Ethical and societal aspects of radiological protection for offspring and next generations

Abstract

Purpose

Over the last decade or so, ethical and societal aspects of radiological protection have received increasing attention. This is also reflected in the publications of the International Commission on Radiological Protection (ICRP). The current paper aims at identifying relevant ethical and societal topics which should receive attention in the context of radiological protection for offspring and next generations.

Materials and Methods

We present a non-comprehensive review of the subject, based on presentation made at an ICRP workshop in Budapest in 2022. We first discuss the ethical values promoted by ICRP, and the application of these values in cases of (potential) pre-conceptual and prenatal radiation exposures. We then consider experience gained after the Fukushima accident indicating particular societal concerns about the health effects of such exposures.

Results and Conclusions

Beneficence/non-maleficence, prudence, justice and dignity, the “core values” of the system of radiological protection have special roles to play when heritable and/or in utero effects are to be considered. Prudence, in particular, must be taken account of in view of the fact that solid scientific data in humans are largely lacking in this area, and it is necessary to rely on insights from animal experiments as well as theoretical considerations. As regards societal considerations, the perception of risk among (potentially) affected populations needs to be taken seriously. Accountability, transparency, and inclusivity, the “procedural values” promoted by ICRP for the practical implementation of the system of radiological protection play a central role in overcoming skepticism and creating trust. Stakeholder involvement should emphasize cooperation and dialogue, which allows for the joint evaluation of an exposure situation by experts and affected people.

Keywords:

• Ethics
• society
• radiation protection
• ICRP
• heritable
• in utero

1. Introduction

There is no question that standards of radiological protection have to be based on solid scientific evidence and sound technological expertise, but over the last few decades an awareness has also grown of the importance of related ethical and societal aspects. The International Commission on Radiological Protection (ICRP) has taken account of this by reviewing “The ethical foundations of the system of radiological protection” in its Publication 138 (ICRP 2018), the first to be fully dedicated to the topic. Ethics was also addressed in a few earlier documents of the Commission, such as Publication 91 on “… the impact of ionising radiation on non-human species” (ICRP 2003b), or Publication 122 on “… geological disposal of long-lived solid radioactive waste” (ICRP 2013), and a new publication is underway discussing “Ethics in radiological protection for medical diagnosis and treatment” (work in progress, ICRP Task Group 109). Further, ethical considerations will certainly play an important role in the upcoming recommendations on “Reasonableness and tolerability in the system of radiological protection” (work in progress, ICRP Task Group 114) and “Application of the principle of justification “(work in progress, ICRP Task Group 124).

As for the societal aspects, they have been part of the Commission’s recommendations for a very long time, being associated with the implementation of the principle of optimization taking into account “economic and social factors” (ICRP 1977). It is however interesting to note that the vocabulary has changed slightly and that the term “societal” has come to replace “social” in the latest general recommendations of the Commission (ICRP 2007). This development certainly reflects the efforts to increasingly address the concerns of society, especially in connection with the introduction of stakeholder involvement in the optimization process.

Although no special publication has been dedicated to the topic, a recent paper by members of the Commission on “Keeping the ICRP recommendations fit for purpose” acknowledges that “there have been many requests for more guidance on how to balance societal, economic, and other factors in the optimization of protection and safety, requiring input from many fields of expertise“, and that “ICRP is aware of various efforts that may help to make the balancing of factors more transparent“. Publication 101b (ICRP 2006) is mentioned as an example of a document which includes societal aspects of radiological protection, and it is implied that these aspects will also be addressed in upcoming recommendations.

Ethical and societal perspectives are also of great relevance for the assessment of pre-conceptual and prenatal radiation exposure. The importance attached to children’s health and well-being in all societies around the world, and the fact that people’s concerns relate to their immediate offspring as well as future generations, demands special attention for the topic. The ICRP Workshop on “The effects of ionising radiation exposure in offspring and next generations” held on 31 May − 2 June 2022 in Budapest, Hungary, considered pertinent questions in one of its four breakout groups (Group D) on the “Potential impact (of insights into pre-conceptual and prenatal radiation effects) on the System of Radiological Protection”. This article is largely based on presentations made during that workshop and the discussions that followed.

2. Basic ethical considerations

According to Publication 138 (ICRP 2018), the system of radiological protection has been developed taking into account the following four “core values”: beneficence/non-maleficence, prudence, justice and human dignity. To these are added “procedural values“, which come into play for the practical application of the system: accountability, transparency and inclusiveness. Each of these values will be considered below as it applies to the radiation protection of offspring and future generations. This is not to say, of course, that other values already discussed in the literature before and after ICRP 138 are irrelevant (Malone and Zölzer 2016; Malone et al. 2019; Bochud et al. 2020; WHO 2022), but in the discussion which follows, attention is focused on what ICRP has proposed as the ethical pillars of the system.

It should perhaps be noted at this point that all the above mentioned values have prima facie validity, i.e., they all apply at first sight. However, in specific situations there may be conflicting values, in which case they need to be balanced against each other, i.e., their relative importance for the situation at hand must be determined. That is not always easy, may require lengthy discussions, and will possibly lead to somewhat different decisions depending on a community’s or individual’s health status, culture, religion, and philosophical background.

2.1. Beneficence and non-maleficence

In biomedical ethics (Beauchamp and Childress, 1979-2019), these are mentioned as two independent principles in order to emphasize that each applies for itself. The Hippocratic Oath already refers to both, when the physician-to-be swears “to help the sick” and at the same time to “abstain from all intentional wrong-doing and harm” (Hippocrates of Cos 1923). But it is generally understood that it is not always possible to keep both promises: in order to heal, one has to sometimes hurt, for instance in surgery or in radiotherapy, where the aim cannot be achieved without some damage to healthy tissues. Here, in particular, a discussion of the right balance is needed, a weighing of relative (potential) benefit and (potential) harm, both in the short- and long-term. In radiological protection, this is covered by the principle of justification, which states that “Any decision that alters the radiation exposure situation should do more good than harm “(ICRP 2007).

Certain diagnostic procedures in medicine, for example, may be expected to provide more precise and complete information about a medical problem, but at least in individuals who may go on to have children at some stage in the future, the diagnostic advantage has to be weighed against possible genetic effects. In the case of a pregnant patient, or a potentially pregnant patient, the risks of early embryonic death, malformation, severe mental retardation, and cancer induction in the unborn child have to be considered, taking into account that the possible effects will depend on the doses involved. Similar considerations apply where a pregnant woman is diagnosed with cancer and immediate radiotherapy is required. These problems have been acknowledged by ICRP in Publication 84 on “Pregnancy and Medical Irradiation”:

Compared to routine medical radiation practices, medical exposure of a pregnant patient has additional ethical considerations. In evaluation of risks and benefits from medical exposures during pregnancy, at least two individuals need to be considered. The mother may receive direct benefit while the fetus may be exposed without direct benefit. On the other hand, if the mother’s medical problem is life threatening, medical irradiation of the mother may lead to her survival, which obviously directly benefits the fetus.

Apart from such cases in clinical care, a balancing of benefit and harm needs to be carried out in many other planned exposure situations. For instance, employing woman of childbearing age in premises where they could potentially be exposed to radiation, may require such considerations. The ICRP recommends a limit of 1 mSv for the remaining time of the pregnancy after it has been declared and this is also a requirement within the Basic Safety Standards of the European Union (2013/59/EURATOM). In Japan, the limit for total exposure during pregnancy is 2 mSv. In addition, the Japanese Radiation Protection Act prescribes a limit for women of reproductive age of 5 mSv per 3 months, while the German Radiation Act sets the limit for woman of reproductive age to 2 mSv per month organ equivalent dose to the uterus. The scientific rationale of these limits is currently under review. They are mentioned here as examples for beneficence vs. non-maleficence considerations.

The ICRP does not go into details when it recommends a dose limit for pregnant women, but provides some general consideration in Publication 60 (1990):

It is the Commission’s policy that the methods of protection at work for women who may be pregnant should provide a standard of protection for any conceptus broadly comparable with that provided for members of the general public. The Commission considers that its policy will be adequately applied if the mother is exposed, prior to a declaration of pregnancy, under the system of protection recommended by the Commission, including the recommended dose limits for occupational exposure. On this basis the Commission recommends no special occupational dose limit for women in general.

Aviation is also a domain where concerns may arise. The Commission in Publication 132 (ICRP 2016) recommends that “pregnant frequent flyers… adjust their flight frequency to reduce the exposure of their embryo/fetus to cosmic radiation based on self-assessment of exposure “and “for pregnant aircraft crew, airline management should have provisions in place to adjust duties… consistent with the Commission’s recommendations “which, as in the case of other workers, means that the additional dose to an embryo/fetus should not exceed 1 mSv “during the remainder of the pregnancy after its notification”.

Another area in which these two values may be put against each other is emergency management. Evacuation of pregnant woman from a contaminated area may avoid exposure of unborn children to radiation, but it brings with it other risks to health, both physical and mental, and it also requires financial and personnel resources which might be needed elsewhere (Oughton et al. 2021).

To further complicate the matter, clinical and public health views of beneficence might differ. The former deals with the care for individuals whereas the latter with that for the whole community. According to the “Public Health Code of Ethics” developed by the American Public Health Association, “public health programs and policies should be implemented in a manner that most enhances the physical and social environment… in a way that respects the rights of individuals in the community” (Thomas et al. 2002). In spite of the tension that may exist between the community-based idea of public well-being versus the more individual-based notion of human rights, it is clear that both have to be considered together, and the codes for clinical and public health ethics are moving closer and closer (Thomas and Miller 2017; Unger et al. 2020).

The examples mentioned are instructive, not least because they show one of the main challenges of balancing values: the incommensurability, or lack of a common measure, of different criteria. How to weigh the health of a mother against the health of an unborn child? How to weigh the health of an employee against the business interests of the employer? How to weigh the health of potential evacuees against the other problems which have to be dealt with in an emergency situation? And how to weigh individual interests against those of the community? If (radiation-induced) health effects are compared with (other) health effects, it may be possible to calculate potential loss of life (quality adjusted life years – QALY, disability adjusted life years – DALY), but decision making will be much more difficult if health effects stand against economic and societal advantages/disadvantages, requiring the development and application of an appropriate metrics. In the past, the ICRP promoted cost-benefit analysis as a decision-making tool, assigning a monetary value to all benefits and harms to be expected from a particular radiation exposure. It was later realized, however, that the monetization of health effects is fraught with problems, and ICRP has more recently suggested that qualitative approaches should be developed which support decision-making in cases where incommensurable criteria are at stake (Zölzer and Stuck 2019).

2.2. Prudence

Prudence is not part of the “principles of biomedical ethics”, even if Beauchamp and Childress (1979-2019) point out that sometimes “beneficence can (at best) be implemented through precautionary measures”. For certain diagnostic and therapeutic procedures neither the potential benefits, nor the risks may be very well known, so prudent assumptions have to be made. In many clinical situations, of course, this is not the prime consideration. With radiation exposure at high doses, for instance, benefits and harms are relatively clear (after all, tissue reactions used to be called “deterministic effects” because they are relatively well foreseeable). At low doses, however, there are considerable uncertainties. This is why ICRP in the late 1950s adopted the linear-non-threshold (LNT) model (ICRP 1959). It was noted by the Commission that the assumption of the absence of a threshold for stochastic effects should not be “universally accepted as biological truth, but rather, because we do not actually know what level of risk is associated with very-low-dose exposure, it is considered to be a prudent judgment for public policy aimed at avoiding unnecessary risk from exposure” (ICRP 2007).

In its Publication 138 (ICRP 2018), the Commission denotes as prudence “the ability to make informed and carefully considered choices without full knowledge of the scope and consequences of actions.” This echoes, to some extent, the most widely used wording of the Precautionary Principle stating that “When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.” (Wingspread 1998). This principle has also been popularized by the Rio Conference on Environment and Development (UNCED 1992) and has been much debated in connection with the ethics of decision-making in recent years, including the radiological protection domain (Streffer et al. 2004). Those who are in favor of the principle see it as a breakthrough in the management of uncertain risk. For opponents, the principle is mainly a disincentive to entrepreneurship. It has been argued that this debate, often obscured by discussion of particular academic and legal aspects, does not add much to the practical experience of over half a century of gathering knowledge and making reasonable judgments when implementing the optimization principle (Lochard 2016a). This seems to be one of the reasons why the ICRP finally preferred the term “prudence” to that of “precaution”. It certainly better expresses the need for reasonableness. That is to say, prudence is understood as precaution, tempered with due consideration of economic and societal factors. In particular, it implies some solidarity with the vulnerable and marginalized.

Direct epidemiological evidence for cancer induction by radiation is (currently) not available down to a few mSv. For pre-conceptual and prenatal effects, it is largely lacking altogether. The latest analysis of data from Hiroshima and Nagasaki survivors suggests malformations due to parental exposure, but most results are still not statistically significant (Yamada et al. 2021). Malformations due to in utero exposure during organogenesis have not been reported. The only statistically significant human data are those for Severe Mental Retardation due to in utero exposure during brain development (Otake et al. 1996) and those for a reduction of the intelligence quotient (IQ) in the first years of life (ICRP 2003a; Liutsko et al. 2018; Liutsko 2023, this issue of IJRB).

For a large part, risk assessments for effects of either pre-conceptual or prenatal exposures therefore have to be based on animal data (for a discussion see some of the other contributions to this special issue of IJRB). Here it seems important to note that making use of such animal data for purposes of radiological protection in itself relies on the concept of prudence, or precaution. There is some “threat of harm” because effects of pre-conceptual and prenatal radiation exposure have been shown in animals, but it is not known whether the same doses are effective in humans as in animals, and there is not even clarity about the same mechanism being at work.

Even where human data are available, e.g. with respect to radiation effects on brain development, prudence must be invoked. The data as presented in the relevant publications seem to indicate a threshold dose for the induction of severe mental retardation of about 200 mGy, but data on a reduction of the IQ of individuals exposed in utero do not suggest a dose threshold at all (ICRP 2003a). One could therefore argue that it is actually not prudent to assume that doses below 200 mGy during fetal development are safe with respect to fetal brain development.

Because of the uncertainties mentioned, the adoption of duty of care practices vis-à-vis pregnant women and women of childbearing age is particularly important. This must result in the systematic implementation of principles such as 'the right to know’ and 'informed consent’ (ICRP 2000), which will be discussed below. Closely related to duty of care considerations is the need for programs to monitor populations at risk (such as those residing in territories affected by radiation resulting from past accidents or activities), as well as for further research aiming at a reduction of the remaining uncertainties.

2.3. Justice

In the context of radiation protection, justice is primarily discussed as distributive justice, i.e., in relation to the benefits and risks affecting different people or populations, or the inequalities inherent in the distribution of doses unavoidably associated with all exposure situations (ICRP 2018). An example regarding benefits and risks is that, as noted above, of the possible conflict of interest between the mother and the unborn child. This is addressed in Publication 84 on “Pregnancy and Medical Irradiation”:

In situations involving a patient or worker, who is known or suspected to be pregnant, the situation includes not only the risk to the mother but to the foetus as well. In this, setting, the mother has a role-related responsibility to care for her unborn child as well as to make decisions about herself.

It is the role of the various dose criteria proposed by the radiological protection system, namely the reference levels, the dose constraints and the dose limits, to ensure that the doses received by individuals in various exposure situations are not too divergent, so that nobody carries a disproportionally high risk (ICRP 2007).

A point that should be mentioned in this context is the general right of women to choose where they work and to be treated in the same way as their male counterparts. It is sometimes argued that the system does not respect that right, but is quite paternalistic, as ICRP recommends special dose limits to pregnant women, and (in some countries at least) special dose limits are in place for women of reproductive age, irrespective of their current or future intentions in relation to having children (see above).

In a broader sense, justice can be understood to encompass intergenerational equity, or sustainability, which means striving to „meet the needs of the present (generation) without compromising the ability of future generations to meet their own needs” (Brundtland Commission 1987). This concept was already reflected in the 1958 recommendations of the International Commission on Radiological Protection (ICRP 1959), where dose limitation is based on considerations of genetic effects:

Estimates by different national and international scientific bodies indicate that a per capita gonad dose of 6-10 rems (∼60-100 mSv) accumulated from conception to age 30 from all man-made sources, would impose a considerable burden on society due to genetic damage, but that this additional burden may be regarded as tolerable and justifiable in view of the benefits that may be expected to accrue from the expansion of the practical applications of ‘atomic energy‘… In view of these considerations the Commission suggests a limit of 5 rem (∼50 mSv) for the genetic dose…

This 1959 text obviously argues mainly along the lines of beneficence/non-maleficence (as well as prudence), but indirectly refers to intergenerational equity, because the „burden on society” would of course become apparent only in the future. We note that this argument is obviously community-based rather than individual-based.

The protection of future generations has been discussed in more recent publications of the ICRP as well. For example, a whole section of Publication 122 (ICRP 2013) on “Radiological Protection in Geological Disposal of Long-lived Solid Radioactive Waste” is dedicated to the topic. It refers to the “complexity of the situation: on one hand, it is not possible to envisage how society will be organized in the distant future, while on the other hand, the current generation has a duty of care to future generations.” Pre-conceptual and prenatal radiation effects are clearly implied here, although not mentioned explicitly.

2.4. Dignity

Dignity is an attribute of the human condition, which means that each individual deserves unconditional respect, whatever their age, sex, state of health, social condition, ethnic origin and/or religion. This is enshrined in the Universal Declaration of Human Rights, which states that: “All human beings are born free and equal in dignity and rights” (UN 1948).

It is widely agreed that human dignity is the basis of “respect for autonomy”, which means that people affected by radiation, for instance, should be decision-makers in their own case. In planned exposure situations, they should at least be asked for “informed consent” before being exposed. But even in existing exposure situations, and to the extent possible in emergency exposure situation, their voices need to be heard and taken account of. A planned exposure situation of a particular kind may occur in a hospital, where a patient arrives, say, after a car accident and is unconscious, but X-rays diagnostics are urgently required. There may be no time to verify the pregnancy status of the patient. Doctors in such cases will have to sideline considerations of dignity and proceed to act in the presumed best interest of the patient. This is an example of what was mentioned above as “balancing” different values, which all apply prima facie, while their relative importance varies from case to case. Medical professionals in general need training in order to be able to apply radiological protection principles and implement informed consent practices sensibly (Schieber et al. 2020).

Implemented with a view to transparency, accountability and inclusiveness, the radiological protection system indeed respects and promotes the autonomy of people confronted with radioactivity in their daily lives, whether at work, as a patient, or simply as citizens. Experience from Chernobyl and Fukushima has demonstrated that empowering affected people to understand the situation they are facing can help them to make informed decision to protect themselves and restore their dignity affected by the accidents (ICRP 2009; Lochard 2016b; ICRP 2020).

Whereas there seems to be cross-cultural consensus about the values discussed so far (Zölzer 2016), with perhaps some variation with respect to their relative importance, the question of the dignity of the unborn human, or more generally: the moral status of the embryo can be quite controversial (Zölzer 2005):

• Most Hindus and Christians believe that the soul appears in the body at conception and the embryo is therefore a human being worthy of protection, i.e. it has personal dignity.

• Most Jews and Muslims would argue it is “nothing but water “for at least the first 40 days, maybe even 120 days of pregnancy, which nevertheless does not make harming it completely unobjectionable.

• Most Buddhists would consider the unborn just another living being which is not to be harmed, whereas Confucians see social ties as the main sign of personhood, so that the unborn does not have an important moral status, although even in their opinion it should not be harmed unnecessarily.

These are generalizations, of course, and different denominations, or schools of thought within the religious communities mentioned may have different views. In addition, religiously unaffiliated people will find other kinds of considerations more convincing. The list above indicates the degree of disagreement which exists in this area.

It should also be noted that the status of the embryo is usually discussed in the context of abortion, cloning, and stem cell research. Arguments like the ones presented above have not, as far as we can see, yet played any role for radiological protection. However, as an international body, the ICRP might want to take them into consideration, especially in view of the fact that in spite of a strong tendency toward secularization in the Western world, religious views continue to exert influence on people’s value orientations globally. The wide-spread notion of the embryo as an entity that should not be subjected to harm if it can be avoided, might be relevant, for instance, to the above-mentioned discussion of exposure limits for women of reproductive age, which are there to protect the unrecognized fetus.

3. Societal considerations

3.1. A Brief historical perspective

Although it was in the late 1920s that Hermann Muller discovered radiation-induced mutations in fruit flies, which won him the Nobel Prize in Medicine 1946, the genetic effects of exposure to radiation did not attract much public attention until the bombings of Hiroshima and Nagasaki in August 1945. These tragic events were followed by several decades of nuclear weapons testing, and all this had a major impact on the perception of radiological risk (Amrenova et al. 2023, this issue of IJRB).

Nuclear-powered countries made considerable efforts to promote the peaceful use of nuclear energy and to prevent its military use (see, for example, the "Atoms for Peace" speech of US President Eisenhower addressed to the United Nations General Assembly in New York in 1953). Nevertheless, the fear of radiation effects, in particular of genetic effects of radiation, was mounting. Public pressure therefore led to the creation of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in 1955, followed by that of the International Atomic Energy Agency in 1956 which eventually paved the way for the Partial Nuclear Test Ban Treaty banning the testing of nuclear weapons in the atmosphere, in outer space and under water in 1963 (UN, 1963) and the Comprehensive Nuclear-Test-Ban Treaty in 1996 (UN 1996; CTBTO 2021).

Despite these various governmental initiatives, the question of genetic effects remained topical in the minds of the general public, and the accidents at Chernobyl in 1986 and then Fukushima in 2011 showed that this has not changed much over the decades. One of the negative images provoked by the mere mention of radiation is often that of birth defects. This rapid emotional reaction, against which the information processes available to experts are rather powerless (Kahneman 2012), fuels the concerns of people confronted with the presence of radioactivity in their immediate environment, as is the case after nuclear accidents, and can become an additional stress factor for them (Girard and Hériard Dubreuil 1996; Bromet 2014).

It was in the troubled post-World War II context that the ICRP began to consider genetic effects. The latter had already been mentioned in the 1950 Recommendations of the Commission (ICRP 1950). Soon after, in 1952, an informal meeting was held in Stockholm within the framework of a conference organized by the International Joint Committee on Radiobiology to specifically discuss the genetic effects of radiation (mentioned in: NCRP 1957). Later, noting the lack of scientific consensus concerning these effects, the Commission considered in 1956 that it was “prudent to limit the dose of radiation received by gametes from all sources in addition to the natural background” (ICRP 1958). As a consequence, genetic risk became one of the key issues for the recommendations of the ICRP in its Publication 1 in 1959, which proposed reduced exposure limits which were set to “a level at which the assumed risk is deemed to be acceptable to the individual and to society in view of the benefits derived from such activities. “The potential societal impacts and the challenge for future generations were highlighted and from then on remained a permanent concern of the Commission (Amrenova et al. this issue of IJRB).

However, due to limited scientific knowledge on these effects, compared to radiation-induced cancer, addressing heritable effects has always been and still is a real challenge for the radiological protection system. The situation is somewhat better regarding radiation effects during pregnancy, but great uncertainties remain here too. Therefore, taking into account societal concerns regarding pre-conceptual and prenatal radiation exposure is of even greater importance than for radiological protection in general. ICRP Publication 103 continues to consider heritable effects based on prudence, i.e., on conservative estimates derived from animal research. The lack of solid epidemiological evidence from human studies persists (Amrenova et al. 2023, this issue of IJRB). It is however interesting to mention that there has been an evolution in the quantification of these effects: while in 1990 heritable effects thought to represent about 20% of the total detriment, they were only estimated as 2 to 4% in 2007 (see Figure 1).

Figure 1. Detriment-adjusted nominal risk coefficients (%/Sv) for stochastic effects after exposure to radiation at low dose rate.

This situation highlights the uncertainties associated with the evaluation of heritable effects for low, and even moderate level exposures. However, by integrating these effects into the radiation health detriment, ICRP is recognizing the existing concern about heritable effects. By continuing to apply the ethical value of prudence, the Commission also makes a judgment about the societal consequences for the exposed populations which goes beyond purely scientific evidence.

3.2. Concerns about hereditary and in utero effects after the Fukushima accident

Soon after the Fukushima nuclear accident in 2011, Fukushima Medical University (FMU) launched a prefecture-wide epidemiological study of the consequences of the disaster, the Fukushima Health Management Survey (FHMS). Firstly, in a sub-study targeting mothers, it was reported that one in four mothers who delivered within 1 year after the disaster showed a depression tendency, and their common concerns were radiation effects on fetuses and infants (Goto et al. 2015). Secondly, a temporal decline in pregnancy intention was reported, especially among first-time mothers, which was associated with concern about radiation contamination of breast milk (Goto et al. 2019). Follow-up surveys of mothers reported that although no obvious effects on pregnancy outcomes had been reported, over 60% of mothers continued to worry about their children’s health status in general and over 30% about hereditary effects (influences on offspring of their children, i.e., the following generations) even at the time that their children were 4 years old (Ishii et al. 2022). It is also noteworthy that 41% of mothers who gave birth in the disaster year, disclosed having feelings of anxiety associated with the stigma of radiation exposure 4 years post-disaster (Ito et al. 2018). Moreover, such concern about radiation was associated with young women’s attitudes toward future childbirth and parenting (Ito et al. 2018). Another sub-study of the FHMS among residents of coastal areas in Fukushima revealed that 36% of respondents in 2019 answered that hereditary effects were likely to occur (Maeda et al. 2022). Recent studies performed in the Hamadori region around the Fukushima nuclear plant revealed that possible genetic effects are still perceived as very important more than 10 years after the accident (Liu et al. 2022) and this perception is a strong obstacle against returning to their place of residence for those who were evacuated at the time of the accident (Matsunaga et al. 2019).

It is noteworthy that similar to the stigma experienced by A-bomb survivors, those affected by the Fukushima disaster found themselves confronted with rejection and prejudice: “Some people mistakenly perceive that women exposed to radiation should not be allowed to marry or reproduce, and thus many evacuees hide the fact that they were residents of Fukushima after moving to other prefectures” (Oe et al. 2021).

3.3. Considerations about maintaining biological diversity and the conservation of species

Heritable radiation effects in animals and plants can have far reaching consequences for ecosystems. In Publication 103 (ICRP 2007), radiological protection of the environment is defined as “preventing or reducing the frequency of deleterious radiation effects to a level where they would have a negligible impact on the maintenance of biological diversity, the conservation of species, or the health and status of natural habitats, communities and ecosystems” (§30). Thus, heritable effects are implicitly included in the current assessment of the radiological impacts on the environment. The issue will presumably be further addressed by the ICRP in the context of “ecosystem services” (Daily 1997), a concept currently under review for its use in radiological protection (ICRP TG 125). It looks at direct and indirect contributions of ecosystems to human well-being. In doing so, it addresses a wide variety of aspects, including cultural ones, so that it clearly constitutes a break from money-based valuation. Nevertheless, it is still focused on human well-being, because it considers “services” rendered by the environment to humans. We note that ICRP in Publication 91 (ICRP 2003) has gone beyond that, mentioning “preservation” as a guiding principle which “recognises the worth of nature… independent of human needs”. In any case, it is certainly in the interest of both humans and non-humans to assess the possible impact of new scientific developments regarding heritable effects in the environment, and there is a need to reinforce related ethical and societal considerations. The ecosystems services approach is also thought to provide an opportunity to address the protection of the environment in the broader perspective of the sustainable development goals, as defined by United Nations (UN 2015).

3.4. Organization of long-term surveillance

Given the continued existence of strong concerns among the affected populations about the possible occurrence of heritable effects in their children and next generations after a nuclear accident, it is very important to ensure the long-term health surveillance of these populations. In this regard, the SHAMISEN recommendations (Ohba et al. 2021; Liutsko et al. 2021; Oughton et al. 2018) emphasize some needs and challenges associated with long-term health surveillance following a nuclear accident that can be directly applied for the follow-up of affected populations with regard to heritable effects:

• “Encourage a health surveillance strategy that targets the overall well-being of populations” … taking account of the concern of affected populations (Recommendation 3)

• “Clarify objectives and expected results of epidemiological studies, justifying the design and methods and explaining the limitations.” (Recommendation 26)

• “Ensure long-term sustainability of follow-up of populations at risk for comprehensive ascertainment of potential health consequences of nuclear accident.” (Recommendation 27)

These recommendations which emphasize the overall well-being of populations implicitly recognize the strong interaction between radiological protection and the rehabilitation of living and working conditions after a nuclear accident (Schneider and Lochard 2021). The lasting presence of radioactivity in the environment after a nuclear accident indeed affects the well-being of individuals, but also the quality of living together of the affected people (Lochard 2021; Maître et al. 2021). From this perspective, the concept of well-being, but also that of the quality of living together, and their importance in relation to concerns about the possible occurrence of hereditable effects in their children and next generations, should be further developed in cooperation with the populations concerned. The opening of dialogues between lay people and experts, addressing both the scientific aspects and the societal questions around hereditary effects, would certainly be likely to better identify the concerns at stake. Similar dialogues could also be envisaged concerning surveillance. Such dialogues could facilitate communication about radiation risk but also favor the development of practical radiological protection culture and be an incentive for implementing the co-expertise process between affected people, professionals, authorities and experts recommended by ICRP (ICRP 2020; Thu Zar et al. 2022). Dialogue has been demonstrated to be crucial in addressing difficult issues related to the recovery process after nuclear accidents and could potentially help to promote better understanding and response to the issue of heritable effects and possible effects for offspring and next generations.

3.5. Legal issues and probability of causation

Introducing heritable effects in the radiological detriment implies considering legal issues of possible compensation schemes. In this perspective, the first issue to be addressed is to establish a link between exposures and the occurrence of heritable effects within a certain population group. On this basis, it is then necessary to adopt dedicated rules for determining the “probability of causation”. Due to the multigenerational impacts, the rules are not simple to establish: which generation is impacted and what is the objective of the potential compensation scheme for hereditary effects?

The consequences in terms of responsibilities of employers, decision-makers and authorities will have to be discussed for occupational, medical and public radiation exposures. In view of the need for stakeholder involvement, mechanisms will need to be established to discuss possible compensation schemes with (representatives of) affected groups. Due to the possible long-term impacts, the issue of transfer of responsibility will also have to be addressed.

4. Concluding remarks: consequences for radiological protection recommendations

In 2021, ICRP launched a review of the current system of radiological protection, with a renewed focus on both changes to the science underpinning the system as well as how wider society engages with the system. The aims and scope of the review are introduced in Clement et al. (2021), which also makes the key point that “the better the system is understood, the more effectively it can be applied”. Furthermore, ICRP is considering whether a more explicit incorporation of ethics might be beneficial in certain areas, as well as how to further improve communication and stakeholder involvement (Clement et al. 2021).

A number of new areas for consideration are introduced in this paper, while others have been discussed in recent publications by members of the ICRP, including whether it might be possible to define differently detriment for males and females, and/or for people of different ages, and whether the increasing understanding of inter-individual variation in the response to radiation might possibly also be taken into account (Applegate et al. 2020; Clement et al. 2021; Laurier et al. 2021). Newer techniques and technologies to underpin radiological protection processes have also been proposed, for example artificial intelligence, although a number of practicalities associated with this still need to be defined (Larson et al. 2021). All this would mark a steep change in how the system works, and detailed considerations of the societal and ethical impact it would have is certainly warranted. The discussion so far, however, has remained at a fairly general level, and has not addressed our particular area of concern, the radiological protection in relation to pre-natal or pre-conceptual exposure. It may be too early to do so, but the issue needs to be kept in mind.

What we have presented above are some preliminary considerations on the ethical and societal aspects of radiological protection for offspring and next generations. We do not claim to have given a comprehensive literature overview, although it is probably fair to say that studies of the (potential) pre-conceptual and prenatal radiation effects have generally not addressed these aspects.

Looking at the principles of radiological protection, we state that in terms of justification, there is a particular need to assess the potential harm associated with heritable effects in relation to the benefit accruing from certain actions or activities. In particular, there is a need for additional criteria to be integrated with the concept of well-being in the calculation of the radiological detriment. For optimization, further consideration is needed in relation to the acceptable level of risk, which is reached after “reasonable” efforts have been made to reduce exposures. What is “reasonable” must be discussed “taking into account economic and societal factors”, which makes it impossible to decide at the drawing board, but needs stakeholder involvement. Similar considerations apply when it comes to dose limitation. What is “tolerable” for workers, or for the general public, has to take due account of the concerns and needs of the individuals affected. As Clement and colleagues point out, there is an ethical obligation to protect all people under all circumstances, but also to communicate with them in an adequate way (Clement et al. 2021). This can be of key importance, for example, in the discussions around integration of the detriment from heritable effects to underpin any new dose limits.

The perception of risk is and will remain a key aspect related to ethical and societal considerations within the review of the system, and as such, ICRP and its stakeholders have a key task ahead in terms of helping to ensure that ionizing radiation and the associated risks are better understood. This requires accountability and transparency, as well as inclusivity, the main “procedural values” promoted by ICRP for the practical implementation of the system of radiological protection (ICRP 2018). Experience shows that they help overcome skepticism and create trust. Stakeholder involvement should emphasize cooperation and dialogue, which allow for the joint evaluation of an exposure situation by experts and affected people (“co-expertise process”: Lochard et al. 2019; Lochard 2021). This would certainly be beneficial with respect to concerns about pre-conceptional and pre-natal effects as well. Learning from recent experience with COVID-19 could be helpful here as well, for example to gain a better understanding of the above-mentioned economic and societal factors, sustainable development, and the wider concept of well-being (Laurier et al. 2021).

The paper of Clement and colleagues concludes with the statement that “it is important to ensure that the best elements of the system (of radiological protection) remain, and those areas that need to be refined benefit from extensive collaboration. The system must stay true to the best scientific knowledge and robust ethical principles, while remaining practical to implement.” (Clement et al. 2021). Such a process is not simple, and will require greater attention to stakeholder engagement and communication, which should be incorporated into all of the work of the committees and individual task groups. In this paper, we have tried to identify relevant ethical and societal aspects of radiological protection for offspring and next generations, but they have just begun to be addressed in public discourse. If ICRP can ensure that this process continues and input from all stakeholders underpins the review process, then the revised system will truly be fit for purpose.

Declaration of interest

The authors declare no conflict of interest.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.

Notes on contributors

F. Zölzer

F. Zölzer, DSc, is a Professor of Environmental Sciences at the Faculty of Health and Social Sciences of the University of South Bohemia in České Budějovice, Czech Republic. He has worked in different areas of biophysics, radiation biology and environmental health, lately focusing on related ethical questions. He is a member of ICRP Committee 4 and Task Groups 109 and 123.

T. Schneider

T. Schneider, PhD, is Director of the Nuclear Protection Evaluation Centre (CEPN) in France. He is a member of the International Commission on Radiological Protection (ICRP) and chair of its Committee 4. A health economist by training, he is involved in research related to risk-assessment and risk-management of radiological risks, including societal and ethical issues.

E. Ainsbury

E. Ainsbury, PhD, is a radiological protection scientist who leads the Radiation Effects Department at the UK Health Security Agency Radiation, Chemical and Environmental Hazards Division. She is a member of ICRP Committee 1 and Task Groups 118 and 123.

A. Goto

A. Goto is Professor of Health Information and Epidemiology at Fukushima Medical University (FMU), Center for Integrated Sciences and Humanities. She also serves as Professor of International Community Health at the Graduate School of Medicine and Deputy Chief of the Fukushima Health Management Survey (Pregnancy and Birth Survey) at FMU.

L. Liutsko

L. Liutsko, PhD, is currently working at the Catalonian Institute of Health (ICS) and IDIAP Jordi Gol (affiliated to ICS). Previously she was a post-doc and co-principal investigator in the Radiation Programmm of ISGlobal, Barcelona, Spain. She is a member-mentee of ICRP Task Group 121.

G. O’Reilly

G. O'Reilly, PhD, is the Chief Physicist in St. James's Hospital, Dublin. She has been actively involved in the development of radiation safety legislation and guidance for over 20 years, is a member of the Article 31 Group of Experts, advising the European Commission on radiation safety and chairs the Medical Exposures Working Party, a sub-committee to that group.

J. Lochard

J. Lochard is a Professor at Nagasaki University, Japan, and Emeritus member of the International Commission on Radiological Protection (ICRP). An economist by training, he is specializing in the assessment and management of radiation risks. He has 30 years of experience in managing the recovery phases of the Chernobyl and Fukushima accidents.