N.Z. Test May Determine Cause Of Lung Cancer

Press, Volume CII, Issue 30095, 1 April 1963, Page 16

N.Z. Test May Determine Cause Of Lung Cancer

(New Zealand Press Association) WELLINGTON, March 31. Whether smoking causes lung cancer may be decided conclusively by experiments carried out at the Department of Scientific and Industrial Research station at Gracefield by Sir Ernest Marden and Mr M. Collins. More than a year ago some doctors interested in cancer visited the department’s laboratory at Gracefield and Mr Collins decided that he would demonstrate the incidence in smoke of free radicals, molecules of an atom which has not got all its electrons paired.

He was not sure what the outcome would be, but he was quite amazed—and so were the doctors —at the number of free radicals. He could not understand why they were there. Sir Ernest Marsden, a specialist in the field of radio-activity, was interested in Mr Collins’s discovery and they decided to delve further into the reasons for the presence in the tobacco smoke of so many free radicals. They measured the radio-activity and i discovered a link with the number of free radicals Sir Ernest Marsden gathered tobacco samples from many parts of the world for testing. Tobacco from Africa, South America and New Zealand were among the many experimented with. The tobacco was made into cigarettes at a Wellington factory. Standard proprietary brands, including many overseas brands, were tested, and it was found that all contained active radicals and radio-activity, but in varying proportions Lower Radio-Activity The scientists discovered New Zealand-grown tobacco has lower radio-activity than any other tobacco tested. In one case the radio-activity of an overseas tobacco was 60 times greater than the New Zealand product. This also meant that it had the lowest number of radicals. If the hypothesis of the scientists is correct. New Zealand-grown tobacco is possibly the safest in the world. “We have quite a lead on the world in this particular research into the short-life components in the smoke,” said Sir Ernest Marsden. “It could lead to an understanding of the processes of cancer production.” Mr Collins said he and Sir Ernest Marsden were a Little loth to reveal their findings at this stage, but in the broader interests of science and the tremendous amount of work being put into cancer research they thought their discoveries should be made public. Work on the experiments began last August, but is not yet concluded, though there has been sufficient evidence to prove beyond any reasonable doubt that tobaccos tested do contain in varying quantities radio-activity and free radicals. Tests of other

tobacco, which is more timeabsorbing than costly, will be carried out to obtain even more data on the effect of radio-activity and active radicals.

Overseas experiments have been carried out in an effort to produce tumours on animals by using stale smoke condensate “Our tests show that only new smoke contains large quantities of alleged cancerproducing properties,” said Mr Collins. “We assume that the statistical evidence that smoking produces lung cancer is conclusive, so the work we are doing is to try to find out what it is in the smoke which causes the lung cancer.

If the cause is known then it may be possible to reduce the alleged risk. “Previous overseas experiments have shown the existence of chemical cancerproducing agents, but have not shown conclusively that these produce cancer tn biological tests.” he said. "We have been looking for short-lived active components which disappear, say, in 30 seconds in the cigarette smoke and which may be connected with cancer production. It is known that radiation can cause cancer so if we can find a mechanism that transfers this radio, activity to the lung, we have a possible producer of lung cancer.” he said