The Gold Standard for Radiation Eﬀects on People:
Scientiﬁc Value and Ethical Obligations
Scientiﬁc Secretary, International Commission on Radiological Protection

Christopher H. Clement●Overture:Discovery of X Rays to the Second
W o rl d W a r （1895‒1939）

Just months after the discovery of X rays in

November 1895（Röntgen 1895）, radiation damage to theskin was already being observed in early experimental
investigators, including erythema, dermatitis, and ulceration（Grubbé 1933）（Drury 1896）（Leppin 1896）. Nonetheless, X
rays, with their ability to see inside the human body, wereused almost immediately in the medical ﬁeld, including inmilitary ﬁeld hospitals as early as 1897（Churchill, 1898）.
Therapeutic uses were also tested as early as 1896（Belot
1905）.With Curieʼs discovery of radium in 1898（Curie 1898）1

the use of radiation in medicine continued to increase, as didreports of radiation induced damage in practitioners andpatients.
On December 12, 1896, just one year after the
discovery of X rays, the ﬁrst radiological protection
recommendations were published in the Western Electrician
by Wolfram Fuchs（Fuchs, 1896）. He reported having“applied the X-ray to all parts of the body” in 1,400 cases
over nine months, and “but four instances of the slow
healing burns which have lately attracted considerable2

attention through the columns of the press.” Fuchs notedthat “the injury may be regarded as slight in comparison
with the beneﬁts resulting from this wonderful discovery”,
adding, in the next sentence: “however, it is desirable, ofcourse, to prevent the inconvenience and pain of theseʻsunburnsʼ”.
In 1925, the ﬁrst International Congress of Radiology（ICR）was held in London. Here, the International X-ray Unit
Committee, now the International Commission on Radiation
Units and Measurements, was formed. Discussions were also
held regarding creation of an international radiological3

protection committee. This occurred at the second ICR in
Stockholm in 1928, when the International X-ray and Radium
Protection Committee（IXRPC）was created.
Arising from the 1928, ICR were the ﬁrst
“International Recommendations for X-Ray and Radium
Protection”（ICR 1929）. The focus of these recommendations
was on the protection of “X-ray and radium workers” inmedical facilities, and the ﬁrst sentence declared that “The466dangers of over-exposure to X-rays and radium can be
avoided by the provision of adequate protection and suitableworking conditions.” The dangers were considered to be“injuries to the superﬁcial tissues” and “derangements ofinternal organs and changes in the blood”. A key method ofprotection was limitation of working hours, as well asadvising operators to stay “as remote as practicable from the
X-ray tube”, and using shielding around the x-ray tube.
The IXRPC met next during the ICRs held in Parisin 1931, and then in Zurich in 1934. No newrecommendations were produced in 1931. In 1934 the main

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addition was to suggest a level at which “a person in normal
health can tolerate exposure to X rays”. In modern units thiswould be similar to an annual dose of about 500 mSv.
The IXRPC met again in Chicago at the 1937 ICR,
although there were no great advances in the radiologicalprotection recommendations at that time. They did not meetagain before the Second World War.
● I n te rre g n u m: Worl d War I I （1939‒1 9 4 5 ））The Second World War changed many things. Tens

6of millions of people died. Many peacetime endeavours in theaxis and allied countries were interrupted with all focus on
the war eﬀort. Two seminal events occurred during the ﬁnal
stage of the war: the atomic bombings of Hiroshima andNagasaki. To this day, these remain the only uses of atomic
bombs in warfare.
On August 6, 1945, the atomic bomb “Little Boy”
was dropped on Hiroshima. Just three days later, on August
9, 1945, the atomic bomb “Fat Man” was dropped on
Nagasaki. Tens of thousands were killed immediately, andtens of thousands more died in the months that followed.
However, many exposed to the radiation from the atomic

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bombs survived. The number of casualties was not greaterthan those from other major urban bombing campaigns, butthese were caused by two single bombs unlike any that had
been seen before. This massive destructive power, and thelingering concerns about those who had been exposed to thebombs left an indelible scar on the human psyche.
●Metamorphosis:Increasing Knowledge andEv o l v i n g P rot e ct i on (1946‒1990)

Immediately after the war, in September 1945,

Japanese and American scientists established a Joint

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Commission to investigate medical eﬀects of the atomic bombing. Following this, in March 1947, the Atomic
Bomb Casualty Commission（ABCC）was formed to undertake a long range study of the biological and medical
eﬀects of the atomic bombs.
In April 1975, the ABCC was succeeded by the Radiation Eﬀects Research Foundation（RERF）. The
mission of RERF is to conduct research and studies, for peaceful purposes, on the medical eﬀects of radiation67

on man and on diseases which may be aﬀected by radiation
with a view to contributing to the maintenance of the healthand welfare of atomic bomb survivors and to theenhancement of the health of all mankind. Over the years,
the ABCC and RERF have undertaken extensive andvaluable studies of atomic bomb survivors, the results ofwhich are the gold standard in understanding the eﬀects ofradiation on humans.
In the years after the war, aided considerably by
the work of the ABCC and later RERF, a major shift inunderstanding the eﬀects of radiation occurred. It was
becoming clear that there were long-term eﬀects well

9beyond the immediate “injuries to the superﬁcial tissues”
and “derangements of internal organs and changes in the
blood” seen at high doses. Relatively lower doses of radiation
could, in the long term, also lead to cancer and（it wasthought at the time）genetic eﬀects.
Meanwhile, international radiological protection
community also re-emerged after the war. The ﬁrst
International Congress of Radiology since 1937 was held in
London in 1950. There, the IXRPC was renamed as theInternational Commission on Radiological Protection（ICRP）.

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1950 Recommendations of ICRP（ICRP, 1951）
included an expanded list of eﬀects of radiation exposure,based on “still limited experience”:（1）Superﬁcial injuries.
（2）General eﬀects on the body, particularly theblood and blood-forming organs, e.g. productionof anaemia and leukaemias.
（3）The induction of malignant tumours.
（4）Other deleterious eﬀects including cataract,obesity, impaired fertility, and reduction of life span.
（5）Genetic eﬀects.
Now, it was not just about skin reactions and11

ill-deﬁned “derangements”. The picture had become much
more complicated with the introduction of cancer, genetic
eﬀects, and other eﬀects. This complication went far beyond
just a longer list of potential eﬀects. It was not realized that
potentially harmful eﬀects of radiation exposure could not becompletely “avoided by the provision of adequate
protection”. It seemed that the newly discovered eﬀects,
which took a comparatively long time to manifest, could
even occur at relatively low doses.
This lead to recommendations to “reduce exposures12

to all types of ionizing radiations to the lowest possible level”, and also the recommendation of a reduced
maximum permissible level of exposure roughly equivalent to 150 mSv/y in modern units.
Public concern about radiation risks began to grow in the mid-1950s. Not only was the memory of theatomic bombs that dropped over Hiroshima and Nagasaki still fresh, but extensive nuclear weapons testing
was being conducted in the wake of the Second World War, resulting in widespread of radioactive

68contamination. The incident of the Lucky Dragon（Lapp,
1958）（Schreiber, 2012）also inﬂuenced public opinion
signiﬁcantly in Japan and world-wide. The 23-man crew of
the Daigo Fukuryū Maru（Lucky Dragon 5）, a Japaneseﬁshing boat, was caught in the fallout of US nuclear weapons
test “Castle Bravo” at Bikini Atoll on March 1, 1954. The
vessel was far enough away to avoid any eﬀects of the blast,which was 1000 times greater than the bomb dropped on
Hiroshima less than a decade before. However, the crew was
exposed to fallout. Although they did not know theconsequences at the time, some symptoms began to show
during the two-week voyage back to Tokyo. Upon arrival in13

port, the ship, crew, and catch were found to beradioactively contaminated. The crew were treated for acuteradiation syndrome, and one died in September of the sameyear.
The Lucky Dragon and their not-so-lucky crew
were not alone. The Japanese Ministry of Health andWelfare reported that that 856 Japanese ﬁshing vessels andnearly 20 000 crew members had been exposed to radiationfrom the Castle Bravo test. The price of tuna dropped, and75 tons caught during the remainder of the year were found
unﬁt for consumption.

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Protecting the public from radiation exposures was
also high on the list of concerns for ICRP during this period.
Not only were weapons tests being carried out, but nuclear
power and the use of radioactive sources in many ﬁelds
were on the rise.
In this atmosphere, the 1954 Recommendations of
ICRP（ICRP, 1955）marked another important change: theexplicit introduction of protection of the public. Until thistime protection advice had been aimed at “occupational
workers”. Now, with just a single sentence, this was
expanded: “In the case of the prolonged exposure of a large

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population, the maximum permissible levels should be
reduced by a factor often below those accepted for
occupational exposures” i.e. about 15 mSv/y in modern units.
Building on this, and also responding to new
information on radiation eﬀects, the 1958 Recommendationsof ICRP（ICRP, 1959）expanded considerably on its
recommendations for protection beyond occupational
exposure. Explicit mention was made of “members of the
public living in the neighbourhood of controlled areas”, “thepopulation at large”, and “medical exposure”.

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In addition, 1958 saw an important reduction in dose limits, to 50 mSv/y for occupational exposures,and 5 mSv/y for the population at large, with the caution that “permissible doses ... are maximum values; theCommission recommends that all doses be kept as low as practicable, and that any unnecessary exposure be
avoided”.

69There were considerable additional developments
over decades that followed, both in terms of the knowledgeof radiation eﬀects, and the sophistication of the system ofradiological protection. The 1977 Recommendations（ICRP,
1977）introduced the basics of the system of protection thatis still used today. The 1990 Recommendations（ICRP, 1991）
set the dose limits that are now used: 20 mSv/y averaged
over 5 years and no single year over 50 mSv foroccupational exposure; and, 1 mSv/y for public exposure.
Only the recommended occupational dose limit for the lensof the eye has changed since then（ICRP, 2012）.

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The work of RERF continues to be the gold standard in understanding the eﬀects of radiation onhumans. Their work continues, following the remaining population of atomic bomb survivors, and using more
and more sophisticated methods to analyse the results.
Cancer remains the main long-term eﬀect of concern related to radiation exposure. Despite concerns
raised in the 1950s primarily due to some animal studies, direct evidence of genetic eﬀects in humans has notbeen observed. However, new evidence, from the atomic bomb survivor studies and others, is pointing towards
the potential for cardiovascular and cerebrovascular diseases to be important even at low doses and dose rates.
More work is needed in this area to clarify the situation.
To this day, ICRP continues to be the leading international organization with respect to thedevelopment and maintenance of the system of radiological protection. ICRP has published nearly 150 reports
on all aspects of protection from ionizing radiation since 1977 in its dedicated journal, The Annals of the ICRP.
Its recommendations form the basis of radiological protection standards, legislation, guidance, and practiceworld-wide.
In addition to closely following scientiﬁc developments, in recent years, ICRP has also put moreemphasis on clarifying the ethical basis of radiological protection. Today, ICRP Task Group 94 is charged withconsolidating the ethical basis of the recommendations of ICRP to improve the understanding of the system,and to provide a basis for communication on radiation risk and its perception.
This eﬀort has led to some preliminary results, using a core set of ethical values to describe the ethicalbasis of the system:•Beneﬁcence / Non-maleﬁcence: Do good and avoid doing harm;•Prudence: Recognize and follow the most sensible course of action, especially in the face of
uncertainty, avoiding unwarranted risk;•Justice: Fair sharing of beneﬁts and risks; and,
•Dignity: Treatment of individuals with unconditional respect, and having the capacity to deliberate,
decide, and act without constraint.
This early result has been developed in collaboration with a wide variety of people including
radiological protection experts, ethicists, and other individuals with a direct interest in the ethics of radiologicalprotection such as some residents of Fukushima. The work will be reﬁned further in the coming year or two
through broader consultations.
However, the concept of dignity in radiological protection could, and perhaps should, be extended not
only to those being protected, but also to those whose experiences have contributed to the system ofprotection.
We cannot forget the people behind the numbers: those whose exposures have helped progress thescience of radiation eﬀects. The survivors of the bombings in Hiroshima and Nagasaki deserve our respect andgratitude, and to be treated with dignity. This is also true for others whose exposures have contributed to thesum of human knowledge: those exposed due to accidents such as Chernobyl and Fukushima, and those70

routinely exposed as medical patients and at work.
Out of respect, and for the overall beneﬁt of society, scientists and radiological protection professionals
have a duty to make the best use of this information to contribute to the protection of people from detrimental
eﬀects of radiation exposure world-wide. Similarly, there is a duty to treat those eﬀected with dignity.
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