asked the Parliamentary Secretary for Science whether research into the causal relationship of cigarette smoking and lung cancer, undertaken by the Medical Research Council and other scientific institutions that have reported their findings to him, has fully covered the effects of inhaling smoke from tobacco that has been subjected to toxic sprays or grown in soil in which the residue of such sprays is still active.
Research workers of the Medical Research Council and others who have undertaken research on the relationship between smoking and lung cancer have taken the possible effects of toxic sprays into account and have found no evidence that these sprays are a causative factor in the production of lung cancer among cigarette smokers.
In view of the fact that we have had answers which are rather complacent—not from the hon. Gentleman but from the research people—with regard to pesticides and insecticides, is the hon. Gentleman absolutely certain that enough research has been done to enable such a categorical assurance to be given?
When the hon. Gentleman sees my original answer I think he will see that I said that no evidence had been found. I did not mean by that to express absolute certainty that no evidence would be found. Frankly, it is impossible to claim absolute certainty while the mechanism of causation of lung cancer remains uncertain. But research is going on at the Medical Research Council and a certain amount of research is financed by industry.