Response concerning the ICRP Publication „Radiological Protection from Cosmic Radiation in Aviation“:
1) All recommendations mentioned in this publication are already in place within the European Community. Therefore, the document is about 10 years too late. In contrary to the most recent European legislation, laid down in the Council Directive 2013/59/Euratom of the European Union, where the exposure of aircrew to cosmic radiation is considered as a planned exposure situation, ICRP recommends it as an existing exposure situation. ICRP should follow the European legistlation.
2) ICRP should be in a commercially independent position when publishing recommendations. In this document the program codes SIEVERT and EPCARD, the latter provides the dosimetric input for SIEVERT, are explicitly named. Others are not mentioned at all. Although EPCARD was originally development within a research project funded by the European Commission, it is promoted in the document. Since nowadays EPCARD is a commercial code, some of the authors cannot be assumed to be independent of commercial interests.
The detailed description of the way how SIEVERT integrates the dose along a flight path (page 19) does not represent the methods of other codes.
An excellent overview on the existing codes is given by the EURADOS Report 2012-03 "Comparison of Codes Assessing Radiation Exposure of Aircraft Crew due to Galactic Cosmic Radiation" which can downloaded via www.eurados.org . This document is not mentioned at all.
Therefore, I recommend either to name all existing codes which are available, as done for example in the EURADOS Report, or to omit the mentioning of a single code.
3) What is missing in a new ICRP documentation is how to act in case of an intense solar particle event (SPE). It is mentioned on page 18 that it is “almost impossible” to calculate the dose during an SPE in advance and that the retrospective calculations of the dose is associated with large uncertainties “of the order of factor 5 or more”, as published by the EURADOS Working Group 11. Thus, since the scientific problem is still under discussion, recommendations for the radiation protection authorities on how to proceed in case of an SPE are required. Classifying the possible doses owing to an SPE as „marginal“ compared to the lifetime exposure is not an acceptable recommendation.
4) An SPE is not always leading to an enhanced dose rate at aviation altitudes. Here, the description of a GLE, a Ground Level Enhancement of ground based neutron monitors, needs to be included. There are many SPEs during a year, but only a few SPE lead to a significant GLE. And only a very small number of GLEs have the potential to be attributed to an increase of the dose rate at aviation altitudes.
5) What is also missing: what qualifies a code to be used for the calculation of doses during a flight? Nothing is said that approved codes should be used, only. Nothing is said about how to approve codes and nothing is said on the criteria to validate the route doses with measurements. Such kind of recommendations I would expect from ICRP.
6) It is not understandable why frequent flyers, flying owing to their professional duties, are classified as „public“. In addition, there are more professional groups which are exposed to cosmic radiation at altitude; some of them do not have labour regulations as in aviation which limit their working time at altitude. Why does ICRP ignore these groups?
7) According to the reference values of dose rates in ICRU 84 it would be desirable to have a catalogue of city pairs for which the route doses can be calculated on simple assumptions: great circle, average altitudes and flight times. Appendix A is such an approach but the calculations are probably not in line with ICRP 103 (?).
8) The data shown in Fig. 4, Fig. 6 and Fig. 7 are older than 5 years and the references are questionable and not citable or no reference is given at all (Fig. 6).
Summary:
The ICRP document published for consultations summarizes recommendations which are already implemented in the national legislations, at least in most countries of the European Union. The report itself is not in a shape to be published as an ICRP publication. Looking on the list of authors I doubt that all of them contributed to the present version of the publication because some of the authors are experts which should be aware of all the points mentioned above.
I recommended to revise the current version.
Dr. Frank Wissmann
Physikalisch-Technische Bundesanstalt (PTB)
Bundesallee 100
38116 Braunschweig
Germany