to insure the development of public understanding because of the close daily working contacts of these organizations with the people they

serve.

That concludes my formal statement.

Representative HOLIFIELD. Thank you, Dr. Weber.

Mr. Hollister.

Mr. HOLLISTER. Dr. Weber, I think the committee would be interested in having a description of the outlines of the Animas River situation. Was radium the only problem? What were the levels? Were they 2 or 3 or 5 or 10 times?"

Dr. WEBER. Yes, I will be glad to attempt to answer that, Mr. Hollister. I have covered the subject in considerable detail in the covering paper. (See p. 393.)

Dr. WEBER. In response to your specific questions, I can say that on the matter whether more than radium 226 was involved, the answer appears to be "Yes." However, according to the analysis of our laboratory people at Cincinnati and Mr. Holaday also participated in the consultations-the principal contribution in the form of alpha emitters, was from radium. Secondly, these levels did exceed-if I may just leaf through this for the amounts found.

Reading from this special study conducted in 1958:

Based on the findings of this study and the assumption of an average consumption of 2.2 liters of water per day, the calculations indicated that the adult population of Aztec, N. Mex., might be ingesting 7.9 micromicrograms of radium per day, and the population of Farmington about 5.7 micromicrograms of radium per day. Persons residing between the Colorado and New Mexico State line in Aztec and drinking Anamas River water could be ingesting 16.7 micromicrograms of radium per day.

These figures were for the summer months of 1958.

It is believed that during the winter months Aztec and Farmington people would be experiencing daily intakes approximately double the summer months.

So I think the answer to your question is "Yes," the levels have been exceeded for the general population, but are still below those established for the occupational population.

Mr. HOLLISTER. Which population levels are you talking about? Dr. WEBER. The general population levels. Is that the question? Mr. HOLLISTER. Are you talking, for example, about the ICRP recommendations at the one-thirtieth level, are you talking of the NCRP recommendations of the one-tenth level?

Dr. WEBER. The most recent recommendation which we have is the special NCRP levels.

Mr. HOLLISTER. Has the Public Health Service given any special attention to which levels might be appropriate to apply to the problem?

Dr. WEBER. I have not gone into that specifically, Mr. Hollister. At the time this study was done it exceeded the levels then existing. Mr. RAMEY. That would be the old level if it was done a couple of years ago?

Dr. WEBER. That is correct.

Mr. RAMEY. Since then the level has been lowered.

Dr. WEBER. Officially I can't say that the level for ingested materials has been lowered with regard to radium 226. I would have to consult further on that matter. But, as you know, the Federal Radia

tion Council has a specific task force group currently working on this problem of internal emitters. So, as a Federal agency, we are awaiting the results of their study to provide guidelines.

Mr. HOLLISTER. Leaving the question of which population levels we are talking about for the moment, what would the Public Health Service infer from the apparent situation that radium and possibly strontium 90 levels measured with in excess of some population level! What does this mean to the Public Health Service?

Dr. WEBER. As I have indicated here, we would like to test the reliabilities of these levels by relating them to the body burdens that are found. For example, it is my feeling that we can't necessarily expect to find a direct correlation between body burden and clinical effects.

In medicine generally, we find that the degree of underlying pathology does not necessarily bear a direct proportional relationship in terms of appropriate clinical expressions. I can take an example which I give in the basic paper, that of arteriosclerosis of the cerebral vessels. Here, we may have little or nothing in the way of manifestations like cerebral accidents, that is to say "strokes," as they are commonly called, or behavior disturbances.

By the same token, in many instances where there is very little underlying pathology, we might have a considerable degree of clinical manifestations.

So I think the two things that we plan to do here will test the concept, if there is such a one-and I think by implication there is such a one-that the body burden of these internally deposited radioactive substances bears a directly proportional relationship to clinical effects. Secondly, whether in these terms the standards are realistic, either the old standards on which no Federal general guidelines with regard to internal emitters have appeared as yet, or let us say on any formulation of new standard.

Now, I think you refer here possibly to the fact that the Department is following as a guideline the recommendations of the special ad hoc committee of NCRP on strontium 90 levels. These hearings have brought out the fact of their not being acted on officially as yet by the main committee of NCRP, which would involve, for example, a level of 33 micromicrocuries of strontium 90 per liter for the general population. But in the interim we are attempting to follow them as the basis for operating procedures.

Mr. HOLLISTER. By your statement now, one result of the measurements out there was that the Public Health Service did decide to ask the mill to reduce the waste discharge levels. Is that right?

Dr. WEBER. That is correct.

Mr. HOLLISTER. Was this decision made on the basis of some general assessment of how badly it would hurt the mill to do this in terms of reducing the risk, or was this done by applying some standard?

Dr. WEBER. It was done by applying the standard primarily. That is to say, the law which governs practice in connection with the interstate pollution of streams program, which we have cited in the preprint document, requires the Public Health Service to take steps to diminish any source of contamination, and radioactivity is one of them. Therefore, under that authority, the mill was requested to install certain safety procedures, which are effectively reducing the

effluent containing these radioactive contaminants. As a matter of fact, it is believed that the present safety devices which the mill has installed will reduce the amounts in the river to about 1 micromicrocurie per day and therefore get below the presently existing standard of what I think is about 3.33.

Mr. HOLLISTER. Dr. Weber, would it be a reasonable request to ask you or your staff to prepare a short statement compiling the same sort of measurement data that you have in your long statement, and then going on to treat this question of what standards were used in this particular situation and why and how the standards were related to the measured levels and how the decision to speak to the mill people was arrived at? Would this be a fair subject?

Dr. WEBER. Yes, sir, I believe we can go into that.

Mr. HOLLISTER. I would suggest, Mr. Chairman, as a concrete example in point of how one takes recommendations of NCRP and actually goes about solving a problem.

Representative HOLIFIELD. You will submit that, then?

Thank you very much, Dr. Weber. You will be back with us again. this afternoon on the roundtable. We will resume sitting in this room at 2 p.m.

The committee stands adjourned. (The paper referred to follows:)

BRIEF DESCRIPTION OF THE ANIMAS RIVER SITUATION

The States and the Public Health Service have been studying the Animas River pollution since 1934. Beginning in 1950, the Public Health Service made some specific observations and collected some samples relative to the radioactivity in the river. This was followed in 1955 by a reconnaisance survey of eight uranium processing mills, including the Vanadium Corp., at Durango, Colo. In the report of this survey, it appeared that the existing levels of radioactivity were at or near the recommended maximum permissible levels for public water supplies (NCRP-4 μμc./1). The results of this survey indicated, however, that more data was needed to define the pollution situation. The results of the survey were discussed with the State and AEC officials. After the passage of Public Law 660, late in 1956, the Public Health Service had clear authority to undertake investigations of interstate streams leading to abatement action on its own initiative.

On January 27, 1958, Dr. S. J. Leland, director of public health of New Mexico, asked the Public Health Service to study the pollution of the Animas River and to bring the matter to the attention of the AEC. On March 11, 1958, Dr. Leland formally requested the Public Health Service to hold a conference on the interstate pollution of the Animas River under authority of the Federal Water Pollution Control Act, Public Law 660, section 8.

Pursuant to Dr. Leland's request, a formal conference called by the Surgeon General was held on April 29, 1958. It was attended by AEC, State and industrial officials, and the general public. The conferees agreed that the investigation should be expanded to define the type of interstate pollution problem that might exist. Operationally, Colorado accepted responsibility for the report on nonradioactive pollution and the Public Health Service was to conduct an investigation of the radioactive aspects of the pollution problem. In the assessment of the radioactive pollution, the Public Health Service initially compared the levels in the river with those in Handbook 52 of the National Committee on Radiation Protection. At this time the level given in the Handbook for radium 226 was 4×10 μc./ml. for workers, and 4×10 μc./ml. for the general population (applying a factor of one-tenth to the value for workers as indicated in the addendum to HB-59 published in 1957). This is 4 μuc./1. During the year that the survey was being made, there were many professional discussions relative to the standards for ingested radioactivity. These included many questions as to the factor that should be applied to the occupational recommendations of the

NCRP when the tabulated numbers were applied to exposure involving the general population.

In May of 1959, an interim report of the July 1958-June 1959 period was completed by the Public Health Service which indicated that the inhabitants of Aztec and Farmington, N.M., who were using the river as a source, might ingest radium and strontium in excess of the maximum permissible concentration for the general public. Soon thereafter, May 2, 1959, the AEC announced its proposed change in "Standards on Protection Against Radiation" to bring them in accordance with the NBS Handbook 69 (revision of Handbook 52) which increased the maximum permissible concentration for discharge to "unrestricted areas" from 4X100 μc./ml. (4 μμc./1) to 1×10 μc./ml. (10 μμc./1) for "exposure to persons in the neighborhood of a controlled area." On the 22d of this same month, however, the AEC cited the Vanadium Corp. mill at Durango for violation of the "Standards for Protection Against Radiation" and requested a report of planned remedial action by July 1, 1959.

The second session of the Public Health Service public conference on pollution of interstate water of the Animas River was held on June 24, 1959. At that conference, there was agreement by all parties that the Vanadium Corp. of America was discharging uranium mill wastes in such a manner that it was deleteriously affecting the public water supplies at Aztec and Farmington, N.M. It was also agreed that the nonradioactive chemicals discharged to the water by the Vanadium Corp. of America were toxic to fish and aquatic life. The Public Health Service continued to survey the river to check on the effectiveness of the waste treatment systems installed by the Vanadium Corp. of America and later in the year found that the discharges of dissolved radium had been reduced by 80 percent and the radium in the suspended solids by 90 percent.

The extent of radioactive pollution throughout this period was originally judged by the value of the NCRP Handbook 52 value of 4×10° μc./ml. (4× μuc./1) which was one-tenth of the occupational level as recommended in the addendum to HB-59. Later the figure of 10μμc./1 was published in Handbook 69 and in proposed revisions of the AEC regulations for its licensees. This figure was proposed as applicable to "persons in the neighborhood of controlled areas." Concurrently the ICRP suggested the use of one-thirtieth of the occupational level as a maximum exposure level for the general population. This made the radium 226 level 3.3×10-o μc./ml. or 3.3 μuc./1. This represents only a slight change from the original level of 4 puc./1.

During 1958 the average treated water concentration of radium 226 at Aztec and Farmington, N.M. were 3.6 and 2.6 μuc./1, respectively. Raw water users between the State line and Aztec were exposed to average radium concentrations of as much as 7.6 μμc./1 during this period. Investigations of crops irrigated with polluted Animas River water indicated that people might ingest additional radium 226 from local foods.

Concurrent with these judgments based upon concentration the Public Health Service also translated the recommendations into daily intake values for both radium and strontium. The approach taken by the conferees was to consider the possibility of ingestion in excess of the permissible daily amount as well as the concentration of radioactivity in the water per se.

This situation clearly demonstrates the need for specific standards, standard methodology and general professional acceptance of standards. It also illustrates the levels of radioactivity in streams where found to be in excess of the recommended quality criteria can be reduced well below recommended standards by concerted efforts to acquaint the industry and people with the facts.

(Whereupon, at 12:15 p.m., the committee recessed until 2 p.m., this same day.)

AFTERNOON SESSION

Representative HOLIFIELD. The committee will be in order.

The subcommittee will resume its hearings on radiation protection criteria and standards. Our specific subject for this afternoon is concepts of application.

The following statement was submitted by Lt. Col. Joseph A. Connor, Jr., Chairman, Aerospace Nuclear Safety Board, AEC.:)

RELATIONSHIPS BETWEEN AEROSPACE NUCLEAR SAFETY AND NCRP AND

ICRP STANDARDS

Statement submitted by Joseph A. Connor, Jr., lieutenant colonel USAF (MC), Chairman, Aerospace Nuclear Safety Board, U.S. Atomic Energy Commission, at the hearings of the Joint Committee on Atomic Energy on June 1, 1960

The use of nuclear energy in aerospace is being developed in a cautious and responsible manner. It has presented the Atomic Energy Commission with a new dimension for its traditional role in health protection from radiation.

Aerospace applications of nuclear energy introduce possible radiation hazard to the earth's atmosphere and oceans, to other solar system bodies, and to areas in space along probable orbit paths.

Aside from safety considerations, the AEC also has a responsibility to assure that certain long-range scientific studies are not complicated by the introduction of new radioactive materials into outer space or to other solar system bodies. Today, with airpower evolving into aerospace power, nuclear energy holds promise of making possible, and even economically feasible, the realization of advanced concepts in aviation and astronautics.

This presentation will not cover either the need for these devices or the development schedules, since these facts have already been well established in previous testimony received by the Joint Committee on Atomic Energy. This testimony will attempt, rather, to underscore the measures taken for the protection of the public.

To illustrate these concepts, let us consider two military and two peaceful applications:

(a) A manned nuclear-powered aircraft with a range limited only by the endurance of the crew.

(b) The nuclear ramjet, low-altitude, high-speed missile.

(c) The greatly increased power of nuclear rockets making feasible the orbiting of high payload satellites and space stations, as well as interplanetary travel in spacecraft.

(d) The expanded usefulness of satellites powered by small radioisotope units, or by compact nuclear reactors geared to provide kilowatts and even megawatts of power for months or years at a time.

These then, are the benefits attainable by the successful development of aerospace nuclear propulsion. But each of these uses holds forth the possibility of injecting additional radioactivity into our tmosphere. Let us look at the systems individually, and see how the advantages of each balance with the costs of radiation protection to meet current standards.

THE MANNED NUCLEAR AIRCRAFT

In the design of a nuclear-powered aircraft, considerable weight can be saved by the use of special materials in a divided shield, i.e., a portion of the shield is placed at the reactor, and the remainder at the crew compartment. Further, shadow shielding in front of the reactor will provide a core of reduced radiation to the crew. It is advantageous to have as great a reactor-to-crew separation as possible, but there is a point of diminishing return beyond which it costs less weight to add shielding than to extend the fuselage.

To evaluate crew radiation exposure, a Medical Advisory Group was estab lished by the U.S. Air Force School of Aviation Medicine to suggest standards which would be acceptable to the Air Force along with the usual hazards of flight. They considered the sizable factor of safety built into the NCRP recommendations, and the relatively high level of risk associated with any military flying, and proposed a tolerance dose for volunteer crew members somewhat higher than the quarterly NCRP occupational standards, but roughly comparable in effect to the total allowable lifetime occupational exposure. This dose would be received within the training and operational period of 10 years, and was deemed to produce a negligible biological effect in this age group.

The removal of the reactor will be the initial step of a major periodic maintenance check, and its reinstallation will be the final step before takeoff. Thus, the bulk of the maintenance can be done readily. Inspection and repair of the reactor will be done in a special facility. This was demonstrated many times in Convair's successful flight program with the B-36 carrying a flight test nuclear reactor (July 1955–March 1957).

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