Partial transcript of conversation between Professor Chris Busby, Scientific Secretary of the European Committee on Radiation Risk,
Dr Jack Valentin, Scientific Secretary Emeritus International Commission on Radiological Protection.
Part of a public meeting in Stockholm, 22 April 2009 marking the 23rd anniversary of Chernobyl.
CB: As scientists we ought to look at all sources of information, but ICRP has never cited any one of the many articles that falsify [ICRP] or which show your levels of risk are in error. Why?
JV: This puts me in a slightly difficult position, of course, because I tend to agree with you — we should have quoted some of your stuff because since we don’t agree with what you are saying we should then have said why we don’t. […] If you’ve got the Scientific Secretary of ICRP you press a button on its back and it says what it’s supposed to say but I’m retired so I can say what I like But not many people are greatly impressed by the evidence that you bring. It would have been much wiser in that situation to state more clearly why we are not impressed, thus giving you a chance to come back again. [Then we could have a debate and understand why we don’t agree with each other.]
CB: [cited as an example the 2006 ECRR publication Chernobyl 20 Years On and a “Russian studies” section of the 2004 Minority report of the UK Government Committee Examining Radiation Risks of Internal Emitters, CERRIE] … hundreds of references from the Russian language literature showing extraordinary effects from radioactivity – on genomic instability, genetic effects in plants and fish which cannot suffer from radiophobia — an enormous document which has been entirely ignored, suggesting bias.
JV: I have already agreed [ICRP, UNSCEAR, BEIR should not ignore these findings] But we’re not talking here about individual results but on most of them I believe my colleagues would make technical comments [on individual results].
CB: Don’t the leukaemia clusters near nuclear sites falsify ICRP?
JV: but there are other clusters around sites which were proposed for nuclear power stations but the reactors were not built.
CB: That study is confounded by the unused sites being on previously contaminated sea coasts and in areas of high rainfall [and high weapons fallout].
JV: We’re now talking about confounders — that’s the problem we have with all of your [epidemiological] studies. You have insufficient controls. ICRP has no official position on this but in principle people don’t agree and will point to [epidemiological] studies where you get quite contradictory results, for example lowered cancer. Bernie Cohen and radon is the most famous, falsely showing a health benefit of radiation.
CB: These arguments about confounding disappear in the case of infant leukaemia after Chernobyl. The babies were in the womb. The same results from 5 groups in 5 countries published in different journals with doses calculated in microSieverts but statistically significant excesses. How do you explain that?
JV: I can’t, but I don’t think you have enough explanations either. I honestly don’t think you can convince me that you are right. There are technical arguments. We should have emailed reports and gone them slowly and thoroughly. That would be a clever way of continuing a discussion between ICRP and ECRR.
CB: Yes and no, but to get here we have had to be robust, chaining ourselves to nuclear power stations, writing in the literature and using every possible method of publicising that your risk model is bankrupt. Otherwise we wouldn’t be here.
JV: Are you sure you wouldn’t have had more success if you just came up friendly like and talked to the people at the Health Protection Agency? [UK radiation protection advisers]
CB: [refers to long and well known experience of bad faith in various dialogues including by the Chairman and secretariat of CERRIE and the UK government departments involved.]
JV: Yes and I have heard many stories not very favourable to you. It’s a mistake to look back and argue about who did things wrong. Can’t we look forward and be more constructive?
CB: Yes, I agree. I have a question here that I was asked to put to you. It is “Can the ICRP model be used by Governments to predict the consequences of a nuclear accident, in terms of cancer yield?”
JV: Basically no, because the uncertainties we are talking about would be too large; one order of magnitude. You are talking about two orders, but even at the one order I am talking about it’s not useful for that sort of prognosis.
CB: What’s the point of it then?
JV: We’re talking of the upper limit of course. Your most likely number of cases would be X but ten times X cannot be excluded.
CB: Ok, ok, ok, and that means it is useful. So would the Government be formally reasonable, using ICRP risk models to calculate the risks — the cancer yield — from some hypothetical explosion at Barsebeck for example, even if they’d have to say it might possibly be ten times that predicted figure? Formally?
JV: It would automatically be misused by both camps and that therefore is why it is not … you don’t do it like that. You look at individual doses — the highest individual doses and calculate which is the sort of area where people should not live — which is the sort of area where they should have special needs — quick evacuation in case of emergency so this number exercise. I think it’s just silly. It serves no good purpose whether you’re in your camp or a pro-nuclear camp or an ICRP camp.
CB: Well in this case I’m in a political camp […] there are questions that politicians need to know the answer to. When you build new nuclear power stations, or [consider] any nuclear policy, you need to know what would happen if something went wrong. You need some kind of model, and at the moment they are using your ICRP model. Are you saying they should be or they shouldn’t be? You seem to be saying they should use no model at all. Is it guesswork, or what?
JV: Well I certainly wouldn’t say they should use your model because …
CB: ECRR gives the right answer
JV: … no it’s the wrong answer, leading to large expenditure that would not be sensible and could be used to save lives in other [ways]
CB: The draft ICRP Recommendations said that for many internal exposures the concept of absorbed dose was not valid. We would agree with that of course, but it disappeared from the final report. Why?
JV: In fact there is a whole section of the Biological annex which talks about the difficulties. I don’t know exactly why the specific statement disappeared but a person reading those paragraphs in the annex will be able to see there’s huge uncertainty.
CB: We’re not talking about uncertainty but about the impossibility of using absorbed dose for internal nuclides.
JV: ICRP’s position is that it’s possible to use it albeit with large uncertainties.
CB: How large is large?
JV: Two orders is a very large uncertainty.
CB: So it could be in error by two orders for some internal exposures — so we agree?
JV: (laughing) I’d hate for you to go home and say “Jack agreed with me”
CB: but I need an answer
JV: Then the answer is I don’t agree with you. (laughing)
CB: but you just said Two orders of magnitude …
JV: Yes but you can find, I’m sure you can find, an exceptional case, a specific case, where there would be that sort of uncertainty but remember it can go in another direction, and I’m sure that you can find in most cases there are uncertainties which are less than one order of magnitude, which you would find normally. If we look at the existing evidence I don’t think you have enough evidence to prove your case.
CB: The existing evidence is three orders of magnitude, if we take the childhood leukaemia clusters around nuclear sites; three orders.
JV: That’s what you are claiming on the basis of a handful of cases.
CB: I’m claiming it on the basis of the German study, Aldermaston, Sellafield, Harwell and many others […]
End of extract.
Later Professor Busby addressed the Swedish Radiation Safety Authority, SRM. Deputy Director Carl Magnus Larsson said the ICRP model cannot be used to predict the health consequences of accidents. He added that for elements like Strontium and Uranium which bind to DNA national authorities would have the responsibility to assess the risks. Another SRM member said that the Secondary Photoelectron Effect was well recognised, also that in 1977 the ICRP had considered a weighting factor ”n” for elements which bind to DNA but had not implemented it.