One of my associates at the laboratory, Dr. Bustad, is currently preparing a rather extensive study on this point which collects, I would say, having had privileged access to it so far, a surprising number of cases in which it is difficult to say that the effect may not be real. This is perhaps a double or triple negative way of putting it. I could perhaps suggest to the committee that Dr. Bustad make this available to you as soon as it is possible to release it.

I would simply say there is a very clear factor that reduces the number of observations of this kind in the literature; namely, the factor that most responsible observers think it really is not so and there is a rather clear record if your long experiment shows that it is so, you do the experiment over aagin until it does not come out in that way.

Dr. FAILLA. I think we have to put in the record something about this question of averages for the population dose, because it is not only necessary to have the average for the population dose, but also the maximum. Otherwise, you might have some individuals receiving very large doses which when averaged over a large number of people that receive no exposure would make the average low. I think it is very important to bear in mind that in making recommendations for a population you must have not only an average dose, but also a maximum dose for an individual in the population.

Chairman HOLIFIELD (presiding). Gentlemen, we are going to have one more question. We are going around the table with it rather rapidly. We must get out of here by 3:30 and get to the floor to do some voting.

Mr. Hollister?

Mr. HOLLISTER. Would the roundtable like to express its views to the committee on the way in which you think it might be appropriate for the Federal Radiation Council to use or take advantage of the extensive studies of biological data that are done by the National Academy study committees and by the NCRP?

Chairman HOLIFIELD. Dr. Schubert?

Dr. SCHUBERT. I am not sure if I understand your question precisely. Mr. HOLLISTER. I am sure you know of the National Academy studies. These are reported in the National Academy reports on the biological effects of radiation. The NCRP through its various subcommittees, I believe, makes extensive reviews of biological effects data. The question is, how do you think the Federal Radiation Council might take advantage of these studies or should they take advantage of these studies, or should they ignore them?

Dr. SCHUBERT. I think what is true of the Federal Radiation Council in this sense is true of the NCRP which automatically uses all data involving radiation which might have a bearing on biological effects of radiation, particularly in low doses.

If they think it is valid they incorporate it in their standards and in their evaluation of what is dangerous. Certainly the FBC would and should do the same things and use the data from other sources. There are many AEC contract institutions and AEC installations which are also doing long-range studies on the effects of internal emittors and so on. If they have any possible bearing on man then they are, of course, utilized and properly so now.

Dr. CROW. I, of course, think that the Federal Radiation Council should use all the data they can get hold of, whatever the source.

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think it is part of the directive to this council that it is expected to consult at least with the NCRP and with the National Academy of Sciences. I guess that is all I have to say.

Mr. TAYLOR. I cannot see any particular problem here. I think that any group called together or organized to consider this problem would study all information available in the literature. It would particularly study analyses of this data made by other bodies, such as NCRP, I am sure the Radiation Council will and is doing the same thing. I do not think any scientific approach can be made to the problem without doing this virtually automatically.

Dr. LEWIS. It is my impression that the Federal Radiation Council, through its working group, has already made excellent use of the extensive studies made by other committees. I think Report No. 1 of the Council well shows this. I think also that it is a very commendable procedure to have set up a working group which can devote virtually full time to thinking about these problems.

Mr. PARKER. I would like to make a somewhat oblique answer to the question in these terms: I believe one could muster a substantial body of opinion that would say that at the present time in the United States, there are existing, well-qualified, technically expert bodies in the aspects of radiation protection which exclude those terms that were referred to as the social, economic, and political positions.

In addition, this body of opinion would recognize that your committee, Mr. Holifield, is the best informed group of men who have studied and demonstrated a considerable competence in getting hold of all the problems of this radiation position, and that your committee is in a position to call before it the other responsible voices of public opinion which the scientists are repeatedly saying are needed to balance the overall situation.

Possibly, the most useful contribution would be if your committee would consider calling reviews, as it were, of this matter at a public forum at an interval of possibly 2 years or some such period.

Chairman HOLIFIELD. Dr. Failla?

Dr. FAILLA. All that I want to add to the discussion is that these new bodies that come into the picture from time to time have to go through the same painful process that NCRP has been going through, and the people that can supply the information are essentially the same ones. The same people are called upon to present the problem to a new group. It seems to me that it is a waste of scientific manpower to have to do this time after time with one body or another and at frequent intervals. I think the best solution would be if the Federal Radiation Council and NCRP came to some agreement as to what each would do and divide the field, really, rather than having the whole thing gone over again by the Federal Radiation Council.

Dr. NEWELL. Mr. Holifield. I would like first to say that I do agree with what Mr. Parker said. I would also say that the question posed sounded to me like a request for a scientific review article. This, I believe, is not best produced by committee, but is best produced by some individual scientist who is willing to devote himself to collecting the best information he can. I think that this is more nearly the function of the National Academy of Sciences than it is the function of the Radiation Council.

It seems to me the Radiation Council would be in the position of receiving such an article rather than producing it. I also think that the national committee has probably at one time and another listened to men of understanding in this field as widely as any committee of the National Academy has done. Nevertheless, what you have said sounds to me more like a job for the National Academy than it does for the Radiation Council. I will say this: Some of our national laboratories are probably in the position to produce such a document if you really meant it wholeheartedly that we do need such a summary document.

Dr. SNYDER. I think as a practical matter, the Federal Radiation. Council in the immediate future will have to go outside to seek information. It will certainly take time to build up the extensive staff that would be necessary to assemble and judge the information itself.

A glance at the roster of names of members of the NCRP and ICRP will show the vast diversity of disciplines that are represented there. This is also true of the testimony that is the basis of the Report No. 1 of the FRC. At the present time the FRC must somehow gather together the testimony from outside its own organization. This technical knowledge and expertise may be very well placed within Government, if one prefers, or it may be sought from such agencies as the National Academy or NCRP. This is a matter, I think, for the FRC to consider and decide what its working relationship should be with these independent organizations. It is clear that the FRC has a very important function that is not covered by these other agencies. It is the proper place, in my opinion, where this balancing of national interests and the interests of society against the risks of radiation hazards should take place.

Dr. MORGAN. As already pointed out in these hearings, there is a wealth of information on radiation protection. Nevertheless, there is a scarcity of data in establishing acceptable exposure levels. But there is an even greater scarcity of trained personnel that have competence in this field of health physics or radiation protection.

It seems to me that it follows definitely that the Federal Radiation Council should call in the experts in these many different disciplines; disciplines of physics chemistry, health physics, biology, geology, meteorology, and so forth, all of which are involved. So, rather than a man putting on a different hat and coming and joining permanently with many others as members of the Federal Radiation Council and building up an immense organization to represent all of these disciplines, it seems to me more practical to call in from time to time the experts that are now members of the National Committee on Radiation Protection, the United Nations Scientific Committee on the Effects of Atomic Radiation, and the National Research Council, and use to full advantage these forces and these organizations that already exist.

Chairman HOLIFIELD. In other words, your thought is that the function of the Federal Radiation Council should be evaluating body, possibly anoverall coordinating body and a policymaking body from the standpoint of dealing with the different agencies charged with these responsibilities, rather than an organization that would try to evolve data per se and build a tremendous organization for that

purpose. There are other responsible bodies already in existence, with long traditions of competence which could furnish them the information they need.

Dr. MORGAN. Yes. I feel that this Federal Radiation Council would be in a position to match this information from physics, chemistry, biology, and medicine against the social and industrial aspects and the benefits that one would expect to derive from the use of atomic energy.

Chairman HOLIFIELD. I think on that note, we will conclude today's meeting with the announcement that we will meet in this room Tuesday, May 31, at 10 o'clock.

Our topic will be "Social and Economic Concepts Underlying Radiation Protection Standards." We will again have with us Dr. Russell Morgan, Mr. W. A. McAdams, manager of the Industry Standards of G.E., and Mr. J. Healy, Hanford Laboratories.

In the afternoon, we will have a round table discussion in which those gentlemen and some other gentlemen will take part.

Gentlemen, in conclusion, let me express again the appreciation of the Chair and the committee for your attendance and for the very valuable testimony which you have given.

The committee stands adjourned.

(Supplementary material submitted by Dr. Snyder follows:)

SIGNIFICANCE OF MPC VALUES FOR EXPOSURE

It may be pertinent to clarify further, indeed to pinpoint, a distinction of great importance between an infringement of a primary standard and an infringement of a secondary or tertiary standard. Ideally, the primary standard ought to be a level of biological effect which is judged to be acceptable. There are too little epidemiological data to establish the level of biological effect at the dose levels considered here. Thus, in most cases, the only primary standard available is that of a limit on dose.

The environmental standard or MPC is a secondary standard and is designed to achieve the specified primary standard. The estimation of the environmental standard involves many assumptions which are seldom realized in practice. To be specific, the MPC values in NCRP Handbook 69 are estimated on the basis of an exposure of 50 years' duration. Thus for Sr it is estimated that after 50 years of exposure at the MPC level the amount in the body is expected to reach this level of the primary standard. In practice the environmental level will not be constant, and generally only the high values are considered newsworthy and reach the press. The public either does not see, or forgets, many compensating elements of the situation and adjustments which have to be considered. If exposure is for fewer than 40 hours per week, the MPC level can be higher without the exposure exceeding the primary standard. If the level is not constant, it is the average level which needs to be considered, and in most situations it is an average over a fairly long period, 13 weeks or a year, which is indicated as the appropriate period. In addition, there may be more technical corrections— if the chemical form is one not readily soluble in body fluids, a correction may be indicated. These many adjustments that can and should be made in the handbook values to adjust them to a particular situation are one of the reasons why a competent health physicist is needed to properly implement the basic recommendations.

Perhaps this can be illustrated by reconsidering an estimate concerning an increase in the leukemia rate that might ensue from population exposure. Dr. Walter Selove, earlier in these hearings, indicated that the background level of radiation might be responsible for 10 percent of the present leukemias. This estimate cannot be considered as established and, in fact, is open to serious question. If it were established we would have a basic standard of the best kind, i.e., a level of biological effect that can be expected from a known level of exposure.

Dr. Selove used this estimated dose-effect relation to consider the increased incidence of leukemia that might be expected if the population dose were 0.5

rem/year from Sr. Since his remarks might be interpreted as implying that the NCRP and ICRP recommend such a value I wish to reconsider the question. The presently recommended body burden of Sr" for occupational exposure is 2μc and for population exposure the ICRP has suggested that substantially onethirtieth of that value be used. The corresponding dose to the bone is about 0.2 rem/year averaged over the skeleton. But the dose to marrow would be still less and might average about one-third of this according to the estimates given in my preprint material. This reasoning might indicate an increase of 7 percent if the basic assumption that 10 percent of leukemia is due to background.

However, no short-term exposure slightly in excess of the MPC level would produce this body burden. Accordingly to the present estimates it would require many years of exposure at the MPC level to accumulate this amount in the body. In practice there will be seasonal and yearly fluctuations in the amount of Sr actually present in food and water and these amounts will vary from one geographical area to another. Any slight excess of Sr above the MPC for populations which may reach the headlines does not indicate a 7-percent increase of the leukemia rate in this country. The 7-percent estimate must be revised downward since it is unlikely all our foodstuffs are contaminated to this extent, it must be revised downward if only a fraction of the population is consuming the food, and finally it must be revised downward unless the entire population is to continue using such food for many years to come. These adjustments to take account of the size of the population involved, of the fraction of the total daily intake of food and water that is involved, and to take account of the exposure period, are typical of many adjustments that must be made in applying MPC values to an actual exposure situation.

(Whereupon, at 3:30 p.m., the subcommittee was recessed, to reconvene at 10 a.m., Tuesday, May 31, 1960.)