Comments of the Federal Agency for Nuclear Control (FANC: Belgium) on the draft 2005 Recommendations of ICRP
The present comments are focusing on the issues the FANC considers to be crucial after having reviewed the draft 2005 ICRP Recommendations, taking into account the results of the EU Conference on 4th November 2004 devoted to the Critical Review of these Recommendations. They are not intended to give an exhaustive list of all the identified questions.
1. The principle of justification should clearly remain one of the three basic pillars of the system of dose limitation, together with optimisation of protection and dose limits. In the current situation, it does not only apply to types of practices at the level of the regulatory authorities, but has become a component of the safety culture at all levels, including in the management of practical situations and individual exposures (not only medical exposures). Because justification makes everyone aware of his responsibilities, the fading of this principle really undermines the current system of radiation protection.
2. Dose limits (in normal situations) and intervention levels (in accidental or preexisting situations), both based on risk approaches, should also remain basic pillars of the system of dose limitation. Dose constraints are a very useful tool to guarantee equity and to favour good practice: their promotion is welcome, if embedded in the system of justification/optimisation/dose limits (in a graded approach where regulatory constraints are completed with local operational constraints). Holistic presentations, like in Table S1, are mixing the concepts and the rationales and the reference to the background is in no way a good basis “to judge the need of action”. It should be clearly stated that the current concepts, rationales and figures used in radiation protection (and based on ICRP recommendations) are still valid and that the Table S1 should be considered as a communication tool.
3. The new risk coefficient proposed for radiation-induced hereditary diseases should be seriously reassessed. When evaluated on comparable bases (risk for the first generation, for 2 generations, …) , the genetic risk is not reduced in the UNSCEAR 2001 Report by comparison with the UNSCEAR 1993 Report. The sharp decrease of the genetic risk coefficient recommended by ICRP in its new draft is based only on its choice to take now the effect on the generations farther than the second as being zero. ICRP justifies this decision by radiobiological data suggesting that the major contribution to the genetic risk comes from large deletions expressing themselves essentially in the first generations and by the numerous uncertainties involved in the estimation of the long term genetic risk. Doing this, ICRP recognizes on the one side that considerable uncertainties still exist in this field but, on the other side, it paradoxically claims that enough is known as regards the mechanisms of radiation-induction of genetic effects to allow to ignore the possibility of significant long-term risks. On scientific grounds, it is plausible that the genetic risk coefficient could be higher than the new ICRP estimation and even higher than its old estimate. One can doubt whether the risk evaluation in the ICRP draft recommendation can be considered as a balanced position according to the present scientific knowledge. The new evaluation of the genetic risk by ICRP evokes also ethical questions. By giving an authoritative message that the genetic risk is lower (and therefore of lower concern), while ignoring deliberately possible long-term victims, ICRP adopts an ethically disputable attitude. First, ICRP takes a position exactly opposite to the application of the principle of precaution (understood here as recommending measures of precaution or prevention to avoid plausible but uncertain serious detrimental effects). Secondly, due to its scientific authority, ICRP influences the societal and regulatory actors that have actually to decide on the necessity to apply or not precaution measures. As an example ICRP’s position is likely to discourage medical practitioners from making efforts to limit or avoid gonadal exposures.
4. The persisting uncertainties and the new experimental evidences in the field of the effects of in utero exposure are not sufficiently emphasized and taken into account in the draft 2005 ICRP recommendations. There are new data concerning the role of genetic predispositions in facilitating the radiation induction of congenital malformations after irradiation during the first weeks of pregnancy (including the pre- and post-implantation periods). In these cases, the cause of the congenital malformation may not be an increased loss of cells (classic deterministic effect) but rather the persistence of unrepaired or misrepaired DNA-damaged cells. The policy implications of these recent studies have been discussed recently during a EU Scientific Seminar on Effects of in utero exposure to ionising radiation during the early phases of pregnancy (proceedings available on the web site of the European Commission: Radiation Protection 131). In this context, the reduced attention for the protection of pregnant women in the draft ICRP Recommendations, for instance in the section concerning the medical exposures and in the case of the prolonged exposure situations (§118), must be strongly challenged.
5. Globally, the issue of the individual differences (due to age, gender, genetic susceptibilities, …) is not appropriately taken into account in the draft recommendations, even in the high exposure situations. This issue should be carefully discussed and reassessed.
6. Uncertainties may be significant in internal exposures (at least for some radionuclides). Currently these are hardly mentioned and taken into account, although there are clear implications in the field of the possible application of the precautionary principle.
7. The principle of exclusion levels for artificial radionuclides is not acceptable. The scope of the regulation in radiation protection is not defined only by a set of numerical values: regulatory provisions may follow from the application of the principles of justification (toys,..) and optimisation, whatever the present activity concentrations. The FANC considers therefore that exclusion levels for artificial radionuclides are not justified, although exemption levels for bulk amounts of material containing radionuclides of artificial origin (as proposed by IAEA in the Safety Guide RS-G-1.7) can be useful. Exclusion levels for natural radionuclides may be considered but such figures must be assessed carefully as the currently proposed values may lead in some particular situations to very high exposures. However that may be, the usefulness of a set of values for radionuclides of natural origin is not so obvious, as a case by case approach is often more recommended in this field.