What’s safer, the radiation dose or the protective action? Developing a tool for justified protective actions in nuclear and radiological emergencies

The lower the dose, the 'safer' you are… but is that really the case in an emergency? The inferred (non-discernible) risks from radiation for low doses (below 100-200 mSv) are applied rigorously for emergency planning. However, the observable risks associated with protective actions, e.g. evacuation, have not yet been fully evaluated. Experience from the Fukushima Daiichi accident and hurricanes in the USA indicates there will be an observable increase in mortality associated with evacuating and dislocations particularly for residents of facilities for long stays and the elderly. In addition, mental health effects have been possibly the most severe health effects associated with past major nuclear power plant emergencies. A tool is needed to evaluate protective actions to ensure they are justified considering both the health risks of radiation exposure and protective actions. An analysis was performed of mortality and mental health effects associated with protective actions compared with the inferred radiation-induced deaths averted by protective actions. The results were presented in terms of absolute risk (cases per 1000) of health effects, which is an understandable way to compare and communicate risks. The analysis indicates that taking protective actions consistent with dose criteria typically used in many countries could result in observable deaths when trying to prevent the inferred (non-discernible) radiation-induced deaths. Residents of facilities for long stays and the elderly are particularly vulnerable.