In a contributed article published in The Daily Times (Salisbury, MD), the American Lung Association of Maryland cites the Centers for Disease Control and Prevention (CDC) in claiming that a mere 30 minutes of secondhand smoke exposure can cause death in a nonsmoker who is merely at risk for, but does not have, severe existing heart disease. The Lung Association also claims that secondhand smoke causes emphysema in nonsmokers.
According to the article: "The Centers for Disease Control and Prevention have reported that as little as 30 minutes' exposure to secondhand smoke can have a serious and even lethal effect for people with heart disease or at risk for heart disease."
Also according to the article: "Secondhand smoke causes heart disease, lung cancer, asthma, emphysema and stroke." (emphasis is mine)
The Rest of the Story
While it may not immediately strike readers as being completely fallacious because it is hidden behind the authority of the CDC, it is simply untrue that a mere 30 minutes of secondhand smoke can cause death from cardiac causes in a nonsmoker who is at risk for heart disease, but does not actually have severe pre-existing coronary artery stenosis (i.e., very severe heart disease).
If you don't have heart disease to begin with, being exposed to secondhand smoke for 30 minutes cannot possibly cause heart disease; thus, it cannot kill you from cardiac causes. It takes many years for heart disease to develop. Thus, a mere 30 minutes of exposure cannot plausibly cause heart disease to occur. A person without pre-existing heart disease who is exposed to secondhand smoke for 30 minutes does not need to worry about having a heart attack or dying from any heart-related ailment.
The mere fact that a person is at risk of heart disease - meaning that he or she has risk factors such as being male, having high cholesterol, having a family history of heart disease, or having high blood pressure or diabetes - does not in any way make a person susceptible to having a heart attack from 30 minutes of secondhand smoke exposure. The only thing that could make one susceptible, at least theoretically, is having severe coronary artery disease to begin with.
There is evidence that secondhand smoke exposure can aggravate angina in patients who have existing heart disease. Thus, it is at least possible that a brief exposure to secondhand smoke could trigger a heart attack in someone with severe heart disease. But it would be impossible for a brief exposure to trigger a heart attack in someone without severe heart disease, even if that individual had a myriad of risk factors for heart disease.
The statement by the American Lung Association clearly implies that a person who is merely at risk of heart disease, but does not have heart disease, could die from a heart attack due to 30 minutes of secondhand smoke exposure. After all, the statement says that such an exposure can be lethal to someone "with heart disease OR at risk for heart disease." If the statement was intended merely to convey the idea that 30 minutes of secondhand smoke could trigger a fatal heart attack in someone with heart disease, then it should not have included the clause "OR at risk for heart disease."
It appears to me that the inclusion of that clause is intended to scare healthy people (albeit those with heart disease risk factors) that they could die from merely a brief exposure to secondhand smoke.
To me, that represents scare tactics. Inappropriate scare tactics, because the claim is untrue. Why would we want to scare healthy people into thinking that they could drop dead from merely a 30 minute exposure to secondhand smoke? I don't know, but one possibility is that scaring people into believing the risk is that great might increase support for the ever-expanding smoke-free agenda, which now aims - apparently - to ban smoking not only indoors but just about everywhere outdoors as well. Even if the intention were to scare people into supporting workplace smoking bans (which I support), I don't think it is appropriate to use false or misleading information to advance even a well-justified policy.
One might argue that the American Lung Association is not making the claim, but is merely repeating a claim that was made by CDC. This argument fails, however, because to the best of my knowledge, the CDC never claimed that 30 minutes of secondhand smoke exposure can cause a fatal heart attack in an otherwise healthy nonsmoker. What the CDC stated is that people who have heart disease or are at risk for heart disease should avoid secondhand smoke exposure given what CDC sees as its potential to trigger a heart attack in someone with heart disease. That makes sense because a person with risk factors for heart disease could have heart disease, but not know about it. But such a warning is very different from implying that a person who has risk factors for heart disease, but does not have heart disease, can have a heart attack from 30 minutes in a smoky room.
One might also argue that the American Lung Association is referring not to death from a heart attack or heart disease, but from asthma. A brief secondhand smoke exposure could potentially trigger a fatal asthma attack. However, I believe this argument fails because from the context of the statement, it is quite clear that the Lung Association is not talking about asthma risk. The CDC statement that is referred to was delivered in the specific context of a warning about the cardiovascular health effects of secondhand smoke. Moreover, if that was the intention of the statement, should it not have stated that a 30 minute exposure could be lethal to those who have asthma?
And for that matter, why 30 minutes? A 5-minute exposure could potentially trigger an asthma attack. The 30 minute figure comes from the Otsuka et al. study, which found that 30 minutes of heavy exposure to secondhand smoke causes endothelial dysfunction in healthy nonsmokers. So it seems clear that this claim is referring to death from heart disease, rather than asthma.
I have already explained why I think it is not appropriate to claim that secondhand smoke causes emphysema in nonsmokers, so I will not repeat that argument here. Suffice it to say that neither of the two recent, comprehensive reports on the health effects of secondhand smoke (those issued by the Surgeon General and by the California EPA) concluded that secondhand smoke causes emphysema.
Readers of this blog will know that I fully support workplace smoking bans as well as bans on smoking in outdoor areas where people cannot easily avoid exposure to secondhand smoke. They will also know that I believe chronic exposure to secondhand smoke can cause heart disease. But it is just not true that brief exposure to secondhand smoke can cause a fatal heart attack in a person who doesn't already have severe coronary artery disease.
I think it's wrong to make such a claim. Not only is it untrue and unsupported by the science, but it also flies in the face of common sense and even a meager understanding of medicine. It is deceptive. It also scares people unnecessarily. And perhaps worst of all, it undermines people's appreciation of the hazards of active smoking. If a mere 30 minutes of secondhand smoke exposure can cause a nonsmoker to drop dead from a heart attack, then why should active smokers be so concerned about their own risk? It makes it sound like active smoking is no worse than a very brief exposure to secondhand smoke. In fact, it makes it sound much worse. I don't recall any public health organization warning smokers that a mere 30 minutes of smoking could cause them to drop dead from a heart attack.
Finally, I should make it clear that I am not necessarily putting all the blame on the American Lung Association. I think that the CDC may be partly responsible, because apparently it gave the impression that brief secondhand smoke exposure could be fatal to healthy nonsmokers who had risk factors for heart disease. I don't know that the CDC was clear enough in its article on this subject to avoid people misinterpreting its conclusions. I do sense that there was a little bit of an attempt at sensationalism to make that article more startling (see: Pechacek TF, Babb S. Commentary: How acute and reversible are the cardiovascular risks of secondhand smoke? BMJ 2004; 328:980-983).
That article begins as follows: "Could eating in a smoky restaurant precipitate an acute myocardial infarction in a non-smoker? As unlikely as this sounds, a growing body of scientific data suggests that this is possible."
I think that introduction could be viewed as overly sensationalistic because it does seem to imply that a brief smoke exposure could trigger a heart attack in a healthy nonsmoker. It does not qualify the situation by making it clear that it refers only to a nonsmoker with severe pre-existing coronary artery disease.
If you go on and read the rest of the article, you'll see that the authors never actually state that acute secondhand smoke exposure poses a heart attack risk to anyone other than nonsmokers with existing heart disease. The CDC does not state that a brief exposure to secondhand smoke can cause a heart attack in someone without severe heart disease to begin with. But I do see how someone could get that impression, especially from the way the introduction reads, without any qualification of who is potentially at risk of dropping dead after 30 minutes in a smoky restaurant.
I think it would be very important and helpful for the CDC to explicitly clarify the conclusions in this article, in order to avoid the kind of misrepresentation of the science that is becoming more and more widespread. It would only help the tobacco control movement, not hurt it, because it would help avoid fallacious claims like those of the American Lung Association which threaten to harm the credibility and undermine the perceived integrity and ethical standards of the entire tobacco control movement.