Monday, October 30, 2006

Anti-Smoking Advocate Claims that Seconds of Tobacco Smoke Exposure Can Cause Heart Attacks in Nonsmokers

As I noted last Monday, the amount of time that it apparently takes for secondhand smoke to cause a heart attack has dropped from 30 minutes to 20 minutes to 5 minutes and ultimately, to 30 seconds.

Now, however, an anti-smoking advocate is claiming that mere seconds of exposure to secondhand smoke - the amount of time it would take to simply pass through a room with smokers - is enough to cause heart attacks among nonsmokers.

According to this advocate, who is a cardiologist in Minnesota and whose heart center is affiliated with a Minnesota anti-smoking organization, just passing through a smoke-filled room is enough to trigger a heart attack.

As he wrote in an opinion column in the October 22 edition of the St. Cloud Times:

"In the study of medicine and public health, every now and then a finding comes along that is so groundbreaking that the world is literally never the same. ... A recent, landmark study out of Pueblo, Colo., that links exposure to secondhand tobacco smoke to an increase in the rate of heart attacks is yet another. ... The study, which was published in Circulation: A Journal of the American Heart Association, found that hospitalizations for heart attacks declined significantly in that city after a comprehensive smoke-free workplace law, including restaurants and bars, was implemented on July 1, 2003. ... The study also appears to support the recent findings of the U.S. Surgeon General that there are no safe levels of exposure to secondhand tobacco smoke and that simply passing through a smoke-filled room can trigger heart attacks in nonsmokers."

The physician who makes this claim practices at the Central Minnesota Heart Center, which has representation on the Board of Directors of the St. Paul-based Minnesota Smoke Free Coalition. He also links to the Smoke Free Communities anti-smoking group in an earlier letter to the editor in the St. Cloud Times. This group is in fact coordinated out of the Central Minnesota Heart Center.

The Smoke Free Communities group itself claims that: "short term exposure to secondhand smoke while having lunch or a drink or two can trigger a heart attack in people who are at risk, particularly the elderly."

Smoke Free Communities also claims that: "In 30 minutes of secondhand smoke exposure, your arteries stiffen; your blood thickens and becomes more 'sticky,' and your body'’s ability to process cholesterol is diminished. This stress on your cardiovascular system can be the prelude to a heart attack."

The Rest of the Story

I can't tell you how many times I've witnessed this scenario. A guy tries to make it across a room where smoking is taking place, and before he can even make it to the other side of the room, he keels over and drops dead or unconscious from a heart attack.

I'm not sure why we need research and a cardiologist to tell us that mere seconds of secondhand smoke exposure causes people to have heart attacks, when common sense and general experience would tell us that people are dropping dead of heart attacks all the time when trying to pass through rooms where smoking is occurring.

Seriously - this claim flies in the face of common sense and our collective experience. That doesn't mean the claim is wrong, but it does mean that in order to support such a claim, one would need to provide strong evidence or documentation of this risk. However, I am aware of no evidence or documentation that 10-15 seconds of secondhand smoke exposure (the time it would take to pass through a smoky room) causes heart attacks in nonsmokers. And to my knowledge, no such evidence has ever been presented.

But what makes this claim really inappropriate and unfortunate is the fact that it is not merely trying to portray one individual's opinion of the risk of acute secondhand smoke exposure, which the public might dismiss as being exaggerated. Instead, the claim being made is actually that the United States Surgeon General has concluded that merely passing through a smoky room causes heart attacks in nonsmokers.

If you re-read the opinion piece, you'll see that the writer is not simply offering his own opinion, but is communicating to the public that the Surgeon General drew such a conclusion.

This is untrue. If you read through the 727-page Surgeon General's report (you don't actually have to do it if you're pressed for time - I've read through the entire thing), you will not find any conclusion or finding that passing through a smoky room causes heart attacks in nonsmokers, or that very brief exposures (such as 15-30 seconds) in any setting cause heart attacks.

I suppose that if one only read the Surgeon General's propaganda statements, which do imply that a brief exposure to secondhand smoke can cause heart attacks and heart disease, but failed to actually read the report for oneself, one could perhaps be misled into thinking that the report concluded that brief exposure causes nonsmokers to have heart attacks. However, I think if you are going to publicly represent the conclusions of the Surgeon General to the public, you have a responsibility to read the report and understand the science. In addition, to take the vague term - "brief" - and translate that into the amount of time it takes to pass through a smoky room is an unwarranted exaggeration of even the misrepresented findings.

Importantly, this does not appear to merely be an errant claim of one particular anti-smoking advocate. The Smoke Free Communities group, which appears to be coordinated by the Central Minnesota Heart Center, is itself claiming that 30 minutes of secondhand smoke exposure causes heart attacks in nonsmokers.

Its first claim above - that exposure to tobacco smoke while having a drink or two can trigger a heart attack in people at risk - is an undocumented one. It is basically just speculation. Sure, there is evidence that 30 minutes of secondhand smoke exposure may cause platelet activation. But whether that increased platelet activation caused by a single, short-term exposure to secondhand smoke, if not prolonged or repeated, can actually trigger a heart attack, or whether it does so with any regularity, is speculation. There is no evidence or documentation I am aware of that would support such an extrapolation. Especially not to the point where it we can go around making this claim widely to the public with any scientific integrity.

Smoke Free Communities' second claim above is, at best, misleading because it implies that anyone exposed to 30 minutes of secondhand smoke exposure could potentially suffer a heart attack due to that exposure.

This is not true. Even if one extrapolates from the evidence of tobacco smoke's short-term effects on platelet aggregation and endothelial dysfunction and does not require any actual evidence that such short-term exposure could cause a heart attack, one could only speculate that a heart attack could be triggered in an individual with severe, pre-existing coronary artery disease.

However, this statement by Smoke Free Communities is not qualified in this way. It could easily be interpreted by the public as meaning that anyone exposed to secondhand smoke for 30 minutes is at risk of a heart attack. This is quite unfortunate, because for the overwhelming majority of the public, there is absolutely no concern that a short-term exposure to secondhand smoke could cause a heart attack. It is simply not plausible.

So why scare people unnecessarily?

The answer, it appears, is that anti-smoking groups are intentionally trying to increase the emotional appeal of their secondhand smoke messages, and they're not letting the actual science get in the way.

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