Personnel protection in the use of radioactive isotopes.

Artificially produced radioactive isotopes are distributed by the Atomic Energy Commission according to strict rules on account of the dangers inherent in the handling of such materials. Before an individual can obtain radioisotopes, he has to present evidence that he possesses the knowledge, facilities and equipment to meet the minimum standards of safe handling. The Isotopes Division in Oak Ridge, Tennessee, is anxious to help the users in matters of protection and makes available to them articles or pamphlets on this subject, as well as expert advice. It may be assumed, therefore, that the reader is familiar with recent publications on the subject or may get the available information by simply asking for it. Also, a comprehensive report on "Safe Handling of Radioactive Isotopes and Fission Products" is being prepared by the National Committee on Radiation Protection, and will soon be ready for distribution. Accordingly, in the present article no attempt will be made to cover the whole subject, and in fact only a few topics will be discussed, which in the opinion of the writer deserve special emphasis. The mental attitude of the worker plays an extremely important part in the problem of protection. Most people who have received some cursory instruction, are very careful at the start. Sooner or later a minor "emergency" arises and the individual decides that it is necessary to disregard some rules. The "emergency" might consist simply in not having allowed enough time for the preparation of a sample to be used on a patient at a specified time. Perhaps the surgeon is waiting for the material in the operating room. To save time, the worker then goes through the necessary manipulations without using the protection devices provided for the purpose. For some time thereafter, he might be a little apprehensive and think that perhaps he got too large an exposure. However, unless the exposure was really excessive, he cannot detect any ill effects from it and after a few such experiences he is apt to conclude that the danger of overexposure has been exaggerated, or that perhaps he is particularly resistant to radiation. Every worker must be made to realize that radiation injury may not become apparent or serious for many years. This is true even in the case of a single exposure or a few exposures taking place within a matter of weeks. Recently the writer heard of a case in England in which cancer of the skin developed 40 years after the patient had been treated with X-rays in the same region for another ailment. In numerous radiologists, and technicians, cancer of the skin of the hands has developed 15 to 25 years after they started to work with X-rays or radium, although the bulk of the exposure occurred during the first few years when the danger of radiation was not fully realized. The individual worker simply has no way of telling what constitutes a safe exposure from his own experience. By the time that some tissue damage becomes evident to him, it may be too late to do anything about it and eventually serious injury or death may result. Therefore, each worker should accept the permissible limits of exposure set by competent authorities and should strive by all possible means to keep his exposure well below these limits at all times. In this connection it is well to point out that no matter how careful an individual may be, an occasional overexposure is apt to occur through some accident or through carelessness on somebody else's part. If the person has maintained his exposure well below permissible limits, he is in a better position to escape injury if such overexposures do occur through circumstances beyond his control. Furthermore, the worker should never exceed the permissible limits of exposure on the ground that after some definite date he will no longer work with radiation. Conditions may change and he may decide to continue working with radiation indefinitely. It is not good judgment to acquire a handicap needlessly. People with considerable knowledge of the subject sometimes get in trouble by attempting to estimate the dosage rate in a region in which they are