The roles of science, ethics and politics are identified in respect of the risks of exposure to low-dose radiation. Two case studies, the epidemiology of the United Kingdom nuclear test veterans and the risks to civilians associated with the military use of depleted uranium, are considered in the context of their ethical framing, scientific evaluation and political resolution. Two important issues for the present and future, the safe management of UK radioactive waste and the future of nuclear power, in which the science of low dose effects will be crucial and where the ethical issues are much more complex, are introduced. Specific consideration is given to the potential hereditary effects of ionising radiation in relation to the current state of radiobiological knowledge. It is concluded that for science to be useful in public health policy making there needs to be some reform from within the profession and the political imperative for freely independent scientific institutions.