System Of Radiological Protection Research Articles

A Revised System of Radiological Protection Is Needed.

The system of radiological protection has been based on linear no-threshold theory and related dose-response models for health detriment (in part related to cancer induction) by ionizing radiation exposure for almost 70 y. The indicated system unintentionally promotes radiation phobia, which has harmed many in relationship to the Fukushima nuclear accident evacuations and led to some abortions following the Chernobyl nuclear accident. Linear no-threshold model users (mainly epidemiologists) imply that they can reliably assess the cancer excess relative risk (likely none) associated with tens or hundreds of nanogray (nGy) radiation doses to an organ (e.g., bone marrow); for 1,000 nGy, the excess relative risk is 1,000 times larger than that for 1 nGy. They are currently permitted this unscientific view (ignoring evolution-related natural defenses) because of the misinforming procedures used in data analyses of which many radiation experts are not aware. One such procedure is the intentional and unscientific vanishing of the excess relative risk uncertainty as radiation dose decreases toward assigned dose zero (for natural background radiation exposure). The main focus of this forum article is on correcting the serious error of discarding risk uncertainty and the impact of the correction. The result is that the last defense of the current system of radiological protection relying on linear no-threshold theory (i.e., epidemiologic studies implied findings of harm from very low doses) goes away. A revised system is therefore needed.

Science-informed Policy Making for Protecting People and the Environment from Radiation.

The process to arrive at the radiation protection practices of today to protect workers, patients, and the public, including sensitive populations, has been a long and deliberative one. This paper presents an overview of the US Environmental Protection Agency's (US EPA) responsibility in protecting human health and the environment from unnecessary exposure to radiation. The origins of this responsibility can be traced back to early efforts, a century ago, to protect workers from x rays and radium. The system of radiation protection we employ today is robust and informed by the latest scientific consensus. It has helped reduce or eliminate unnecessary exposures to workers, patients, and the public while enabling the safe and beneficial uses of radiation and radioactive material in diverse areas such as energy, medicine, research, and space exploration. Periodic reviews and analyses of research on health effects of radiation by scientific bodies such as the National Academy of Sciences, National Council on Radiation Protection and Measurements, United Nations Scientific Committee on the Effects of Atomic Radiation, and the International Commission on Radiological Protection continue to inform radiation protection practices while new scientific information is gathered. As a public health agency, US EPA is keenly interested in research findings that can better elucidate the effects of exposure to low doses and low dose rates of radiation as applicable to protection of diverse populations from various sources of exposure. Professional organizations such as the Health Physics Society can provide radiation protection practitioners with continuing education programs on the state of the science and describe the key underpinnings of the system of radiological protection. Such efforts will help equip and prepare radiation protection professionals to more effectively communicate radiation health information with their stakeholders.

The ICRP and Its System of Radiological Protection

The ICRP and Its System of Radiological Protection

The Review of the ICRP System of Radiological Protection – practical feedback from members of the Australasian Radiation Protection Society

The Review of the ICRP System of Radiological Protection – practical feedback from members of the Australasian Radiation Protection Society

Developing the system of radiological protection to enhance its contribution to sustainable development

Developing the system of radiological protection to enhance its contribution to sustainable development

Future application of the ICRP system of radiological protection: views from UK professionals

Future application of the ICRP system of radiological protection: views from UK professionals

A European reflection on the revision of the System of Radiological Protection

A European reflection on the revision of the System of Radiological Protection

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

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.

ICRP workshop on the review and revision of the system of radiological protection: a focus on research priorities—feedback from the international community

In September 2022, the International Commission on Radiological Protection (ICRP) organised a workshop in Estoril, Portugal, on the ‘Review and Revision of the System of Radiological Protection: A Focus on Research Priorities’. The workshop, which was a side event of the European Radiation Protection Week, offered an opportunity to comment on a recent paper published by ICRP on areas of research to support the System of Radiological Protection. Altogether, about 150 individuals participated in the workshop. After the workshop, 16 of the 30 organisations in formal relations with ICRP provided written feedback. All participants and organisations followed ICRP’s view that further research in various areas will offer additional support in improving the System in the short, medium, and long term. In general, it was emphasised that any research should be outcome-focused in that it should improve protection of people or the environment. Many research topics mentioned by the participants were in line with those already identified by ICRP in the paper noted above. In addition, further ideas were expressed such as, for example, that lessons learned during the COVID-19 pandemic with regards to the non-radiological social, economic and environment impacts, should be analysed for their usefulness to enhance radiological protection, and that current protection strategies and application of current radiological protection principles may need to be adapted to military scenarios like those observed recently during the military conflict in the Ukraine or the detonation of a nuclear weapon. On a broader perspective, it was discussed how radiation research and radiological protection can contribute towards the Sustainable Development Goals announced by the United Nations in 2015. This paper summarises the views expressed during the workshop and the major take home messages identified by ICRP.

Preserving awareness for oversight – towards a resilient system at social level over centuries and millennia

Abstract. A resilient system at social level can be understood as one where society, at any point in time, takes responsibility for the repository system and acts to preserve the basic conditions for future generations to take responsibility and responsible decisions. The idea of societal responsibility is included in the notion of oversight, which was introduced by the Nuclear Energy Agency (NEA, 2011) and taken up by the International Commission on Radiological Protection (ICRP, 2013) for its guidance in the field of geological disposal of long-lived radioactive waste. In ICRP (2013) oversight is defined as “`watchful care' [that] refers to society `keeping an eye' on the technical [repository] system and the actual implementation of plans and decisions”. Oversight is a crucial concept in the ICRP's system of radiological protection, since “the level of oversight affects the capability to control the source, i.e. the waste and the repository, and to avoid or reduce potential exposures”. Three categories or “levels” of oversight are distinguished: “direct oversight”, when the waste is still easily accessible; “indirect oversight”, when sections or all of the repository is sealed, and the waste is no longer readily accessible; and “no oversight”, when there is no “watchful care” of the repository anymore. In a collective statement on the preservation of records, knowledge and memory (RK&M), the Radioactive Waste Management Committee (RWMC) of the NEA asserts the relevance of maintaining oversight over geological repositories for as long as practicable and states that there is no intention to abandon geological repositories, either before or after closure. The RWMC adds, “Preparing for future RK&M preservation is best addressed while waste management plans are being designed and implemented, and funding is available for this important component of long-term planning” (NEA, 2014); i.e. it is considered a relevant topic today. But while the RWMC has explicitly adopted the ICRP position on the relevance of maintaining oversight for as long as practicable, some other institutions do not mention oversight in their guidance, leaving the degree to which the guidance mentioned is approved of in the community somewhat open. While societal decisions on how to organise and exercise post-closure (i.e. “indirect”) oversight may be decades away, the discussion on preservation strategies for RK&M has indeed started, a first milestone being NEA (2019). At a recent conference in Dessel, Belgium, organised by the NEA's Expert Group on Awareness Preservation (EGAP), new ideas and aspects were presented. The discussions revealed, however, that participants felt that a “common vision” in the community (meaning both the international expert community and any interested parties) would be beneficial to help focus discussions on RK&M preservation strategies. At the panel session, it should be discussed – by international experts in the fields of awareness preservation and oversight and the plenary – whether the ICRP and NEA position on oversight could be the conceptual basis for such “vision building” in the community. If so, the original question of what needs to be done today with respect to the preservation of RK&M would be projected onto the question of what needs to be done in the future with respect to organising and exercising post-closure oversight. Hence, the panel session aims to facilitate an exchange on the concept of indirect oversight promoted by the ICRP (2013) and its relation to the preservation of RK&M today.

New operational quantities (RBE × D p lens/Φ) for eye lens neutron dosimetry as a function of energy and angle of incidence in the ICRU 95 formalism

This paper is a continuation of a study published recently by the authors. It presents and discusses computed personal absorbed dose in the lens of the eye (D p lens/Φ), and a relative biological effectiveness (RBE)-weighted absorbed dose (in terms of an newly proposed operational quantity RBE × D p lens/Φ), conversion coefficients for the lens of the eye for neutron exposure at incident energies from thermal to ∼20 MeV and at angles of incidence from 0° to 90° in 15° increments, at 180° and for rotational incidence irradiation geometry (from 0° to 360° in 5° increments). These conversion coefficients were obtained from a simulation model developed for this study that contains the stylised eye model, embedded in the adult UF-ORNL mathematical phantom, whereby the previously stated RBE-weighted absorbed dose was obtained using the proposed RBE versus neutron energy distribution compiled in a previous paper by the authors. The simulations carried out for this study using the Monte Carlo N-Particle transport code version 6.2, were conducted in a realistic human eye model, for the left and right sensitive and whole volume of the lens of the eye, considering the recent proposed redefinition of the operational quantities for external radiation exposure in International Commission on Radiation Units and Measurements (ICRU) report 95. A comprehensive set of tabulated data for neutron fluence-to-dose conversion coefficients (D p lens/Φ in pGy cm2) and RBE-weighted absorbed dose (RBE × D p lens/Φ in pGy cm2) conversion coefficients is included in this paper as a function of incident neutron energy and angle of incidence. Data for D p lens/Φ (pGy cm2) are compared to similar data from the literature for validation of our model. Data for RBE × D p lens/Φ (in pGy cm2), were also compared to the equivalent operational quantity H p(3,α)/Φ (in pSv cm2) conversion coefficients calculated at 3 mm depth in a cylindrical phantom for different incident neutron energies and angles of incidence from 0° to 75° in 15° increments to demonstrate the relevance of this newly proposed operational quantity for doses resulting in tissue reactions (deterministic effects) which should be quoted in Gray (RBE-weighted absorbed dose, RBE × D (Gy)), rather than Sievert (Sv) which is reserved for stochastic effects. The current neutron weighted absorbed dose (RBE × D p lens) is proposed for the tissue reactions in the eye-lens for neutron radiation as per National Council on Radiation Protection and Measurements report 180 and in line with the recent proposal for the review and revision of the System of Radiological Protection to Keeping the International Commission on Radiological Protection (ICRP) recommendations fit for purpose. This method would bring better alignment between the dose limits in ICRP 118 and the new operational quantity consistent with the units of the new eye-lens dose limits without being overly conservative. The utilization of the proposed new operational quantities, as outlined in ICRU 95, has the potential to address the ongoing challenge in enforcing regulatory limits for neutron eye dose, specifically the use of Gy instead of Sv. It should be noted that the applicability of this will vary from country to country as in many countries the legislation is likely to mandate the use of H p(3) until the regulation is amended. This approach can serve as an interim solution while awaiting the issuance of the new ICRP general recommendations, which is expected to take several years. Implementing the new operational quantities can contribute to enhancing the accuracy and effectiveness of neutron eye dose limit enforcement.

In‐house manufactured benchtop XRF spectrometer

AbstractThe growing efficiency of agribusiness depends on the development of technology. A key challenge regards the determination of plant mineral content, which help farmers to make a decision about fertilizer use. Currently, such nutritional status diagnoses are made based on wet chemical methods; they are usually slow and generate chemical wastess. In this context, an in‐house manufactured XRF benchtop for agri‐samples is proposed in this study. This XRF system was furnished with a manual primary filter changer, vacuum chamber, dual interlock radiological protection system, which were installed in the equipment cover, and light signals. Analytical capabilities were also evaluated. The equipment presented spurious peaks of Ti, Fe, Ni, and Zn, which is not ideal for some agronomical applications; this issue might be overcome in the future by means of additional primary filters. The total x‐ray spectrum counting rate is roughly one magnitude order lower than two other commercial XRF systems, but the signal‐to‐noise ratio is quite similar. The vacuum chamber under partial vacuum improves the Al, Si, P and S signals from 1.5 to 2.2. The limits of detection (LOD, mg kg−1) for P (261), S (168), K (68), and Ca (50) macronutrients and Mn (14), Fe (15), Cu (9), and Zn (8) micronutrients are close to the ones reported in the literature. The limits of detection for P, S, K, and Ca are suitable for plant analysis.

The scientific basis for the use of the linear no-threshold (LNT) model at low doses and dose rates in radiological protection

The linear no-threshold (LNT) model was introduced into the radiological protection system about 60 years ago, but this model and its use in radiation protection are still debated today. This article presents an overview of results on effects of exposure to low linear-energy-transfer radiation in radiobiology and epidemiology accumulated over the last decade and discusses their impact on the use of the LNT model in the assessment of radiation-related cancer risks at low doses. The knowledge acquired over the past 10 years, both in radiobiology and epidemiology, has reinforced scientific knowledge about cancer risks at low doses. In radiobiology, although certain mechanisms do not support linearity, the early stages of carcinogenesis comprised of mutational events, which are assumed to play a key role in carcinogenesis, show linear responses to doses from as low as 10 mGy. The impact of non-mutational mechanisms on the risk of radiation-related cancer at low doses is currently difficult to assess. In epidemiology, the results show excess cancer risks at dose levels of 100 mGy or less. While some recent results indicate non-linear dose relationships for some cancers, overall, the LNT model does not substantially overestimate the risks at low doses. Recent results, in radiobiology or in epidemiology, suggest that a dose threshold, if any, could not be greater than a few tens of mGy. The scientific knowledge currently available does not contradict the use of the LNT model for the assessment of radiation-related cancer risks within the radiological protection system, and no other dose-risk relationship seems more appropriate for radiological protection purposes.

The History of the Linear No-Threshold Model and Recommendations for a Path Forward

The intent of this paper and the accompanying video series is to inform the scientific community about the historical foundations that underpin the linear no-threshold (LNT) model's use for cancer risk assessment. There is a clear distinction here: this effort is about the history of how LNT came to be the regulatory paradigm and model for cancer risk assessment that it is today and not a discussion of the pros and cons of the LNT model. The overarching goal of this effort is to reframe the conversation around low-dose response models in light of this history and to determine how this history influences the scientific understanding of low-dose radiation responses. The timing of this series is intentional, as the International Commission on Radiological Protection (ICRP) has embarked on a mission to review the entire system of radiation protection. This effort necessarily requires rigorous scientific debate that must be based in fact. The history of the LNT model is paramount to this discussion, and it warrants consideration. Unfortunately, rather than engendering respectful debate, the topic of cancer risks associated with low dose radiation exposures has forged two disparate and sometimes contentious camps: (1) low doses, no matter how low, present some form of health risk and (2) an alternative model better represents the actual risks. The video series, conceived by John Cardarelli II, current President of the Health Physics Society (HPS), features Edward Calabrese, professor of toxicology in the School of Public Health and Health Sciences at the University of Massachusetts at Amherst, being interviewed by HPS Past-President Barbara Hamrick, CHP, JD, with support from Daniel Sowers, the Chair of the HPS Public Information Committee, and HPS Executive Director Brett Burk. Emily Caffrey, the Chief Editor of our Ask-the-Experts website (https://hps.org/publicinformation/ate/), was invited to watch the completed series as an independent peer reviewer. Further, an email address, factcheck@hps.org, was created to allow for peer-review by the scientific community to facilitate ongoing discussion and allow for corrections to the record as necessary. It is the sincere hope of this team that this work inspires new discussions about the system of radiological protection. We encourage everyone in this field to watch all 22 episodes to be informed about the underpinnings of current regulatory policy in the US.

International commission on radiological protection report 152(2022): Radiation detriment calculation methodology

Full Reference: ICRP 2022. Radiation detriment calculation methodology. ICRP Publication 152. Ann. ICRP 51 (3) Publisher: SAGE Publication, UK Pages: 103 ISBN: 9781529619003 Year: 2022 Price: UK £183.75 (Online) The International Commission on Radiological Protection’s Publication 152 (ICRP Publication 152) entitled “Radiation Detriment Calculation Methodology” was published in 2022 by SAGE Publications, UK. As described by the ICRP, this Publication is part of a thorough review launched by it on the System of Radiological Protection following ICRP Publication 103 published in 2007. Publication 152 provides a historical review of the radiation detriment calculation methodology since ICRP Publication 26 (1977) for the purpose of radiological protection. The concept of radiation detriment was introduced by the ICRP in its Publication (1973) which has been developed further by it over the last few decades. The ICRP defines radiation detriment as the excess of stochastic health effects in a group of individuals exposed to low-level radiation and their descendants compared with a nonexposed group. It is determined from sex-averaged and age-at-exposure-averaged lifetime risk estimates for a set of organs and tissues, taking into account the severity in terms of quality of life in nonlethal conditions and length of life lost. The ICRP notes that although the current scheme of radiation detriment calculation is well established, it needs to evolve to better reflect changes in population health statistics and progress in scientific understanding of radiation health effects. In this regard, update on parameters such as the reference population data and cancer severity and some improvement in cancer risk models based on the accumulation of recent epidemiological findings have been carried out. The update in this Publication should be considered an improved and corrected version of Annex A.4 of Publication 103. Radiation detriment was defined initially as the mathematical “expectation” of harm incurred in a group from radiation exposure (ICRP, 1973, 1977a). The harm in this definition was intended to encompass deleterious effects of all sorts, including the socioeconomic impact. However, only health effects were considered in practice, and hence, detriment was expressed as the expected value of the weighted number of health effects to be experienced by the group. Detriment was redefined in Publication 60 (ICRP, 1991) as a multidimensional concept that can be expressed in a variety of ways depending on the purpose. At the same time, the ICRP continued efforts to aggregate different aspects of detriment into a single quantity, and the methodology was further refined in Publication 103 (ICRP, 2007). It is currently defined as the excess of stochastic health effects in a group of individuals exposed to low-level radiation and their descendants compared with a nonexposed group. It is determined from sex-averaged and age-at-exposure-averaged lifetime risk estimates for a set of organs and tissues, taking into account the severity in terms of quality of life in nonlethal conditions and length of life lost. Publication 152 is divided into six sections comprising 103 pages, including the abstract, executive summary, references, and the annexure. Section 1 is “Introduction” which provides the background and need for bringing out the current publication. Scope and objective have been elaborated in this section, along with the structure of the Publication. Section 2 entitled “Historical Development” provides a review of the quantitative expression of radiation detriment starting from ICRP 26 (1977). It specifically describes earlier ICRP Publications dealing with the subject, namely ICRP Publications 27 (1977), 45 (1985), 60 (1991), and 103 (2007), and highlights how the calculation method has adapted to progress in scientific knowledge. It especially brings out the modifications incorporated in Publication 103 (ICRP, 2007) in terms of the adoption of a new detriment calculation methodology as compared to ICRP 60 (1991). One major change in ICRP 103 was the move to nominal risk calculation based on cancer incidence data rather than cancer mortality data. For clarification, the detriment calculated using this methodology is specifically called “radiation detriment,” and the term “detriment” means radiation detriment hereafter unless otherwise noted. Section 3 “Calculation of Radiation Detriment” is, to my mind, the most important section of this publication. It first details the computation process used in Publication 103 (ICRP, 2007) and then points out the programming errors in the calculations of the nominal risk coefficients in it. Despite a considerable increase in the nominal risk coefficients of bone marrow, breast, and ovarian cancers due to recalculations, it is shown that impact on overall nominal risk is limited (4%). Data sources, risk models, computational methods, and the rationale for the parameter values adopted are explained for each step of the process. In Publication 103, nominal risks were calculated based on cancer incidence, using the most up-to-date information at the time. Nevertheless, when adjusted for severity, the resulting detriment values were quite similar to those in Publication 60 (ICRP, 1991). It was, therefore, concluded that the approximated overall fatal risk coefficient of 5% per Sv on which international radiation safety standards were based continued to be appropriate for the purposes of radiological protection. It is demonstrated that the correction of errors does not change this conclusion. Therefore, the ICRP concluded that the miscalculations of the nominal risk coefficients and radiation detriments have no implications for operation of the System of Radiological Protection. Section 4 “Sensitivity of Radiation Detriment Calculation” presents the interesting results of a series of sensitivity analyses that examined the impact of selected parameters on radiation detriment. The aim of the analysis was to identify major sources of variation and uncertainty in the calculation of radiation detriment. The analysis found that parameters of substantial impact on radiation detriment are sex, age at exposure, dose rate effectiveness factor (DDREF), dose assumption, and lethality fraction. The parameters with the least impact are lifetime risk metric, minimum latency period, maximum attained age, and minimum QOL factor. Section 5 “Potential Evolution” discusses ways to identify the issues and possible ways to provide directions for the future evolution of radiation detriment, which could be a crucial part in the development of the Commission’s General Recommendations. Section 6 “Summary and Conclusions” summarizes the main conclusions, and includes suggestions for future improvement. It points out that radiation detriment needs to evolve depending on changes in cancer incidence and survival rates, and on advances in scientific understanding of radiation health effects. Further, it suggests that a full description of calculation steps and development of open-source software for calculating radiation detriment is necessary to improve transparency. It is also desirable to improve the way, in which radiation detriment is expressed and communicated so that nonspecialists can have a balanced perspective on the health risks of radiation, the ICRP points out. Annexure A of Publication 152 provides the updated baseline and demographic data in the form of seven tables. One aspect of Publication 152 that stands out is its comprehensibility despite dealing with a complex subject. The calculations and analyses described with graphs and tables aid in the transparency and comprehensibility of the document. The Publication can serve as a valuable and authentic resource material for medical physics practitioners and students and for all those interested in research, teaching, and practice in the area of radiological protection. The cost of the international paperback edition of the Publication is £183.75 from SAGE Publishing as found on the Internet (link: https://uk.sagepub.com/en -gb/eur/icrp-publication-152-radiation-detriment - calculation-methodology/book284987). As per the ICRP policy since 2018, all issues of Annals of the ICRP are free to access other than the current and the two most recent volumes.

Can Low-Level Ionizing Radiation Do Us Any Harm?

The current system of radiological protection relies on the linear no-threshold (LNT) hypothesis of cancer risk due to humans being exposed to ionizing radiation (IR). Under this tenet, effects of low doses (i.e. of those not exceeding 100 mGy or 0.1 mGy/min. of X- or γ-rays for acute and chronic exposures, respectively) are evaluated by downward linear extrapolation from regions of higher doses and dose rates where harmful effects are actually observed. However, evidence accumulated over many years clearly indicates that exposure of humans to low doses of radiation does not cause any harm and often promotes health. In this review, we discuss results of some epidemiological analyses, clinical trials and controlled experimental animal studies. Epidemiological data indicate the presence of a threshold and departure from linearity at the lowest dose ranges. Experimental studies clearly demonstrate the qualitative difference between biological mechanisms and effects at low and at higher doses of IR. We also discuss the genesis and the likely reasons for the persistence of the LNT tenet, despite its scientific implausibility and deleterious social consequences. It is high time to replace the LNT paradigm by a scientifically based dose-effect relationship where realistic quantitative hormetic or threshold models are exploited.

ICRP PUBLICATION 153 Approved by the Commission in September 2022.

Veterinary use of radiation in the diagnosis, management, and treatment of disease has expanded and diversified, as have the corresponding radiological protection concerns. Radiological exposure of personnel involved in veterinary procedures and, where applicable, members of the public providing assistance (e.g. owners or handlers) has always been included within the system of radiological protection. Veterinary practice is now addressed explicitly as the modern complexities associated with this practice warrant dedicated consideration, and there is a need to clarify and strengthen the application of radiological protection principles in this area. The Commission recommends that the system of radiological protection should be applied in veterinary practice principally for the protection of humans, but with explicit attention to the protection of exposed animals. Additionally, consideration should be given to the risk of potential contamination of the environment associated with applications of nuclear medicine in veterinary practice. This publication focuses primarily on justification and optimisation in veterinary practice, and sets the scene for more detailed guidance to follow in future Recommendations. It is intended for a wide-ranging audience, including radiological protection professionals, veterinary staff, students, education and training providers, and members of the public, as an introduction to radiological protection in veterinary practice.© 2022 ICRP. Published by SAGE.

On radiation protection and climate change – a summary

planned for construction as well as those at proposal stage. However, the ethics of nuclear power is increasingly under challenge due to the incidents at the Chernobyl and Fukushima Daiichi nuclear power plants, and concerns over radioactive discharges, safe management of radioactive waste and lack of an operational repository for spent nuclear fuel. Central to these concerns is the perceived unique radiological risk of nuclear power. But in a world where Climate Change presents a threat to the entire planet, is nuclear power and the associated radiological risk not ethical? Exploring the interplay between climate change ethics and the International Commission on Radiological Protection (ICRP)’s System of Radiological Protection, we consider the major contribution that new nuclear power stations can make to climate change mitigation, through decarbonisation of power systems, and finally unpick the case for nuclear power in this new world of climate change ethics.

On the operational quantity for eye lens neutron dosimetry considering ICRU 95 report

For planned occupational exposure situations, the International Commission on Radiological Protection (ICRP) publication 118 recommends an equivalent dose limit for the lens of the eye of 20 mSv yr−1 averaged over 5 yr with no single year exceeding 50 mSv. Regulatory authorities of various jurisdictions worldwide followed some or all, of the ICRP recommendations and implemented reduced occupational lens of eye dose limits in their legislation. As compliance with the eye-lens dose limit will be based on the summation of doses received from all types of radiation, applicable to a variety of workplaces, the contribution of neutrons to eye lens dose will be important where it contributes a significant fraction of the total dose to the eye lens. This work presents and discusses computed personal absorbed dose (D lens/Φ), and personal dose equivalent (H p(3)/Φ) as well as a newly proposed relative biological effectiveness (RBE)-weighted absorbed dose (RBE × D lens/Φ) conversion coefficients for the lens of the eye for neutron exposure at incident energies from thermal to ∼20 MeV. The D lens/Φ coefficients were obtained from a simulation model developed for this study that contains the stylised eye model embedded in the adult UF-ORNL mathematical phantom. The modelling techniques used in these simulations were also used to calculate H p(3)/Φ for the International Commission on Radiation Units and Measurements (ICRU) slab and cylinder phantoms. All simulations carried out for this study utilised the Monte Carlo N-Particle (MCNP) series of codes. The results are compared with the related published data. The issue of compliance with the current equivalent dose limit for the lens of the eye is addressed from a neutron perspective considering the recent proposed redefinition of the operational quantities for external radiation exposure in ICRU report 95. The use of a radiation weighted absorbed dose (RBE × D lens, in Gy) is proposed for the tissue reactions in the eye-lens for neutron radiation as per the National Council on Radiation Protection and Measurements report 180, and in line with the recent review and revision of the System of Radiological Protection To Keeping the ICRP Recommendations Fit for Purpose, which states that RBE weighted dose should be used for high-Linear energy transfer (LET) radiations such as neutrons. This confirms the earlier statement in ICRP publication 92, paragraph 297 and reiterated in the Executive summary, paragraph (q) of ICRP publication 118. The proposed approach would provide an operational quantity consistent with the units of the new eye-lens dose limits without being overly conservative.

Justification of dose limits—historical development, ethical basis, and the way forward

The dose limits recommended by the International Commission on Radiological Protection have undergone considerable changes in the course of the past 90 years, and different arguments have been put forward for their justification. This has been largely due to new insights of radiation research, but changing perceptions of the related ethical values have also played a role. The current paper reviews important stages in this development and attempts to derive some implications for the Commission’s next general recommendations. Above all, it suggests that it is essential to present clear and consistent justification strategies for dose limits (and related values), compatible with the core values of the system of radiological protection, especially prudence and justice.