‘Curing May Affect Radiation'

Press, Volume CIII, Issue 30348, 25 January 1964, Page 16

‘Curing May Affect Radiation'

(N.Z. Press Association) ■ NELSON, January 24. The processing of tobacco has a possible influence on the effect of radioactivity on it, Sir Ernest Marsden said in his report on recent experiments concerning the relation of tobacco and lung cancer.

The report says: “There is the possible influence of curing, ageing and fermentation. These are important also from the point of view of quality—properly carried out they result in the destruction of irritating ingredients and the development of the pleasing taste and aroma. “These processes, however, do not affect the intrinsic

radio-activity of the tobacco which is an atomic, not a molecular phenomenon, but the chemical change involved in processing may well affect the free radical production by the radioactive alpha particles. “The first effects of radiation on living matter are physical, in that they affect atoms and molecules, irrespective of their arrangement in living structures,” Sir Ernest Marsden said. “A result is the splitting of molecules into fragments known as radicals and ions. These fragments are deprived of the chemical stability characteristic of the original molecule.” All the essential constituents of body cells, and in particular complex molecules like proteins and nucleo-pro-teins (genes), could be affected through the action of radicals, he said. They could also be injured by radiation directly without

the intervention of radicals. The respective role of the direct and indirect action of radiation was not yet clear, but-it was probable that in most effects both modes of action operated. Sir Ernest Marsden said: “One suspects that modern cigarette tobacco may possibly be not aged and fermented so fully as say 30 years ago, and even with the same radio-activity this may affect free radical production, and thus possible lung cancer production. “Again, to complete the story of complications, there is the possible carcinogenic effect (and free radical production) of some modern flavourings. “The subject of flavourings is highly secret. They can be used to mask inadequate maturation. I know of one substance used in United States cigarettes which is highly suspect,” Sir Ernest Marsden said.

There was no generally accepted hypothesis as to the factors in smoke which actually caused lung cancer. The known correlation was only statistical.

Certain carcinogenic chemical components were present in tobacco but were in such minute quantities that none had yet been proved as the connecting link.

The exact cause of any form of cancer was not known, nor exactly how or why body cells changed their normal state of regular growth, began multiplying riotously and produced tumours, and spread through the body, destroying and invading other tissues. “It is known that radioactive radiations can cause such a change, directly or indirectly, and also that socalled carcinogenic chemicals can cause the same sort of change, probably by a similar kind of protein molecular interaction,” he said.