Jim Malone is Robert Boyle Professor (Emeritus) of medical physics at Trinity College Dublin. He worked halftime with the International Atomic Energy Agency (IAEA) (Vienna) for several years and continues as a consultant with both the agency and WHO. He was dean of the School of Medicine and Faculty of Health Sciences at Trinity College Dublin; chairman of the Geneva-based International Electrotechnical Commission’s (IEC) committee for global standards for medical imaging equipment. He has over 300 publications and numerous conference papers/keynote addresses. He has wide interests in the humanities and has contributed to thinking on the ethics basis for radiation protection in medicine. He has been involved in organising numerous summer schools involving science, medicine and the humanities. Friedo Zölzer is professor and head of the Institute of Radiology, Toxicology and Civil Protection at the Faculty of Health and Social Sciences of the University of South Bohemia in České Budějovice, Czech Republic. He is a radiobiologist with a strong interest in ethics, regularly lecturing and publishing in the area. He has significantly contributed to the development of a new approach to ethics of radiation protection at the international level, among others as a member of the International Commission on Radiological Protection’s (ICRP) task group on ‘Ethics of Radiological Protection’ and has been the organiser of a widely recognised biennial series of international symposia on the ethics of environmental health, in which medical applications for radiation played an important part. Gaston Meskens is a theoretical physicist with over 15 years’ experience of research related to sustainable development, energy, climate change and radioactive waste management. He works part-time with the Centre for Ethics and Value Inquiry of the Faculty of Arts and Philosophy of the University of Ghent and with the Science and Technology Studies group of the Belgian Nuclear Research Centre SCK•CEN . His research focusses on a human rights perspective on intellectual capacity-building in the interest of global sustainable development governance. At SCK•CEN, he co-founded the Programme of Integration of Social Aspects into Nuclear Research in 1999. The programme takes nuclear technology as a case, in order to critically study the complexity of risk-inherent technology assessment from the perspective of social justice and sustainable development. Recently, he has been a key contributor to the ethics framework for radiation protection for the International Commission on Radiological Protection (ICRP). At SCK•CEN, he works as researcher, writer, lecturer and mediator of dialogue on ethics in relation to science and technology. Christina Skourou, is a clinical radiotherapy physicist at the St. Luke’s Radiation Oncology Network in Dublin, Ireland, where she is involved in numerous radiotherapy clinical trials and is a member of the network’s Research Ethics Committee. She has served as the chair of the American Association of Physicists in Medicine (AAPM) Task Group 109, revising the Code of Ethics and, as of January, 2019, is the chair of the AAPM Ethics Committee. Christina holds a PhD in biomedical engineering (Dartmouth College) and an MA in medical ethics and law (Queen’s University Belfast).