Wednesday, December 12, 2007

Anti-Smoking Groups Using Misleading Scientific Statements to Support Smoking Bans

Not only have more than 100 anti-smoking groups made misleading scientific claims about the acute effects of secondhand smoke, but these deceptive statements are being used to support the need for smoking bans. Today's example comes from Missouri, where Smoke-Free St. Louis is citing, in support of a smoking ban, a statement that 30 minutes of secondhand smoke causes heart damage similar to that of active smokers and that it reduces the ability of the heart to get life-giving blood.

The misleading health claim comes not from Smoke-Free St. Louis itself, but from the national anti-smoking group Americans for Nonsmokers' Rights (ANR), which is arguably the leading source of information for anti-smoking advocates throughout the nation who are promoting smoking bans.

The statement is: "Just thirty minutes of exposure to secondhand smoke can cause heart damage similar to that of habitual smokers. Nonsmokers’ heart arteries showed a reduced ability to dilate, diminishing the ability of the heart to get life-giving blood."

The Rest of the Story

First of all, I support the efforts of Smoke-Free St. Louis to promote a smoking ban for workplaces, bars, and restaurants in St. Louis. However, I do not support the use of misleading and deceptive scientific statements in order to promote such a ban. The ultimate blame, of course, lies at the door of ANR, which exaggerated the results of the Otsuka et al. study so much that they turned an important scientific finding into a blatant misrepresentation of the truth.

It is not true that 30 minutes of secondhand smoke exposure causes any heart damage, much less damage that is similar to that sustained after many years of active smoking. It is also not true that the hearts of nonsmokers exposed to secondhand smoke for 30 minutes are impaired in their ability to get life-giving blood.

In fact, the Otsuka et al. study, which is the one being relied upon for this statement, actually demonstrated that there is no impairment of basal coronary artery blood flow in subjects exposed to high levels of secondhand smoke for 30 minutes. The study itself documents that there was not any reduced ability of the heart to get life-giving blood!

Thus, the statement is contradicted by the very study which ANR claims supports it.

There is, in fact, no evidence that 30 minutes of secondhand smoke causes any heart damage. Does it impair the function of the cells lining the coronary arteries? Yes. But does that cause heart damage? No.

If sustained over many years, the endothelial dysfunction caused by tobacco smoke exposure could result in atherosclerosis. However, this is not going to occur from a 30-minute exposure. So it is massively deceptive to suggest that a 30 minute exposure causes heart damage, much less that it causes heart damage that is similar to that observed in long-term active smokers, who may have developed severe coronary artery stenosis and suffered heart attacks which destroyed heart muscle.

The Smoke-Free St. Louis web site also cites the invalid conclusions from the Helena and Pueblo studies, which I have already discussed in great detail.

But my chief concern is the citation of ANR's highly deceptive statements about the acute effects of brief secondhand smoke exposure on the heart.

Given the real scientific evidence about the hazardous effects of secondhand smoke exposure, why does ANR need to exaggerate and distort the truth? And why do anti-smoking groups around the country have to cite this garbage, when they could be relying strictly on valid science?

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