evaluates the data obtained from 2011 and 2012.

METHODS

The target group consisted of residents aged 15 years or younger who had lived in the evacuation zone. The health checks were performed on receipt of an application from any of the residents. The checks, which included the measurements of height, weight, blood pressure, biochemical laboratory findings, and peripheral blood findings, were performed as required.

RESULTS

1) A total of 17,934 (64.5%) and 11,780 (43.5%) residents aged 15 years or younger received health checks in 2011 and 2012, respectively. 2) In both years, a number of male and female residents in the 7-15 year age group were found to suffer from obesity, hyperlipidemia, hyperuricemia, or liver dysfunction. Furthermore, pediatric aged 15 years or younger were commonly observed to suffer from hypertension or glucose metabolic abnormalities. 3) A comparison of data from 2012 and 2011 demonstrated that both males and females frequently showed increased body height and decreased body weight in 2012. The prevalence of hypertension, glucose metabolic abnormalities, or high γ-GTP values in males and females in the 7-15 year age group in 2012 was lower than that in 2011. However, the prevalence of hyperuricemia among residents in the 7-15 year age group was higher in 2012 than in 2011.

CONCLUSIONS

These results suggested that some residents aged 15 years or under who had lived in the evacuation zone had developed obesity, hyperlipidemia, hyperuricemia, liver dysfunction, hypertension, or glucose metabolic abnormalities. Therefore, we think that it is necessary to continue the health checks for these residents in order to ameliorate these lifestyle-related diseases.

The Fukushima Health Management Survey: estimation of external doses to residents in Fukushima Prefecture

The Fukushima Health Management Survey (including the Basic Survey for external dose estimation and four detailed surveys) was launched after the Fukushima Dai-ichi Nuclear Power Plant accident. The Basic Survey consists of a questionnaire that asks Fukushima Prefecture residents about their behavior in the first four months after the accident; and responses to the questionnaire have been returned from many residents. The individual external doses are estimated by using digitized behavior data and a computer program that included daily gamma ray dose rate maps drawn after the accident. The individual external doses of 421,394 residents for the first four months (excluding radiation workers) had a distribution as follows: 62.0%, <1 mSv; 94.0%, <2 mSv; 99.4%, <3 mSv. The arithmetic mean and maximum for the individual external doses were 0.8 and 25 mSv, respectively. While most dose estimation studies were based on typical scenarios of evacuation and time spent inside/outside, the Basic Survey estimated doses considering individually different personal behaviors. Thus, doses for some individuals who did not follow typical scenarios could be revealed. Even considering such extreme cases, the estimated external doses were generally low and no discernible increased incidence of radiation-related health effects is expected.

Psychological distress and the perception of radiation risks: the Fukushima health management survey

Objective

To assess relationships between the perception of radiation risks and psychological distress among evacuees from the Fukushima nuclear power plant disaster.

Methods

We analysed cross-sectional data from a survey of evacuees conducted in 2012. Psychological distress was classified as present or absent based on the K6 scale. Respondents recorded their views about the health risks of exposure to ionizing radiation, including immediate, delayed and genetic (inherited) health effects, on a four-point Likert scale. We examined associations between psychological distress and risk perception in logistic regression models. Age, gender, educational attainment, history of mental illness and the consequences of the disaster for employment and living conditions were potential confounders.

Findings

Out of the 180 604 people who received the questionnaire, we included 59 807 responses in our sample. There were 8717 respondents reporting psychological distress. Respondents who believed that radiation exposure was very likely to cause health effects were significantly more likely to be psychologically distressed than other respondents: odds ratio (OR) 1.64 (99.9% confidence interval, CI: 1.42–1.89) for immediate effects; OR: 1.48 (99.9% CI: 1.32–1.67) for delayed effects and OR: 2.17 (99.9% CI: 1.94–2.42) for genetic (inherited) effects. Similar results were obtained after controlling for individual characteristics and disaster-related stressors.

Conclusion

Among evacuees of the Fukushima nuclear disaster, concern about radiation risks was associated with psychological distress.

IMMEDIATE MENTAL CONSEQUENCES OF THE GREAT EAST JAPAN EARTHQUAKE AND FUKUSHIMA NUCLEAR POWER PLANT ACCIDENT ON MOTHERS EXPERIENCING MISCARRIAGE, ABORTION, AND STILLBIRTH: THE FUKUSHIMA HEALTH MANAGEMENT SURVEY

BACKGROUND

The Fukushima Pregnancy and Birth Survey was launched to monitor pregnant mothers' health after the Great East Japan Earthquake and Fukushima Daiichi Nuclear Power Plant (NPP) accident. Several lines of investigations have indicated that a disaster impacts maternal mental health with childbirth. However, there is no research regarding mental health of mothers with fetal loss after a disaster. In this report, we focus on those women immediately after the Great East Japan Earthquake and Fukushima NPP accident and discuss their support needs.

MATERIALS AND METHODS

Data regarding 61 miscarriages, 5 abortions, and 22 stillbirths were analyzed among the women who were pregnant at the time of the accident in the present study. We used a two-item case-finding instrument for depression screening, and compared the childbirth group with the fetal loss groups. We also analyzed mothers' opinions written as free-form text.

RESULTS

Among the three fetal loss groups, the proportion of positive depression screens was significantly higher in the miscarriage and stillbirth group than in the childbirth group. Mothers' opinions were grouped into six categories, with pregnancy-related items being most common, especially in the miscarriage and stillbirth groups.

CONCLUSION

A higher proportion of Fukushima mothers with fetal loss, especially those with miscarriage and stillbirth, had depressive symptoms compared to those who experienced childbirth. Health care providers need to pay close attention to this vulnerable group and respond to their concerns regarding the effects on their fertility.

A report from the 2013 international symposium: the evaluation of the effects of low-dose radiation exposure in the life span study of atomic bomb survivors and other similar studies

The RERF International Low-Dose Symposium was held on 5-6 December 2013 at the RERF campus in Hiroshima, Japan, to discuss the issues facing the Life Span Study (LSS) and other low-dose studies. Topics included the current status of low-dose risk detection, strategies for low-dose epidemiological and statistical research, methods to improve communication between epidemiologists and biologists, and the current status of radiological studies and tools. Key points made by the participants included the necessity of pooling materials over multiple studies to gain greater insight where data from single studies are insufficient; generating models that reflect epidemiological, statistical, and biological principles simultaneously; understanding confounders and effect modifiers in the current data; and taking into consideration less studied factors such as the impact of dose rate. It is the hope of all participants that this symposium be used as a trigger for further studies, especially those using pooled data, in order to reach a greater understanding of the health effects of low-dose radiation.

Meeting report: suggestions for studies on future health risks following the Fukushima accident

In October 2013, the Radiation Medical Science Center of the Fukushima Medical University and the Section of Environment and Radiation of the International Agency for Research on Cancer held a joint workshop in Fukushima, Japan to discuss opportunities and challenges for long-term studies of the health effects following the March 2011 Fukushima Daiichi Nuclear Power Plant Accident. This report describes four key areas of discussion -- thyroid screening, dosimetry, mental health, and non-radiation risk factors -- and summarizes recommendations resulting from the workshop. Four recommendations given at the workshop were to: 1) build-up a population-based cancer registry for long-term monitoring of the cancer burden in the prefecture; 2) enable future linkage of data from the various independent activities, particularly those related to dose reconstruction and health status ascertainment; 3) establish long-term observational studies with repeated measurements of lifestyle and behavioural factors to disentangle radiation and non-radiation factors; and 4) implement primary prevention strategies targeted for populations affected by natural disasters, including measures to better understand and address health risk concerns in the affected population. The workshop concluded that coordinated data collection between researchers from different institutes and disciplines can both reduce the burden on the population and facilitate efforts to examine the inter-relationships between the many factors at play.

The basic data for residents aged 16 years or older who received a comprehensive health check examinations in 2011-2012 as a part of the Fukushima Health Management Survey after the great East Japan earthquake

AIM

To assist in the long-term health management of residents and evaluate health impacts after the Tokyo Electric Power Company's Fukushima Daiichi Nuclear Power Plant accident in Fukushima Prefecture, the Fukushima prefectural government decided to conduct the Fukushima Health Management Survey. This report describes the results for residents aged 16 years or older who received the health check examinations and evaluates the data obtained from 2011 and 2012.

METHODS

The target group consisted of residents aged 16 years or older who had lived in the evacuation zone. The health check examinations were performed on receipt of an application for a health check examination from any of the residents. The examinations, including measurements of height, weight, abdominal circumference/body mass index (BMI), blood pressure, biochemical laboratory findings, and peripheral blood findings, were performed as required.

RESULTS

1) A total of 56,399 (30.9%) and 47,009 (25.4%) residents aged 16 years or older received health checks in 2011 and 2012, respectively. 2) In both years, a number of male and female residents in the 16-39 year age group were found to suffer obesity, hyperlipidemia, hyperuricemia, or liver dysfunction, and the prevalence of obesity and hyperlipidemia among residents increased with age. Furthermore, the proportion of residents with hypertension, glucose metabolic abnormalities or renal dysfunction was higher in those aged 40 years or older. 3) The frequencies of obesity, hypertension and hyperlipidemia among residents in 2012 were lower than those in 2011. However, the prevalence of liver dysfunction, hyperuricemia, glucose metabolic abnormalities and renal dysfunction among residents was higher in 2012 than in 2011.

CONCLUSIONS

These results suggested the number of residents who had lived in the evacuation zone with obesity, hyperlipidemia, hyperuricemia, liver dysfunction, hypertension, glucose metabolic abnormalities, or renal dysfunction increased with age in all age groups. Therefore, we think that it is necessary to continue with health check examinations for these residents in order to ameliorate lifestyle-related disease.

Evacuation after the Fukushima Daiichi Nuclear Power Plant Accident Is a Cause of Diabetes: Results from the Fukushima Health Management Survey

The Great East Japan Earthquake and Fukushima Daiichi nuclear disaster in 2011 forced the evacuation of a large number of residents and created changes in the lifestyle of the evacuees. These changes may have affected the evacuees' glucose metabolism, thereby leading to an increase in the incidence of diabetes. This study included Japanese men and women who were living near the Fukushima Daiichi Nuclear Power Plant in Fukushima prefecture before the disaster. Subjects subsequently underwent annual health checkups with a focus on metabolic syndromes, which were conducted under the Health Care Insurers. Using the Comprehensive Health Check survey, we analyzed changes in the glucose metabolism before and after the disaster. A total of 27,486 subjects underwent follow-up examinations after the disaster, with a mean follow-up period of 1.6 years. After the disaster, the prevalence of diabetes increased significantly, and we observed that the incidence of diabetes was significantly greater among evacuees than among nonevacuees. Furthermore, multivariate logistic regression analysis revealed that evacuation was significantly associated with the incidence of diabetes. In conclusion, this is the first study to demonstrate that evacuation is associated with the incidence of diabetes. This information may be used to guide follow-up recommendations for evacuees.