Abstract
Various reports have shown that internal and external exposure levels of local residents after the accident at Fukushima Daiichi nuclear power plant were very low. However, there are serious postdisaster health effects in the form of increased prevalence of diabetes and other chronic conditions. Stress, changes in the social environment and in living arrangements, and disruption in healthcare support provided by a network of people have resulted in increasing the cost of care and changing patients’ behaviour, such as delay in visiting a hospital. In addition to radiation protection, it is necessary, when looking after the health of Fukushima residents, to focus on human networking, social infrastructure, and protection of culture and history that are intangible, and not to overlook their roles in health.
1. INTRODUCTION
The city of Minamisoma is located in Hamadori in Fukushima Prefecture. After the accident at Fukushima Daiichi nuclear power plant, three evacuation zones were set within the city: one within a 20-km radius of the plant, another between 20- and 30-km radiuses of the plant, and the third outside the 30-km radius. As vertical radioactive contamination differed between locations within the city, the evacuation zone demarcation was not consistent with the degree of contamination and became one of the causes of inequality, conflict, and other issues. Minamisoma Municipal General Hospital, located near the coast within the 30-km radius of Fukushima Daiichi nuclear power plant (approximately 23 km from the plant), was the only hospital in the 30-km radius evacuation zone to maintain outpatient services in the immediate aftermath of the Great East Japan Earthquake. It played a central role not only in postdisaster health care but also in radiation response. This article reports on the current radiation exposure levels in the Soso region, and provides an overview of the health effects of the nuclear disaster.
2. RADIATION SCREENING TESTS AND RADIATION EXPOSURE TO DATE
Various reports have shown that internal and external exposure levels of local residents after the Fukushima nuclear accident were very low. In particular, there has been successful containment of internal exposure, which became a long-term issue in the case of the nuclear incident at Chernobyl.
In Minamisoma, Minamisoma Municipal General Hospital led an effort to commence internal exposure screening tests for residents in July 2011 (Hayano et al., 2014), and external exposure screening tests using integrated dosimeters in October 2011 (Nomura et al., 2015). Both tests are currently ongoing. At Minamisoma Municipal General Hospital, difficulties were encountered in measuring internal exposure using an on-vehicle whole-body counter when the screening was introduced in July 2011 because the vehicle did not provide sufficient radiation shielding. In September 2011, whole-body counters were installed in the hospital and have since been used for screening. In total, some 100,000 people have been screened. For approximately 99% of all children, including elementary and middle school students, in the city, internal exposure levels were below the minimum level for detection (Tsubokura et al., 2015a). Similar results have been observed in other municipalities.
More than 5 years since the disaster, internal exposure levels on the order of several thousand or several tens of thousands of becquerels are still being detected in those who regularly consume wild boar, wild birds, wild vegetables, or mushrooms that are highly contaminated, with a frequency of about several persons per 10,000 people (Tsubokura et al., 2014). However, internal exposure levels are not likely to increase for those who consume foods distributed through regular channels.
External exposure levels have also been maintained at low levels. The total exposure dose for elementary and middle school children in Minamisoma who underwent external and internal exposure screening tests in 2012 was between 0.025 and 3.49 mSv year−1 (median 0.70 mSv year−1). Results showed that the annual exposure dose was <1 mSv year−1 for 77.9% of the children (Tsubokura et al., 2015b).
3. INCREASED PREVALENCE OF CHRONIC CONDITIONS
As described above, radiation exposure levels of local residents have been maintained at low levels, and it is unlikely that radiation will affect their health directly, such as by damaging cells in their bodies. However, there are serious postdisaster health effects in the form of increased prevalence of chronic conditions.
The increased prevalence of diabetes is particularly serious. The number of patients with diabetes has been increasing every year, and in some age groups, the prevalence rate has increased by approximately 5% since the earthquake. Nomura et al. reported that higher risk of diabetes, compared with the predisaster level, has persisted for several years (Nomura et al., 2016). While similar results were observed in the Fukushima Health Management Survey, it is noteworthy that similar trends can be observed among residents living outside the evacuation zones. It is well known that diabetes is a risk factor for myocardial infarction and cerebral infarction. It has been reported that the number of patients with cerebral infarction admitted to Minamisoma Municipal General Hospital has more than doubled since the nuclear disaster (Gilmour et al., 2015).
In addition, diabetes has been associated with increased risk of cancer. It has been reported that the hazard ratio for cancer incidence among patients with diabetes is approximately 1.2, and that the risk of liver and pancreatic cancers, in particular, is approximately twice as high for patients with diabetes. It is anticipated that the risk of cancer from diabetes and other lifestyle-related diseases is greater than that from radiation exposure.
4. WHY IS THE PREVALENCE OF CHRONIC CONDITIONS INCREASING AND WHICH GROUPS ARE AFFECTED?
Why is the prevalence of diabetes increasing? Stress, changes in the social environment, and changes in living arrangements may be some of the factors, but the answer is not known conclusively. Results of the Fukushima Health Management Survey showed that the prevalence of diabetes increased more among residents from evacuation zones than among residents from outside evacuation zones. On the other hand, a study on residents of the cities of Minamisoma and Soma found no difference in the prevalence of diabetes based on whether or not residents had evacuated (Nomura et al., 2016). Results of research conducted at Minamisoma Municipal General Hospital, published in July 2016, showed that among the patients with diabetes who continued to receive treatment at the hospital after the disaster, deterioration was greater among patients living in urban centres compared with patients living in suburbs (Leppold et al., 2016). It is essential that further research is conducted and interventions undertaken for selected target groups.
In terms of intervention, it is important not to link onset of diabetes or deterioration in diabetic condition to the patient’s behaviour or character traits. Physical exercise, healthy eating, and diet therapy are basic to controlling diabetes. However, although fast food, for instance, may be bad for the body, one should not forget that there are many people, due to financial difficulties, who have few other economically viable options. The only thing that can be done is to inform people about such circumstances, and to engage repeatedly in outreach to patients through health seminars, frequent visits, and other educational activities.
5. SOCIAL FACTORS OF HEALTH CARE
If diabetes is the most significant health problem, the most serious social problem is the loss of informal care since the disaster. Informal care can be described as regular care and assistance to the person requiring support that is made possible through a network of people. For example, consider an elderly person admitted to hospital for pneumonia. Before the disaster, he could have been discharged after a few days’ stay and returned home. However, this can no longer happen because there is no younger generation who can look after him at home. He cannot go and live in a cramped temporary housing unit because it is not barrier-free. As a result, the hospital stay becomes longer and he grows physically weaker. He may have to look for a residential care home, otherwise he cannot be discharged. As a result, he becomes physically weaker and becomes ill again. The cure rate declines. The birth rate in Fukushima Prefecture has rebounded sharply since the disaster. There is a shortage of kindergarten teachers, and many advertisements for them. On the other hand, the postdisaster evacuation, the issue of radiation, and changes in the social structure have been harmful to health, which was formerly protected by a network comprising the local community, neighbours, and family members. A study by Dr Morita of Soma Central Hospital showed that nursing care costs per elderly person in Minamisoma have increased 1.3 fold since the disaster (Morita et al., 2016).
Health problems in temporary housing are becoming long-term problems. A study by Dr Shimada of Minamisoma Municipal General Hospital found that the prevalence of diabetes and other chronic conditions was high even in Summer 2015. Many of those who have secured a new home in the last 5 years, and have a network that allows them to live with their families, have already left temporary housing units. On the other hand, those whose family ties have been disrupted and who have difficulty managing their own health tend to remain in temporary housing. For patients with diabetes who find themselves in such circumstances, it is important that measures are implemented at the individual level, and dietary control and exercise are promoted. There is no point in arguing that stress is the underlying problem for such patients.
Dr Ozaki of Minamisoma Municipal General Hospital reported that the time taken from a patient with breast cancer finding a lump in the breast for the first time to visiting a hospital has increased since the disaster (Ozaki et al., 2016, submitted). The delay in visiting a hospital may contribute to discovery of breast cancer at more advanced stages. Although the cause is not known, it was found that there was a strong tendency for those not living with their children to visit a hospital less frequently. Some readers may have the experience of visiting a hospital only at the insistence of their children. The absence of members of the younger generation in patients’ homes tends to keep patients away from hospitals, even when they feel something is wrong with their health. Changes in familial relations bring about changes in behaviour related to hospital visits.
6. CONCLUSION
The accident at Fukushima Daiichi nuclear power plant caused serious radioactive contamination, second only to the Chernobyl nuclear disaster which was rated level 7 on the International Nuclear Events Scale. Health effects of radiation exposure are normally at the core of various effects of radiation disasters. Fortunately, the radiation exposure levels for Fukushima residents were shown not to be significant. On the other hand, a significant health risk has resulted from changes in the social environment and life arrangements, increased prevalence of diabetes and other chronic conditions, and loss of interpersonal relations.
Future measures should focus not only on radiation protection, but also on human networking, social infrastructure, and protection of culture and history that are intangible. The disaster has raised issues that had been embedded in this region since before the disaster, for which there are no quick solutions. There is a need to recognise that the effect of a nuclear disaster is not limited to radiation, and that other effects of the disaster have an even greater impact on health. It is time that society as a whole came to consider what could be done to solve these problems.
Healthcare professionals are not necessarily required to take extraordinary actions. What would be required can be summed up as maintaining the existing healthcare system, working together with other professionals, and engaging in daily practice. There is a shortage of healthcare professionals in the region, particularly nurses and young healthcare staff members. There is a need to create a mechanism for providing incentives for young healthcare professionals to work in Fukushima, so that they can see their jobs in Fukushima in a positive light. Fukushima is drawing national attention because of the radiation issue. As time passes and attention wanes, the community will have to think how it can differentiate itself from other regions in order to survive. Presentations at scientific conferences, publication of articles, and close inter-regional and international exchange are important components of such efforts.