§ 7. Sir R. Russell
asked the Lord President of the Council and Minister for Science what consideration has been given by the Medical Research Council to the harmful effects of benzpyrene in the fumes emitted by diesel engines.
§ Sir R. Russell
Is not this chemical the same as is present in cigarette smoke? As cigarette smoking has been condemned as a possible cause of cancer and as this chemical is present in far greater concentration in diesel fumes, should not a similar kind of warning be issued about it?
§ Mr. Hogg
The relationship between cigarette smoking and lung cancer is well established, but it is not established in 234 relation to cigarette smoking which of the possible carcinogens causes the cancer. As far as I know, the concentration in diesel fumes, as and when they are ingested in the atmosphere, is nothing like as great.
§ Mr. Dudley Smith
Nevertheless, does my right hon. and learned Friend understand that quite a number of medical experts believe that diesel fumes are a contributory cause towards lung cancer, particularly in built-up areas? In view of the seriousness of this matter, will he ask the Medical Research Council to look further into it?
§ Mr. Hogg
My hon. Friend should distinguish two or three separate issues. The first is whether air pollution causes lung cancer. The answer is almost certainly "Yes", just as with greater certainty cigarette smoking does. That diesel fumes in particular out of the various and many components of air pollution in cities cause lung cancer is a much more questionable proposition. Indeed, I am told that the exhaust of an ordinary petrol engine is much more likely to be suspect.