Protective actions in the late phase - intervention criteria and decision-making

Major countermeasures in the late phase of a nuclear or radiological accident where long-lived radionuclides have been dispersed in the environment are relocation/resettlement, foodstuff restrictions, agricultural countermeasures and cleanup of contaminated areas. A short overview of late phase countermeasures is given together with the recommendations from the international radiation protection organisations ICRP, IAEA and from the EU on the levels of their introduction. The derivation of these intervention levels is briefly addressed. Decisions on late phase countermeasures include factors or attributes describing benefits from the countermeasure and those describing harm. In analysing the inputs to the decision, it is necessary to decide on the relative importance of each factor. Although there has essentially been a broad acceptance internationally of the principles for intervention, it has not been possible to reach agreement for the purpose of defining a net benefit based upon the exact weighting to be attached to each of the attributes influencing the decision to take a protective action. Major attributes would include those related to radiological protection, and those related to social and psychological issues. Some of these attributes are discussed in the paper and the role of radiation protection in the final decision-making process is elaborated in some detail. It is concluded that optimisation of the overall health protection is not a question of developing radiation protection philosophy to fully include socio-psychological factors. It is rather a question of including these factors - in parallel with the radiological protection factors - in cooperation between radiation protection experts and e.g. experts in social and psychological sciences under the responsibility of the decision-maker. The overall optimisation of the total health protection, i.e. the final decision on the introduction of long-term countermeasures is therefore the sole responsibility of the decision-maker. It is further concluded that it seems to be an illusory goal to arrive at internationally accepted intervention levels based on an “optimisation” of overall health protection, which includes all the relevant radiological protection and non-radiological protection attributes.