Thursday, March 30, 2006

Another Anti-Smoking Group Makes Fallacious Scientific Claims in Support of Smoking Bans

In a fact sheet provided on its web site, entitled "Secondhand Smoke: The Science," Americans for Nonsmokers' Rights (ANR) claims that:

"Even a half hour of secondhand smoke exposure causes 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

This claim, like similar claims made by Action on Smoking and Health (ASH) and SmokeFreeOhio (SFO), is completely fallacious. Except this one is far worse.

At least ASH and SFO were merely claiming that eating a hamburger in a smoky restaurant would increase the risk of a heart attack. What ANR is claiming is that doing so causes heart damage.

I'm sorry, but this is completely inappropriate and irresponsible. It's basically telling the public that any time they are exposed to secondhand smoke for 30 or more minutes, they are suffering heart damage. And this is completely false.

Presumably, ANR is extrapolating from the Otsuka study which showed that a 30-minute exposure to secondhand smoke can induce endothelial dysfunction in nonsmokers. But endothelial dysfunction is not damage to the heart. In fact, it's not really damage at all, because it is a completely reversible change. In fact, it is the same thing that happens when you eat a hamburger.

By this logic, one could just as easily and just as "correctly" claim that eating a hamburger in a smoke-free restaurant causes heart damage similar to that of habitual smokers.

It's one thing to make an extrapolation, but this is just ridiculous.

Not only is this irresponsible because it is completely fallacious and because it might unduly scare nonsmokers into thinking that they have suffered heart damage if they have even breathed in a few wisps of secondhand smoke, but it is also irresponsible because this fact sheet completely undermines our efforts to educate smokers about the hazardous cardiovascular effects of smoking by giving them the false impression that the damage that might be caused to their hearts from smoking is no more than that of someone who breathes in drifting smoke for a half hour on a street corner.

And I've only analyzed the first part of the statement.

The second part of the statement is also completely fallacious.

Thirty minutes of exposure to secondhand smoke does not reduce the heart's ability to get life-giving blood.

Just think about it. If this were true, Otsuka and his colleagues would likely be in prison now for putting the lives of human subjects at risk. At very least, it would have been unethical for them to expose subjects to something that put their hearts at risk of not getting life-giving blood.

If ANR were correct, then we would see people keeling over from heart attacks all over the place due to brief secondhand smoke exposures. And for that matter, we'd also see people keeling over from heart attacks due to eating hamburgers, cheeseburgers, and the dreaded tater tots. After all, if endothelial dysfunction means that your heart is not able to get life-giving blood, then eating too many french fries could kill you on the spot.

The truth is (if you actually read the Otsuka article) that this study found that a 30-minute exposure to secondhand smoke actually had no effect on coronary blood flow. It did not compromise the coronary circulation, damage the heart, or deprive the heart of life-giving blood.

On the contrary, the study reported that: "Passive smoking exposure had no effect on basal coronary flow velocity in either group." In other words, this study documents that a 30-minute exposure to secondhand smoke does not present a threat of reducing coronary blood flow in patients without severe coronary disease.

So the very study that these anti-smoking groups are relying upon to make their scientific claims actually refutes the very claims that these groups are making.

The clear implication of ANR's claim is that smoking is no worse in terms of cardiovascular risk than being exposed to 30 minutes of secondhand smoke (since it claims that the heart damage incurred is the same as that among smokers). Why should smokers quit smoking then? If they are going to suffer the same amount of heart damage from a half hour of secondhand smoke as from their own smoking, then they might as well be able to enjoy their cigarettes.

I'll be honest. I am still in a bit of shock over all of this. While I realized that things were getting bad in the anti-smoking movement, I didn't realize that they were this bad.

It's one thing when a single fanatical organization stretches the science and makes some inaccurate claims to support its policy agenda. But when you have the two major organizations in the country that promote smoking bans making completely fallacious claims to support the agenda, it's difficult to simply write it off.

The truth is that the anti-smoking movement is in danger of losing the public's trust. It is, in fact, violating the public trust by disseminating, quite widely (and by several prominent groups) completely inaccurate scientific information.

It is an embarrassment to me that the ANR "fact sheet" is titled "Secondhand Smoke: The Science." It would be more appropriately named "Secondhand Smoke: The Lack of Science" or "Secondhand Smoke: The Perversion of the Science."

To call what ANR has done an overzealous or errant extrapolation is probably an injustice to the term. These claims are not what I would view as exaggerations. They are what I would view as completely erroneous.

It just occurred to me that the tobacco companies reading my blog must be getting a real kick out of this. For years, they have been accused by the anti-smoking groups of lying, deceiving, and misleading the public and making inaccurate or misleading health claims. And now they sit back and watch as one by one, anti-smoking group after anti-smoking group is caught making not merely misleading, but completely fallacious scientific claims.

It certainly seems to me that this puts us in the very uncomfortable position of having to convince the public why we should have more credibility than the tobacco companies themselves.

I can't get up in front of the media or the public with a straight face and argue that "their scientific inaccuracies are very bad but ours are just small technicalities." Or to argue that we should still be trusted on scientific issues because "not everything we say is a complete distortion of the scientific facts."

I think that this is a crisis situation for the tobacco control movement. I actually think we should stop what we are doing for a few days and take stock of exactly what we are disseminating to the public. I think we need to get our house in order, and to get it in order immediately.

If we don't correct this problem, and quickly, we are going to lose all credibility.

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