Evolution of radiation protection for medical workers

Within a few months of discovery, X-rays were being used worldwide for diagnosis and within a year or two for therapy. It became clear very quickly that while there were immense benefits, there were significant associated hazards, not only for the patients, but also for the operators of the equipment. Simple radiation protection measures were implemented within a decade or two and radiation protection for physicians and other operators has continued to evolve over the last century driven by cycles of widening uses, new technologies, realization of previously unidentified effects, development of recommendations and regulations, along with the rise of related societies and professional organizations. Today, the continue acceleration of medical radiation uses in diagnostic imaging and in therapeutic modalities not imagined at the turn of this century, such as positron emission tomography, calls for constant vigilance and flexibility to provide adequate protection for the growing numbers of medical radiation workers.

The 42nd Lauriston S. Taylor Lecture: Radiation Dosimetry Research for Medicine and Protection-A European Journey

The assessment of doses related to exposures to ionizing radiation is an essential part of all applications of ionizing radiation including radiation medicine, radiation protection, radiation biology, radiation epidemiology, and also industrial uses of radiation. Absorbed dose is generally considered to be the fundamental quantity of radiation dosimetry. It is a metrologically sound quantity for which even primary standards exist for some materials, and it is used routinely in practice. However, there is no unique correlation between absorbed dose and the radiation-induced biological effect considered. There are also different objectives of radiation dosimetry for different applications. In radiation protection, quantities are required to set meaningful exposure limits and to implement the principle of optimization. In radiation therapy, the dependence of clinical outcomes on temporal aspects of the irradiations must be accounted for. In radiation diagnostics, quantities are needed to enable and monitor optimization of radiation dose and image quality. In radiation protection and in therapy with high linear-energy-transfer radiations, appropriate methods and parameters are needed to account for differences in radiation quality. These limitations of the quantity absorbed dose have led to the use of a multiplicity of dose quantities and dose modification factors. Radiation dosimetry continues, therefore, to be a field of active research regarding fundamental and conceptual aspects, taking account of advances in technologies, of novel methods in radiation therapy and diagnostics, and of progress in computational dosimetry. Dosimetry of high-energy radiations such as cosmic radiation encountered at flight altitudes and during space missions as well as at high-energy accelerators has become an important issue. In Europe, collaboration and coordination of radiation research in general, and dosimetry research in particular, are playing an important role. Dedicated research programs of the European Commission have been and still are very valuable and include collaborations with institutes in Eastern Europe and non-European countries. Several current and recent research topics in radiation dosimetry are addressed based on research carried out within European research programs, at European research centers including the European Organization for Nuclear Research (known as CERN), in European particle therapy projects, and at national metrological institutes. One focus is the quantification of radiation quality in radiation protection and in high linear-energy-transfer radiation therapy with emphasis on measurements with low-pressure proportional counters. Another focus is dosimetry of high-energy radiations with respect to measurements of cosmic radiation and at CERN's high-energy accelerators.

A History of the International Commission on Non-Ionizing Radiation Protection

Concern about health risks from exposure to non-ionizing radiation (NIR) commenced in the 1950s after tracking radars were first introduced during the Second World War. Soon after, research on possible biological effects of microwave radiation in the former Soviet Union and the U.S. led to public and worker exposure limits being much lower in Eastern European than in Western countries, mainly because of different protection philosophies. As public concern increased, national authorities began introducing legislation to limit NIR exposures from domestic microwave ovens and workplace devices such as visual display units. The International Radiation Protection Association (IRPA) was formed in 1966 to represent national radiation protection societies. To address NIR protection issues, IRPA established a Working Group in 1974, then a Study Group in 1975, and finally the International NIR Committee (INIRC) in 1977. INIRC's publications quickly became accepted worldwide, and it was logical that it should become an independent commission. IRPA finally established the International Commission on Non-Ionizing Radiation Protection (ICNIRP), chartering its remit in 1992, and defining NIR as electromagnetic radiation (ultraviolet, visible, infrared), electromagnetic waves and fields, and infra- and ultrasound. ICNIRP's guidelines have been incorporated into legislation or adopted as standards in many countries. While ICNIRP has been subjected to criticism and close scrutiny by the public, media, and activists, it has continued to issue well-received, independent, science-based protection advice. This paper summarizes events leading to the formation of ICNIRP, its key activities up to 2017, ICNIRP's 25th anniversary year, and its future challenges.

Consequences of the radiation accident at the Mayak production association in 1957 (the 'Kyshtym Accident')

This paper presents an overview of the nuclear accident that occurred at the Mayak Production Association (PA) in the Russian Federation on 29 September 1957, often referred to as 'Kyshtym Accident', when 20 MCi (740 PBq) of radionuclides were released by a chemical explosion in a radioactive waste storage tank. 2 MCi (74 PBq) spread beyond the Mayak PA site to form the East Urals Radioactive Trace (EURT). The paper describes the accident and gives brief characteristics of the efficacy of the implemented protective measures that made it possible to considerably reduce doses to the exposed population. The paper also provides retrospective dosimetry estimates for the members of the EURT Cohort (EURTC) which comprises approximately 21 400 people. During the first two years after the accident a decrease in the group average leukocyte (mainly due to neutrophils and lymphocytes) and thrombocyte count was observed in the population. At later dates an increased excess relative risk of solid cancer incidence and mortality was found in the EURTC.

Determining Nuclear Fingerprints: Glove Boxes, Radiation Protection, and the International Atomic Energy Agency

In a nuclear laboratory, a glove box is a windowed, sealed container equipped with two flexible gloves that allow the user to manipulate nuclear materials from the outside in an ostensibly safe environment. As a routine laboratory device, it invites neglect from historians and storytellers of science. Yet, since especially the Gulf War, glove boxes have put the interdependence of science, diplomacy, and politics into clear relief. Standing at the intersection of history of science and international history, technological materials and devices such as the glove box can provide penetrating insight into the role of international diplomatic organizations to the global circulation and control of scientific knowledge. The focus here is on the International Atomic Energy Agency.

Contributions from Women to the Radiation Sciences: A Brief History

Contributions from men to radiation science are well known, particularly the early contributions from such luminaries as William Roentgen, James Chadwick, Niels Bohr, Robert Oppenheimer, and the like. Although not ignored per se, beyond Marie Curie and Lise Meitner, the contributions of female nuclear scientists are not as widely recognized. This paper provides a concise historical summary of contributions to radiation science from the discovery of radiation through the current status of international leadership within the radiation protection community. Beyond lead scientists and academics, this paper also considers support personnel as well as the role women have played in the advancement of radiation epidemiology.

Contribution of Harold M. Swartz to In Vivo EPR and EPR Dosimetry

In 2015, we are celebrating half a century of research in the application of Electron Paramagnetic Resonance (EPR) as a biodosimetry tool to evaluate the dose received by irradiated people. During the EPR Biodose 2015 meeting, a special session was organized to acknowledge the pioneering contribution of Harold M. (Hal) Swartz in the field. The article summarizes his main contribution in physiology and medicine. Four emerging themes have been pursued continuously along his career since its beginning: (1) radiation biology; (2) oxygen and oxidation; (3) measuring physiology in vivo; and (4) application of these measurements in clinical medicine. The common feature among all these different subjects has been the use of magnetic resonance techniques, especially EPR. In this article, you will find an impressionist portrait of Hal Swartz with the description of the 'making of' this pioneer, a time-line perspective on his career with the creation of three National Institutes of Health-funded EPR centers, a topic-oriented perspective on his career with a description of his major contributions to Science, his role as a mentor and his influence on his academic children, his active role as founder of scientific societies and organizer of scientific meetings, and the well-deserved international recognition received so far.

Historical Patterns in the Types of Procedures Performed and Radiation Safety Practices Used in Nuclear Medicine From 1945-2009

The authors evaluated historical patterns in the types of procedures performed in diagnostic and therapeutic nuclear medicine and the associated radiation safety practices used from 1945-2009 in a sample of U.S. radiologic technologists. In 2013-2014, 4,406 participants from the U.S. Radiologic Technologists (USRT) Study who previously reported working with medical radionuclides completed a detailed survey inquiring about the performance of 23 diagnostic and therapeutic radionuclide procedures and the use of radiation safety practices when performing radionuclide procedure-related tasks during five time periods: 1945-1964, 1965-1979, 1980-1989, 1990-1999, and 2000-2009. An overall increase in the proportion of technologists who performed specific diagnostic or therapeutic procedures was observed across the five time periods. Between 1945-1964 and 2000-2009, the median frequency of diagnostic procedures performed substantially increased (from 5 wk to 30 wk), attributable mainly to an increasing frequency of cardiac and non-brain PET scans, while the median frequency of therapeutic procedures performed modestly decreased (from 4 mo to 3 mo). Also a notable increase was observed in the use of most radiation safety practices from 1945-1964 to 2000-2009 (e.g., use of lead-shielded vials during diagnostic radiopharmaceutical preparation increased from 56 to 96%), although lead apron use dramatically decreased (e.g., during diagnostic imaging procedures, from 81 to 7%). These data describe historical practices in nuclear medicine and can be used to support studies of health risks for nuclear medicine technologists.

Focal role of tolerability and reasonableness in the radiological protection system

The concepts of tolerability and reasonableness are at the core of the International Commission on Radiological Protection (ICRP) system of radiological protection. Tolerability allows the definition of boundaries for implementing ICRP principles, while reasonableness contributes to decisions regarding adequate levels of protection, taking into account the prevailing circumstances. In the 1970s and 1980s, attempts to find theoretical foundations in risk comparisons for tolerability and cost-benefit analysis for reasonableness failed. In practice, the search for a rational basis for these concepts will never end. Making a wise decision will always remain a matter of judgement and will depend on the circumstances as well as the current knowledge and past experience. This paper discusses the constituents of tolerability and reasonableness at the heart of the radiological protection system. It also emphasises the increasing role of stakeholder engagement in the quest for tolerability and reasonableness since Publication 103.

Federal Directions in Radiation Regulations: Making the "Old" New Again

The radiation regulatory scheme in the United States must periodically evolve and adapt to ensure that public health, workers, and the environment are properly protected in view of accepted societal values and the advance of science, technology, and medical practices. Federal regulators must use best judgment in weighing a multitude of factors and considerations. In the early 21st century, a few dependable but tired and antiquated "workhorses" of regulation have been reworked already--but many more remain that likely need reworking. Three primary points of discussion on current directional influences on federal radiation regulation merit examination: • In 2015, what are the stressors driving societal and policy changes and how might these dynamics be forcing reexamination of old regulations? • What are the things that make a "good" regulation and an effective rule? • What are the thorny issues that the federal government is wrestling with and what are some of the notable activities in federal radiation regulations and guidance that are underway? This journal article was presented at the 2015 Annual Meeting of the National Council on Radiation Protection and Measurements and served as a broad overview of federal regulatory actions and issues.

History and Organizations for Radiological Protection

International Commission on Radiological Protection (ICRP), an independent international organization established in 1925, develops, maintains, and elaborates radiological protection standards, legislation, and guidelines. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) provides scientific evidence. World Health Organization (WHO) and International Atomic Energy Agency (IAEA) utilise the ICRP recommendations to implement radiation protection in practice. Finally, radiation protection agencies in each country adopt the policies, and adapt them to each situation. In Korea, Nuclear Safety and Security Commission is the governmental body for nuclear safety regulation and Korea Institute of Nuclear Safety is a public organization for technical support and R&D in nuclear safety and radiation protection.

Twelfth Annual Warren K. Sinclair Keynote Address--the Influence of the NCRP on Radiation Protection in the United States: Guidance and Regulation

The Warren K. Sinclair Keynote Address for the 2015 Annual Meeting of the National Council on Radiation Protection and Measurements (NCRP) describes the Council's influence in the development of radiation protection guidance in the United States since its founding in 1929 as the U.S. Advisory Committee on X-Ray and Radium Protection. The National Bureau of Standards (NBS) was the coordinating agency for the Advisory Committee, and its reports were published as NBS handbooks. In 1946, the Advisory Committee was renamed the National Committee on Radiation Protection and remained so until NCRP was chartered by the U.S. Congress in 1964. In 1931, the U.S. Advisory Committee on X-Ray and Radium Protection proposed the first formal standard for protecting people from radiation sources as NBS Handbook 15 and issued the first handbook on radium protection, NBS Handbook 18. Revised recommendations for external exposure were issued in 1936 and for radium protection in 1938 and remained in force until 1948. Throughout its 86 y history, the Council and its predecessors have functioned as effective advisors to the nation on radiation protection issues and have provided the fundamental guidance and recommendations necessary for the regulatory basis of the control of radiation exposure, radiation-producing devices, and radioactive materials in the United States.

Evolution of the Radiological Protection System and its Implementation

The International System of Radiological Protection, developed, maintained, and elaborated by the International Commission on Radiological Protection (ICRP) has, for the past 50 y, provided a robust framework for developing radiological protection policy, regulation, and application. It has, however, been evolving as a result of experience with its implementation, modernization of social awareness of a shrinking world where the Internet links everyone instantly, and increasing public interest in safety-related decisions. These currents have gently pushed the ICRP in recent years to focus more sharply on particular aspects of its system: optimization, prevailing circumstances, the use of effective dose and aspects of an individual's risk, and consideration of the independent implementation of the international system's elements. This paper will present these issues and their relevance to the ICRP system of protection and its evolution. The broader framework of radiological protection (e.g., science, philosophy, policy, regulation, implementation), of which the ICRP is an important element, will provide a global, equally evolving context for this characterization of the changing ICRP system of radiological protection.

["Epistemic Negotiations" and the Pluralism of the Radiation Protection Regime: The Determination of Radiation Protection Standards for the General Population in the Early Years After World War II]

Radiation protection standards for the general population have constituted one of the most controversial subjects in the history of atomic energy uses. This paper reexamines the process in which the first such standards evolved in the early postwar period. While the existing literature has emphasized a "collusion" between the standard-setters and users, the paper seeks to examine the horizontal relationship among the standard-setters. It first examines a series of expert consultations between the United States and the United Kingdom. Representing a different configuration of power and interest, the two failed to agree on the assessment of genetic damage and cancer induction whose occurrence might have no threshold and therefore be dependent on the population size. This stalemate prevented the International Commission on Radiological Protection (ICRP), established in 1950, from formulating separate guidelines for the general public. Situations radically changed when the Bikini incident in 1954 led to the creation of more scientific panels. One such panel under the U.S. Academy of Sciences enabled the geneticists to bridge their internal divide, unanimously naming 100 mSv as the genetically permissible dose for the general population. Not to be outdone, ICRP publicized its own guidelines for the same purpose. The case examined in this paper shows that the standard-setting process is best understood as a series of "epistemic negotiations" among and within the standard-setters, whose agendas were determined from the outset but whose outcomes were not.

38th Lauriston S. Taylor lecture: on the shoulders of giants - radiation protection over 50 years

Most advances in science, technology, and radiation protection are not truly new ideas but rather build upon a foundation of prior work and achievements by earlier generations of scientists and researchers. This paper summarizes major achievements over the last 50-70 y in the various areas involved in radiation protection as well as giving information about some of those who were, and are, significant contributors.

Historical trends in radiation protection, policy and communications: 1964 to the present

The past 50 y have seen substantial developments in radiation epidemiology, technology, dosimetry, regulations, and protection efforts. During the last five decades, radiation communication has also evolved, growing more sophisticated as communication science and practice have advanced and matured. This talk covers the trends in radiation protection over the past 50 y, illustrated by progress in science and practice of risk communication and changes in societal expectations, and examines challenges that will confront radiation risk communication in the future.

Human population studies and the World Health Organization

This essay draws attention to the role of the WHO in shaping research agendas in the biomedical sciences in the postwar era. It considers in particular the genetic studies of human populations that were pursued under the aegis of the WHO from the late 1950s to 1970s. The study provides insights into how human and medical genetics entered the agenda of the WHO. At the same time, the population studies become a focus for tracking changing notions of international relations, cooperation, and development and their impact on research in biology and medicine in the post-World War I era. After a brief discussion of the early history of the WHO and its position in Cold War politics, the essay considers the WHO program in radiation protection and heredity and how the genetic study of "vanishing" human populations and a world-wide genetic study of newborns fitted this broader agenda. It then considers in more detail the kind of support offered by the WHO for these projects. The essay highlights the role of single individuals in taking advantage of WHO support for pushing their research agendas while establishing a trend towards cooperative international projects in biology.

Thirty-sixth Lauriston S. Taylor Lecture on radiation protection and measurements--from the field to the laboratory and back: the what ifs, wows, and who cares of radiation biology

My scientific journey started at the University of Utah chasing fallout. It was on everything, in everything, and was distributed throughout the ecosystem. This resulted in radiation doses to humans and caused me great concern. From this concern I asked the question, "Are there health effects from these radiation doses and levels of radioactive contamination?" I have invested my scientific career trying to address this basic question. While conducting research, I got acquainted with many of the What ifs of radiation biology. The major What if in my research was, "What if we have underestimated the radiation risk for internally-deposited radioactive material?" While conducting research to address this important question, many other What ifs came up related to dose, dose rate, and dose distribution. I also encountered a large number of Wows. One of the first was when I went from conducting environmental fallout studies to research in a controlled laboratory. The activity in fallout was expressed as pCi L⁻¹, whereas it was necessary to inject laboratory animals with μCi g⁻¹ body weight to induce measurable biological changes, chromosome aberrations, and cancer. Wow! That is seven to nine orders of magnitude above the activity levels found in the environment. Other Wows have made it necessary for the field of radiation biology to make important paradigm shifts. For example, one shift involved changing from "hit theory" to total tissue responses as the result of bystander effects. Finally, Who cares? While working at U.S. Department of Energy headquarters and serving on many scientific committees, I found that science does not drive regulatory and funding decisions. Public perception and politics seem to be major driving forces. If scientific data suggested that risk had been underestimated, everyone cared. When science suggested that risk had been overestimated, no one cared. This result-dependent Who cares? was demonstrated as we tried to generate interactions by holding meetings with individuals involved in basic low-dose research, regulators, and the news media. As the scientists presented their "exciting data" that suggested that risk was overestimated, many of the regulators simply said, "We cannot use such data." The newspaper people said, "It is not possible to get such information by my editors." In spite of these difficulties, research results from basic science must be made available and considered by members of the public as well as by those that make regulatory recommendations. Public outreach of the data is critical and must continue to be a future focus to address properly the question of, "Who cares?" My journey in science, like many of yours, has been a mixture of chasing money, beatings, and the joys of unique and interesting research results. Perhaps through our experiences, we can improve research environments, funding, and use of the valuable information that is generated. Scientists that study at all levels of biological organization, from the environment to the laboratory and human epidemiology, must share expertise and data to address the What Ifs, Wows, and Who Cares of radiation biology.

Communication of benefits and risks of medical radiation: a historical perspective

X-rays were discovered by Wilhelm Röntgen in 1895. Within one year, benefits of x-rays, such as visualization of fractures, and detriments, such as x-ray dermatitis, were recognized. Nobel Laureates Pierre and Marie Sklodowska Curie discovered the radioactive element radium in 1898, and a year later the application of radiation to cure cancer was reported. A significant price was paid for this: Marie Curie died of aplastic anemia related to her radiation exposure, and her daughter Irene Joliot Curie, Nobelist for radiochemical research, died of radiation-induced leukemia. Internationally developed radiation protection recommendations were formalized starting in the late 1920s. The increasing use of ionizing radiation in medical diagnosis and radiation therapy has brought significant societal benefits. Known risks of therapeutic radiation include coronary artery disease and secondary malignancy. However, recently concerns have been raised of possible very small but incremental increases in malignancies due to diagnostic medical radiation. Patients are largely unaware of, and referring physicians and even radiologists often underestimate, the carcinogenic effects of radiation. There is a need to determine the appropriateness of imaging tests that use ionizing radiation prior to performance; optimize imaging protocols to reduce unnecessary radiation; include patients in the decision process and encourage and enable them to track their radiation exposure; and promote education about medical radiation to patients, referring physicians, radiologists, and members of the public. The basic radiation protection principles of justification, optimization, and application of dose limits still pertain.

The history of IRPA--up to the millennium

Since its foundation, the International Radiation Protection Association (IRPA) has grown to become the international voice of the profession of radiological protection. When it came into being in 1965 the existence of such a profession had only recently been recognised, but already there was seen to be a need for coordination and exchange of information and views internationally. As with all such organisations, the early years and decades were taken up with the development and evolution of the organisation, but there comes a time when, if the history is not documented, it gradually gets lost. Recognising this, the Executive Council (EC) created the role of archivist and historian, and appointed Geoff Webb with a brief to compile the history of IRPA. This article is the result and covers the developments leading up to the formation of IRPA and from then to the year 2000. An expanded version with more names and photographs is available through IRPA.

Fifty years of individual monitoring of ionising radiation in Switzerland: history, trends and perspectives

In the last 50 y, individual monitoring of ionising radiation in Switzerland underwent substantial development, strongly influenced by type of applications of ionising radiation, monitoring technologies, knowledge of health risks, protection philosophies and regulatory frameworks. The role of individual monitoring in the system of radiation protection moved from a passive, a posteriori control of limits towards an important and more interactive tool for optimisation. Dose trends for occupational exposures document these developments. In the future, new and emerging dose intensive applications in medicine and an increasing demand for international harmonisation, particularly in Europe, will pose new challenges in individual monitoring.

A Brazilian government external individual monitoring service: experience since 1972

Instituto de Radioproteção e Dosimetria, a Brazilian government research institute, provides individual monitoring services since 1972. Its dosemeters are: film-based thorax for whole body photons, thermoluminescence dosimetry (TLD) albedo for whole body neutrons and TLD ring for extremity photons. About 6000 radiation workers are currently being monitored with film dosemeters in 256 different facilities in Brazil, most of them working in health-related activities. Around 400 Brazilian radiation workers are monitored with TLD albedo neutron monitor and about 500 workers use TLD rings. This paper describes the monitoring systems used, presents the results obtained in internal quality programs and in intercomparison exercises and analyses the measured dose values from 1985 to 2009.