PART 2.5: HEALTH
MARCH 2015
The concern about health damage from radiation exposure, and particularly the vulnerability of children, has made it the single most contentious issue surrounding the Fukushima disaster. Health concerns are the reason people were evacuated, and prompted many families to mistrust official assurances and move away on their own. The problem is exacerbated by the fact that the most likely radiation-related diseases, such as cancer and leukemia, will not appear for years after the exposures, and will only be detected by large-scale, long-term monitoring. The government quickly got such programs up and running, and the results so far give cause for cautions optimism, but it is too early to tell, and inadequate transparency and poor communication have left many citizens suspicious.
— Introduction
In the wake of a nuclear disaster health concerns are paramount. The concerns include thyroid cancer, leukemia, other cancers, birth defects, other diseases, and the possibility of DNA mutations which might affect future generations. Some of these concerns may be well-founded, some not, but regardless they weigh heavily on families and individuals who must make quick decisions about whether or not to evacuate, whether or not to let their children play outside, whether or not to eat local food or drink local water, whether to risk getting pregnant. Uncertainties abound, and this stressful situation can be compounded by actions by government and other authorities which destroy trust.
We think affected populations have had many legitimate grievances in this regard after the Fukushima disaster. It would seem impossible for people not to question whether or not the government was doing everything could to ensure their health and safety, to ask whether or not justice was being done, in terms of compensation and accountability, and to question how people could really be compensated for such massive damage to their lives anyway.
As far as health risks are concerned, they usually are accompanied by a great deal of uncertainty. For most health risks it is almost always impossible to say conclusively how many people will get sick in any particular situation, and this is also true of risks from radiation. In addition, the vehemence of the arguments about radiation and health seem to make nearly paralyzing doubt unavoidable for people whose families have been exposed.
In any potential health crisis, risk estimates are almost always based on incomplete information. But even when good data is available we’re usually left with no more than a “range of probability” that any percentage of the population will contract a disease. In fact, in our current situation, the uncertainty, which is closely linked to how good the underlying information is, is rarely less than a factor of 2, i.e. +/- 2x, while in many cases it’s an order of magnitude or more, i.e. +/-10x. This is actually normal, but humans are poorly equipped psychologically to deal with this kind of uncertainty.
For radiation-related illnesses, the risk is considered to be proportionally related to the dose of radiation received. The system for estimating doses is extremely complex, and there have been good arguments that it should be replaced with something simpler, particularly when it comes to communicating with the public. But one fundamental principle which should be kept in mind is that dose estimates based on actual measurements of radiation in or on the body (in-vivo measurements) are inherently less uncertain than those which have been based on radiation measured in the surrounding environment (ambient doses); on estimates, not actual measurements, based on records which suggest how much radioactivity the person may have been exposed to or how much radioactive food they may have eaten (dose reconstruction); or on historical statistics that look at correlations between disease incidence and living in a particular place (ecological studies). Estimates based on in-vivo measurements are vastly preferable to and more reliable than reconstructions or simulations. Nevertheless they do not entirely eliminate uncertainty.
Since late 2011 an increasing amount of in-vivo data for people exposed to Fukushima radiation has been available, collected by both government researchers and by independent groups. But a crucial gap exists in our knowledge of what people were exposed to, particularly for thyroid exposures to I-131, in the first weeks of the accident. This is because not enough in-vivo thyroid dose or other screening was done, and what is available was done under very suboptimal conditions. But when combined with the other available data, it seems like it may be enough to help make acceptable thyroid risk estimates. For chronic exposures through food and from the environment, much more reliable in-vivo data has generally been available since late 2011, but it usually must be used with caveats.
2.5.1 — Thyroid disease findings
Many people are aware that quite a few children from Fukushima have been diagnosed with thyroid cancer. Because it is also known that many children contracted thyroid cancer after the Chernobyl disaster, it has been easy to come to the conclusion that the Fukushima cancers are radiogenic as well. The fact that very few children in Fukushima received potassium iodide as a protection would seem to lend plausibility to this idea. However, the situation is more complex, and also more uncertain. Nevertheless, it is most likely that the thyroid cancers found so far in Fukushima are not caused by radiation exposure. However, the possibility of some, even quite a few, appearing in future years cannot be ruled out.
In order to understand why this is so, it’s important to understand how a large-scale screening program like the one in Fukushima is designed to work.
— The goal is to determine if the incidence rate of thyroid cancer is increasing.This requires at least 3 rounds of screening of the same population.
— The first round, called “initial screening,” which started in late 2011 and has recently been (almost) completed, should reveal the normal baseline prevalence of the disease, i.e. the percentage of people who normally have it at any given time. An analogy would be a survey to determine how many students in a school normally have asthma in a given year.
— The second round, called “full-scale screening,” which began last year and will continue through 2016, should reveal the normal incidence of the disease, i.e. how many new cases appear in a given year. By analogy, after finding out how many students have asthma altogether, we check to see how many new cases appeared in the school after the first survey was done.
— The third round, scheduled to begin in 2016, should reveal if the incidence rate is increasing. In Chernobyl, the incidence rate was seen to increase rapidly after a few years and continue increasing for over 20 years. This will be the strongest evidence that radiogenic thyroid cancers are appearing. By analogy, if the incidence rate of asthma in the school was seen to climb markedly in subsequent years, we might look for causes or plan medical intervention.
Many diseases such as cancer have latency periods, which is the amount of time that is known to pass between an exposure that causes the disease and its actual appearance. Many cancers have latency periods measured in years, even decades, while since the Chernobyl accident, which showed that the latency period of pediatric thyroid cancer had been greatly overestimated, the expert consensus is that at least 3 to 5 years will elapse between exposure to radioactive iodine (I-131) and the appearance of thyroid cancers in exposed children. Like many medical consensuses, the agreement about thyroid cancer’s latency period might change with new evidence. But the initial thyroid screening in Fukushima is widely agreed by specialists to have been done early enough that any cancers that may have been found would not have been due to radiation. We must point out that there are dissenters to this opinion, but very few, and as far as we know no thyroid specialists with strong reputations among them.
Nevertheless the findings have been surprising, and while the government and medical officials who set up the screening program deserve credit for getting it up and running so quickly, they also failed to adequately inform the public about how the overall process was intended to work, or to manage their expectations. Because few large-scale screenings are done anyway for any purpose, it always means entering unknown territory. The planners should have said at the outset, “Don’t be surprised if we find a lot of cancers in the first round.” As it is, medical professionals we have spoken with who have held counselling sessions for Fukushima residents have said that when they have asked how many people understood that the first round of thyroid screening was intended to establish the normal baseline prevalence of the disease, not a single person has raised their hands. We consider this a massive and consequential failure of communication. In addition, while results have generally been reported in a timely fashion, they’re never as full and as informative as the public, as well as other specialists and researchers, need. All of this has continued to cast a pall of suspicion over the entire process in the eyes of skeptics, and to leave the program’s organizers open to accusations of cover-up. We believe the results are sound, as are the committee’s basic conclusions. We also want to stress that it will be several years before we will be able to definitively determine if there is an increase in thyroid cancer among the Fukushima population.
— Results and interpretation
Fukushima Prefecture Health Survey thyroid screening program:
— Preliminary screening (“first round”- for baseline)
Of 367,687 Fukushima residents who were 18 years and under at the time of the accident and therefore eligible to be screened, 298,577 have been screened so far. Results for 297,046 have been determined.
There have been 109 suspected cancer cases, of which 87 have been confirmed by surgery (rate of 0.03%).
— Full-scale screening (“second round”- for normal incidence)
385,000 people are eligible for this round, and 220,000 were targeted to be screened in FY2014; 106,068 were actually screened. Results have been reported for 75,311 individuals so far, about 1/5 of the entire cohort intended to be screened.
A total of 8 suspected cancers were found (1 confirmed, 7 suspected) (rate of 0.01%)
English translations of official reports:
What does this mean?
The results of the first round of screening in Fukushima revealed an unexpectedly high prevalence of thyroid cancer. If these cancers are due to radiation, then the second round of screening should show a similarly high incidence of new cases, and the incidence rate should be seen to increase every year after that. Also, a clear correlation between the incidence rate and the radiation doses received by the children in different parts of Fukushima would be evident. If, on the other hand, the cancers discovered so far are normal and not due to radiation, then the second round will reveal relatively fewer new cases, with no correlation to exposures, and the incidence rate in following years will be similar. The initial results of the second round of screening are consistent with this so far, but it is still too early to tell.
Since 2012 we have been consulting outside experts, including Sir Dillwyn Williams, of Cambridge Univ., a leading endocrinologist who, together with Keith Baverstock and others made a crucial effort to get the thyroid cancer outbreak after Chernobyl acknowledged as being due to radiation. Since that time his continued work on the Chernobyl thyroid cancer issue has been considered essential reading for anyone seriously interested in the subject. A few of his many important texts, including some co-authored with Baverstock, are listed below:
Scientific Correspondence to the Journal Nature from Sept. 1992, announcing that radiogenic thyroid cancer had been found in children in the Chernobyl area (Baverstock, Williams, Demidchik, et al)
The Chernobyl Accident 20 Years On: An Assessment of the Health Consequences and the International Response (Baverstock and Williams, 2006)
Twenty years’ experience with post-Chernobyl thyroid cancer (Williams, 2008)
Radiation carcinogenesis: lessons from Chernobyl (Williams, 2009)
In early 2012, after the first screening results had been reported, Dr. Williams pointed out to us that:
— The observed incidence of any cancer in a population depends on the method used to look for it.
— Any systematic survey will find more cases than the normal system of waiting for the patient or relatives to notice a problem.
— The more sensitive the screening system the larger number of cases will be found.
— This is particularly true for slow growing cancers like thyroid, where it takes a considerable time for the earliest cancer to grow from just a few cells to a detectable lump.
— The chance that the current apparent increase in thyroid tumours is due to radiation exposure is very low.
— The tumors likely pose little health threat.
— High-resolution ultrasound screening is a new technique, and reveals many harmless anomalies.
— Not enough time has passed for radiogenic tumors to appear.
— The doses are uncertain, but appear too low in nearly all areas to cause a detectable increase.
— Unlike at Chernobyl, milk and other contaminated food was stopped soon.
— Unlike at Chernobyl, Japanese children have sufficient iodine in their diet.
— The initial screening study will show the normal baseline prevalence of thyroid tumors.
— It’s too early to know for sure how many new cases will arise (incidence), we will have to wait at least 4 years.
(personal communication)
The kind of “screening effect” Williams described is well-documented in the health literature, particularly for thyroid cancers:
NYT: An Epidemic of Thyroid Cancer? (Dr. Gilbert Welch, Nov 5, 2015)
The Lancet: Overdiagnosis and screening for thyroid cancer in Korea (Lee & Shin, Nov. 2014)
We shared Dr. Williams’ expert opinion online and directly with health professionals and others who were concerned about how to interpret the early findings. As more data became available, similar opinions were expressed by Baverstock, Demidchik, Tronko, Ivanov, Jacob, and other leading experts:
— It’s still too soon for the cancers to be caused by radiation.
— If radiation was the cause, then children under 5 would develop the cancers first first, but there have been none in that age group so far.
— There is no clear correlation with dose levels
Most of these experts have said that it’s still too early to know, but we can expect some increase in the future. The consensus on this is strong. And we are now at the 4-year point, where it would not be surprising for some radiation-related thyroid cancers to start appearing.
There are dissenters, however, who believe:
— The rate seems to be increasing 2011–2014.
— Maybe there is a correlation with dose levels.
— Maybe the latency period is actually shorter than 3–5 years.
The evidence presented to support these opinions so far has not been very strong, and based on all of the evidence, there seems to be little likelihood that they’re right. Nevertheless it’s important to give them a fair hearing:
Thyroid Cancer under 19 in Fukushima: the Second Report (Tsuda, 2014)
In late 2012 — mid 2013 a comparison survey was done with 4365 children in Aomori Pref., Yamanashi Pref.,and Nagasaki Pref. The ages, 3–18 years, were not perfectly matched to the Fukushima cohort, which was 0–18, and the sex ratio was somewhat different as well. Nevertheless the findings were quite similar to what has been found in Fukushima. Again, the surveys are not perfectly comparable, and the size of the cohort is statistically very small. But it appears to be strong evidence that the Fukushima findings are not unusual.
Japan Environ. Ministry: Preliminary report March, 2013; Detailed report, (Hayashida, et al, Dec., 2013)
Followup report:
Nature: Thyroid ultrasound findings in a follow-up survey of children from three Japanese prefectures: Aomori, Yamanashi, and Nagasaki (Hayashida, et al, 2015)
Even with the uncertainties about doses, both the available in-vivo measurements and the most thorough reconstructions all indicate that thyroid doses in Fukushima (average/mean about 20- 50 mSv maximum possibly 150 mSv) were many times lower than at Chernobyl (average 400–450 mSv, maximum well over 1000 mSv).
How much thyroid cancer are we likely to see?
One reasonable estimate of the amount of thyroid cancer we might expect over the next 50 years has been done by so Jacob, et al, 2014:
— The new baseline (normal prevalence) may be about 7x higher than previously believed.
— Based on the estimated percentages, in the next 50 years, with 330,000 people being studied, about 7300 will be diagnosed with thyroid cancer.
— About 300–1000 of these will be new cases (incidence) due to radiation.
— Most of these would not cause health problems if not discovered (i.e. they would be “subclinical”).
Ultrasonography survey and thyroid cancer in the Fukushima Prefecture (Jacob, et al, 2014)
This study acknowledges many uncertainties, and is not conclusive. But many doctors are worried that the effort to search for radiogenic thyroid cancers is already leading to overdiagnosis and unnecessary operations. As mentioned above, this is a well-documented problem with thyroid cancer screening.
Several leading doctors wrote an article in May 2014 calling attention to this risk and recommending that the thyroid screening program be reconfigured to minimize the risk of unnecessary diagnosis and treatment:
The Lancet: Time to reconsider thyroid cancer screening in Fukushima (Shibuya et al, 2014)
Knowing what we know now, the pros and cons of continuing the screening program appear to be:
Pros:
— Screening reassures the great majority of the population that they do not have a cancer.
— Operating on tumors detected by screening in children may prevent the development of “more difficult to treat” cancers at a later age.
Cons:
— Screening raises the level of concern in the population generally.
— Some, possibly many, of the operations may have been for “technical cancers” which would not have progressed to a dangerous stage.
— Operations carry a risk of complications, even though these are extremely rare in skilled hands.
Will the Fukushima thyroid screening program create more health problems than it solves? Williams suggests that:
“It was appropriate to set up the screening program for those exposed to Fukushima fallout; on balance I believe it will benefit the population as well as providing information that will be very important in the event of another accident. Open discussions with the public to consider all the results and decide on the appropriate future course of action are extremely important.”
(personal communication)
So far, most experts generally agree with the interpretation of thyroid screening results stated by the gov’t but many people do not believe them. Part of the reason is, as mentioned above, that they have many legitimate grievances, and the purpose of the program, as well as the results, have been very poorly communicated. The best thing to do to improve the credibility of health screening, in our opinion, would be to improve the transparency of the process. The problems are not scientific as much as they are social and communication-based, and rooted in an overly bureaucratic mindset. If we could, as Williams has suggested, offer screening on an individual basis, with an explanation of the risks and benefits, concentrating on the most likely age and dose-exposure groups only, and find a way to involve the communities in the decision making process, then maybe the current public anxiety can be mitigated. However, it looks like entrenched dysfunction now.
— Independent tests
At least one well-organized independent thyroid screening of a similar age group has been carried out in Fukushima and reported in the scientific press. In many regards it is more comprehensive and informatively reported than the official Fukushima Prefecture program. While the numbers screened, 1137 persons, are too small to either confirm or contradict the official screening, the findings provide a reality check, and can be said to generally support it:
PLOS One: The Thyroid Status of Children and Adolescents in Fukushima Prefecture Examined during 20–30 Months after the Fukushima Nuclear Power Plant Disaster: A Cross-Sectional, Observational Study (Watanobe, et al, Dec. 2014)
The work was done under the guidance of an independent medical foundation, the Radiation Countermeasures Research Institute for Earthquake Disaster Recovery Support.
In addition to thyroid ultrasound, thyroid-related blood and urine tests, as well as dose estimates, were done. The authors gave several caveats against regarding their findings as conclusive. They concluded:
“The results obtained revealed no discernible deleterious influences of the emitted radioactivity on the young thyroid. In addition, we did not find any significant relationship between the thyroid ultrasonographic findings and thyroid-relevant biochemical markers….
…Whether all the negative results in the current study suggest an insignificant health impact of the FNPP1 accident or reflect the relatively early implementation of thyroid examinations in the wake of the accident, must await forthcoming studies.”
They also pointed out that none of the available data so far “can decidedly disprove the involvement of the FNPP1 accident in the pathogenesis of at least part, if any, of the above-mentioned 104 cases of confirmed or suspected thyroid cancer [i.e., found in the Fukushima Prefecture screening].”
(We wish to thank Sir Dillwyn Williams for his advice and input during the drafting of this section)
2.5.2 — Internal contamination screening (WBC)
The risk of internal contamination from cesium and other radionuclides that have been inhaled or ingested is one of the larger concerns in radiation exposure situations like the Fukushima accident. Because contamination such as cesium can remain in the environment for decades, and end up in food plants and animals, the risk of chronic exposure lasting months or years must be guarded against. As described in the “Food” section above, food intervention and testing is one of the primary tools for guarding against this. Results of internal contamination screening of Fukushima residents with whole body counters (WBC) give cause for cautious optimism than chronic internal exposures have at this point been minimized and can continue to be controlled.
Data from 3 types of programs are available:
— Fukushima Prefecture, whose results very incompletely reported.
— Local governments, such as Minamisoma, Hirata, Soma, etc., which are often the most complete and accurate surveys
— NPOs, such as CRMS and others, which range widely in quality and completeness.
Though their reliability and transparency differ, prefectural, municipal, and independent tests all indicate that internal contamination of Fukushima residents is many times lower than in Chernobyl, with peak levels as much as 10 times lower, and average levels 100 times lower. Food screening results, both official and independent, reinforce this conclusion. Nevertheless, “outliers,” that is, individuals with higher contamination levels, are still found. These have invariably been elderly people who continue to eat wild mushrooms and other foods which are highly contaminated, despite having been advised against it.
— Fukushima prefecture WBC program
Fukushima Pref. has been conducting its own WBC screening program, and reporting results several times a year. To date this program has screened 242,974 people, and given estimated doses 1mSv or over for 26 of them, meaning that over 99% have had less than 1mSv to date. On the one hand this is good news. But actually, most informed observers consider Fukushima Pref.’s reporting of WBC screening results to be incomplete and uninformative. In particular, while they provide detailed demographic breakdowns according to age sex, location, etc., they do not give a breakdown of the levels of internal contamination actually found, nor of how in many people contamination was undetected (ND).
The fact is that in order to have a one-year dose of 1 mSv, a child 3–7 years old would need to have a cesium intake (Cs-134 plus Cs-137) of approximately 14,500 Bq., while an adult would need approximately 48,000 Bq.. But the public and experts consider it important to know about much smaller body burdens and doses as well, particularly in order to help evaluate how effective food intervention has been. In particular, people have been monitoring how many children have body burdens above 10 Bq/kg, because there have been studies (albeit unreliable ones) which suggest that risks increase sharply above this level. Since 2012 several experts have criticized Fukushima Pref. for not providing this body burden breakdown data, in both Bq/body and Bq/kg, and some have helped establish much more helpful and informative WBC programs in various parts of Fukushima.
In fact, we have heard from reliable sources that the reason Fukushima Pref. does not provide these breakdowns is that their WBC screening protocol does not include weighing each person, even though this is generally considered an absolute minimum necessity in this kind of screening. There may be workarounds, such as using statistics to estimate body weights, and in fact individuals who have been screened are apparently told their body burdens in Bq/body, so they can calculate the Bq/kg themselves, though this data is not made publicly available. Like the communication failures for the thyroid screening, these problems could have been avoided if at the outset, while planning the programs, the responsible committees had given due consideration to both what the public needs to know and to what would be most useful to food intervention counselors and planners.
Fukushima Pref. WBC screening report, Jan. 2015
— WBC Screening programs administered by local governments
In contrast, since 2011, some municipal governments, such as Minamisoma and Hirata, have taken the lead in providing well-planned and well-run WBC screening programs, mostly under the guidance of Dr. Ryugo Hayano and Dr. Masaharu Tsubokura of Tokyo University. Their results are also the most completely and informatively published, and have withstood repeated peer-review. Gradually other local governments, such as Soma, Iwaki, and Kawachimura, have begun to adopt similar standards. These programs are independent of both the prefectural and central governments, and in fact some municipal doctors have complained about the lack of cooperation and information-sharing with prefectural officials.
Among the important features of these municipal surveys are:
— Repeated testing of residents is done to assess changes over time and effectiveness of interventions.
— Families are measured together whenever possible.
— One-to-one counseling is done after tests.
— Development of new technologies for accurately measuring infants and small children, such as the “BabyScan”.
— Clear demographic breakdowns of results by age, gender, etc..
— The teams examine correlations between sources of food, drinking water etc.. and internal contamination levels.
— Excellent graphs and visualizations are provided, as well as internet blogs to explain results.
In late 2011, almost 40% of children in Minamisoma had internal contamination above a detection limit of 250 Bq/ body.Their initial doses shortly after the accident can only be estimated because WBC devices were not available.
The detection rate declined throughout 2012, and effectively reached zero (though a 20kg child could still have as much as 12 Bq/kg and not be detected). By late 2013, largely due to effective counseling about food sources, the detection rate for adults in Minamisoma also approached zero, and remained effectively zero for children.
Detection rates for both adults and children in Minamisoma are basically zero at present, but keeping them low will require continual monitoring and counseling. The results in Hirata City and in most municipalities with similar screening and counseling programs have been similar. This does not mean these people do not have any cesium in their bodies; if it is an amount below 250 Bq/body, or in the case of children screened using the BabyScan device, 50 Bq/body, then it will not be detected.
(WBC data from the City of Minamisoma)
A recent paper describing WBC results from the town of Miharu, where nearly every schoolchild, over 1300 in all, has been scanned more than once, and no internal cesium has been detected since 2012:
Whole body counter surveys of Miharu-town school children for four consecutive years after the Fukushima NPP accident (Hayano, et al, 2015)
So far, good WBC screening data for many Fukushima residents — about 118,000 individual scans, including multiple scans for many people — is available from programs like this, with good datasets dating back to late 2011. The results cannot be considered conclusive, but because they include people from many parts of the prefecture, and are supported by testing of food and family meals, we think they can be considered very indicative. We believe this testing has reliably shown that the chronic internal doses to these populations are currently less than 0.01–0.1mSv/year. While it is believed that even small doses like this carry some health risk, the broader consensus suggests that it very small.
Despite the extremely high quality and conscientiousness of these test procedures and analysis, the doctors and researchers running these programs have occasionally been criticized by anti-nuclear groups and individuals seeking to cast doubt on their findings. We have examined the data and the screening protocols closely, however, and have concluded that such criticism is unfounded. This is, quite simply, the best data available on internal contamination of Fukushima residents, and it is extremely reliable.
— Independent programs
In addition to the prefectural and municipal programs, there have been a handful of WBC screening programs run by citizens’ groups. These programs generally use less sensitive equipment than the municipal or prefectural programs, and their quality and results have been uneven. Nevertheless, though these groups are specifically motivated to provide an independent check of official data, their findings generally support it.
The longest-running and largest program so far has been run by CRMS in Fukushima City. Data from 2014 tests does not seem to be available yet, however results from 2011–2013 are (please note that this organization underwent a split in late 2013, in which its Fukushima City lab, which had been conducting the WBC screening, split from the rest):
Between Oct. 2011 and Dec. 2013, 5042 persons were scanned. Over 80% were reported to have no internal cesium, at detection limits which varied but were claimed to be as low as 150 Bq/body (We think this is implausibly low given the equipment used, the overall test conditions, and other technical factors, and suggests that in many cases noise has been misidentified as cesium detections through overzealousness). Nevertheless, as in the municipal programs, very few individuals had over 10Bq/kg of internal cesium.
Taken together, the prefectural, municipal, and independent internal contamination screening results indicate that chronic internal contamination in Fukushima is so far being adequately controlled, due to extensive food screening. As has frequently been stated, WBC screening done soon after the first exposures can give a good idea of how big those exposures were, but in fact, while good data from the early weeks of the disaster is available for US military personnel and a few researchers and foreign nationals, very little is available for Fukushima residents until fall of 2011. These tests can help establish a plausible upper limit to the early exposures, but not much more.
— WBC Scams
It was called to our attention last year that a clinic in Tokyo was providing fee-based WBC services, which we were encouraged to check out. Two SAFECAST volunteers went there, received scans, and were given quite implausibly high test results and a sales pitch. Discussing the system, etc., with the clinician, it quickly became apparent that it was uncalibrated, or as we suspect, miscalibrated to give high readings. The clinic has been using their WBC results to sell extremely expensive treatments, such as sauna mats which they claim eliminate internal cesium through “hormesis,” as well as dietary supplements. The information and technical explanations they gave us were also incorrect, and not surprisingly, the clinician attempted to discredit the municipal programs. Other researchers have also visited the clinic, and come to the same conclusion, that its measurements were false, and complaints have apparently been made to local government. Nevertheless, as far as we know, this clinic is still in business, and has scanned and given false results to over 2000 people.
— Comparison to Chernobyl
In most areas of Chernobyl, internal contamination was many times higher than what’s been found so far in Fukushima, and has been higher on average even in recent years. During the first several years after the Chernobyl accident, average internal contamination in many areas were between 100,000–300,000 Bq/body, and reached an average in the 1990’s of about 10,000–20,000 Bq/body, compared to few detections over 250 Bq/body in Fukushima since late 2011. In Chernobyl levels have been between 20–40 Bq/kg as recently as 2008, while so far, in Fukushima, very few people have been found with more than 10 Bq/kg.
It’s important to note that internal doses in Chernobyl generally decreased until 1990–91, when the Soviet Union collapsed, and then increased again for several years as food screening was cut back. This is probably the greatest future risk for Fukushima residents in terms of internal contamination, and the reason both conscientious food screening and internal contamination screening will need to be continued for many years.
2.5.3 — External Exposures
External exposures can be assessed in several ways, and different methods are considered appropriate for different uses. Measures of ambient radiation in the environment, taken with a handheld survey meter or geiger counter, for instance, or from a fixed monitoring post, which provide a measure technically known as “ambient dose equivalent,” can be used to arrive at estimates of what people who stay in that environment might be exposed to, and from that, their possible doses (“effective dose”). Converting from ambient doses to people’s doses involves a fairly complicated modeling process in which the person is represented by an imaginary sphere. The results are intended to over-estimate doses to people, so as not to underestimate their possible risk, and to provide a ballpark estimate that can be useful for many crucial decisions in times of emergency.
It is much more accurate to use personal dosimetry, which involves small measurement devices worn on the body itself and usually kept on at all times, called “personal dosimeters” (but also colloquially as “glass badges,” which is one common type) to estimate doses to individuals (known as “personal dose equivalent”). These devices are calibrated using an actual physical dummy, called a “phantom,” which simulates the human torso, and characterizes how the dosimeter itself will respond to known quantities of radiation coming from every direction. The conversion from personal dose equivalent to effective dose is more straightforward, and has less inherent uncertainty than that from ambient doses. In addition, since an individual is wearing the dosimeter constantly it accurately records the radiation levels actually encountered. Nevertheless, this is also considered to be an over-estimation. Natural background radiation is taken into account, and usually subtracted from actual recorded readings, and when results are reported they usually specify whether or not background radiation is included. Personal dosimetry is the preferred method for evaluating actual external exposures, particularly when medical intervention might be necessary.
Ambient doses can also be estimated from known ground contamination, and from that, personal doses can be derived. While this kind of modeling can be quite sophisticated, of the three methods described here it is the most uncertain. If good personal dosimetry is available, it should be used instead. If personal dosimetry isn’t available, but ambient doses are, then they should be used. Ground contamination measurements are essential for understanding environmental effects and for food, but are considered the least desirable data on which to base individual dose estimates, particularly if better dosimetry is available.
A very detailed and technical explanation of this issue can be found in these texts:
Dose Quantities and Units for Radiation Protection (Chapter 2 of Radiation Protection in Nuclear Medicine, 2013; Soren Mattsson and Marcus Soderberg)
Calibration of radiation protection monitoring instruments (IAEA Safety Reports Series No. 16., 2000)
— Personal dosimetry
Virtually every municipality in Fukushima has done many “glass badge” surveys since 2011, involving large proportions of the population. This is actually unprecedented. When the various current protection guidelines were established, this kind of wide scale availability and deployment of personal dosimetry for the public would have been considered technically and financially unfeasible, and so it is not really anticipated in prior official recommendations. Until now, different cities in Fukushima have used devices from different manufacturers, and there’s been no real standardization in how the results are reported. Also, there has been no independent oversight. Nevertheless, results have consistently shown that the doses actually received by people in Fukushima have been much lower than what’s been estimated based on ambient dose rates, usually half or less. They suggest that since the programs were started in fall 2011, the majority of external exposures were already under 2 mSv/yr, with a large proportion already under 1 mSv. These findings have met with some public skepticism, however, but no actual manipulation or misrepresentation of the reported data has been demonstrated so far.
Many dosimeters simply provide a cumulative reading, but recent designs are available which show the levels on an hour-to-hour basis. This is very useful for identifying the locations where the highest exposures are received, so decontamination can be more effectively targeted and residents can be counseled to avoid those locations. Some towns already provide such counseling, and are sharing their experiences with potential counselors in other areas. The government has announced its intention to use doses based on personal dosimetry for more decisions regarding areas to reopen to residence. The idea has met with opposition and suspicion from some quarters, but technically it is sound, for the reasons described above.
Fukushima City’s personal dosimetry program results have been regularly reported, and provide a useful illustration of external exposure trends. Fukushima City has a large affected population and can be regarded as fairly representative of the exposures experienced by people living in unevacuated areas; many evacuated areas are populated in the daytime by groups of decontamination workers whose doses are also being recorded, and while a few people are living in these places illegally, the number of these residents is few.
36,767 children and pregnant women living in Fukushima City were given personal dosimeters in Oct-Dec. 2011. Less than half had additional external exposures over 1mSv/yr. A few children receiving doses far above average, and the causes, were also identified. In most cases the highest dose records were from people who left their badges outdoors for long periods, or allowed them to go through an airport X-ray machine.
16,223 children under middle-school age were again given glass badges to wear from Nov. 2012 to Jan. 2013. Results showed that 88.7% had additional exposures below 1mSv/yr, a sharp decline in doses compared to the previous year.
The doses showed a modest decline in 2013, based on data from 10,100 children given glass badges from Sept. to Nov., 2013. Of these, 93.48% had additional exposures below 1mSv/yr, and no child received an exposure above 5mSv/yr.
Fukushima City “glass badge” results, 2014 (no graph yet available):
Based on results from 46,436 residents, covering Sept. — Nov. 2014, 95.57% had estimated additional exposures below 1mSv/yr. The 8,616 children under 15 had an estimated average exposure of 0.08 mSv for the year, while 37,820 who were over 16 had an estimated average exposure of 0.12 mSv.
Again, we stress that these findings are not conclusive, and other towns have had slightly different experience. In 2012–2013, for instance, only 66% of the residents of the town of Date had estimated additional exposures below 1mSv/yr, though 94% were less than 2 mSv/yr. But the trend is comparable, and importantly, since fall 2011 very few people have been found to have as much as 5 mSv/yr in any town. We wish, of course, that personal dosimetry results were being reported clearly and in a more standardized fashion, and made more easily available.
As for internal contamination, personal dosimetry for the public is not generally available for the first weeks and months of the disaster, and in all reports so far, with the exception of Daiichi plant workers and the US military, doses for that period are based on ambient dose measurements, ground contamination measurements, and environmental and biological modeling, all of which bring uncertainties, as described above.
— Trends
In conclusion, citizens have many legitimate grievances about health testing programs, and independent oversight is still lacking. Lack of trust causes people to doubt even reliable data and conclusions. The health risks from the Fukushima NPP accident will never be zero. Nevertheless the best screening and research to date suggest that an outbreak of radiation-induced thyroid cancer is unlikely, though not impossible, and that additional internal and external doses can be kept below 1mSv/yr for the vast majority of the population if effective screening programs are continued. This may not be “safe enough” in the eyes of many citizens, but it is realistic. To achieve and maintain even this, however, will require a long-term commitment on the part of the government to conscientious, well managed monitoring of the environment, food, and health.
If past experience is any guide, we can’t assume that this will happen without the constant awareness and expressed will of citizens. All should continue their efforts to gather and share information, and to press for independent oversight where needed.
2.5.4 — Mental health
In the wake of any disaster, psycho-social effects, such as stress, PTSD, depression, sleep disorders, chronic anxiety, physical symptoms, family problems, breakdown of community support, and others, are a known outcome. This has been true for people affected by the 2011 earthquake and tsunami in Tohoku, and also for residents of Fukushima and elsewhere who have suffered from the nuclear disaster or are afraid they will. While the known physical disease risks from the levels of radiation exposure that the Fukushima public has been estimated to have encountered will be manifested in increased probabilities that will unfold over years, psychosocial effects are very real and very serious already, and affect almost the entire population to some degree.
For purposes of compensation, years ago the Japanese government adopted the concept of “disaster-related deaths.” While this is an administrative category and not a medical one, by using it families and government officials seek to identify people whose lives have been cut short by stress and other negative effects of evacuation, including the more than 50 elderly who died during the evacuation itself. The most recent report, from March 4, 2015, put the toll at 1,867, making Fukushima the only disaster-hit prefecture where these deaths outnumber those caused by injuries suffered during the earthquake and tsunami itself (1603 people).
Fukushima Minpo/ Japan Times: Death toll grows in 3/11 aftermath, March 15, 2015
The Lancet: Loss of life after evacuation: lessons learned from the Fukushima accident (Tanigawa et al, 2012)
It is widely recognized that in comparison to most Western nations, Japan is very inadequately provided with mental health care services. Most affected towns have greatly increased their mental health counseling staff since 2011, and these specialists do their best to help evacuees. Nevertheless, elderly living alone have been found dead, sometimes after days or weeks have passed. In some municipalities, though privacy laws generally prohibit it, newspaper and milk delivery personnel have been enlisted to help keep an eye on at-risk elderly people.
The increased stresses of evacuation, isolation, and a feeling of hopelessness about the future seem to be reflected in recent suicide statistics. While the suicide rate in Japan overall has been declining since 1997, since 2011, Fukushima has seen an increase, but not in every age group.
This document from Fukushima Pref. gives a good breakdown of suicides there though 2013.
Fukushima’s suicide rate is still not the highest in the country, but has climbed strikingly in rank compared to other prefectures since 2011. As the report makes clear, the increase is driven primarily by two age demographics: 80 yrs and older, male and female, and under 20 (male) and 20’s-30’s (female). The increase in the older group is probably rooted in loss of family and community support as well as declining health, and the increased difficulty of getting adequate care. Many young people in Fukushima, on the other hand, have expressed fears that they face a life of debilitating illness, will never be able to get married, etc., and the increase in suicides in this group may be rooted in these kinds of fears.
Basic vital statistics for Japan as of March 2015, including suicide rate data.
There are many kinds of health consequences after a disaster, and psycho-social aspects seem to be recognized by government officials who are trying to provide adequate counseling and care, and to solve the underlying problems, but these same problems seem to be underappreciated by the wider public, who to date have concentrated on the likelihood of cancer and other diseases.
(end of section 2.5)
TO OTHER SECTIONS:
2.1- Issues at Fukushima Daiichi Nuclear Powerplant (FDNPP)
2.3- Environment and Decontamination
2.5- Health
