Brian Monteith: BMA’s ‘facts’ prove to be all smoke and mirrors

DO YOU believe what your doctor tells you? When the doctors’ trade union, the British Medical Association, speaks out, do you think it must be a reasoned and rational opinion based upon hard evidence?

I would expect most people would give an unequivocal yes to the first question but be more hesitant about the second simply because, as Adam Smith identified, when groups of people from a profession or trade get together they tend to conspire against the public interest rather than put it first. Nonetheless I think people would give the BMA the benefit of the doubt because they are doctors, not butchers, brewers or bakers.

Last week we found out that doctors, as represented by the BMA, can no longer be trusted. The BMA is no more worthy of trust than any political leader, union boss or second hand car salesman.

Last Wednesday the BMA in London and Edinburgh issued a call for a ban on smoking in cars – all cars, no matter who is in them. It argued a ban is necessary because smoking in a car exposes drivers and passengers to “23 times more toxins than a smoky bar”. Now there’s little room for equivocation there: not twice as dangerous, not 20 times as dangerous but exactly 23 times as dangerous as a smoky pub.

Such evidence must have seemed insurmountable and unchallengeable to our politicians, who like to think they act on evidence rather than their prejudices or how public sympathies might influence their re-election. If the danger to people’s health is 23 times as bad as that offered by smoky pubs and politicians have already banned smoking in those, then surely they would act to ban smoking in cars? That the logical extension of this argument could and would be used to suggest banning smoking in anyone’s own private home seemed plain, but the BMA is keeping its powder dry on that issue for now.

When I read of the BMA’s announcement it brought a wry smile to my face, for I know something of the claim about the dangers from tobacco smoke in a car and was surprised by the sheer gall of the statement – either the BMA is so stupid to not have checked its evidence, or it knew the claim was baseless and was peddling a lie to the public in the hope it would be believed without question. Either defence would be a reason for doubting anything the BMA might say on any subject ever again.

Last year, concerned about the veracity of unsubstantiated claims undermining a genuine debate about second-hand smoke, Australian researchers Ross MacKenzie and Becky Freeman from the school of public health at the University of Sydney tried to source a similar claim that second hand smoke is “23 times more toxic in a vehicle than in a home”. They found that it first originated in a January 1998 report from the Rocky Mountain News of Denver, Colorado.

A bill to control smoking in cars introduced by a Colorado senator elicited an erroneous press release by her supporters citing a 1992 study of tobacco-specific N-nitrosamines in indoor air. That study did not, however, make the 23 times claim as quoted in the Rocky Mountain News.

From an untrue quotation in a press release it then evolved to become “evidence” and was adopted unquestionably by mainstream academic peer review literature for the next 12 years.

Similar phrasing appeared in the journal Tobacco Control and Nicotine and Tobacco Research, while an Ontario Medical Association’s 2004 paper conferred further respectability. In January 2008, the Canadian Broadcasting Corporation referred to the same “Colorado study” which was then picked up by the US-based Action on Smoking and Health and ASH Scotland. Soon it was cited without origin by Australian media reports, a peer-reviewed journal and a press release issued by the Australian Medical Association while state and federal politicians echoed the claims.

The lie was then peddled by ASH Ireland and repeated in the Irish Medical Times and Irish Times, while the European Respiratory Journal published a 2009 paper citing the Ontario paper of 2004. This led to the Sunday Times reporting the 23 times claim, which was in turn referenced in a daily news release from ASH UK and on the websites of the European Lung Foundation and the Oxford Health Alliance.

At no point did any of these self-proclaimed august and reputable bodies seek to check their facts. MacKenzie and Freeman had shown the claims to be nothing more than an urban myth. That the 23 times as toxic claim has, thanks to the BMA, morphed from comparison with a house to a smoky pub is surely no coincidence – for people understand that smoking has been banned in pubs but for homes remains only an ambition with anti-tobacco campaigners who talk about a “smoke-free Europe”.

The BMA’s position did not last even a day under scrutiny. By Thursday it was forced to concede that there was indeed no evidence for the 23 times as toxic claim and instead referred to new evidence that smoke in a car “could be” 11 times as bad. Yet even this claim does not stand up for it is based upon the ridiculous notion that opening a window of a car makes no difference to toxin levels when a study it cites contradicts this.

The American Journal for Preventative Medicine reported smoking in a car with closed windows generated particulate concentrations of 272 micrograms per cubic metre of air compared to a range of 206 in smoky bars in Massachusetts and 412 in New York – but a car with its windows open gave just 51 micrograms per cubic metre. Nowhere is there evidence for 11 times the amount of toxins.

I do not exaggerate about not trusting anything the BMA say in future. The whole edifice of modern medicine is based upon hard evidence being rigorously tested ahead of being put before the public. For the BMA to so blithely or cunningly mislead the public deserves the strongest condemnation and the perpetrators to be removed from office.

Trust me, I’m a doctor? Is there anyone left to trust?

• Brian Monteith is policy director of ThinkScotland.