Een handboek, dat wereldwijd verspreid wordt onder anti-rokenorganisaties, bevat de meest overdreven beweringen die er maar over meeroken gezegd kunnen worden. Dat is de mening van Dr. Michael Siegel, al 21 jaar beroemd om zijn gedegen meeroken onderzoek.
Het handboek wordt vanuit de Verenigde Staten verspreid door organisaties als de American Cancer Society en de International Union against Cancer (IUCC). Het bevat informatie en kant-en-klare citaten en moet dienen als bijbel voor de anti-rokenorganisaties. Volgens Siegel is een groot deel van de aangeboden informatie misleidend en wetenschappelijk volstrekt onjuist. “De informatie lijkt vooral te zijn uitgezocht op sensatiewaarde”, zegt Siegel, en “wetenschappelijke ‘feiten’ worden hierbij selectief en buiten hun verband geciteerd”.
While ClearWay Minnesota has removed its inaccurate claim that secondhand smoke exposure reduces coronary blood flow in healthy young adults, there are still close to 100 anti-smoking groups making fallacious or misleading claims that I think need to be retracted or corrected.
But one which I think is the most problematic is the claim made by the American Cancer Society (ACS), International Union against Cancer (UICC), and Campaign for Tobacco-Free Kids (TFK) in their strategy guide, entitled “Building Public Awareness About Passive Smoking Hazards.” This document is being disseminated worldwide through the GLOBALink website.
The document is attributed to the ACS and UICC, but TFK is apparently also one of the groups offering this guide to the global tobacco control community: “On behalf of the American Cancer Society, The International Union Against Cancer, the Campaign for Tobacco-Free Kids, and the many wise and experienced colleagues who contributed to this lengthy project, we are deeply pleased to offer this series of guides, Tobacco Control Strategy Planning to the global tobacco control community.”
There are 4 reasons why I think the inaccuracies in this document are particularly important:
1. The claims in question are very deceptive, and in one case, the claim is so outrageous as to put the scientific credibility of the entire tobacco control movement at stake.
2. The claims are being made in the specific context of advising anti-smoking organizations worldwide specifically what to tell the public. So it isn’t just that the ACS, UICC, and TFK are making these claims. They are encouraging other anti-smoking groups worldwide to make these same specific claims and they are even providing the specific wording. In other words, they are encouraging what amounts to a campaign of deception.
3. The claims are being suggested in the specific context of trying to increase the emotional appeal of the secondhand smoke message. It almost appears as if the strategy guide is first deciding what would be most sensational to tell the public, and then scrounging to try to find some science that will support such statements. The document readily admits that the purpose of these statements is to try to sensationalize and dramatize the effects of secondhand smoke.
4. The claims are in a prominent guide that has worldwide exposure. This is not just some isolated local anti-smoking group getting a little carried away.
Here are the specific claims and why they are false or deceptive:
A. “Immediate effects of secondhand smoke include cardiovascular problems such as damage to cell walls in the circulatory system, thickening of the blood and arteries, and arteriosclerosis (hardening of the arteries) or heart disease, increasing the chance of heart attack or stroke.”
This is the statement that is absurd, in addition to merely being deceptive and inaccurate. While it may be reasonable to state the immediate effects of secondhand smoke include damaging cell walls (endothelial dysfunction) and thickening of the blood (platelet activation and aggregation), it is absolutely false to state that the immediate effects of secondhand smoke include arteriosclerosis – hardening of the arteries or heart disease.
Atherosclerosis is a process that takes many years to develop. Among active smokers, the process usually takes at least 20 years to develop, often even more. It is extremely rare to see a smoker in his or her 30’s with coronary artery disease.
So if it takes 20 or more years for an active smoker to develop coronary artery disease, then how is it possible for a nonsmoker to develop atherosclerosis or heart disease in 30 minutes?
B. “Short-term exposure to tobacco smoke has a measurable effect on the heart in nonsmokers. Just 30 minutes of exposure is enough to reduce blood flow to the heart.”
This statement is merely deceptive, not absurd. While it is true that short-term exposure to tobacco smoke has a measurable effect on the heart in nonsmokers, it is deceptive (if not inaccurate) to state that just 30 minutes of exposure reduces blood flow to the heart.
The truth is that 30 minutes of exposure reduces coronary flow velocity reserve, not blood flow to the heart. The coronary flow velocity reserve decrease is a sub-clinical effect, measurable only under experimental conditions, that is transient. The truth is that the same study being used to back up this claim actually found no reduction in baseline coronary blood flow, or blood flow to the heart.
The clear implication of the statement is that someone who is exposed briefly to secondhand smoke will experience reduced blood flow to the heart, which the public will generally (and correctly) associate with a heart attack. This implication is simply untrue. There is no risk of cardiac ischemia (inadequate blood flow to the heart) from a brief secondhand smoke exposure in a healthy person.
C. “Nonsmokers who are exposed to secondhand smoke in the home have a 25 percent increased risk of heart disease. As is the case with active smoking, much of the cardiovascular effect is due to acute poisoning.”
This claim is “merely” misleading. Calling exposure to secondhand smoke “acute poisoning” implies that acute exposure causes clinical damage. But the effects of acute exposure on the cardiovascular system are transient and sub-clinical. There is no permanent impairment of function and any “damage” done is physiologic or sub-clinical.
In fact, the same claim could be made about eating a Big Mac. Eating a high-fat meal also causes endothelial dysfunction and platelet activation. But clearly, it would be misleading to state that eating a Big Mac represents “acute poisoning.” So it is equally misleading to suggest that a brief exposure to secondhand smoke is “acute poisoning.”
While I agree that the effect of chronic exposure to secondhand smoke, over many years, is to increase the risk of heart disease (and the 25% figure is consistent with the literature), it is very misleading to suggest that acute exposure represents “acute poisoning.”
D. “People who are routinely exposed to secondhand smoke, such as workers in restaurants and bars, can expect their risk of lung cancer to triple.”
This is classic cherry-picking, something we always accuse the tobacco industry of doing. The strategy guide chooses a single study to try to show that chronic secondhand smoke exposure triples the risk of lung cancer; however, the rest of the literature suggests a much smaller relative risk – something on the order of about 1.3, which is a 30% increased risk, not a tripling of risk. Even if one focuses on restaurant and bar workers, the evidence from a number of studies suggests an increased risk on the order of about 1.5 to 2 at the most.
So to pick one study which found a tripling of risk is very misleading. And in fact, if one wants to base one’s claim on just one study, then one could just as easily pick a study that found no increased risk (there are plenty to choose from) and tell the public that they can expect no increased risk of lung cancer from routine secondhand smoke exposure.
Believe me, this is not a game that we want to start playing.
E. “There are immediate and substantial effects from secondhand smoke. For example, 30 minutes of breathing secondhand smoke makes blood platelets get as activated as in habitual pack-a-day smokers. These activated platelets damage the lining of arteries, which leads to heart disease. If they form a blood clot that lodges in a coronary artery, we call that a heart attack. If it lodges in the brain, we call it a stroke.”
The first part of the statement is correct. There is, indeed, evidence that 30 minutes of secondhand smoke exposure does activate platelets as in habitual smokers and these activated platelets do damage the lining of arteries.
However, from here, the statement goes downhill. It is not true that the damaged lining of arteries (endothelial dysfunction and damage) that results from 30 minutes of exposure to secondhand smoke leads to heart disease. In fact, it does not lead to heart disease. It is transient and reversible and cannot lead to heart disease. As I emphasized above, it takes more than 20 years of platelet activation and endothelial damage from active smoking to cause heart disease, so how can the platelet and endothelial effects of 30 minutes of secondhand smoke cause heart disease?
It is also untrue that the activated platelets resulting from a 30-minute secondhand smoke exposure can form a blood clot that lodges in a coronary artery (causing heart disease) or in the brain (causing a stroke). This is extremely deceptive, because it implies that 30 minutes of secondhand smoke exposure puts individuals at risk of heart attacks and strokes.
But unless you already have severe coronary artery or carotid artery disease, you’d have to be exposed to secondhand smoke for a lot more than 30 minutes (try 30 years) before the effects on platelets and the endothelium would put you at risk of suffering a heart attack or stroke.
This is what I would call scare tactics. In my opinion, this is a clear example of misrepresenting and distorting the science in order to try to sensationalize the perceived effects of secondhand smoke. It is taking a transient, physiologic, sub-clinical effect and presenting it as a chronic, life-threatening effect that doesn’t exist. All in an apparent effort to make the effects of secondhand smoke sound much more immediate than they actually are.
As much as we apparently want to tell people it in order to scare them, heart attacks and strokes resulting from the development of blood clots are not one of the established immediate effects of secondhand smoke. They are risks of chronic exposure, not effects that occur immediately.
Here is why I believe that the strategy guide is explicitly acknowledging that the claims which are provided are crafted specifically to dramatize the secondhand smoke message and create a more emotional appeal:
Speaking about the message that 30 minutes of secondhand smoke causes platelet activation which results in blood clots that may lodge in coronary arteries or in the brain, causing heart attacks and strokes, the document states:
“This message is effective because it provokes an emotional response in almost any listener. Effective messages are characterized by this combination of sound science and emotive language. An effective message has several key components:
- It equates the damage from passively breathing smoke to the damage from direct smoking. We know that the public is more aware of the dangers of smoking than of dangers from secondhand smoke.
- It conveys the fact that even short periods of exposure are harmful.
- It evokes an emotional reaction from the use of scientific terms.
- It utilizes startling and memorable imagery.
- It clearly states the risk of grave health conditions such as heart attacks and strokes.”
It appears, then, that to be effective, a secondhand smoke message must convey the immediate effects of exposure, evoke an emotional reaction, use startling imagery, and state the risk of heart attacks and strokes. But what if the evidence does not support the combination of these elements? What if the evidence does not support a conclusion that heart attacks and strokes are an immediate effect of secondhand smoke exposure?
Apparently, the answer is simple: don’t worry about it. Make the claim anyway.
The strategy guide makes an equally troubling statement about the need to emphasize to the public the immediate benefits of smoking bans in terms of heart attack reduction:
“Another message that may encourage the public to take action concerns a 2002 case study conducted in Helena, Montana (USA). Researchers found that, in the six months following the enactment of a new smoke-free workplace law, heart attack frequency declined significantly. This message is effective for several reasons.
- It offers a positive indication of what can happen to public health when people stop smoking and breathing secondhand smoke in public places.
- It indicates that a ban on smoking in public places can reduce the incidence of heart attacks for smokers and nonsmokers alike.
- It demonstrates that the health benefits of clean indoor air ordinances are virtually immediate.
- It provides more scientific evidence that smoke-free workplace policies improve health and save lives, which should encourage communities around the world to take action to protect the health of their citizens.”
The problem is that the evidence does not support the elements that apparently make the message effective. As I have explained in detail, the study provides very weak evidence that there was a significant decline in heart attacks in the first place, that it was attributable to the smoking ban in the second place, and that it was due to reduced secondhand smoke exposure in the third place. In fact, the study did not even assess the smoking status of heart attack patients, making it impossible to conclude that “a ban on smoking in public places can reduce the incidence of heart attacks for smokers and nonsmokers alike.”
But again, apparently the lack of scientific evidence is not enough to stop the strategy guide from recommending that this is the message that anti-smoking groups should communicate to the public. It is an effective message, so let’s communicate it, even though there is insufficient evidence to support it.
The Rest of the Story
It should be important to an organization like the American Cancer Society – which funds its own scientific research and depends on its scientific credibility to reach the public on a large number of cancer issues – to make sure that its public communications are accurate. To put out an absurd claim such as the statement that 30 minutes of secondhand smoke exposure causes atherosclerosis seems to me to undermine the scientific credibility of the organization, and you would think they would want to immediately correct this. Especially when they are telling hundreds of anti-smoking groups around the world to say the same thing to the public.
Not only do I think it hurts the scientific integrity and credibility of these organizations, but I think it hurts the scientific credibility and integrity of the entire tobacco control movement.
It is one thing to make a mistake, but the real measure of integrity is whether or not that mistake is corrected. We’ll see how these organizations respond, but based on the lack of response from most of the groups in tobacco control which have made similar false statements, I would be surprised if these groups care enough about the truth to acknowledge a mistake and correct it.
Honestly, my impression is that the tobacco control movement doesn’t really care about honesty and the truth; we are too concerned with scaring people about the exaggerated immediate effects of brief tobacco smoke exposure in order to generate a strong emotional appeal and garner support for the agenda – an agenda which I strongly support (at least as far as workplace smoking bans are concerned).
To me, the most concerning aspect of this story is that the strategy guide acknowledges that its express goal is to dramaticize and sensationalize the health effects of secondhand smoke by scaring people about the immediate, deadly impact that it can have. It is not that the document first reviews the research which supports these claims and then says, “Secondhand smoke really can cause heart disease in 30 minutes, so this is what we should tell the public.” Instead, it appears that the document advises groups what claims would be the most sensational, and then scrounges around for evidence to support these claims, relying upon wild exaggerations and scientific misinterpretations and misrepresentations in order to accomplish this.
I will report here at week’s end whether or not the inaccurate and deceptive claims in the strategy guide are retracted or corrected, or you can check the guide directly here.
Immediate effects of secondhand smoke include atherosclerosis???
Brief exposure to secondhand smoke causes acute poisoning???
Routine secondhand smoke exposure triples your risk of lung cancer???
Thirty minutes of secondhand smoke reduces blood flow to the heart???
If anti-smoking groups actually follow the advice of the American Cancer Society, International Union against Cancer, and Campaign for Tobacco-Free Kids and make these claims to the public, how can we expect anyone to believe us when we actually tell the truth?