Nationwide Increase in Cryptorchidism After the Fukushima Nuclear Accident

The "GU-GU-RU" project to eliminate discrimination related to the health effects of the Fukushima nuclear accident

BACKGROUND

Although 12 years have passed since Great East Japan Earthquake and following Fukushima nuclear accident, approximately 40% of Japanese citizen still believe that the current radiation exposure in Fukushima residents will likely/ very likely to cause genetic effects of radiation. This incorrect understanding could continue unexpected discrimination and prejudice towards those from Fukushima now and in the future. In order to provide updated knowledge and eliminate rumors related to radiation, Japanese Ministry of the Environment has launched "GU-GU-RU" project in 2021 with consisting of five sections.

OBJECTIVE

(1) To discuss the objectives and effects of the "GU-GU-RU" project (results after the first year), (2) to present administrative measures that may be effective in the long-term to prevent unjustified discrimination and prejudice, and (3) to eliminate rumors in the event of future large-scale disasters, including radiation disasters.

METHODS

We showed the contents of each sections carried out under the project and observed the result of first-year activities in each section.

RESULTS

Among the programs, the "Radiation College" has steadily produced positive results, with nearly 1,300 students participating and 50 students sharing their thoughts and ideas. In addition, the project has adopted strategies such as creating and broadcasting a TV program and collaborations with manga, which are expected to have a significant impact on society.

CONCLUSIONS

Compared to previous efforts on disseminating information related to health effect of radiation exposure, the "GU-GU-RU" project has taken a different approach in providing primary data of radiation and its health effects, which could become a better understanding of health effects of radiation for the general public, in order to eliminate rumors that may lead unjustified discrimination and prejudice.

External Doses Available for Epidemiological Studies Related to the Fukushima Health Management Survey: First 4-month Individual Doses and Municipality-average Doses for the First Year

BACKGROUND

One of the components of the Fukushima Health Management Survey (FHMS) is the Basic Survey, which estimates individual external doses for the first 4 months after the 2011 nuclear power plant accident. However, external exposure continues long-term. According to estimations by international organizations, the external dose during the first year accounts for a significant part of the long-term dose. Thus, the present study was intended to estimate the first-year doses by extrapolating the Basic Survey results.

METHODS

For most municipalities of non-evacuated areas, ambient dose rate had been continuously measured for at least one designated point in each municipality after the accident. In the present study, a municipality-average dose received by residents for a period was assumed to be proportional to the ambient dose measured at the designated point of that municipality during the same period. Based on this assumption, 4-month municipality-average doses calculated from the Basic Survey results were extrapolated to obtain first-year doses.

RESULTS

The extrapolated first-year doses for 49 municipalities in the non-evacuated areas had a good correlation with those estimated by UNSCEAR, although the extrapolated doses were generally higher (slope of the regression line: 1.23). The extrapolated municipality-average doses were in reasonable agreement (within 30%) with personal dosimeter measurements, suggesting that the extrapolation was reasonable.

CONCLUSION

The present paper reports the first 4-month average doses for all 59 municipalities of Fukushima Prefecture and the extrapolated first-year doses for 49 municipalities. The extrapolated doses will be the basis for future epidemiological studies related to the FHMS.

The Effects of the Great East Japan Earthquake on Perinatal Outcomes: Results of the Pregnancy and Birth Survey in the Fukushima Health Management Survey

There are limited studies on the long-term effects of natural/environmental disasters, especially nuclear disasters, on obstetric outcomes. This study aimed to review the results of perinatal outcomes immediately after the Great East Japan Earthquake (GEJE) and the Fukushima Daiichi Nuclear Power Plant accident, as well as their long-term trends over 8 years, in the Fukushima Health Management Survey. The annual population-based Pregnancy and Birth Survey is conducted as part of the Fukushima Health Management Survey. The Fukushima Prefecture government launched it to assess the health conditions of pregnant women and their neonates after the GEJE. The self-reported questionnaire was sent to 115,976 pregnant women by mail from January 2012, with 58,344 women responding to the questionnaire (50.3% response rate). Pregnancy complications, such as gestational hypertension, respiratory diseases, and mental disorders, increased in some women who were pregnant at the time of the earthquake and immediately after the earthquake. However, the direct effects on newborns, such as preterm birth, low birth weight, and congenital anomalies, were not immediately clear after the earthquake. Although there were significant differences in the occurrence of preterm birth and low birth weight among the districts, there was no change in the occurrences of preterm birth, low birth weight, or anomalies in newborns in Fukushima Prefecture from the fiscal year 2011 to the fiscal year 2018. Therefore, the long-term effects of the post-disaster radiation accident on perinatal outcomes are considered to be very small.

Time and spatial trends of operated cryptorchidism in France and environmental hypotheses: a nationwide study from 2002 to 2014

STUDY QUESTION

Is there an evolution in the risk of operated cryptorchidism in France and does local geographical environment appear as an important trigger for this defect?

SUMMARY ANSWER

We observed an increase of the risk of operated cryptorchidism in boys under the age of 7 years during the period 2002-2014 and a strong spatial heterogeneity, with the detection of spatial clusters suggesting environmental factors.

WHAT IS KNOWN ALREADY

Epidemiologic data on cryptorchidism are scarce and its etiology is poorly understood. As part of the testicular dysgenesis syndrome, cryptorchidism is suspected to be a male genital developmental disorder caused by endocrine disruptor chemical (EDC) exposure during the prenatal period.

STUDY DESIGN, SIZE, DURATION

This was a retrospective and descriptive study using data from the French national hospital discharge database, in the 2002-2014 study period. We built an indicator to reflect incident cases of operated cryptorchidism in boys under the age of 7 years in metropolitan France, with an algorithm using specific codes for diseases (ICD-10 codes) and surgical acts (CCAM codes).

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study population was composed of 89 382 new cases of operated cases of cryptorchidism in boys under the age of 7 years. We estimated the temporal evolution of the incidence rate. We fitted a spatial disease-mapping model to describe the risk of cryptorchidism at the postcode scale. We used Kulldorff's spatial scan statistic and Tango's flexibly shaped spatial scan statistic to identify spatial clusters.

MAIN RESULTS AND THE ROLE OF CHANCE

The estimated increase in the incidence of operated cryptorchidism from 2002 to 2014 was equal to 36.4% (30.8%; 42.1%). Cryptorchidism displayed spatial heterogeneity and 24 clusters (P < 0.0001) were detected. The main cluster was localized in a former coal mining and metallurgic area in northern France, currently an industrial area. The cluster analysis suggests the role of shared socio-economic and environmental factors that may be geographically determined and intertwined. The industrial activities identified in the clusters are potentially the source of persistent environmental pollution by metals, dioxins and polychlorinated biphenyls.

LIMITATIONS, REASONS FOR CAUTION

The indicator we used reflects operated cases of cryptorchidism, with an under-evaluation of the health problem. We cannot exclude a possible role of the evolution and local differences in surgical practices in the observed trends. Our inclusion of boys under 7 years of age minimized the biases related to differences in practices according to age. Regarding the environmental hypothesis, this is an exploratory study and should be considered as a hypothesis-generating process for future research studies.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first descriptive study to address nationwide trends of operated cryptorchidism with detection of spatial clusters, with a very large sample allowing great statistical power. Our results generate plausible environmental hypotheses, which need to be further tested.

STUDY FUNDING/COMPETING INTEREST(S)

This study was entirely funded by Santé publique France, the French National Public Health Agency. All authors declare they have no actual or potential competing financial interest.

TRIAL REGISTRATION NUMBER

N/A.

Short-Term Associations of Ambient Fine Particulate Matter (PM2.5) with All-Cause Hospital Admissions and Total Charges in 12 Japanese Cities

The short-term association between ambient particulate matter ≤2.5 microns in diameter (PM_2.5) and hospital admissions is not fully understood. Studies of this association with hospital admission costs are also scarce, especially in entire hospitalized populations. We examined the association between ambient PM_2.5 and all-cause hospital admissions, the corresponding total charges, and the total charges per patient by analyzing the hospital admission data of 2 years from 628 hospitals in 12 cities in Japan. We used generalized additive models with quasi-Poisson regression for hospital admissions and generalized additive models with log-linear regression for total charges and total charges per patient. We first estimated city-specific results and the combined results by random-effect models. A total of 2,017,750 hospital admissions were identified. A 10 µg/m³ increase in the 2 day moving average was associated with a 0.56% (95% CI: 0.14–0.99%) increase in all-cause hospital admissions and a 1.17% (95% CI: 0.44–1.90%) increase in total charges, and a 10 µg/m³ increase in the prior 2 days was associated with a 0.75% (95% CI: 0.34–1.16%) increase in total charges per patient. Short-term exposure to ambient PM_2.5 was associated with increased all-cause hospital admissions, total charges, and total charges per patient.

Nutrient Imbalance of the Host Plant for Larvae of the Pale Grass Blue Butterfly May Mediate the Field Effect of Low-Dose Radiation Exposure in Fukushima: Dose-Dependent Changes in the Sodium Content

The pale grass blue butterfly Zizeeria maha is sensitive to low-dose radioactive pollution from the Fukushima nuclear accident in the field but is also highly tolerant to radioactive cesium (¹³⁷Cs) in an artificial diet in laboratory experiments. To resolve this field-laboratory paradox, we hypothesize that the butterfly shows vulnerability in the field through biochemical changes in the larval host plant, the creeping wood sorrel Oxalis corniculata, in response to radiation stress. To test this field-effect hypothesis, we examined nutrient contents in the host plant leaves from Tohoku (mostly polluted areas including Fukushima), Niigata, and Kyushu, Japan. Leaves from Tohoku showed significantly lower sodium and lipid contents than those from Niigata. In the Tohoku samples, the sodium content (but not the lipid content) was significantly negatively correlated with the radioactivity concentration of cesium (¹³⁷Cs) in leaves and with the ground radiation dose. The sodium content was also correlated with other nutrient factors. These results suggest that the sodium imbalance of the plant may be caused by radiation stress and that this nutrient imbalance may be one of the reasons that this monophagous butterfly showed high mortality and morphological abnormalities in the field shortly after the accident in Fukushima.

Nationwide Increase in Complex Congenital Heart Diseases After the Fukushima Nuclear Accident

Background After the Chernobyl nuclear accident in 1986, an increase in the incidence of congenital heart disease ( CHD s) in the neighboring countries was reported. In 2011, Japan experienced the Great East Japan Earthquake and the nuclear accidents at Fukushima. However, a nationwide study of their effects has not been conducted yet. Methods and Results We used data covering the period between 2007 and 2014 from the annual surveys conducted by the Japanese Association for Thoracic Surgery, which included almost all of the operations pertaining to 46 types of CHD s in Japan. CHD s were divided into 2 groups based on complexity, the time of occurrence during heart development, and age at operation. We estimated the change in the number of the operations per 100 000 live births between pre- and postdisaster using a negative binomial generalized linear mixed model. Overall, a significant 14.2% (95% CI, 9.3-19.4) increase in the number of operations for complex CHD s in neonates and infants per 100 000 live births was found, whereas those performed for patients of 1 to 17 years old showed no significant change during the study period. Conclusions The number of operations for complex CHD s in neonates and infants in Japan significantly increased after the massive disaster, and its level was maintained thereafter. The number of operations for complex CHD was not equal but closely correlated to the live birth prevalence of complex CHD s. Therefore, some meaningful increase in the live birth prevalence can be assumed; however, the precise cause of the increase is unknown.

Spatiotemporal association of low birth weight with Cs-137 deposition at the prefecture level in Japan after the Fukushima nuclear power plant accidents: an analytical-ecologic epidemiological study

BACKGROUND

Perinatal mortality increased in contaminated prefectures after the Fukushima Daichi Nuclear Power Plant (FDNPP) accidents in Japan in 2011. Elevated counts of surgeries for cryptorchidism and congenital heart malformations were observed throughout Japan from 2012 onward. The thyroid cancer detection rate (2011 to 2016) was associated with the dose-rate at the municipality level in the Fukushima prefecture. Since the birth weight is a simple and objective indicator for gestational development and pregnancy outcome, the question arises whether the annual birth weight distribution was distorted in a dose-rate-dependent manner across Japan after Fukushima.

METHODS

The Japanese Ministry of Health, Labour, and Welfare provides prefecture-specific annual counts for 26.158 million live births from 1995 to 2018, of which 2.366 million births (9.04%) with weights < 2500 g. Prefecture-specific spatiotemporal trends of the low birth weight proportions were analyzed. Logistic regression allowing for level-shifts from 2012 onward was employed to test whether those level-shifts were proportional to the prefecture-specific dose-rates derived from Cs-137 deposition in the 47 Japanese prefectures.

RESULTS

The overall trend of the low birth weight prevalence (LBWp) in Japan discloses a jump in 2012 with a jump odds ratio (OR) 1.020, 95%-confidence interval (1.003,1.037), p-value 0.0246. A logistic regression of LBWp on the additional dose-rate after the FDNPP accidents adjusted for prefecture-specific spatiotemporal base-line trends yields an OR per μSv/h of 1.098 (1.058, 1.139), p-value < 0.0001. Further adjusting the logistic regression for the annual population size and physician density of the prefectures, as well as for the counts of the dead, the missing, and the evacuees due to earthquake and tsunami (as surrogate measures for medical infrastructure and stress) yields an OR per μSv/h of 1.109 (1.032, 1.191), p-value 0.0046.

CONCLUSIONS

This study shows increased low birth weight prevalence related to the Cs-137 deposition and the corresponding additional dose-rate in Japan from 2012 onward. Previous evidence suggesting compromised gestational development and pregnancy outcome under elevated environmental ionizing radiation exposure is corroborated.

Japanese Animals in Calamity

This chapter provides a brief background of the empirical research in this volume by describing the position of companion animals in contemporary Japan and the context of the 3.11 earthquake and tsunami. Today, about 34.3% (Cabinet Office Government of Japan 2010) of Japanese households keep some kind of pet. It is evident from the multiple social surveys that a strong attachment to pets has emerged since the mid-1990s. On 11 March 2011, the Tohoku region in Japan was struck by a large earthquake and the tsunami that followed. This was the largest earthquake on record in Japan. The Fukushima No. 1 nuclear power plant was seriously damaged and released radiation which continues to be an ongoing issue for those living in that part of Japan. The serious damage to humans and other animals caused by the tsunami and the radioactive contamination is outlined. The author provides an overview of the study and shows research questions. Then, she reviews the relevant literature, noting that most of the studies are set in a Western context and pointing to the contributions that might be made by considering how one highly developed Asian society has responded to the plight of pet owners following a major disaster. The chapter ends by showing the structure of the book.

Association between the detection rate of thyroid cancer and the external radiation dose-rate after the nuclear power plant accidents in Fukushima, Japan

A thyroid cancer ultrasonography screening for all residents 18 years old or younger living in the Fukushima prefecture started in October 2011 to investigate the possible effect of the radiological contamination after the Fukushima Daiichi Nuclear Power Plant accidents as of March 12 to 15, 2011. Thyroid cancer in 184 cases was reported by February 2017. The question arises to which extent those cancer cases are a biological consequence of the radiation exposure or an artefactual result of the intense screening of a large population.Experiences with the Chernobyl accident suggest that the external dose may be considered a valid surrogate for the internal dose of the thyroid gland. We, therefore, calculated the average external effective dose-rate (μSv/h) for the 59 municipalities of the Fukushima prefecture based on published data of air and soil radiation. We further determined the municipality-specific absolute numbers of thyroid cancers found by each of the two screening rounds in the corresponding municipality-specific exposed person-time observed. A possible association between the radiation exposure and the thyroid cancer detection rate was analyzed with Poisson regression assuming Poisson distributed thyroid cancer cases in the exposed person-time observed per municipality.The target populations consisted of 367,674 and 381,286 children and adolescents for the 1st and the 2nd screening rounds, respectively. In the 1st screening, 300,476 persons participated and 270,489 in the 2nd round. From October 2011 to March 2016, a total of 184 cancer cases were found in 1,079,786 person-years counted from the onset of the exposure to the corresponding examination periods in the municipalities. A significant association between the external effective dose-rate and the thyroid cancer detection rate exists: detection rate ratio (DRR) per μSv/h 1.065 (1.013, 1.119). Restricting the analysis to the 53 municipalities that received less than 2 μSv/h, and which represent 176 of the total 184 cancer cases, the association appears to be considerably stronger: DRR per μSv/h 1.555 (1.096, 2.206).The average radiation dose-rates in the 59 municipalities of the Fukushima prefecture in June 2011 and the corresponding thyroid cancer detection rates in the period October 2011 to March 2016 show statistically significant relationships.

Cryptorchidism after the Fukushima Daiichi Nuclear Power Plant accident:causation or coincidence?

Cryptorchidism (undescended testes) is among the most common congenital diseases in male children. Although many factors have been linked to the incidence of cryptorchidism, and testicular androgen plays a key role in its pathogenesis, the cause remains unknown in most cases. Recently, a Japanese group published a speculative paper entitled, "Nationwide increase in cryptorchidism after the Fukushima nuclear accident." Although the authors implicated radionuclides emitted from the Fukushima accident as contributing to an increased incidence of cryptorchidism, they failed to establish biological plausibility for their hypothesis, and glossed over an abundance of evidence and expert opinion to the contrary. We assessed the adequacy of their study in terms of design setting, data analysis, and its conclusion from various perspectives. Numerous factors must be considered, including genetic, environmental, maternal/fetal, and social factors associated with the reporting of cryptorchidism. Other investigators have established that the doses of external and internal radiation exposure in both Fukushima prefecture and the whole of Japan after the accident are too low to affect testicular descent during fetal periods;thus, a putative association can be theoretically and empirically rejected. Alternative explanations exist for the reported estimates of increased cryptorchidism surgeries in the years following Japan's 2011 earthquake, tsunami, and nuclear crisis. Data from independent sources cast doubt on the extent to which cryptorchidism increased, if at all. In any case, evidence that radionuclides from the Fukushima Daiichi Nuclear Power Plant could cause cryptorchidism is lacking.