Action on Smoking and Health (ASH) has reiterated its claim that 30 minutes of secondhand smoke increases a nonsmoker's risk of suffering a heart attack to the same level as that of an active smoker.
On its web site, ASH now repeats its claim that "even 30 minutes of exposure to small amounts of drifting secondhand tobacco smoke can increase a nonsmokers' risk of a heart attack to that of a smoker."
ASH states that its claim is based on the following two statements made in the scientific literature:
"the effects of even brief (minutes to hours) passive smoking are often nearly as large (averaging 80% to 90%) as chronic active smoking."
"Even 30 minutes of exposure to a typical dose of secondhand smoke induces changes in arterial endothelial function in exposed non-smokers of a magnitude similar to those measured in active smokers."
The Rest of the Story
This claim by ASH is not only inaccurate, but it is absurd on its face. There is no way that 30 minutes of secondhand smoke can increase the risk of a heart attack to the same level as that observed in a chronic, active smoker. If this were true, then the tobacco industry could legitimately claim that: "active smoking is no worse [in terms of heart attack risk] than being exposed to drifting tobacco smoke for 30 minutes." Obviously, a smoker's risk of a heart attack is far greater than the risk for a nonsmoker exposed to secondhand smoke for a half hour.
So ASH has got it completely wrong here. But how? How could ASH so thoroughly distort the science that it became blatantly false?
The answer is that ASH has conflated endothelial dysfunction with heart attack risk. Both statements #1 and #2 above relate to endothelial dysfunction. What the key study found (there is really only one study here, but the same study is being referred to in both statements) is that 30 minutes of secondhand smoke exposure increased endothelial dysfunction (as measured by coronary flow velocity reserve) to the same extent in nonsmokers as in smokers.
The study did not find that 30 minutes of secondhand smoke increases heart attack risk to the same level as that of smokers.
Had ASH stated: "even 30 minutes of exposure to small amounts of drifting secondhand tobacco smoke can increase a nonsmokers' risk of endothelial dysfunction to that of a smoker," or "even 30 minutes of exposure to small amounts of drifting secondhand tobacco smoke can decrease nonsmokers' coronary flow velocity reserve to that of a smoker" then the statement would
have been correct.
But by distorting the statement to assert that a nonsmoker's risk of a heart attack is increased to the same level as that of a smoker, ASH has factually misrepresented the truth.
I am not accusing ASH of intentionally lying. Another possibility is that they are lawyers and not physicians, simply do not understand the difference between measuring endothelial dysfunction and measuring heart attack risk, and are simply out of their league in interpreting science like this. However, if this is the explanation for this scientific misrepresentation, then it is still inexcusable. A public health organization that puts itself forward as being a trustworthy source of medical and scientific information to the public has a responsibility, I believe, to be reasonably careful in crafting its public communications. If scientific incompetence is the explanation for ASH's dissemination of false information, then ASH remains guilty of failing to exercise even the most minimal level of care in communication of health information to the public.
There are a number of adverse implications of ASH's actions.
First, by blatantly distorting and misrepresenting the science, ASH has threatened the credibility and reputation of all of us in tobacco control. It is quite obvious, even to much of the lay public, that ASH's claim is absurd. There is no way that 30 minutes of secondhand smoke exposure can put nonsmokers at the same level of heart attack risk as smokers. I am afraid that people are going to realize this and realize that the tobacco control movement is misrepresenting the science. While it is one particular group making this claim, I think people will attribute the behavior more generally to the entire movement.
Second, by being untruthful in its health claims, ASH has threatened the scientific integrity of the tobacco control movement. There is an ethical public health standard of honesty in scientific communication which I believe ASH is violating here (whether intentional or not) and it reflects poorly on the entire movement, even groups which are not making this claim.
Third, by distorting the science so severely, ASH risks undermining the public's appreciation of the hazards of active smoking and undermining years of public health efforts to educate the public about the severe cardiovascular disease harm of cigarettes. If the public truly believes that the heart attack risk associated with active smoking is only as bad as that produced by breathing drifting tobacco smoke for a half hour, then the public's perception of the severity of the heart attack risk of active smoking will certainly decrease. This statement could easily lead smokers to believe that they are not at a particularly high risk of a heart attack. It could easily deter smokers from quitting and undermine efforts to prevent youths from starting to smoke.
Remember that in an equation, it doesn't matter which side you put first. If you state that A = B, then you are also stating that B = A.
Thus, if you state that a nonsmoker's risk of a heart attack after exposure to 30 minutes of tobacco smoke is the same as that of a smoker's, you are also stating that a smoker's risk of a heart attack is merely that of a nonsmoker who breathes in drifting smoke for a half hour.
Had ASH stated the claim that way, I think it would have been immediately obvious to people that they were pulling their legs. In fact, if the tobacco industry put out such a claim (which they could easily do based on ASH's statement), I am sure anti-smoking groups would be attacking the industry for making such an absurd claim.
In fact, I have a brilliant idea for the tobacco industry which I'd like to pass along. They can, without any risk of liability, point out to their smoking consumers that "Even anti-smoking groups agree that your risk of suffering a heart attack is no higher than that of someone who doesn't smoke but merely breathes in tobacco smoke for 30 minutes."
I would make that the basis of an education campaign directed to all smokers, and to the public. I would call the "Understand Your Risk" campaign. In all literature or other communications produced by the campaign, I would clearly cite Action on Smoking and Health for the statement, so that there is no risk of liability for making a false claim. In the statements, I would make sure to specify: "according to an anti-smoking group....".
Since ASH didn't specify a maximum smoking duration in its claim, as a tobacco company, I believe I could safely reassure my long-term customers of 30-40 years not to worry, because their risk of a heart attack is no worse than it would be if they had never smoked, but had simply once walked into a smoky bar for a half hour.
Clearly, ASH's claim also undermines the importance of the dose-response relationship between cigarette smoke exposure and heart attack risk. If it is true that a smoker's risk of a heart attack is no higher than someone who walks into a smoky rib shack for 30 minutes one time, then smoking for 40 years doesn't put you at any increased heart attack risk as smoking for 20 years, or for 1 year for that matter. Smoking 4 packs a day isn't any worse than smoking a few cigarettes a day. And most devastatingly, quitting smoking apparently will not reduce your heart attack risk at all if you still hang out with your smoking friends for a half hour on occasion. So why quit smoking?
Before closing, I think it is important to point out that ASH's original claim, which it maintains to this day on this web page, appears to be false. ASH claims that "the CDC has warned that breathing drifting tobacco smoke for as little as 30 minutes ... can raise a nonsmoker’s risk of suffering a fatal heart attack to that of a smoker."
However, I can find no evidence that the CDC has indeed warned that "breathing drifting tobacco smoke for as little as 30 minutes can raise a nonsmoker's risk of suffering a fatal heart attack to that of a smoker." The CDC did warn that breathing secondhand smoke for as little as 30 minutes can reduce coronary flow velocity reserve to that of a smoker. But nowhere did CDC warn that brief tobacco smoke exposure increases heart attack risk to that of an active smoker.
My argument of course hinges on their being a critical difference between the finding of reduced coronary flow velocity reserve and the finding of an increased heart attack risk. In fact, having reduced coronary flow velocity reserve does not equate to being at an increased risk of a heart attack. In the healthy volunteers who were studied by Otsuka et al., there was no increased heart attack risk faced by these patients. Had there been such a risk, then the study would have been unethical and it never would have been approved by an institutional review board. Certainly, the subjects would have had to be warned that they would face an increased risk of heart attack and possibly death.
Moreover, eating a hamburger reduces coronary flow velocity reserve to roughly the same extent as in an active smoker. Would it therefore be accurate for ASH to claim that "eating a single hamburger can increase a person's risk of a heart attack to that of a smoker?" Of course not. If you walk into McDonald's and order a hamburger, you may be at risk of disease, but not from immediately keeling over from a heart attack.
Luckily, the tobacco companies are a little more honest than ASH is being here, and they have not taken this opportunity to claim publicly that: "Smoking puts you at no more risk of a heart attack than eating a single hamburger." Based on ASH's statement, the tobacco companies could accurately make such a claim. The tobacco companies aren't misrepresenting the science about this. Why is ASH?