An anti-smoking health group is publicly claiming that 25% of all bar workers exposed to secondhand smoke will die of heart disease caused by that tobacco smoke.
If true, this means that about 100,000 of the 474,000 bartenders in the U.S. will die of heart disease due to secondhand smoke exposure at their workplaces. It also means that bar workers face an astronomically high mortality rate (1 in 4).
According to the British Heart Foundation: "We know that regular exposure to secondhand smoke increases the chances of developing heart disease by around 25%. This means that, for every four non-smokers who work in a smoky environment like a pub, one of them will suffer disability and premature death from a heart condition because of secondhand smoke. No responsible government could allow such an appalling public health anomaly to continue."
This statement was also carried to the public in at least one newspaper article. This is North Scotland quoted the Foundation as stating that: "for every four non-smokers who work in a smoky environment like a pub, one of them will suffer disability and premature death from a heart condition because of second-hand smoke."
These claims were apparently made in support of the recently implemented ban on smoking in Scotland pubs and restaurants.
The Rest of the Story
This claim about the health impact of secondhand smoke exposure among bar workers is blatantly false. It stems from a confusion between relative risk and absolute risk of disease.
Relative risk is the difference in risk of disease between individuals exposed to a particular hazard and those not exposed. The relative risk of heart disease death in pub workers due to secondhand smoke is reported here as being approximately 1.25, which means that pub workers are 25% more likely to die from heart disease than they would be if there were no smoking in pubs.
Absolute risk refers to the actual risk of developing a disease if one is exposed to the hazard. A 25% absolute risk of dying prematurely from heart disease among bar workers would mean that 1 in 4 bar workers would be expected to die prematurely from heart disease.
The problem is that the British Heart Foundation statement equates absolute risk with relative risk. While the relative risk of heart disease among exposed nonsmokers is about 1.25, meaning that exposed bar workers are 25% more likely to die from heart disease due to their exposure, the absolute risk of a bar worker dying from heart disease attributable to secondhand smoke exposure is nowhere close to 25%.
The shame here is not merely that an anti-smoking group is using false scientific claims to support public policy but that it is completely unnecessary to do so. There is enough evidence, I believe, of the hazards of secondhand smoke exposure for bar and restaurant workers that we can promote policies to protect the health of these workers without having to resort to misleading and inaccurate public statements and the blatant distortion of the truth.
I think we can effectively promote responsible public health policies while at the same time being truthful. And to be honest, I think we'd be a lot more effective if we did so.
After all, eventually all of these fallacious claims that we're making are going to tip off the public and the media to the fact that we can't be trusted to accurately present the science. And then it's going to become impossible to convince them of the legitimate facts about secondhand smoke - facts that need to be communicated to the public, and for which we need the public's trust.
What's at stake is simply too important to throw it all away just so that we can make some claims that sound very dramatic and alarming.
The truth is enough to support the policies that most of us in tobacco control are working towards. There's no need to go beyond simply telling the truth. And if we don't stop doing it, it's going to destroy our credibility. Then we won't be able to convince anyone of even the true facts about the dangers of secondhand smoke.