Volume 2

Government policy on the management of risk / House of Lords, Select Committee on Economic Affaris.

  • Great Britain. Parliament. House of Lords. Select Committee on Economic Affairs.
Date:
2006
Catalogue details

Licence: Open Government Licence

Credit: Government policy on the management of risk / House of Lords, Select Committee on Economic Affaris. Source: Wellcome Collection.

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    14 February 2006 suffer that final step. Those people would probably be at greater risk of damage from breathing other people’s smoke than lifelong non-smokers would be, because lifelong non-smokers are going to have so few cells that are at risk of that final step. But, of course, when studying people who have smoked for 10 years or 20 years and then stopped, it is very difficult to work out exactly what their risk would be without passive smoking, so it is difficult to do reliable epidemiological studies of them. So, people have done epidemiological studies of lifelong non- smokers because it is a cleaner comparison. It is however, the ex-smokers, those who have stopped, who are probably going to suffer the greatest absolute risk as a result of exposure to other people’s smoke, at least in terms of cancer. Q384 Lord Macdonald of Tradeston: | am just trying to see if you can break it down into categories. Presumably, non-smoking shepherds would be much healthier than non-smoking traffic wardens. Professor Sir Richard Peto: There probably would not be a very big difference. The amount of exposure from cigarette smoke is so much greater than the amount that you would get from the ambient air outside in the city, certainly nowadays, that there is not so much difference between non-smokers in urban and rural populations. There are some differences, but they are really quite small. Q385 Lord Macdonald of Tradeston: What I was heading towards is the suspicion that the next way this is taking us might be the banning of smoking in the home, and I wondered what evidence you would bring forward that would allow that debate to take some sensible form. Professor Sir Richard Peto: | do not want to be cast in the role of advocating banning smoking in public places or in private places. What I am concerned with is that enormous risks should be taken seriously, like the extent to which smokers kill themselves—there is about a 50 per cent chance that a person who smokes cigarettes and continues to do so will be killed by tobacco, which is vastly greater than almost any other risks around. It is the relative importance of this that I somehow want to get across. But, we are concentrating now, because this is your task, on the effects of breathing other people’s smoke, although the main way smokers kill people is by killing themselves, not by killing other people—they are a lot better at killing themselves than they are at killing other people. Q386 Chairman: It is very difficult, but the message lam getting is that when you look at the evidence that is put forward by the tobacco companies to say there is not any serious evidence, or when,you get evidence put forward by people who are totally opposed to smoking of any sort, then when you come to deal with the question of passive smoking you would be sceptical about any of the evidence that is produced on either side, further than you have indicated. Professor Sir Richard Peto: I think there has got to be some risk. The extent to which active smoking is causing cancer, heart disease and lung cancer is enormous. There is about a 50 per cent chance that a smoker who carries on smoking will eventually be killed by this, and that is definite. When you place the same mix of chemicals, more or less, in to the general air, it must cause some risks, so I think the statement that there is some risk to non-smokers is well- founded; you would have to use the most extraordinary, implausible metaphysical arguments to argue for threshold doses below which there is zero risk, especially in a world where there are a lot of ex- smokers whose lungs are already well off any zero on the dose response relationship. The definite statement is that some people are killed by breathing other people’s smoke, and then there is reasonable uncertainty about the number killed. I am sorry— there is bound to be wide uncertainty when you are trying to measure risks like this. There is, however, a rather odd finding, which seems to come up repeatedly, of quite a marked excess of mortality from heart disease among those exposed to other people’s smoke. This is odd because the hazard is much bigger than you would expect from extrapolation from the hazards faced by smokers. It is not impossible, but it is odd, and in the case of heart disease, the apparent risks in passively exposed non- smokers are bigger than one would have expected. It is possible, however, that there are paradoxical dose response relationships, with rather substantial risks at low doses. To take an extreme example, if you plotted the probability of sneezing against the dose of smoke, smokers on the whole do not make themselves sneeze but they can quite easily make non- smokers sneeze. This example shows that there can be a medical effect with a very odd dose response relationship. It is not impossible, therefore, that passive smoking produces a substantial risk of heart disease, and if that were so then it would represent a really substantial public health hazard. There is argument as to whether such a hazard is real, and there is still reasonable disagreement about this, but I do not think there is reasonable disagreement with the statement that smokers do kill some non- smokers. Q387 Lord Skidelsky: I just want to ask a supplementary. You would be reluctant then to commit yourself to a statement such as that in first report of the Select Committee on Health: “It is currently estimated that second-hand smoking causes at least 12,000 deaths each year in the United Kingdom . . .”, which was repeated by the Secretary