Worry About Fall-Out In America

Press, Volume CII, Issue 30155, 12 June 1963, Page 14

Worry About Fall-Out In America

“Americans seem, in general,'very worried about radioactive fall-out, and many spoke quite seriously to me about coming to New Zealand to get away from it,” Mr J. J. Tait, senior physicist to the North Canterbury Hospital Board, said yesterday. Mr Tait has just returned from six months on an International Atomic Energy Agency fellowship to Berkeley, California, followed by a month in Britain on a grant by the Canterbury and Westland division of the British Empire Cancer Campaign society.

Among the firsi things that struck him in the United States was the presence everywhere of notices showing the way to the nearest fall-out shelter.

At Berkeley, Mr Tait carried out post-graduate work at the University of California. He made a machine to plot the dosage within the body of a patient exposed to radiation from the university’s 164 in cyclotron, which although primarily a physics research tool, is also used for a few hours a week for medical purposes. While in the United States, Mr Tait visited physical research laboratories and hospital physics departments in Los Angeles. San Francisco. Chicago, Washington, and New York. In Britain, he carried out an extended tour of similar institutions.

“My impression was that Britain is, in general, ahead of the rest of the world in the medical use of radiotherapy and medical physics.” said Mr Tait. He was struck by the high salaries paid to hospital and other physicists overseas, and the excellent research facilities with which they were provided. Salaries in Britain for these workers started at about the same level as in New Zealand, but the ceilings were very much higher. New Techniques

Mr Tait saw several new techniques overseas which he thinks may be useful here if facilities can be arranged One is the use of high-pres-sure oxygen in conjunction with radiotherapy, a possibility which is already under investigation by the Christchurch Hospital radiotherapy department. Another idea, which Mr Tait says is “a minor improvement but relatively easily arranged.” is to use compensation filters during supervoltage X-ray therapy to allow for the contours of the patient’s body. Another again is the use of phosphorus-32 uptake

in tumours as an indicator of enhanced sensitivity to radiation. A group of scientists at Bristol have found that the amount of phosphorus-32 taken up by a tumour varies in a predictable cycle, and the therapeutic radiation is much more effective at one point in the cycle than at others. These results have yet to be confirmed by other workers in this field but the belief was. Mr Tait said, that the method "shows a lot of promise.’’ Some of the radioisotopes in use overseas had not been used in Christchurch, but much of the work for which they were used was carried out here with different isotopes, said Mr Tait. In other cases, the methods were not applicable to the situation here. For example, oxygen--15 used in lung studies at the Hammersmith Hospital could only be used “next door to a reactor” because its half-life was about two minutes Nevertheless he would suggest the use of certain isotopes new to North Canterbury. For one thing, radioaetive xenon might be used instead of dxygen-15 in lungfunction studies similar to those at Hammersmith.

Another new technique concerned the use of chromium--51-tagged red blood cells, for

checking the activity and position of the spleen. Up to now, the investigations had been carried out by coating the cells with antiserum, but Mr Tait had found the job done just as well by killing them by heating.

Mr Tait had been asked to look, while overseas, into the possibility of an electromyograph unit being built here for the physiotherapy department (Electromyography is the measurement of electric potentials in the nerve and muscle systems.) He saw several such units at work and hopes to build one soon in Christchurch. Shielded Room

A facility which he hopes one day to see provided in Christchurch, but which may be ruled out for the moment because of dost, is a special shielded room for counting low levels of radio-activity. This would make whole-body counting possible and have great uses in metabolic studies and certain other investigations. He intends to look into the cost of installing such a room.

As a result of Mr Tait’s trip, improvements will be built into the scintillationscanning machine under construction for the radioisotope laboratory at the Christchurch Hospital. It will give a visual picture of the progress of radio-active substances through a patients body.

An improvement in radiological techniques which Mr Tait is sure will come eventually, but which is likely to be ruled out for the time being because of cost, is television monitoring in fluoroscopy, both for X-ray diagnosis and for radiotherapy localisation. Television monitoring would protect staff by moving them away from radiation hazards, and would be of benefit to patients in reducing the amount of radiation dosage.