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Low Dose Radiation Research Programs
The symposium featured presentations from four representatives with experience in organizing research in low dose radiation in the United States, Europe, Japan, and Canada, and one representative with experience in global radiation research coordination. Experts were asked to focus their presentations on the following issues:
- Impetus for organizing the programs,
- Long-term strategy of these programs,
- Coordination with other programs within the country and internationally, and
- Strengths and limitations of these programs.
The experts’ remarks are summarized in the following sections.
2.1 DEPARTMENT OF ENERGY’S (DOE’S) PAST LOW DOSE RADIATION PROGRAM, UNITED STATES
The Energy and Water Appropriation Act of 1998 directed DOE to initiate a 10-year program to understand how radiation affects living organisms. The Act was sponsored by Senator Pete Domenici (New Mexico), whose interest in low dose radiation issues was generated from the scientific debate regarding the appropriateness of the linear no-threshold (LNT) model in radiation protection. Dr. Tony Brooks (Washington State University, Tri-Cities [emeritus]), who served as chief scientist for the program,
noted that the sequencing of the genome and the development of gene expression arrays and multiple cell and molecular biological techniques, provided the springboard for the program to measure biological responses in the low dose (less than 100 milligray [mGy]) and low dose rate (less than 10 mGy/hr) region that was not possible in the past. Initially the program focused solely on radiation biology research, but it later supported one epidemiological study—the Million Worker Study (see Section 4.1.2 for more information).
The program was administered by DOE’s Office of Science. That office was responsible for identifying research priorities, awarding contracts, organizing peer reviews, and monitoring work in progress. Funding for the Low Dose Radiation Research Program reached a high of $28 million and progressively dropped to about $13 million as priorities of the department shifted. The program was finally terminated in 2016.
Dr. Brooks noted the program’s numerous contributions to advancing scientific knowledge of low dose radiation effects. Specifically, he said that the program contributed to the discovery that radiation effects go beyond induction of DNA damage to the cells that directly absorb the dose. Therefore, it challenged DNA-centered theories of radiation-induced damage such as the target theory, which has provided the basis for assuming that radiation dose relates linearly to DNA damage. Dr. Brooks added that the DOE low dose radiation research program provided evidence of systemic non-targeted effects of radiation, including bystander effects and genomic instability measured in cells not directly “hit” by the radiation. Additional contributions of the program included better understanding of adaptive protective responses, molecular pathways activated by low dose radiation, gene expression as a function of dose and dose rate, and systems biology applied for complex responses. According to Dr. Brooks, DOE’s low dose radiation research program also triggered interest in low dose radiation research worldwide.
Despite these successes, Dr. Brooks was critical of the program not having a strategic plan to guide its research priorities. He also said that the program did not have the impact on radiation protection policy that it was originally envisioned to have. Nevertheless, in his view, much of the program’s research findings suggest that the LNT model overestimates risks at low doses and alternative dose–response relationships appear more appropriate for radiation protection.
Dr. Brooks published a book titled Low Dose Radiation: The History of the U.S. Department of Energy Research Program, which summarizes the problems, research advances, and publications from the DOE program.
2.2 MULTIDISCIPLINARY EUROPEAN LOW DOSE INITIATIVE (MELODI), EUROPE
MELODI is a European radiation protection research platform with a focus on research on health effects following exposure to low dose ionizing radiation.1 It was established in 2010 following the recommendations of the High Level Expert Group on European Low Dose Risk Research. Currently, MELODI has more than 40 members from 18 countries who represent national bodies, universities, and research institutes committed to low dose radiation research (Kreuzer et al., 2018). Dr. Michaela Kreuzer (Federal Office for Radiation Protection, Germany) noted that MELODI does not include industry representation in its membership to avoid potential conflicts or perception of conflicts.
A major activity for MELODI is the establishment and regular updating of a long-term strategic agenda for research on low dose radiation. Furthermore, MELODI supports the availability and maintenance of key infrastructures for research activities, training, and education (Kreuzer et al., 2018). In addition, MELODI organizes scientific and stakeholder workshops to promote the visibility of low dose radiation research, to summarize the results obtained so far, and to identify further gaps.
Research supported by MELODI is multidisciplinary and engages epidemiologists, radiation biologists, dosimetrists, and other investigators. It focuses on the following key research topics:
- Dose and dose rate dependence of cancer risk,
- Non-cancer effects, and
- Individual radiation sensitivity.
The organization of funding and integration is described in detail elsewhere (Kreuzer et al., 2018; Salomaa et al., 2017). Briefly, the European Network of Excellence DoReMi (2010–2016) funded by the Euratom FP7 radiation protection program served as an initial operational tool for establishing MELODI and setting up the structures for sustainable integration of research on low dose radiation risk in Europe. Subsequently, the Open Project for European Radiation Research Area (2013–2017) continued the work in establishing a program in radiation protection research in Europe and ran several calls for research projects. Currently, radiation protection research in Europe is organized within the CONCERT European Joint Programme Co-fund Action (2015–2020) and research in implications of
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1 Dr. Kreuzer noted that MELODI defines “low dose” as the dose where there are scientific uncertainties about risks. For example, for cancer risks, low dose radiation is about 100 mSv but for cardiovascular effects, it is about 500 mSv.
medical low dose radiation exposure is organized within the MEDIRAD EU project. Funding for CONCERT and MEDIRAD totals about €30 million within the 5-year project duration (or €6 million annually).
Recognizing the impacts of social influences on radiation protection, a number of research institutes and universities in Europe developed a prospective strategic research agenda for supporting the coordination of research on social and ethical considerations relevant to radiation protection. This strategic agenda for the newly established research platform SHARE (Social Sciences and Humanities) identified several research directions such as understanding the social, psychological, and economic impacts of radiation protection policies, stakeholder engagement and participatory processes in radiation protection research, and risk communication (Perko et al., 2019). The mechanisms for funding the strategic research agenda for SHARE remains to be determined, but Dr. Kreuzer said that it will likely remain separate from MELODI.
2.3 INSTITUTE FOR ENVIRONMENTAL SCIENCES (IES), JAPAN
IES was established in 1990 out of concerns about the potential effects of emissions from the Spent Nuclear Fuel Recycling Plant in Rokkasho Village, Aomori Prefecture, on the environment and human health. As such, the main mission of IES is to monitor radioactive emissions released to the environment and their effect on human health. It accomplishes this through research activities conducted by its Radioecology and Radiation Biology Departments.
The Institute currently has two mouse facilities conducting experiments on long-term low dose rate (0.05, 1, and 20 mGy/day) and medium dose rate (200 and 400 mGy/day) exposures to gamma-rays, comparable to the doses accumulated by radiation workers. Investigation parameters include changes in the animals’ lifespan, incidence rates of cancer and non-cancer diseases, chromosome abnormalities, and transgenerational effects. Dr. Ignacia Braga-Tanaka III summarized some key findings from research carried out at IES on chronic low dose rate radiation exposures in mice (see Braga-Tanaka et al., 2018). Based on that research, chronic low dose rate exposure may induce small biological effects.
IES receives funding from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan through the Aomori Prefectural Government. Dr. Braga-Tanaka explained that research projects are proposed by IES investigators and submitted first to the Institute’s head of research for in-house approval prior to submission to the Aomori Prefectural Government and MEXT for final approval. Approved projects are evaluated at different stages by external expert advisory committees.
IES publishes annual reports submitted to the Aomori Prefectural Government and scientific publications to disseminate its research findings. It also communicates its findings to the public and conducts a series of seminars annually in various areas around Aomori Prefecture to promote scientific understanding of radiation safety for the environment and human health. IES also conducts facility tours, an annual open house, and science classes for children.
Other institutes in Japan that conduct low dose radiation research include the Central Research Institute of Electric Power Industry, the Research Institute for Radiation Biology and Medicine, Hiroshima University, the National Institute of Radiological Sciences, and the Radiation Biology Center at Kyoto University. Dr. Braga-Tanaka noted that Japan does not currently have a nationally coordinated agenda for low dose radiation research and that research at IES is not coordinated with any other national or international institutes or organizations.
2.4 CANADIAN NUCLEAR LABORATORIES (CNL)
CNL in Chalk River, formerly known as Atomic Energy of Canada Limited, began research on low dose radiation in 1948. The laboratories have the largest low dose radiation program in the country and contain a globally unique animal low dose irradiation facility that has been used to address mechanistic questions about the biological effects of low doses, including genetic, epigenetic, and immunological effects. This facility has also been made available to international collaborators.2 More recently, researchers at CNL have been exploring novel areas of research such as the dosimetry and health consequences of space radiation and the use of low dose radiation in cancer therapy and regenerative medicine (Wang et al., 2019).
Current funding for low dose radiation research at CNL is $7 million per year; about 20 percent of this funding is provided by the nuclear power industry and specifically the CANDU Owners Group. Past research-funding organizations included Health Canada and the Canadian Nuclear Safety Commission.
Research funding is accessible only to CNL scientists. To access the funding, CNL scientists submit research proposals, which are reviewed by federal agency representatives and are scored based on their responsiveness to federal research priorities. Dr. Dmitry Klokov identified the lack of peer review and external competition for funding of research projects
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2 For example, Dr. Klokov noted that CNL made the facility available to the French Institute for Radiological Protection and Nuclear Safety to perform experiments in rodents to assess tritium toxicity and its implications for radiation protection.
as limitations of the current approach at CNL and likely an impediment to the quality of research. He also noted that researchers at CNL are typically not eligible to apply for external funding and, because of that, they inherently lack the incentive to publish their findings in scientific journals to promote their work.
Dr. Klokov’s view is that CNL lacks a well-defined long-term strategy to organize the research and that the organization would benefit from better coordination with other institutes nationally and internationally. Health Canada and the Canadian Nuclear Safety Commission are addressing some of these issues by working toward developing a national low dose radiation research program.
2.5 EFFORT FOR GLOBAL COORDINATION, ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT/ NUCLEAR ENERGY AGENCY (OECD/NEA)
Dr. Ted Lazo (OECD/NEA) said that there is a large amount of research in low dose radiation conducted around the world and there are ongoing efforts to effectively collaborate. The NEA Committee on Radiological Protection and Public Health felt that the global nature of ongoing work merits consideration of some level of global coordination. To address the need for global coordination, OECD/NEA organized a scoping meeting in 2018, which brought together 35 participants from 13 countries, including the United States, to discuss priorities of low dose radiation research, available funding sources, and existing mechanisms for coordination and collaboration.
Participants of the OECD/NEA scoping meeting concluded that global coordination has the potential to improve cost effectiveness of existing research, improve research efficiency, facilitate data sharing and improve the quality of results, increase international awareness of research, and facilitate access to unique facilities. Dr. Lazo envisioned that this global coordination can lead to globally shared databases for radiation biology and epidemiology studies as well as for tissue samples. He recognized, however, that global coordination will involve costs and that it may raise intellectual property and other concerns among participating researchers.
To address these and other issues, participants of the OECD/NEA scoping meeting recommended that a high-level group should be established by OECD/NEA to support the development of a global coordination initiative. The expectation is that this group could help participating countries to orient their low dose radiation research programs in a coordinated fashion, and to make recommendations as to best practices in planning,
implementation, and reporting of results. In Dr. Lazo’s opinion, research funding organizations need to be the focal point in achieving this coordination. He added that the strategic research agenda development process used by MELODI could be a starting point for global coordination of priorities in low dose radiation research.
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