1/ Morgan, Karl Z. Suggested reduction of permissible exposure to plutonium and other transuranium elements. American Industrial Hygiene Association Journal, v. 36, August 1975: 567-575.

2/ Petkau, A.

Effect of 22Na+ on a Phospholipid Membrane. Health Physics, v. 22, March 1972: 239-244.

3/ Little, J.B., et al. Lung Cancer Induced in Hamsters by Low Doses of Alpha Radiation From Plutonium-210. Science, v. 188, May 16, 1975: 737-738.

4/ Yulish, Charles B, et. al. Low Level Radiation: A Summary of Responses to Ten Years of Allegations by Ernest Sternglass in Proceedings of the Fifth International Conference on Science and Society. Herceg-Novi, Yugoslavia. Charles Yulish Assoc. New York. July 9, 1973.

5/ United Nations Scientific Committee on the Effect of Atomic Radiation. Report to the General Assembly: Ionizing Radiation: Levels and Effects. Vols. I and II. New York. United Nations Publications. 1972. (E 72-IX-17).

6/ Radford, E.P. and E.A. Martell, "Polonium-210: lead-210 ratios as an index of residence times of insoluble particles times from cigarette smoke in bronchial epithelium", Proceedings of the Fourth International Symposium on Inhaled Particles and Vapours, Edinburgh, 22-26 September 1975, Pergamon Press, Ltd., and Martell, E.A., "Tobacco radioactivity and cancer in smokers", American Scientist, 63, 404-412, July-August 1975.

Protection of Special Groups

Dr. Morgan. Going on to question four, What are the various subgroups besides the general population whose exposure to radiation deserves a special attention, such as uranium miners, workers at operating reactors, reprocessing plants, etc.?

Dr. Caldicott?

Dr. Caldicott. I would like to point out as a pediatrician that there are sections of the community who are far more sensitive to the radiation than others and to these individuals you cannot apply the linear hypothesis necessary. Infants are 11 times more susceptible to radiation than adults. Older children are four times more sensitive to radiation.

Children who have asthma between the ages of one to four have 3.7 times the risk of developing leukemia from radiation. Children who have allergic disease and who have had inter-uterine x-ray exposure have 24.6 times the chance of developing leukemia.

The reason that children and fetuses are so susceptible to radiation is because the cells are rapidly dividing, and it is these rapidly dividing cells that are sensitive to radiation. Extrapolating from this, the fetus in the first three months is the most sensitive organism in the human life cycle to radiation because all of the organs of the human being are being formed in the first three months of gestation.

There are several effects that can occur from radiation during this period. There can be damage to the developing organs. There can be congenital heart disease or various congenital deformities.

This is caused by somatic mutation or mutation in the developing cell that is formed in that particular organ.

The fetus can be damaged by a mutation within its gonads, the testes or the ovary, which therefore transmits this mutation to future generations. There can be damage from another point of view, from a carcinogenic point of view, in that one of its cells may be damaged and the regulator gene that controls the rate at which that cell divides is damaged and the cell may divide. Hence, the fetus is extremely sensitive to radiation. Dr. Morgan. Dr. Bond?

Dr. Bond. I certainly agree with what has been said. This has been recognized for a number of years. It is taken into account very extensively in the BEIR Committee Report and by other groups that have to do with setting of standards. Physicians and others are admonished to keep radiation exposure to the fetus to a minimum, and actually the exposure standards for the fetus contained in the mother who is a radiation worker are more restrictive than for the adults.

Dr. Bond. It is a recommendation

tion of the NCRP.

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it is a firm recommenda

Dr. Ellett. The NRC did not change the recommendation.

Dr. Bond. Let me say that the recommended standards apply to the fetus, which of course, of necessity, applies to the mother.

Dr. Morgan. Dr. Ellett, did you wish to comment?

Dr. Ellett. Yes.

We will get into this later, but it might help to clear things up a little bit now.

When we say standards, we have to be careful about what we mean. Dr. Bond referred to recommendations from the NCRP. These are recommendations, not standards. They have not been implemented by standard-setting agencies, that is as far as I know.

Let us be careful today, because we are dealing essentially with a lay audience. In referring to a recommendation by NCRP -let us say "recommendation." When we say "standard," let us refer to something that is law, i.e. legally binding.

This is, in a sense, a governmental hearing to see how information can be used by the Congress. I would not like them to have a false impression that things exist that do not exist.

Dr. Morgan. Dr. Mattson?

Dr. Mattson. Dr. Morgan, one brief comment.

Dr. Ellett properly said that the ICRP and the NCRP have made recommendations regarding the dose to the fetus being limited to some lower number than the occupational exposure limits for adults, since the increased radio-sensitivity of children which we are discussing here today has been pretty well accepted by radio-biologists for some years now.

Present Federal radiation standards do not now contain such a provision. Such a provision was recommended by the Atomic Energy Commission in January, 1975. It was put out for public comment at that time.

In following through on that recommendation, the people I work for have issued a guide to females employed in the nuclear industry, the people that we license, telling them of this increased radio-sensitivity of the fetus should they become pregnant and advising them of the actions that are available to them under law.

You can well imagine that there are other competing interests in this nation with respect to discrimination in employment of

spect to invasion of privacy. There are several points of law that act very strongly in this field, one being the Supreme Court decision on abortion; the other being Title VII of the Civil Rights Act of 1964.

Thank you.

Dr. Morgan. Thank you, Dr. Mattson. Dr. Archer?

Dr. Archer. I think we can summarize these special subgroups exposed to radiation fairly quickly.

If we skip the entire population, who are exposed to background radiation, ignore the exposure of everybody to radiation from nuclear reactors and a little bit of nuclear fall-out, we can summarize occupational exposures quickly.

There are a number of occupational groups who are exposed to radiation, and in the past, there have been considerable numbers of over-exposures. These were mostly among medical radiologists, x-ray technicians, dentists, and dental technicians. There have been a number of studies showing excess cancer among these groups.

But, with the advent of modern radiation protection techniques and controls, it is my feeling that few of them are being really overexposed any more. Uranium miners are another group that has been overexposed in the past; we now have an exposure standard for them which gives them substantial protection. I am not at all sure that the mine operators can reduce exposure much more than they have done.

There is still some risk for uranium miners, I think, just as there is some risk in all radiation exposure.

Luminescent dial painters are another exposed group. They formerly used radium for painting dials on watches, clocks, etc. and developed many bone cancers as a result. Introduction of good handling techniques and a switch to tritium has eliminated this problem.

In the practice of medicine in the past, some patients have been overexposed to radiation. The most noted ones are those who were injected with solutions of radium or thorium for various reasons. Thorotrast (containing thorium) was used as a medium for x-ray contrast. Those radioactive substances are not being used anymore. However, there are some physicians, especially dermatologists, who use x-rays to treat some nonmalignant diseases. Such treatment sometimes results in worse disease than the patient originally had.

It seems to me that this overexposure is unnecessary. In the past, some patients, like tuberculosis patients with gastrointestinal symptoms, have received overexposure to x-rays. There is little overexposure now of tuberculosis patients. For some types of gastrointestinal symptoms, it is still standard to order a gastrointestinal series of x-rays periodically. That has become unnecessary now in many cases because there are better tech

niques for investigating disorders of the esophagus, stomach, duodenum and colon. I am referring to the flexible fiberoptic endoscopes. Workers in plants reprocessing uranium fuel are about the only persons in the nuclear industry who are likely to be currently overexposed.

Dr. Morgan.

For the record, Dr. Archer, I wonder if you would indicate to us how many cases of carcinoma among uranium miners have occurred?

Dr. Archer. I can tell you about our study group of uranium miners.1/ We do not know how many uranium miners there are. We

have estimated that there have been somewhere between 15,000 and 20,000. We have about 4,000 of them in our study group.

In the study group, there have now been 170 lung cancers. Over half of those are of the small-cell undifferentiated type. This type is much more frequent among uranium miners than other people.

Mr. Goodman. I would like to ask if any studies are being made of the populations in the vicinity of the mill tailings?

Dr. Burr. Offhand, I do not know of any.

Mr. Goodman. May I recommend such?

Dr. Burr. You may. We have had studies in some of the high background areas in South America. We have not been able to do studies in comparable areas in India. India has been doing studies themselves.

Mr. Goodman. If we may return to the United States

Dr. Burr. We are continuing studies of uranium miners. I did not mention this.

This work now is devoted more towards studies of sputum cytology.

Mr. Goodman. Some fifteen years ago, Schubert and Lapp reported in their book some 5,000 low-level plutonium exposures at Hanford.

ers?

Is anything being done, epidemiologically, about those work

Dr. Burr. The Transuranium Registry involves the plutonium workers. This is the study that has been going on a number of years and is a follow-up study, and does involve the Hanford work

ers.

I mentioned that more recently we have initiated, at the Los Alamos Laboratory, an epidemiological study of the plutonium workers that will be more extensive.

The answer to your question is yes.

Dr. Morgan. Are there any further questions?