|The recent history of ICRP 2005 appears to some as “jumping as a lion and ending as a bed-rug”. There have even been discussions to develop alternative basic radiation protection recommendations, taking into account many of the recent results in radiation biology, epidemiology, but also socio-economic factors, cost/benefit considerations, and so on.
ICRP Secretary Jack Valentin will remember a European Parliament hearing some years ago in Brussels, in which some radiophobiacs complained about ICRP being an ex nihil self-appointed and self-reproducing NGO without any democratic legitimation. He remarked that the same applies to Greenpeace as well as many other well-known organizations, and that the state of affairs would be even worse if ICRP would include official delegates from militantly anti-nuclear governments (probably including Germany).
There are old proposals, dating back at least to Alvin Weinberg in the 1950ies, to take the wide (and obviously harmless) variations of natural background radiation as a yardstick for establishing a threshold. Others suggested the death toll in other energy-producing industries, e.g. the global death rate per TWh for various fossile fuels, collapsing hydroelectric dams, etc., as a basis for comparison with nuclear power and the many benefits of radiation sources in industry and research, not to mention medical diagnostics and therapy.
The ICRP response is hidden in the first lines of ICRP 2005 (S2): “This aim (to provide an appropriate standard of protection to man) cannot be achieved on the basis of scientific concepts alone”, and later (184): “This was achieved by world-wide decisions by governments, courts, public inquiries…” But why? It may be obvious to some of the seasoned personalities in the international “radiation protection senior establishment”, who are usually active in several overlapping capacities in different bodies. However, some naïve practitioners working on their daily tasks still assume that ICRP recommendations are NOT influenced by (or even based on) the changing patterns of current political trends, publicized/public opinion, Political Correctness, compromises between opposing ideologies, and other complicating factors - instead of an unbiased, non-selective evaluation and implementation of solid contemporary scientific facts.
In S4, it is said that ICRP 2005 represents “the natural evolution and further clarification of the 1990 Recommendations”. Does the introduction of the “stakeholders” (S11) represent such a clarification? The immediate association with this somewhat unusual term is probably “shareholders”. It requires some research in dictionaries to find out that a stakeholder is “the holder of the stakes of a wager”, and that a stake is “a stick or post pointed at one end to be wagered in a game, race, or contest” (American College Dictionary). The most recent Langenscheidt edition defines: “Somebody who administers the stakes in a game or bet.” Now we know whose opinion is so important.
It is stated (S6) that “there is presumed to be some probability of health effects even at small increments of exposure above the natural background”. This statement could be confirmed by a multitude of serious studies about the positive health effects of moderate increases of radiation exposures. One of the most recent example is the preprint of a 51-page study on Radon Therapy, with the recent ICRP Main Commission member and UNSCEAR chairman Alexander Kaul as one of its six well-known authors. It confirms that even small radiation doses can, as demonstrated in several clinical double-blind studies, have beneficial effects on painful arthritic and rheumatic diseases - without the nasty and frequwently lethal side-effects of non-steroid antirheumatic drugs (see www.radiz.de/Radon_als_Heilmittel_Vorabdruck).
This is not the place to discuss again the old question whether the low population exposure limits of 1 mSv/y, and the extremely low (0.04 % of the average natural exposure!) 0.01 mSv/y as constraint limit (Table S1), make any radioprotective sense. We all know about a plentitude of persons dealing with NORM materials far exceeding 0.01 mSv/y. Probably the main reasons for such limits are vested interests as a multibillion source of income for relevant industries in decommissioning, remediation, instrument manufacturing, consulting, media fear-mongering, for otherwise useless administrators, etc., as well as for activists promoting anti-radiation, anti-nuclear politics. Clearly they want “to keep the radiation hazard alive” by all means – including perhaps many health physicists and radiation researchers fearing for their comfortable job.
This is a also a matter of ethics. In Germany, in economically difficult times there are many better uses for research, education health care, etc., for the billions which could be saved by simply raising the release limit by a factor of ten to 0.1 mSv/y - certainly without any detrimental health effects in the population. The situation is similar in other countries. For instance, the U.S. Congress General Accounting Office released 2000-07-14 a statement that the scientific basis of radiation standards is inclusive: “A disagreement between federal agencies over what level of radiation exposure is safe was not based on scientific evidence and could cost the taxpayer billions in unnecessary spending…The question, is it justified to spend money if you are not sure that there is some benefit derived from spending that money?” At least some companies in this profitable field will certainly benefit…”
One remembers conversations on occassions such as the IRPA Congress in Sidney and an IAEA Conference in Sevilla, when Dan Beninson remarked that the only benefit of LNT is that it simplifies book-keeping – and that something was deeply wrong with the official radon assessments. Later, according to suggestions by Roger Clarke for future ICRP actions including modifications of the LNT/collective dose hyothesis (to which Bo Lindell remarked in an after-dinner speech in Stockholm: “Only over my dead body!”), re-consideration of a lower value for the RBE of alphas should be on the ICRP agenda for future activities. Other Main commission members also said that this value would need correction, and Herwig Paretzke recently translated translated RBE into “Radiobiologist’s Biggest Error”.
ICRP is certainly aware that current national residential radon regulations in many countries specify limits much below the ICRP 2005 Recommendations of 600/1000 Bq/m³. For example, EPA limits residential radon in the USA to 138 Bq/m³, and the EU considers 250 Bq/m³ as European compromise between different national regulations. In general, experience shows that it is easy to lower limits, but politically difficult to raise them to previous and/or more reasonable levels.
It was, therefore, not surprising to find in Table S3 the Weighting Factor for alphas still at 20. Some softening of this statement in the draft (77) (“a weighting factor of 20 for alphas may be a rough conservative estimate”) and 104 (“it is recognized that for a number of sites, e.g. the lung, there are significant differences”) unfortunately does not improve the actual practical situation. As we know, most serious scientists in this field consider 5-10 closer to a reasonable average between various end points, considering the Ra dial painters, Pu in the lungs in Russian reprocessing plants, Hanford dog studies, and so on. If interested in details, a recent review (K. Becker, Health Effects of High Radon environments in Central Europe: Another Test for the LNT Hypothesis?, Nonlinearity in Biology, Toxicology, Medicine 1/1, 3-35, 2003) may be useful.
S15 states: “It is self-evident that the Recommendations are restricted to sources which cannot be controlled by reasonable means”, and S23 “natural sources insofar as they are controllable” Such statements raise many questions regarding the interpretation of ”controllable by reasonable means”. Almost everything is controllable at high costs to the taxpayer or industry. The multibillion projects of reducing radon emanation from overground waste heaps in former uranium mining areas in East Germany, and extraordinary decommissioning costs for a small reprocessing plant in Karlsruhe/Germany, are among many recent examples. How about mines in countries where expensive new anti-radon ventilation measures would result in bancruptcy of the company, or even seriously damage a whole national economy? How about mines in Namibia where X-ray checks of departing miners for swallowed diamonds, or of smugglers arriving in European/US airports with drug packets in the intestines, are prohibited because they are not medically indicated, age-checks of illegal immigrants by a X-ray check of the hand, etc. etc.?
There still is the old question about the application of quite different double-standards between the highly variable “natural” and medical exposures on the one hand, an the exceedingly tightly controlled “artificial” sources on the other hand. Do we really need such double-standards, and how much money and manpower – not to speak of concerns for their personal safety among the less-informed people – could be saved by a less restrictive approach to setting limits?
Everybody can certainly agree with the statement (37) that “the relation between exposures and health effects is complex.” This should be explained. And what does this statement (48) exactly mean: “Averaging of absorbed dose… is only possible under the assumption of LNT. All protection quantities rely on this hypothesis”? Did I miss here some hidden explanation? This also applies to 106-109. As far as I know, genetic radiation effects have never been seen in humans, so how can “lethality adjusted heriditary effects justified by the data” (what does this mean to the reader?) be justified?
As a cell cannot distinguish between sources of radiation, some readers may ask why there are three separate classes (129): “Occupational exposures, medical exposures, and public exposures”. Things become even more interesting in No. 200: “The Commission considers that collective dose is not to be used on its own in making decisions, because it may aggregate information excessively. For making decisions, a large dose to a small number of people is not equivalent to a small dose to many people…”
Why is it only “considered” without any clear and specific recommendations? There are more cloudy considerations, e.g. in 202:, where a “dose matrix to be considered should involve the number of exposed individuals, dose distribution in time, age, and gender”. This is one of the topics where clear and precise numerical figures are badly needed! More importantly, could this imply a departure from LNT? Actually, looking at the graph on p. 18 of the recent IAEA booklet “Radiation, People and the Environment”, in which the background dose is properly considered (average of about 200 mSv lifetime dose excluding, and 400 mSv including medical exposures – with the well-known wide variations), there is a clearly indication of a threshold - and there is no obvious reason why such a threshold could not be fixed on a higher dose level.
Among the topics left out in Chapter 10 on potential exposures, there are the much-discussed “dirty bombs” for the wide distribution of radioactive materials in order to create public chaos and close down important infrastructure facilities, based on current limits. I understand that in the U.S., where this issue has been under careful study for anti-terrorist reasons, new limits permitting much higher population doses than the ICRP have been proposed for dirty-bomb emergencies.
Many questions could be raised about the new Chapter 11: “The Commission recognizes that there is a need to explore further the nature of “risk” that may apply to other species…”. As far as I know, the only species which has a LD 50 slightly lower than humans are goats and pigs. Should we limit their annual exposures to 0.8 mSv? On the other hand, there are many animals and plants which are orders of magnitudes less sensitive, down to some bacteria which are essentially radiation resistant. Should we really spend valuable time and money on such exotic considerations, e.g. the potential radiation sensitivity of not yet discovered species (perhaps including the Loch Ness Monster?). And do AIDS virus, mosquitos, and other unpleasant creatures also require radiation protection? An experienced, and consequently somewhat cynical friend suspected, during a meeting on this subject in Taormina/Sicily a few years ago, that the main purpose of issues such as stakeholders, obscure creatures, ethics, and philosophy is simply promotion of Meeting Tourism to pleasant locations…