In an effort to over-dramatize the dangers of very brief exposure to secondhand smoke, a number of anti-smoking groups are telling lies to the public about the short-term cardiovascular effects of secondhand smoke.
Today, I highlight four of these groups and the lies they are disseminating to the public.
1. Kentucky Center for Smoke-Free Policy, University of Kentucky College of Nursing
According to a one-page "fact sheet" on secondhand smoke and heart disease, dated this year (2010):
"Even brief exposure to secondhand smoke can trigger a heart attack. ... In 20-30 minutes, fat and blood clots build up in the arteries, increasing the chance of heart attacks and stroke. After 2 hours of secondhand smoke exposure, the heart rate speeds up and leads to abnormal heart rhythms (which can lead to death)."
The "fact sheet" cites the 2001 Otsuka study published in JAMA to support these claims. However, the Otsuka study did not find that 30 minutes of secondhand smoke exposure results in a build up of fat and blood clots in the arteries, increasing the chance of heart attacks and strokes. Nor did it find that 2 hours of exposure caused abnormal heart rhythms which could lead to death.
In fact, both of these statements are outright lies. You don't get a build up of fat and blood clots in the arteries in just 30 minutes. What happens in 30 minutes is that the cells lining your coronary blood vessels do not function normally, leading to a reduction in coronary flow velocity reserve. This damage to the blood vessel lining is reversible. However, if repeated over and over again and sustained for many years, these effects could contribute to the formation of atherosclerosis (hardening of the arteries). But it is a lie to state that 30 minutes of tobacco smoke exposure results in a build up of fat and blood clots in the arteries that increases the chance of a heart attack or stroke.
It is also untrue that 2 hours of exposure to secondhand smoke causes potentially catastrophic cardiac arrhythmias. What short-term tobacco smoke exposure can do is reduce heart rate variability. This is an important finding in that it provides biologic plausibility for the finding of a relationship between chronic secondhand smoke exposure and heart disease, but it does not mean that an individual exposed to tobacco smoke for 2 hours is at increased risk of dying of a cardiac arrhythmia.
This claim actually relates to a study by Pope et al., not to the Otsuka study. See my previous post for a detailed discussion of this lie.
2. Florida Department of Health
According to a presentation posted online by the Florida Department of Health: "Non-smokers exposed to secondhand smoke for just 30 minutes experience hardening of the arteries."
The study used to support this claim is also the Otsuka study. However, that study did not show that nonsmokers exposed to secondhand smoke for just 30 minutes experienced hardening of the arteries. It merely showed that they sustained vascular injury in terms of endothelial damage. The subjects in the Otsuka experiment certainly did not experience hardening of the arteries. The Institutional Review Board would never have approved such a study if there was even a possibility that the subjects would develop atherosclerotic heart disease as a result of the 30 minute tobacco smoke exposure.
Obviously, this claim is a lie. It is impossible for a person to develop hardening of the arteries in just 30 minutes. Even an active smoker needs to smoke for many years before developing hardening of the arteries. You don't have 17 year old smokers walking around with hardening of the arteries.
3. Maricopa County Department of Public Health
According to a "fact sheet" disseminated by the Maricopa County Department of Public Health: "Nonsmokers exposed to secondhand smoke for just 30 minutes experience hardening of
the arteries."
Just as with the lie from the Florida Department of Health, the study used to support this claim is also the Otsuka study. However, once again, that study did not show that nonsmokers exposed to secondhand smoke for just 30 minutes experienced hardening of the arteries. It merely showed that they sustained vascular injury in terms of endothelial damage. The subjects in the Otsuka experiment certainly did not experience hardening of the arteries. The Institutional Review Board would never have approved such a study if there was even a possibility that the subjects would develop atherosclerotic heart disease as a result of the 30 minute tobacco smoke exposure.
Obviously, this claim is a lie. It is impossible for a person to develop hardening of the arteries in just 30 minutes. Even an active smoker needs to smoke for many years before developing hardening of the arteries. You don't have 17 year old smokers walking around with hardening of the arteries.
4. Americans for Nonsmokers' Rights
According to a "fact sheet" being disseminated by Americans for Nonsmokers' Rights (ANR): "Just thirty minutes of exposure to secondhand smoke can cause heart damage similar to that of habitual smokers."
This, too, is a lie. Nonsmokers exposed briefly to secondhand smoke do not suffer heart damage similar to that of habitual smokers. In fact, they do not suffer heart damage at all. Brief tobacco smoke exposure does not cause heart damage. What is does cause is endothelial damage (reversible vascular injury to the cells that line the coronary arteries). Heart damage refers to actual damage to the heart muscle, such as one sustains after myocardial ischemia or a heart attack.
Believe me, the subjects in the Otsuka experiment did not suffer heart damage. If they did, they could sue the university for causing this damage. The IRB would never approved the study if it was even thought that the tobacco smoke exposure might cause heart damage.
ANR is disseminating a lie that distorts the truth and makes brief tobacco smoke exposure sound much worse that it actually is. No, 30 minutes of smoke exposure is not going to cause heart damage. However, it may cause vascular damage to the endothelium that - if repeated and sustained over a long period of time, could eventually lead to atherosclerosis.
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. Not from just 30 minutes of exposure.
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.
This claim is not only untruthful, but it undermines the public's appreciation of the very real hazards of active smoking. If the public were to take ANR at its word, they would believe that smoking causes heart damage only as bad as a brief secondhand smoke exposure. Obviously, this is not true. The heart damage caused by chronic active smoking can be severe and even fatal. But there is no heart damage from a mere 30 minutes of exposure.
Given the real scientific evidence about the hazardous effects of secondhand smoke exposure, including the development of heart disease among individuals with chronic secondhand smoke exposure, why does ANR need to resort to a lie?
The Rest of the Story
The shame in all of these lies is that they are completely unnecessary. Isn't the truth enough? Shouldn't we be able to convince policy makers to protect nonsmokers from exposure to secondhand smoke by relying upon the proven health risks of chronic secondhand smoke exposure? We don't need to tell lies in order to advance sound public policies which protect nonsmokers from secondhand smoke exposure. The truth is enough.
Beyond the ethical considerations in spreading lies to the public, there are two additional considerations. First, these lies threaten to destroy the credibility of anti-smoking groups. If the public believes that we are lying about some aspects of secondhand smoke, then the public may likely dismiss everything we say, even our other statements which are true. Second, by exaggerating the effects of short-term secondhand smoke exposure and declaring that such effects are equivalent to those from active smoking, we may actually be undermining the public's appreciation of the hazards of smoking itself. We are also distorting the public's appreciation of the relationship between dose and response. Why should a smoker quit smoking if he believes that just 30 minutes of secondhand smoke exposure will cause the same amount of heart damage that he has sustained over his lifetime?
I would like to think that what distinguishes the tobacco control movement from the tobacco industry is that we tell the truth and do not tell lies to the public. Apparently, this is not always the case. Unless someone acts quickly to clean up what is passing for science among tobacco control organizations, we will not be able to hold on to our contention that we in tobacco control tell only the truth. Like so many other social movements, it appears that we, too, are lying to the public in ways that exaggerate and distort the actual science.
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