Mr. John Hallasked the Minister of Health what evidence he has to show the relative importance of cigarette paper as against tobacco as a factor in causing lung cancer.
§ Mr. Iain MacleodThe statistical association between heavy cigarette smoking and cancer of the lung has led to intensive attempts to detect carcinogens both in cigarette tobacco and in cigarette paper. So far these are inconclusive, but recent publications in this country indicate the presence of certain chemical substances with such carcinogenic potentialities in the combustion products of cigarette paper. I understand that further research has also indicated their presence in tobacco.