Ichinose, M.

Review:

A Philosophical Inquiry into the Confusion
over the Radiation Exposure Problem
Masaki Ichinose†
The University of Tokyo
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan† Corresponding author, E-mail: ichinose@l.u-tokyo.ac.jp[Received December 24, 2015; accepted January 29, 2016]

In this paper, I discuss from a philosophical viewpoint the so-called radiation problem that resulted
from the Fukushima Daiichi Nuclear Power Station
accident after the Great East Japan Earthquake in2011. The starting point lies in the conceptual distinction between “damage due to radiation” and “damage caused by avoiding radiation.” We can recognize
the direct “damage due to radiation” in Fukushima as
not serious based on the empirical data so that I focus upon the problem of the “damage caused by avoiding radiation,” particularly the damage due to evacuation actions. Actually, evacuation actions caused morerefugees to die of suicide and diseases than supposed.
Obviously, there is a practical problem on whether theforceful and emergent evacuation was needed. In addition, I will point out that some people psychologically
had negative feelings about the radiation problem altogether, for example, absurdity, discomfort, anxiety,or distrust, where some of them tend to twistedly solve
those by giving moral censure to people and the product in affected areas. This brought about serious harmto people in Fukushima. I will interpret some people’s
careless adoption of precautionary principle and their
misunderstanding of the legal standard in radiation
protection as being latent in this tragedy.
Keywords: the Fukushima Daiichi Nuclear Power Station accident, radiation exposure, evacuation, precautionary principle, legal standard in radiation protection

1. “Harm” or “Damage” in the Radiation
ProblemIn this paper, the author, a philosophical researcher, discusses the so-called radiation problem that resulted fromthe Fukushima Daiichi Nuclear Power Station accident
following the Great East Japan Earthquake and the direction that the discussion on this problem should take,organizing the points of the argument from a philosophical viewpoint. The basic impetus of this paper is to focus on the problem around the “effects of radiation exposure on health” apart from the “pros and cons of nuclear power plants.” The theme “effects of radiation exposure on health” is significant irrespectively of the “pros770

and cons of nuclear power plants” because we are always exposed to radiation and considerably so duringsome medical treatments or other situations. In addition,
various problems caused by the nuclear accident cannot
be solved simply by deciding to decommission nuclear
power plants. I would like to assert that, if one associates the “effects of radiation exposure on health” and related problems with the “pros and cons of nuclear power
plants,” a political theme, or ideology, such understanding is biased. Therefore, this paper does not consider the“pros and cons of nuclear power plants.”
Why are radiation problems controversial? This isbecause of the potential “harm” of radiation exposure.
Therefore, “harm” or “damage” should be discussed firstand foremost with regard to the radiation problem. So
then, what is “harm?” The “harm” of a tsunami disaster is obvious. Almost 20 thousand victims were killed
and myriads of people have had to take shelter after losing their homes. This is the main damage of the disaster called “3.11.” Further, what is the “harm” caused byradioactive diffusion and radiation from the nuclear accident? This question is challenging with regard to radiation
problems. It is true that people living in Fukushima andEast Japan suffered from more unnecessary radiation exposure than in normal conditions when radioactive materials were released because of the nuclear accident. However, it is difficult to logically state that the release of radioactive materials or more radiation exposure than normal is “harmful.” This is because it cannot be regarded as“harmful” if a small amount of released radiation materials or unnecessary additional exposure does not adversely
affect one’s health1 . Moreover, as mentioned above, radiation exposure and even additional exposure occurred
before the nuclear accident. The world and space arefilled with radiation, regardless of the amount. However,
can the difficulties of evacuees owing to forced and voluntary evacuation, including stress, health deterioration,
increased suicides, and increased deaths, be considered“damage” and “actual harm”? Although this view makes
1. Refer to the following: ‘living organisms that lived and evolved on theearth acquired capability to repair DNA damage at the cell level causedby radiation and active oxygen inhaled and respond to decrease error
rates. As a result, more radiation is required to cause the effective number
of DNA cut (the number of effective hits). Considering DNA repair andadoptive responses, biological dose as a standard for “low dose” can begreater than the above 0.2 mGy’ (Doi et al., 2007, p. 65).

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A Philosophical Inquiry into the Confusion
over the Radiation Exposure Problem

2081
825
387
290
203
130
62
46
2081
16
26
14 825387 290203 130
862 46 16 26 1445
6
7
External exposure dose (mSv)8
Source: Asahi
2 Shinbun Digital on February 20, 2012

Persons

5591

8

6

7

8

2

Fig. 1. Distribution of external exposure dose of Fukushima residents (mSv: millisieverts; excluding
those involved in radiation work).

sense, the problem is whether the difficulties represent“damage due to radiation.” Perhaps these effects should
instead be called “damage caused by avoiding radiation.”
Note that the concept of “damage” is used in a broad
sense. In other words, “damage” here includes various
matters that would not have occurred without the nuclear
accident such as acute and late radiation disorder, deathsof disease and suicides, physical and mental health deterioration, anxiety and a sense of alienation, economic hardship, a pervasive sense of avoidance against produce from
affected areas, education problems in children, domestic
discord, and mental abuse (I personally suffered considerably from mental abuse that ignored the context in myargument by the skewed criticism of my peers). However,“deaths” as typical forms of “damage” are the main focus
in this study.

2. “Damage due to Radiation” and “Damage
Caused by Avoiding Radiation”
The conceptual differentiation between “damage due
to radiation” and “damage caused by avoiding radiation”
is the starting point for addressing the radiation problem.
This differentiation can also be expressed as an introduction of the concept that it is rational to select options withless risk by differentiating and comparing the risks of radiation exposure versus that of evacuation to avoid radiation exposure. The risk of radiation exposure can roughly
be calculated if the radiation dose is known. Regarding
the Fukushima Daiichi Nuclear Power Station accident,
additional and unnecessary external exposure was calculated to be within 5 mSv in many cases of victims in
Fukushima (mostly within 1 mSv), while internal exposure registers almost zero at presently, four years after the

Journal of Disaster Research Vol.11 No.sp, 2016

accident, even though the very small dose of estimatedinitial exposure was conjectured.
Let us look at the data. According to “Asahi Shinbun
Digital,” on February 20, 2012, the distribution of external
exposure dose owing to the Fukushima Daiichi Nuclear
Power Station accident, shown in Fig. 1, was obtained
from 9750 residents in Namie Town, Iitate Village, andKawamata Village of Fukushima, which excluded workers from the nuclear power plants, for the four months
following the accident2 .
Radiation doses for more than 94% of residents wereat 5 mSv or less, and those of almost 99% of residents
were at 10 mSv or less. As areas of the research matrix
are close to the Power Station and suffered from relatively
high doses of radiation, the doses of radiation were probably lower in other areas in Fukushima. The above data obtained are for four months; therefore, yearly doses would
be higher. However, yearly doses would be much lower
than that of the value multiplied by three because of natural attenuation (dilution owing to diffusion and settlementin the earth).
The website of Fukushima City includes measurement results of effective doses using glass badges forthree months from September to November 2013 for
10,100 students of elementary and junior-high school,
which indicated a significant decrease in radiation doses.
Fig. 2 lists estimated values of yearly doses based on themeasurements from these three months3 . Its vertical axis
stands for the number of people, and the horizontal one
mSv per year.
More than 93% of subjects showed radiation doses of
1 mSv or less per year, whereas 99% showed radiation
doses of 2 mSv or less. In some cases, external radiation
2. http://www.asahi.com/health/news/TKY201202200195.html
3. http://www.city.fukushima.jp/uploaded/attachment/29075.pdf

771

Ichinose, M.

(persons)
10,000

9,441

9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000

593

0

0

0

0

0

0

0

0

0

0

57

6

3

0

0

0

0

0

<3

<4

<5

<6

<7

<8

<9

<10 <11 <12 <13 <14 <15 <16 <17 <18 <19 <20

0

<1

<2

Distribution of yearly estimated dose value (mSv)
Source: Fukushima City 's Website

Fig. 2. Distribution of yearly estimated dose value measured by Fukushima City.

exposure is evaluated by multiplying the air dose per hour,which is obtained by monitoring posts, by 24 and 365; but
the effective dose from external radiation is even lower
than the values of the air dose multiplied by 24 and 365, as
indicated by the above data obtained by a worn gauge foraccumulated doses such as glass batches. An approximate
comparison through the website of Fukushima University
in Fukushima City reveals that the air dose on the “roadin front of the center of dormitory” of the Kanayagawa
campus on November 7, 2013 was 0.3 mSv per hour4 .
When multiplied by 24 and 365, the value is 2628 µ Sv,
or 2.628 mSv. Compared to this, the accumulated dose
obtained by glass batches above is significantly lower. In
the formal criteria, the actual radiation dose is calculatedby (air dose × 8 + air dose × 16 × 0.4) assuming that one
spends 16 hours indoors per day and that the effects ofradiation are reduced by 40% indoors (See Tasaki 2012,
p. 93). Since radiation is blocked by buildings or otherobjects, the actual radiation dose is estimated to be almost
half of the value simply calculated using the air dose. In
fact, measured values can be lower than estimated values.
In any case, radiation exposure risks should be evaluated by taking the values of effective doses based on accumulated dose gauges. Furthermore, radiation materials from the nuclear power plants will naturally attenuate
owing to diffusion into the air and the ground before thephysical half-lives. Alternatively, some materials are estimated to be stable and closely bonded to soil particles
without being absorbed into plants or mixing with the water. Sho Shiozawa said “Cs is soluble in water to form
cations and it is characterized by the fact that it is easily
fixed to soil and organic substances such as living plants
and does not readily move with water” (Shiozawa 2012, p.
15). Overall, risks of cancer deaths due to the Fukushima
power plant accident are currently extremely low, exclud4. http://www.fukushima-uac.jp/guidance/top/fukudai-housyasen-H25.html#toku

772

ing workers from the plants, even if the “LNT hypothesis”
is adopted5. As for internal radiation exposure, detailed
and accurate measurement results using whole body counters have been reported by Ryugo Hayano, a physicist,and Tsubokura Masaharu, a doctor. It was clarified thatinternal radiation exposure was almost 0 in April 2013,
even though there had been initial radiation exposure byradioactive iodine in the first phase of the accident6 . For
5. Kunikazu Noguchi remarked as follows on Date City, Fukushima Prefecture: “If appropriate dose reduction measure such as decontaminationin living areas are taken for residents with higher external radiation exposure dose, evacuation is unnecessary. It is considered that externalradiation dose is further reduced in the city more than one year after June
2013. Considering the situation in Date City, I think people can live in thenorthern and central areas of the prefecture at ease (Kodama, Shimizu,
Noguchi 2014, p. 88). At the moment, risks to concern can be omitted.
6. Shinji Tokonami from the Hirosaki University reported investigation results on the front page of morning “Asahi Shimbun” on March 9, 2012,
on initial exposure of radioactive iodine: Some people were exposed toalmost 90 mSv of radioactive iodine to the thyroid immediately after the
nuclear power plant accident. However, this is the equivalent dose to thyroid and different from the effective dose used for radiation protection.
Considering that almost all iodine gathers in the thyroid, an estimatedvalue of initial exposure can be obtained by converting equivalent dosesof thyroid to effective dose. Equivalent doses of thyroid can be transformed to effective doses by multiplying by 0.04, the tissue-weighting
coefficient. The resultant effective dose is 3.6 mSv. This is the maximum estimated value for initial exposure reported in “Asahi Shimbun.”
Immediately after the accident, the equivalent dose was confused withthe effective dose, prompting turmoil.
The fact that the air dose was considered equivalent to the effective doseto the body was also a factor of confusion. Normally, the effective doseis one-fifth of the air dose. More specifically, according to Masaharu
Tsubokura, who works in affected areas, ‘air dose of 0.23 µ v/h’ is thevalue obtained by calculating the “yearly additional 1 mSv” per hour.
The government has the target of 1 mSv per year of additional exposure in the long run . . . From the research results using Glass badges
from September to November 2012, the results of 520 pupils who wore
glass badges firmly were adopted. The values indicated by the glass
badges are known to be very close to the damage amount (effective dose)to the body. The study compared the values of glass badges and exposure amounts that were estimated by the method designated by thegovernment based on air doses in front of subjects’ homes. Results
were . . . that exposure amounts estimated by the method designated by
the government were approximately three times the values obtained using glass badges. In other words, when one lives in places with air
doses of 0.6 µ Sv/h, they are exposed to radiation of 1 mSv per year’(http//apital.asahi.com/article/fukushima/2012012 000016.html). Something was wrong when considering the dose. This experience should betransmitted to the world and next generations.

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A Philosophical Inquiry into the Confusion
over the Radiation Exposure Problem

example, they said “radioactive cesium was not detectedfrom ‘all’ students of elementary and junior-high schools
in Miharu town in medical examination in the fall 2013”(Hayano, Tsubokura, et al., 2013, p. 161). The question
then is how to evaluate these radiation exposure dose values.
Such estimation is based not only on epidemiological evidence but also on pure logic. My reasoning is asfollows: During medical treatments, we are sometimes
exposed to doses of radiation greater than that of the
Fukushima power plant accident; and if death risks dueto the exposure dose in Fukushima is high, then our society would be a very short-lived one. Quite to the contrary,
however, Japan is the world’s top country for longevity.
This reasonably suggests that radiation exposure at approximately 5 mSv would not cause a significant increasein death risks7 . Of course, radiation exposure risk is not 0.
However, such risks cannot be identified because they areminimal. Cancer death risks are complex, and multiple
confounding factors should be considered. In this connection, although the epidemiological evidence is questioned
and such questions make sense to some extent for casesof radiation exposure of 100 mSv per year, they can begroundless for cases of radiation exposure of 5 mSv orless per year. Thus, risks should be evaluated based on“quantities.”
Moreover, even if these risks become a reality, they
are late and cause only “possible” deaths. In contrast,“damages caused by avoiding radiation” including stresscaused by evacuation actions, health deterioration, increased suicides, and increased deaths are not late but
have occurred. The deaths of those who perished during
evacuation are not “possible” but “actual” deaths. Clearly
this point must not be neglected. From the perspective oflost life expectancy, the “damage caused by avoiding radiation” is far greater than “damage due to radiation” inthe case of Fukushima.

3. Damage due to Evacuation Actions
The above notion can be understood by comparing“damage due to radiation” and “damage caused by avoiding evacuation” in the Fukushima power plant accident:
namely, the comparison of health effects between (1)cases of possible “damage due to radiation” for those who
remained in affected areas in Fukushima (except for thoseareas close to the Daiichi Nuclear Power Station) after
the accident, and (2) cases of “damage by avoiding radiation” associated with evacuation. Regarding point (1),it was consoling that no one killed or seriously injured af7. According to the 2011 “New edition Life safety environment radiation”
edited by the Nuclear Safety Research Association, the national dose ofJapanese people is 5.98 mSv per year, and the effective dose of naturalradiation is 2.1 mSv per year. Therefore, the average medical exposureof Japanese people is 3.88 mSv. Under this condition, the death rate
is not significantly increased, rather longevity is promoted, so it would
be safe to say that death risks would not considerably increased under
exposure of approximately 5 mSv per year (In most cases, those living
in Fukushima are exposed to accumulated radiation of 1 mSv or less peryear). Refer to https://www.nsra.or.jp/library/book.html

Journal of Disaster Research Vol.11 No.sp, 2016ter acute symptoms were reported. Therefore, late cancer
and cancer deaths are the only problems of (1). In addition, stresses and anxieties when living in an environment
with possible radiation exposure and the inconvenienceof insufficient living conditions and infrastructure should
also be considered.
According to the estimation as of 2012 made by Hoeve and Jacobson, environmental engineers from Stanford
University, the number of lives saved by evacuation in the
Fukushima power plant accident was three at the least,
28 as optimized, and 245 at most. Conversely, if (1) is
selected and people remained in the affected areas, an additional 3 to 245 cancer deaths are estimated. In contrast,in the case of (2), or as evacuation actions were undertaken, more than 1800 victims died due to disaster-relatedcauses. Disaster-related deaths in Fukushima Prefecture
were far more than those in Miyagi Prefecture (approximately 900) and in Iwate Prefecture (approximately 400).
The effects of the Fukushima power plant accident are obvious. More deaths were caused in the case of (2), whenevacuation actions were taken (see Hoeve & Jacobson,2012). In addition, as discussed in the previous paragraph,no one was killed due to acute symptoms resulting fromradiation; so the deaths of case (1) are estimated “possible” ones, while those of case (2) are “actual” deaths thathave occurred. The difference in lost life expectancy cantheoretically be regarded as infinite unless possible deathsin the future and deaths that have occurred are treatedas equivalent from the standpoint of metaphysical fourdimensionalism.
I believe cancer deaths due to radiation exposure area tragedy, without a doubt. At the same time, however,deaths due to evacuation activities are also surely tragic. I
am firmly convinced that deaths due to evacuation efforts
should also be considered to the same extent as cancer
deaths due to radiation exposure. Some overly emphasize
the dangers of radiation exposure, saying that “any kind ofradiation exposure is dangerous” and “it is natural to feelanxiety about radiation exposure,” and they are treated asif they embodied social justice in many cases. However,this absolutely does not mean deaths due to evacuation actions need not be considered. All “deaths” are sad. Moreover, “deaths” that are about to occur are more significant
than “deaths” that might occur in the future. Discoursesthat do not deal with such significant “deaths” are dishonest and harmful to the society. Tragedy and damage suchas the significant “deaths” that are about to occur must be
prevented by the whole society.
Related to this point, after I published A philosophy confronting the problem of radiation exposure, researchers from the Faculty of Medicine, the Universityof Tokyo, where I am based, released research results of a
“retrospective cohort analysis” called “Death risk analysis
for elderly citizens due to evacuation after the Fukushima
nuclear power plant accident.” The report includes thefirst detailed data, which seem to be the most reliable
presently available on evacuation-related deaths after the
Fukushima nuclear power plant accident. The main findings of the report can be summarized as follows:773

Ichinose, M.

• The death rate of elderly citizens increased 2.7-foldafter evacuation.
• However, the death rates differ depending on evac-

uation facilities, requiring consideration of evacuation processes, services, and nursing care and foodin each facility.
• The risks of first evacuation are higher than those of

successive evacuations.
• Evacuation of elderly citizens comprehensively re-lated to deaths, and evacuation immediately after theaccident was not necessarily the optimal selection.
• Rather than an “immediate evacuation,” staying infamiliar environments should be prioritized to wait
and see about the circumstance; and care must be
enhanced in shelters if evacuation is necessary.
• The risks of evacuation must also be considered infuture disasters.
(Nomura, Gilmour, Tsubokura, Yoneoka, Sugimoto,
Oikawa, Kami, and Shibuya 2013)
We should sincerely listen to such reports on actual
damages and resultant proposals. While the report covered elderly citizens, it can be easily be conjectured
that other citizens suffered from damages other thandeaths. Evacuation includes different types ranging between forced and voluntary evacuations, and the differences in evacuations between those who moved to otherareas in Fukushima Prefecture and those moved outside
it are significant. In addition, family composition, household budget, and health conditions vary widely. However,a macroscopic viewpoint to roughly categorize objects
is inevitable in statistical and epidemiological thought.
There is no need to reject such human wisdom.
I have good reason to highlight the significance of classification of the forms of “evacuation.” I think there
are two objections that always arise when discussing the“damage” resulting from evacuation activities; these arepotential factors to expand the range of actual damage as
can be seen in the present case. The two objections are:(i) Does evacuation-related damage derive from the nuclear accident and radioactive materials diffusion, since itwould not been caused without the nuclear accident? (ii)
Are evacuees criticized if evacuation activities are generally regarded as harmful? As I mentioned, evacuation
activities vary so widely that it is too rough to generalize their activities as “evacuation” as a whole. Concerning (i), I approve of the causal specificity using the counterfactual conditional sentence “evacuation-related deaths
would not have occurred without the nuclear accident.”
However, the question is whether there were other factors that could have been artificially handled between theoccurrence of the nuclear accident and the ensuing damage. I want to make it clear that the counterfactual conditional sentence “so many people would not have suffereddamage if forced evacuation actions had not been taken,”which uses a temporal axis extending beyond the nuclear
accident, is worth considering (this point was studied in
774

Ichinose (2015a)). Staying rather than evacuating could
be feasible even after the nuclear accident, as opposed to
the fact that the nuclear accident had already happened
and could not be canceled after the accident. Thus, thecause of the related damage could theoretically be attributed to the evacuation actions. More accurately, thepossibility of such causal specificity should be considered at least in order to objectively understand the circumstances. By doing so, the generally accepted notion thatradiation should definitely be avoided would be reflected
upon in a calm manner; thus, current damage would be
reduced and lessons for the future provided for certain.
Counterfactual conditional sentences with antecedents
retrospective to pre-accident such as “if the nuclear power
plant had been decommissioned” and “if facilities including backup power sources had been better prepared”
can justly be connected to the consequent “many people
would not have suffered damage,” as well as counterfactual conditional sentences with antecedents focusing on a
post-accident “if forced evacuation actions had not beentaken.” The decisive point here is the philosophical question regarding which counterfactual conditional sentence
should be adopted as the most acceptable. Regarding thisphilosophical question, I hypothetically propose a policy
to estimate the degree of acceptability of a counterfactual
conditional sentence using a function of “manipulability”
and “temporal distance” from the consequence. I positthat the most immediate way with the highest manipulability is the most realistic (not radical, at a low cost, andwith the fewest side effects). When temporal factors are
disregarded, the degrees of manipulability of decommissioning nuclear power plant, preparation of backup powersources, and cancellation of forced evacuation activities is
not 0. Let us suppose that the three degrees of manipulability are equal (which is reasonable enough as temporalfactors were disregarded). However, even if we adopt this
supposition, the temporal distance from the consequence(increased disaster-related deaths) is clearly the shortest
for the cancellation of forced evacuation activities. According to this idea, the counterfactual conditional sentence “if forced evacuation activities had not been taken,
so many people would not have suffered damage” is themost realistic and acceptable.
Some may argue that my discussion compels people totolerate radiation exposure, but this argument is a straw
man. The key problem is ultimately the health problems
due to the nuclear accident, and thus the “life” problem.
Therefore, health and “lives” are prioritized. It would domore harm than good if health deteriorates and “lives” arethreatened by avoiding radiation exposure. I am not insisting on tolerance to radiation exposure, but am proposing
to protect health and “lives” by doing our best in actual
circumstances. We must not lose sight of our true goal.
I will sincerely respond to objection (ii) above. Evacuation activities immediately after the accident when there
was no sufficient information do not deserve any indictment. I would have undertaken evacuation activities likewise if I had lived near the Fukushima Daiichi Nuclear
Power Station. I suggest considering the option of going
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A Philosophical Inquiry into the Confusion
over the Radiation Exposure Problem

home if one finds difficulties in the evacuation activities
after a certain period of time and if their home is safe tolive in when the quantity of radiation material diffusion
due to the accident is largely identified. I admit that somevictims may choose to live in a shelter and this choice
may be better in terms of risk management in many cases.
Yet, some might oppose to me by saying that if my assertion has only such a narrow implication, it is too roughto classify ‘damage due to evacuation activities’ as one
type. I can respond to this opposition, ‘The rough classification is effective when grasping epidemiologic phenomena from the macroscopic viewpoint; and the possible causal relationship (or correlation relationship at least)
obtained using this classification will certainly facilitate
policy-making under similar circumstances in the future.’
On the contrary, rejecting such an understanding becauseof a wide variety of circumstances will lead to the risk ofincreasing actual damages by repeating the same mistakes
in the future: The possibility of staying in their home isconcealed, and avoiding radiation exposure is retained as
the only option.
Someone may counter that evacuation deaths should be
prevented by improving evacuation facilities rather thanstaying home even if they admitted the circumstances surrounding disaster-related damage. This is based on theview that because radiation exposure is dangerous, evacuation is the first priority and damages due to evacuation
should be avoided by preparedness. However, this view
includes two issues: 1) The fact that quantity matters inradiation exposure is neglected. If the quantity or the doseis small, then people do not have to rush to shelters andleave their homes. The situation should be reviewed before making a decision. 2) The possibility of taking adequate measures to enhance evacuation facilities in advance should be questioned. If the same level of livelihood can be maintained after evacuation or movement (interms of physical, mental, economic, and social aspects),
then no evacuation-related deaths will occur. However,is it possible to realize such ideal preparedness? I thinkthat would be very difficult because of physical and financial problems. The manipulability of such preparedness
is quite low. In fact, no states and societies have beenable to afford to do so. Consequently, it should be clearly
noted that evacuation has death risks including a risk inthe sense of the difficulty of enhancing evacuation facilities beforehand when addressing problems in future disasters. People are presumably aware of this point using
some imagination. Imagine what you might feel if you
were instructed to immediately take in refugees for about
one year. The difficulty will quickly be understood.

4. “Sensation of ‘Not”’ and “Moral Dilemma”
However, why did the above, easy-to-understand position not prevail? Why was difficult evacuation, or more
precisely, only difficult evacuation recommended? Moreprecisely, why were so many people firmly convinced thatthey had no option but to evacuate under pressure, andJournal of Disaster Research Vol.11 No.sp, 2016

why had they to die? By addressing these questions, thereal nature of damage of the radiation problem due to the
Fukushima nuclear power plant accident is highlighted. I
think what I want to call the sensation of “not” madethe radiation problem more confusing – this sensation includes a “sense of the absurd” and a “sense of discomfort” resulting from unnecessary, useless, additional radiation exposure as a fault of the government and powercompany, a “sense of anxiety” about future health conditions, and a “sense of distrust” for information transmission from the relevant agencies that were sometimes
incorrect and changing. The real nature of the damage ofthe radiation problem and the diffusion of radiation materials seems to originate from the sensation of “not” in away.
The background of the sensation of “not” is that we regard radiation as a threat, or an icon of fear. Japanesepeople especially feel this way because we experienced
Hiroshima, Nagasaki, the Daigo Fukuryu Maru, and theJCO critical accident. Furthermore, the radiation problem
can be deemed a man-made disaster, unlike tsunami disasters. When responsibility is accountable (and it should
be strictly pursued) and anger can be directed to some entities, one’s sense of the absurd, anxiety, and discomfort
increases. It should also be taken into account that the understanding of general citizens who have silently acceptednuclear power plant administration as being partly responsible for the nuclear accident, in turn becomes a selfdeceiving sense of distrust and discomfort. The sensationof “not” manifests as an unconscious, self-defensive response to disguise one’s own errors.
When the sensation of “not” becomes strong enough,one will avoid the sensation. The sense of the absurd
and discomfort are associated with anger and movements
toward investigation of responsibility, leading to movements against the nuclear power plant. The society isthen sunk in a morass; a stressful world appears in whichprospects for the future are hard to attain. In addition, thesense of anxiety emerged as immediate evacuation, worsening the situation in some cases. The sense of distrust
produced an unproductive reality where experts on radiation protection and radiation medicine were accused ofbeing “scholars patronized by the government” in addition to the general condemnation against the government
and power company. In such a way, the sensation of “not”
turned to a negative feeling as a matter of course.
On top of these negative circumstances, a more serious one has arisen: many people take actions to avoid thesensation of “not,” but this action in turn does harm tosome people. Movements against nuclear power plants
are decisively persuasive because a nuclear power plant
accident can endanger human lives. Recall the JCO critical accident in 1999. However, to decommision nuclear
power plants altogether takes time; the problem of thetime required for decommissioning a reactor and the issue of waste disposal are undeniable. Moreover, these
problems cannot be solved by a single country. Nuclear
power plants in neighboring and other countries relate to
us and to all of humanity. So then, movements toward775

Ichinose, M.

the decommissioning of nuclear power plants should expect a continual struggle requiring considerable endeavor.
However, as described above, those in affected areas will
still feel anxieties confronting the danger of death at thismoment. Currently, urgent demands are for the provisionof medical services and increases in administrative healthnurses caring for individuals frequently. From the perspective of the victims, movements against nuclear power
plants in Tokyo or other areas are somewhat unsympathetic. The sense of danger for nuclear power plants canbe shared (although I understand the danger of thermal
power plants in multi-layered meanings as well). However, the question remains of how to deal with the ongoing problems in affected areas. Might direct supports for
those who are trying to restore their lives and tolerate radiation exposure be possible? Can the energy for demonstrations against nuclear power plants be directed instead
to direct supports for affected people? Is the order of priorities incorrect? It is inevitable to yield to such a senseof frustration.
In other words, the responses to a sense of the absurd
and to discomfort produce a harmful sense of alienation,or being-left-alone for affected people although those responses are based on a morally justifiable motivation (respect for human lives). With regard to this point, I argued
in another paper that the “metaphysical approach,” which
addresses extensive, long-term issues such as the pros andcons of nuclear power plants, and the “epistemologicalapproach,” which intends to solve urgent, actual damage
in the present, are different impulses and sometimes compete with each other when confronting the nuclear accident. The two approaches should not be confused witheach other. My interpretation is that such confusion is
one factor in the disarray related to the radiation problem(refer to Ichinose, 2015a, p. 25).
Furthermore, a large number of people who lived in
East Japan including Fukushima Prefecture took refuge
driven by anxiety about future health, especially for theirchildren, which caused harm. I mentioned the fact that
evacuation increased deaths. In addition to this, evacuation activities inversely caused harm to those who remained in the affected area through moral censure to
the decision to remain in evacuation recommendation areas (children may be endangered), discrimination against
those remaining in evacuation recommendation areas, anda pervasive sense of avoidance to produce from evacuation recommendation areas. The scheme in which actions
based on a morally justifiable motivation to protect children’s health do harm to those in affected areas is also
apparent here8 . It is difficult to make assertive remarks
about whether to evacuate or not based on current radiation doses in Fukushima. One can evacuate if they want
and the radiation exposure dose will be reduced by evacu8. Proposals for temporal refuge for affected children imply that it is dangerous to stay in affected areas, doing harm to those still living in affectedareas, although they are from good intention that can morally be justified.
Judgment must be based on “dose” and individual decision-making must
be respected. Careless proposals neglecting data from outside affectedareas are not allowed even if they are from good intentions. The aphorism “the road to hell is paved with good intentions” should be recalled.

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ating; this does not mean that staying in affected areas will
surely be hazardous to one’s life. Rather, it would be safe
to say that staying in affected areas will not jeopardize
one’s life. Radiation doses are so low that one can live
in affected areas with appropriate attention. The action
policy is judged by each individual. Based on this background, I want to focus on the tragedy in which morally
justifiable evacuation actions do harm to others.
Similarly, experts were rejected by some people as“scholars patronized by the government” because of theirsense of distrust. This rejection or abuse may originate ina sense of justice. However, by doing so, researchers who
try to make sincere statements based on their expertiseand experience may be compromised or hesitate to makestatements, resulting in confusion and depriving affected
people of opportunities to access the opinions of experts.
Here again, actions from morally acceptable motivations
do harm to others. I call this situation a “moral dilemma.”
I would like to express my opinion that the core or the nature of the present radiation problem is a “moral dilemma”
emerging from the sensation of “not.”5. Causal Relationship Between Radiation Exposure and Cancer Deaths
How can we get out of this “moral dilemma?” It is myunderstanding that a possible course is to correctly andobjectively estimate the health effects of additional radiation exposure caused by the nuclear accident on the human body using the presently available collective knowledge of human beings. In other words, the source of thesensation of “not,” especially the “sense of anxiety” needs
be examined in detail as to whether it is a truly justified
sense or not, and we should make efforts to patiently remove the “sense of anxiety” when it is likely to be unnecessary. Never evaluate the sense of anxiety of people
as “natural anxiety” from the outset. This is begging thequestion, and it causes a hundred harms and not a single
gain because confusion and anxiety will only increase.
In fact, the most sincere and effective way is to calmly
consider “degrees” of danger and to repeat examinations
gradually, although this method is seemingly long.
To help follow this plan, I want to propose a question on the causal relationship between radiation exposure and cancer deaths from the perspective of a philosophy researcher, as partly described above in relation toevacuation-related deaths. To estimate the health effectsof radiation “correctly and objectively” is nothing lessthan to calmly discern the “causal relationship” between
radiation exposure and its effects on the human body.
Firstly, an obvious point from the beginning is as follows:
The causal relationship in question is NOT the “necessary” causal relationship without exception. The problem
is the causal relationship between radiation exposure andincreased cancer death rates, provisionary setting aside
the issue of the exposure amount. It is clear that “probability” matters here. Such a causal relationship is called“probabilistic causality” in the philosophical context. The

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A Philosophical Inquiry into the Confusion
over the Radiation Exposure Problem

simplest form of probabilistic causality can be expressedusing the inequality relationship of “conditional probabilities” (hereafter referred to as “Equation P”) as follows:
Equation P : P(E| C) > P(E| ∼ C)
The idea is that, when comparing “the probability of E
when C occurs” and “the probability of E when C does
not occur,” the former is larger; then, for the time being,“C is the cause of E” can be regarded as true. To apply thisto the present case, “radiation exposure of general victims
due to the Fukushima nuclear power plant accident (excluding workers in the plant)” is substituted with “C,” andthose who “die of cancer” with “E.” If Equation P holds
true, then the causal relationship between radiation exposure and cancer deaths can temporarily be expected.
However, we have theoretical issues piling up. The
question of whether the inequality relationship of Equation P holds true arises in the case of Fukushima when
considering the fact that the external radiation exposure
was 5 mSv or less and the internal exposure was almost 0,
combined with the findings regarding the radiation exposure of human beings thus far. This point is highly doubtful from a logical point of view; as mentioned above,
we are sometimes exposed to radiation doses equivalent
to that of the power plant accident during medical treatments; nevertheless, we do not live shorter, but longer. We
are sometimes exposed to additional radiation: natural radiation from soil (recall Kerala in India and Ramsar inIran), cosmic radiation when boarding airplanes, external
and internal exposure in radon spring, and exposure from
granite buildings (e.g. the Grand Central Station in N.Y.
and the Diet Building in Japan). If accumulated, exposure
doses may be above 5 mSv. However, such radiation exposure is not controversial in the world except for casesof excessive medical exposure. To be precise, as long asa specific phenomenon has not occurred, such exposure
is not discussed. If that is the case, it can be reasoned
that demonstrating the relationship in Equation P using
data for the present levels of radiation exposure from the
Fukushima nuclear power plant would be extremely difficult as long as the laws of the world are constant to somedegree (this is our basic understanding of the world, although philosophers can question this).
Another emerging problem is the possibility of “common cause.” Even if a clear relationship between radiation
exposure due to the nuclear accident and cancer deaths
is found applicable to Equation P, the causal relationshipbetween them cannot be determined immediately for theoretical reasons. For example, the possibility of the following case cannot be excluded: A “specific genetic condition” is a factor of increasing the possibility of “cancer
deaths,” and at the same time, the same genetic factor isthe cause of inducing “damaged cells due to ionizationand excitation resulting from radiation exposure.” If sucha common cause generates both results of “damaged cells
due to ionization and excitation resulting from radiation
exposure” and “cancer deaths,” then cancer death rates remain the same even when radiation exposure is avoided.
In addition, some difficulties that statistic, epidemioJournal of Disaster Research Vol.11 No.sp, 2016

logic thoughts always encounter are anticipated such as“overdetermination” and “Simpson’s paradox.” “Overdetermination” means multiple factors cooperatively cause
a single result; i.e., in the case of “cancer deaths,” it is difficult to estimate the degrees of contribution of radiation
exposure to the result because multiple factors such as diet
habit, human relationships, smoking, sleeping, exercise
are comprehensively entangled in addition to radiation exposure. This can be further explored from the philosophical viewpoint to find a fundamental difficulty in the individualization of phenomena: Which factor should be considered? The renowned “Simpson’s paradox” is not detailed in this paper. In short, this is a traditional statisticalparadox: In a statistical aggregation divided into Group A
and Group B, even if a relationship between the same factors shows the same inequality relationship of Equation P,
the inequality relationship can be reversed when Group A
and Group B are combined. It is difficult to completely
delete the possibility of “Simpson’s paradox” because astatistical survey necessitates a divided aggregation as thewhole data cannot be obtained at once.
The above matters shed light on the fact that it is quitedifficult theoretically to estimate the causal relationshipbetween “radiation exposure” and “cancer deaths” in relation to the Fukushima nuclear power plant accident. Thisdifficulty facilitates the generation of “moral dilemmas”
in a sense. However, in spite of those difficulties, data
for Equation P should be dealt with seriously, if available. Even though “probabilistic causality” contains theabove difficulty in principal, there is no other way to support the causal relationship but to collect statistical andprobability data. As far as I understand, causal relationships are established as “scenarios” that people postulate
based on collected objective data. It is desirable to establish “scenarios” of more persuasive and reasonable causal
relationships through social discussions by collecting objective data.

6. Legal Standard and Precautionary Principles
However, it seems that these discussions are seldom accepted. The background of this is, I believe, the problemof the legal standard of “1 mSv per year” and the idea of“precautionary principles.” These problems have brought
about further confusion about the “moral dilemma.”
Let us review the problem of the legal standard of“1 mSv per year.” Immediately after the nuclear power
plant accident, it was pointed out that “1 mSv per year”
was stipulated in acts as the upper limit of the radiation
exposure of the general public excluding natural and medical exposure; however, the value was exceeded due tothe accident, violating the relevant acts. From then on,
the standard of “1 mSv per year” has seemingly becomea premise for discussion and decontamination work has
been planned based on that value. However, the standardof “1 mSv per year” is not for the limitation of exposurefor the general public but for released radiation doses infacilities handling radioactive materials in a precise sense.

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As a matter of fact, however, if the upper limit of released
radiation dose in facilities handling radioactive materials
is “1 mSv per year,” then the upper limit of radiation doses
for the general public must be “1 mSv per year” or lower.
In addition, discussions have already taken place with presupposing that the radiation limit of the general public is“1 mSv per year.” Under this scenario, the notion that
“1 mSv per year” as the exposure limit should be temporarily accepted in order to ensure the possibility of general discussion, whereupon we need to examine the significance of the notion, even though we have to note that
this exposure limit is not implying the real boundary toharm human bodies but is stipulated only by way of caution. In any case, if the upper limit of “1 mSv per year”
for the general public were flatly rejected because there
are no acts that support the value, then mutual communication would stagnate.
I felt strange about the use of “1 mSv per year” immediately after the accident because the value was wielded as
an absolute authority like a royal coat of arms. However,a short inquiry can make us understand that the ground of
the authority lies in this proposition:‘The legal standard of “1 mSv per year” ought to beobserved.’
The absolute correctness of this proposition formed thecore of the authority. However, the proposition is absolutely correct in the range it denotes, but the correctness of
it is based on the definition of “law” concept: ‘a law ought
to be observed.’ This can be expressed, as the proposition
is a priori correct from the definition rather than from its
meaning. In other words, the proposition proposes nothing with substance. It has only empty truth. However, if
the correctness is set forth, and the absolute correctness isconverted to authority, then this correctness is implicitly
replaced with the a priori correctness of another proposition related to laws: ‘criminal laws banning murder andviolence ought to be observed.’ Further, the correctness is
replaced with the a priori correct proposition that the ‘violation of criminal laws banning murder and violence isdangerous for the human body’ by the definition of “murder and violence.” As a result, the violation of the legal
standard “1 mSv per year” is impressed as if it is dangerous for the human body. This is to say, “double replacement of a priori correctness.” Needless to say, this is an
unfair discussion. Without becoming obsessed with sucha discussion, the relationship between radiation exposureand cancer deaths should be considered based on factual
investigations.
In parallel with the discourse of “1 mSv per year,” thefact that people have unconditionally accepted the application of the concept of “precautionary principle” to theradiation exposure problem induced the “moral dilemmas,” preventing an appropriate causal relationship “scenario” based on objective data from being proposed. The“precautionary principle,” roughly speaking, is the concept that if a specific activity or phenomena can possibly
cause serious, irreversible damage, precautions to avoid
the damage must be taken even when the damage is not778

sure. Many people insisted that the “precautionary principle” be applied to radiation exposure based on the intuition about dangerousness of radiation exposure, and thisidea was disseminated. There are “weak” and “strong”
versions of “precautionary principle,” and their consistency is sometimes questioned. The “precautionary principle” was originally a decision-making principle in thecontext of environmental problems in Europe as opposedto those that consider probability and costs such as “costbenefit analysis.” However, when one risk is avoided, another risk may be introduced. A typical example is when
tap water was avoided because the chlorine in it is considered harmful to human body, but infectious diseases may
still be caused if the chlorine is omitted. The following
critical points have long been proposed: the “trade-off”
between the “target risk” to be prevented and the “countervailing risk” caused by precautionary measures should
be considered. This point was disregarded in the application of “precautionary principle” to the radiation exposure problem for some reason9 . In this case, the “targetrisk” is radiation exposure. What is the “countervailingrisk?” The answer has been mentioned: health problems,
increased deaths, discrimination of evacuees, avoidanceof produce from affected areas, and stress caused by evacuation activities. We should take steps sincerely toward
investigations of the causal relationship between radiation exposure and cancer deaths as well as the creationof a reasonable “scenario,” without rushing to the quick
and harmful response: any radiation exposure should be
avoided (always remembering that “quantity” matters in
the radiation problem).

9. Kyo Kageura asserted the applications of “precautionary principles” toradiation exposure in Fukushima because “it is natural to feel anxieties
about possible risks,” and stated that the application is an “internationallyshared understanding.” (Ichinose et al., 2012. pp. 141-143). This notion is clearly in error, although it appeals to emotion and is accepted bypeople. With regard to “precautionary principles,” because various international criticisms have been proposed including “countervailing risk,”
as discussed in the main body, “internationally shared understanding” isa factual error. Some states in the U.S. rejected applying “precautionary principles” to the danger of electromagnetic waves (Shimegi 2003,
p. 102). The statement of Kageura totally neglects the concept of “quantity” that is fundamental in the radiation exposure problem, so it is anerror and is harmful. As emphasized many times, if quantity is low, radiation exposure does not cause adverse health effects. To advocate ananxiety-provoking thing without this basic recognition urges people tohave anxieties and promotes damage. I would urge those who have madesuch statements to reflect on the serious damage they have caused.
It is also noted that what “serious and irreversible” danger and damage
are is also a problem related to “precautionary principles” in addition to“risk trade-off.” Is “my death” included in such damage regardless of thecause (including staying up late)? All things are irreversible according
to the “second law of thermodynamics.” Via such discussions, a decisive counterargument is derived in relation to “precautionary principles.”If “precautionary principles” are literally accepted, breathing and having
food are prohibited because the world is filled with risks regardless of theamount. However, such the prohibition relates to “life.” Thus, following “precautionary principles” causes serious and irreversible damage.
As Sunstein pointed out, application of “precautionary principles” will
result in “paralyzing” in which the application of “precautionary principles” itself is prohibited (Sunstein 2007, pp. 125-126). Some cases
discuss the application of the precautionary principle with considering
the magnitude of risks and the probability of the relevant phenomenon
by avoiding these difficulties. However, these cases are not considered inthis paper because they do not match the origin of “precautionary principles” that was proposed as an alternative of “cost-benefit analysis,” or“risk trade-off analysis.”

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A Philosophical Inquiry into the Confusion
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7. Survive with “Moral Dilemmas”
We reach the conclusion. Radioactive materials werediffused due to the nuclear accident. We suffered fromsome additional radiation exposure. However, this does
not inevitably do “harm” to us. Rather, it is reasonable
to infer that the possibility of serious damage to humanbody is quite low based on the wisdom of human beingsand the information from the Fukushima nuclear power
plant. Yet, the anxieties of citizens cannot be easily dispelled. The motivation of voluntary evacuation can bemorally justified and understood considering children’s
health, and thus the liberty of those who voluntarily evacuated should absolutely be respected. However, as discussed in relation to the “precautionary principle,” an action for avoiding one risk may induce another risk, causing harm. Evacuation lives may impair the health of evacuees and evacuation actions can unintentionally highlightthe fact that an affected area is too dangerous to live in,resulting in the avoidance of produce from affected areas.
An action includes good and bad aspects. In this case,one option for individuals is to judge and make decisions
by themselves, and to just practice without appealing toand recommending something to others. This is to adhere
to one’s own action policy without involving others andaccusing others from their own perspective.
However, I estimate a more reasonable policy that minimizes damage as a whole: Except for areas close to the
Fukushima Daiichi Nuclear Power Station, evacuees cango home if possible (unless their home is too damaged toinhabit because of their long absence) and return to theirnormal lives with reasonable care (to not continue eatinghome-grown vegetables or move close to hotspots unnecessarily), recognizing that serious damage is unlikely tooccur in the current radiation exposure situation. Thismeans to calmly receive objective data and make decisions related to one’s life based on an understanding of rational, causal relationships. However, “more reasonable”
is different from “surely reasonable.” Those who wantto evacuate and stay in shelters may be reasonable. One
should have a strong mind if they want to reconstruct theirlives on land with flexible container bags holding contaminated soil. I believe the way to survive with the “moral
dilemmas” of the present radiation exposure problem isto practice and make decisions silently without involving
others because each thing has good and bad aspects.
In any case, the health problem is to consider “life anddeath” in reverse. The disaster that occurred is regarded
as a chance to consider “life and death” more deeply inorder to obtain lessens for the future, keeping in mind that
this will be linked to the eulogy for victims of the tsunami
disaster.

[2] T. Hoeve and M. Z. Jacobson, “Worldwide health effects of the
Fukushima Daiichi nuclear accident,” Energy & Environmental Science, DOI: 10.1039/c2ee22019a, 2012.
[3] M. Ichinose, “A philosophy confronting the problem of radiation
exposure,” Chikuma Publishing Company, 2013 (in Japanese).
[4] M. Ichinose, “Life is valuable, and life is mortal: Philosophical reconsideration on self-deception lurking within the debate concerning radiation exposure in the case of Fukushima,” PhilosophicalStudies, Vol.33, pp. 1-48, The department of Philosophy, The University of Tokyo, 2015a (in Japanese).
[5] M. Ichinose, “A Philosophical fragment on “Life is mortal”: Difference and Continuity between Humans and Animals,” ‘Inochi (Life)’
Reconsidered, The Society of Philosophy, Japan, pp. 46-74, 2015b
(in Japanese).
[6] M. Ichinose, K. Ito, K. Kageura, T. Kodama, S. Shimazono, and
K. Nakagawa, “Morals on low dose radiation exposure,” Kawade
Shobo New Publishing Company, 2012 (in Japanese).
[7] K. Kodama, S. Shimizu, and K. Noguchi, “Science and social studyof radiation exposure,” Kamogawa publishing company, 2014 (inJapanese).
[8] S. Shiozawa, “Radiation contamination in rice fields and its transmission to rices,” The Journal of the Japanese Society of Irrigation,
Drainage, and Rural Engineering, Vol.89, No.7, pp. 15-18, 2012 (inJapanese).
[9] N. Shimegi, “Present Status of the Precautionary Principle on Risk
Management,” Bulletin of Seigakukan University, Vol.15, No.2, pp.
91-107, 2003 (in Japanese).
[10] S. Nomura, S. Gilmour, M. Tsubokura, D. Yoneoka, A. Sugimoto,
T. Oikawa, M. Kami, and K. Shibuya, “Mortality Risk amongst
Nursing Home Residents Evacuated after the Fukushima Nuclear
Accident: A Retrospective Cohort Study,” PLOS ONE on line,
March 27, 2013.
[11] C. R. Sunstein, “Worst-Case Scenarios,” Harvard University Press,
2007.
[12] H. Tasaki, “Elementary knowledge to live confronting troublesomeradiation,” Asahi Publishing Company, 2012 (in Japanese).
[13] M. Doi, R. Kanda, H. Yonehara, S. Yoshinaga, and Y. Shimada,“Low dose radiation and health effects,” National Institute of Radiological Sciences, 2007 (in Japanese).

Name:
Masaki Ichinose

Affiliation:
Professor of Philosophy, Ph.D., The Universityof Tokyo

Address:
7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan

Brief Career:
1995 Associate Professor, The University of Tokyo
2007- Professor, The University of Tokyo
2011- Honorary Fellow, The University of Oxford

Selected Publications:• “Hybrid Nature of Causation,” In Ethics for the Future of Life,
Proceedings of the 2012, Uehiro-carnegie-Oxford Ethics Conference, by T.
Uehiro (Ed.), the Oxford Uehiro Center for Practical Ethics, University of
Oxford, pp. 60-80, June 2013.
• “Normativity, probability, and meta-vagueness,” Synthese,
DOI:10.1007/s11229-015-0950-7, Springer, October 2015.
• “An Essay towards an Epistemology of Responsibility: A Probabilistic
Approach,” Philosophical Studies, Vol.34, The Department of Philosophy,
The University of Tokyo, pp. 1-32, March 2016.

Academic Societies & Scientific Organizations:

References:[1] R. Hayano, M. Tsubokura, M. Miyazaki, H. Satou, K. Satou,
S. Masaki, and Y. Sakuma, “Internal radiocesium contaminationof adults and children in Fukushima 7 to 20 months after the
Fukushima NPP accident as measured by extensive whole-bodycounter surveys,” Proceedings of the Japan Academy Series B,
Physical and Biological Sciences, Vol.89, pp. 157-163, 2013.

Journal of Disaster Research Vol.11 No.sp, 2016

• Hume Society• Philosophical Association of Japan779