Passive smoke gets in their eyes
Second-hand smoke is assumed to be dangerous. But where is the hard evidence?
‘Why should I have to inhale your second-hand smoke?’
This is a common refrain of those who want to ban smoking in public places: that it is one thing for smokers to destroy their own lungs, but why should the rest of us have to face the health risks of passive smoking?
But the facts about passive smoking are far from set in stone.
— In February 2000, Professor John Copas and Dr Jian Qing Shi at Warwick University analysed the findings of 37 trials that examined the impact of passive smoking – pointing out that research which showed an increased risk of lung cancer was more likely to be published than research which did not. They challenged the claim that those exposed to passive smoking faced an increased risk of lung cancer of 24 percent – pointing out that it is closer to 15 percent. This works out that one or two non-smokers in every 100,000 might be at risk from passive smoking, and only if repeatedly exposed to smoke over many years (1).
— In 1998, Professor Robert Nilsson revealed that the increase in the incidence of lung cancer attributed to passive smoking is one order of magnitude lower than that used to justify regulating environmental risks in the USA – so passive smoking poses less of a risk than natural arsenic in water or eating mushrooms twice a week (2).
— In March 1998 a 10-year study of ‘environmental tobacco smoke’ and lung cancer carried out by the World Health Organisation (WHO) found that there was an estimated 16 percent increased risk of lung cancer among non-smokers married to smokers, and a 17 percent increased risk for workplace exposure to smoke. Given that lung cancer is a relatively uncommon tumour, even WHO had to admit that ‘neither increased risk was statistically significant’ (3).
— In October 1997, researchers at Colorado State University rubbished the link between passive smoking and lung cancer, arguing that the increased risk of lung cancer as a result of ‘environmental tobacco smoke’ could be 60 percent lower than that claimed by some scientists. The researchers reanalysed 35 studies that linked passive smoking and lung cancer among non-smoking women married to smokers, accusing some scientists of overlooking studies that showed little or no effect of passive smoking because they were seen as ‘not worthwhile’. The Colorado State University team concluded that the increased risk of lung cancer from passive smoking could be ‘completely negligible’ (4).
Stop the press: On 9 March 2001, some newspapers reported that the first ‘biochemical evidence’ had been found for a link between environmental tobacco smoke and lung cancer, after researchers at the University of Minnesota published research comparing women who live with smokers with women who live with non-smokers. But the research was based on a tiny sample group: 23 women living with smokers and 22 women living with non-smokers. The study found that the 23 women living with smokers had a higher level of the tobacco-related chemical NNK in their blood than the 22 women living with non-smokers. But, as one article points out, only massive doses of NNK – to the order of the NNK exposure that results from smoking two packs of cigarettes every day for 40 years – causes an increased risk of lung cancer (5).
Brendan O’Neill is coordinating the spiked-conference Panic attack: Interrogating our obsession with risk, on Friday 9 May 2003, at the Royal Institution in London.
No smoking issue
(1) See ‘Passive smoking risk “overstated”’, BBC News Online
(2) Professor Robert Nilsson, ‘Is environmental tobacco smoke a risk factor for lung cancer?’, in R Bate, What Risk?: Science, Politics and Public Health, 1998
(3) See The Economist, 15 March 1998
(4) See ‘Cancer alert on passive smoking is “false alarm”’, Daily Telegraph, 19 October 1997
(5) See ‘Second-hand smokescreen’, Junk Science, 9 March 2001
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