Ethical aspects of radiation protection

Abstract: This aim of this thesis is to examine ethical aspects of radiation protection from ionizing radiation. Radiation protection is the professional field that deals with the protection of humans and the environment from the harmful effects of radiation. The field is based on scientific knowledge of the health effects of radiation, but also on ethical value judgements. This thesis consists of a summary and three essays. Essay 1 gives an overview of ethical issues in radiation protection. Based on this overview four ethical problem areas are identified as central for radiation protection. The first are ethical problems related to uncertainty and the influence of value judgements, especially in scientific risk assessment. The second problem area is ethical issues regarding distributions of risks and benefits between different individuals, both in space and time. The third general problem area is related to limit-setting. A major problem here is how to set limits in an ethically justifiable way when there is no known level of exposure that is associated with a zero risk. The fourth area concerns procedural justice and social decision-making in radiation protection. Essay 2 discusses ethical problems related to the proposal that individual risks below a certain level should be excluded from the system of radiation protection, without any regard to the number of people exposed. It is concluded that there are at least three problems associated with disregarding very small risks: (1) that many small risks to an individual may add up to a large risk for that individual, (2) that many small risks to many individuals may add up to a large expected value of harm, and (3) that a small risk each to many individuals may add up to a large probability that several people are harmed. It is also argued that the proposal is hard to justify in a rights-based ethical setting. Essay 3 examines what makes one distribution of individual doses better than another. This is done by creating a mathematical framework, based on preference logic, in which such assessments of can be made precisely in terms of comparisons between alternative distributions of individual doses. Principles from radiation protection and from parallel discussions in moral philosophy and welfare economics are defined using this framework and then analysed on basis of their formal properties. The analysis shows that there can be efficiency-related problems with a strict application of individual dose constraints. It is concluded that a principle that assigns extra weight to individual doses exceeding a certain limit, in proportion to the size of the excess dose, may be preferable to the standard combination of principles in radiation protection, since it satisfies efficiency related properties better without sacrificing other desirable properties.