Friday, April 11, 2003

Passive smoking

A new report suggests that 12,000 people in the UK die each year as a result of breathing second-hand tobacco smoke (SHS) (1). The report, produced for Action on Smoking and Health (ASH) and the TUC, further notes that among the UK's 53,000 bar workers, '17 percent will die from passive smoking during their working lifetime'. It is suggested that there are about 900 deaths among office workers and 146 deaths among manufacturing workers due to SHS. The conclusion is that there must be a ban on smoking in all workplaces, as improved ventilation could never be adequate to make workplaces completely safe.

Even by the standards of the passive smoking debate, this report is alarmist. The link between second-hand smoke and ill-health has always been controversial. Even in cases where a link has been made, the figures suggested have always been lower. For example, the British Medical Association (BMA) produced a report in November 2002 that suggested a death toll of around 1000 in the UK each year. It is remarkable that the new report has produced a figure 12 times greater.

While a link between SHS and a slightly increased level of illness seems plausible on the surface, no link has ever been proven. Even where studies have found an increased risk of cancer, the increase has been too small to be practically significant. ASH's website suggests the risk of lung cancer for non-smokers is about 10 cases per 100,000 people (1 in 10,000) (2). An ASH factsheet from July 2002 suggests that 'Non-smokers who are exposed to passive smoking in the home, have a 25 percent increased risk of heart disease and lung cancer' (3). In other words, 12.5 cases per 100,000 population (1 in 8,000).

Moreover, studies that show no link are often not published. When these were taken into account by researchers at the University of Warwick, the relative increase in risk fell to about 15 percent (4). An effect this small would usually be dismissed as potentially the product of other kinds of research bias. For this reason, researchers are usually advised to treat with extreme scepticism increases in risk of less than 100 percent.

For anti-smoking campaigners, the passive smoking debate is a perfect stick to beat smokers with. It suggests that, even if a smoker doesn't care about their own health, he should be more careful as regards the health of others. The argument seems to have been very successful, as recent proposals for outright bans on public smoking in New York and Norway suggest. But is it really the place of the authorities to micro-manage our lives through dubious morality dressed up as science?

(1) A killer on the loose [pdf format, 600KB], ASH
(2) Factsheet no.5: smoking and respiratory disease, ASH, July 2001
(3) Factsheet no. 8: passive smoking, ASH, July 2002
(4) Passive smoking risk 'overstated', BBC News, 11 February 2000


Post a Comment

<< Home