Clinical trials Medicine Science Skepticism/critical thinking

“Heresy” versus “true belief” in the epidemiology of secondhand smoke

I’m not sure what to think of Michael Siegel. I’m really not. Even now, I remain of two minds on him.

Dr. Siegel first came to my attention back in July, around the time I was getting into online tussles with a certain opponent of indoor smoking bans, before which I had never heard of him. He’s a Professor in the Social and Behavioral Sciences Department at Boston University School of Public Health who’s made quite a reputation for himself casting a skeptical eye on what he considers to be extreme exaggerations, bad science, and even lies about the risks of tobacco and secondhand smoke. My first encounter with his blog occurred in the context of a discussion of a study of changes in admissions for myocardial infarction before and after the imposition of an indoor smoking ban in Helena, MT.

I had meant to look into his blog a bit further to see if perhaps I had been a bit unfair (or even too soft) on him when questioning his advocacy of a dubious-sounding study, but other topics intervened. I soon forgot about the incident and moved on to other topics; that is, until yesterday, when fellow ScienceBloggers Revere and Jake mentioned Dr. Siegel in the context of a challenge that he had issued to certain groups publicizing what he viewed as scientifically unsupported risks of SHS to provide scientific evidence to back up its statement. The reason these posts caught my attention was because I actually pretty much agreed with Dr. Siegel’s assessment in this case, thus making me wonder if I should take this opportunity to reevaluate my previous assessment of him. Here is the statement to which he objected so strongly, from Action on Smoking and Health (ASH):

Even for people without such respiratory conditions, breathing drifting tobacco smoke for even brief periods can be deadly. For example, the Centers for Disease Controls [CDC] has warned that breathing drifting tobacco smoke for as little as 30 minutes (less than the time one might be exposed outdoors on a beach, sitting on a park bench, listening to a concert in a park, etc.) can raise a nonsmoker’s risk of suffering a fatal heart attack to that of a smoker.

As much as I detest cigarette smoking as the single largest cause of preventable death, which I’ve seen over the years as medical student, resident, and now surgeon and would love to see smoking brought as close to zero as possible, you’ll note that even I didn’t mention this claim, mainly because it’s hugely overblown and misrepresents what the CDC really did warn. This was Dr. Siegel’s challenge:

  1. Please document that the CDC has warned that 30 minutes of secondhand smoke exposure increases a nonsmoker’s risk of suffering a fatal heart attack to the same level as that of active smokers.
  2. Please provide the scientific evidence to back up the assertion that 30 minutes of secondhand smoke exposure increases a nonsmoker’s risk of suffering a fatal heart attack to the same level as that of active smokers.

And, indeed, his challenge is justified because there really is no good evidence to support either point, as he pointed out so well in a recent article he published:

It also appears to be untrue that the CDC claimed that a 30-minute exposure to secondhand smoke “can raise a nonsmoker’s risk of suffering a fatal heart attack to that of a smoker.” What CDC did claim was that “even 30 minutes of exposure to a typical dose of secondhand smoke induces changes in arterial endothelial function in exposed non-smokers of a magnitude similar to those measured in active smokers” [3, p. 981]. This statement was based on findings from a study conducted by Otsuka et al., published in 2001 in the Journal of the American Medical Association (JAMA) [6].

The relevant study [6] experimentally exposed nonsmokers to secondhand smoke for 30 minutes and analyzed changes in endothelial function, as measured by coronary flow velocity reserve (CFVR). The authors reported that acute secondhand smoke exposure resulted in reductions in endothelial function that were approximately equivalent to those observed in active smokers [6].

It is important to note that endothelial dysfunction, especially if transient, is not a direct predictor of myocardial infarction risk. What endothelial dysfunction indicates is the early process of atherosclerosis. As the authors concluded: “The present findings suggest that reduction of CFVR after passive smoking may be caused by endothelial dysfunction of the coronary circulation, an early process of atherosclerosis, and that this change may be one reason why passive smoking is a risk factor for cardiac disease morbidity and mortality in nonsmokers” [6, p. 440].

What this means is that acute exposure to secondhand smoke can result in endothelial dysfunction in nonsmokers that if prolonged and repeated over a long time, could eventually result in atherosclerosis and heart disease. This study provides a potential mechanism for the observed increase in heart disease risk among involuntary smokers. It provides biologic plausibility for a causal relationship between chronic exposure to secondhand smoke and heart disease. But it does not suggest that an otherwise healthy nonsmoker could suffer a heart attack as a result of a 30 minute exposure to secondhand smoke, and it certainly does not mean that a nonsmoker’s risk of a heart attack approaches that of a smoker after 30 minutes of exposure to secondhand smoke.

So what’s the problem? An overzealous antismoking group made an obviously overblown and scientifically unsupportable claim, and Dr. Siegel shot it down appropriately. As Revere says, you don’t fight liars like the tobacco industry by becoming a liar yourself, nor should a scientists check their standards at the door. End of story, right?

And yet…

Perusing Dr. Siegel’s blog, The Other Side of the Story: Tobacco News Analysis and Commentary, again yesterday gave me a most uncomfortable feeling in the pit of my stomach. Peruse it for yourself, and I hope you’ll see what I mean. For one thing, Dr. Siegel seems to revel a bit too much in his self-chosen role of gadfly. However, perhaps what most caught my attention was his frequent use of the term “junk science” to characterize various smoking studies of which he disapproves or that he considers substandard. Whether fairly or not, I had to wonder: Surely Dr. Siegel must be aware of the connotation behind that term and how it’s been appropriated by right wing denialists like Michael Fumento and in particular Steve Milloy. When coupled with his attacks on the claims of tobacco control activists and epidemiological studies on the effects of SHS that he views as dubious, Siegel’s frequent use of the same term, whether he realizes it or not, echoes Fumento and Milloy in a most disturbing fashion―at least to me. Couple this with my recent reading of Chris Mooney‘s The Republican War on Science, in which Mooney traces the history of the use of the term “junk science” by the right wing as a favored label to apply to scientific studies that have findings that either business interests or right-wingers don’t like, and that’s one reason why reading Siegel’s blog, even if he’s absolutely correct and on the side of angels, still leaves me with a distinctly crank-like impression. (His penchant for using multi-colored text doesn’t help, either.) As Mooney described (p. 74, paperback edition):

In a 2004 lecture, University of Texas law professor Thomas McGarity, president of the Center for Progressive Reform, amusingly summed up the conservative worldview with the following slogan: “Our science is sound science and their science is junk science.” Conservatives are wrong on both charges, but they have been vastly successful in getting the rest of the political world to adopt their loaded terminology.

Even Dr. Siegel, who has even gone so far as to say:

To be honest, I’ve seen a lot more deception out of the Campaign for Tobacco-Free Kids these days than I have from the tobacco companies. Perhaps we should be considering legislation to require pre-approval of claims made by the Campaign so that it can be determined that these claims are accurate and not misleading.

I’m sorry, but I find that statement very hard to believe, given the long and sordid history of tobacco companies lying about science for profit and to forestall regulation and being held responsible for the deaths and illness their products cause.

Looking through Dr. Siegel’s blog, in fact, I had a hard time finding any articles in which he had anything good to say about any studies of the effects of indoor smoking bans. Recent posts have savaged a studies from Scotland, Indiana, and Ireland. I looked for a single example of Dr. Siegel praising an SHS study, and I was unable to find one. Surely they can’t all be bad, can they? And if they’re all bad, then I have to wonder: Why does Dr. Siegel still believe that SHS is harmful to health if in his opinion the science of recent studies is so bad? A little balance every now and then would be helpful; it’s little wonder that tobacco cranks love to cite him, given that the overall gestalt of his blog, I’m sorry to have to say, is more than a little crank-like, at least to me. True, I could be mistaking passion for crankery, but even so that’s the impression that, try as I might, I can’t entirely shake.

Finally, what makes me uncomfortable about Dr. Siegel and his stance is that he’s inconsistent. For example, appropriately, he likes to rail against “science by press release.” Damn straight. I find such abuse of science as disturbing as he does. Unfortunately, when it serves his purposes, Dr. Siegel doesn’t appear to be above doing something rather similar, as I noted in July. That’s when he championed a “study” by David W. Kuneman and Michael J. McFadden (a study to which he claimed to have contributed by going over the authors’ data analysis) on his blog before it was ever published. McFadden is a die-hard anti-SHS regulation advocate who runs a website called Pennsylvania Smokers’ Action Network, which features a particularly stupid bit of propaganda called Dissecting Antismokers’ Brains, while Kuneman runs a website called The Smokers’ Club. The study, entitled Do Smoking Bans cause a 27 to 40% drop in admissions for myocardial infarction in hospitals? A preliminary study was published not in a peer-reviewed journal, but on Kuneman’s website.

I suppose I could chalk it up to intellectual honesty that Siegel would be willing to follow the data, no matter who’s analyzing it, but the way he championed the study on his blog (“science by blog release,” anyone?), coupled with his rhetoric, made me uncomfortable and raised significant questions in my mind about either his judgment, objectivity, or both. I also note that the study, as far as I can tell from searching PubMed, still remains unpublished in any peer-reviewed journal two years later. (The American Council on Science and Health (ACSH) and Dr. Siegel seem to be the only ones who still support this study.) When a discussion of Siegel and why his actions bothered me broke out in the comments of a post that I wrote about SHS, Kuneman and McFadden both showed up to defend their unpublished study (and will virtually certainly show up here; they both seem very vigilant at looking for references to their “work”). I asked them why, if Siegel had contributed so much analysis to it, he hadn’t signed on as an author or helped them to get it published. Four months later, I still consider it a legitimate question. Certainly, it’s a question I would have asked Dr. Siegel if I were Kuneman or McFadden.

Revere assures us that “Mike Siegel is no smokers’ rights partisan,” and I don’t think that he is. I believe him when he says that he wants to do everything possible to reduce fatalities from smoking and that he accepts the scientific consensus that SHS causes health problems. Certainly, his publication record and public interviews support these contentions. Moreover, he probably does serve a useful purpose in keeping activists honest. I do, however, think that Siegel has shown poor judgment, certainly in the case of the McFadden and Kuneman article, and in using rhetoric that is perhaps a little too easily appropriated by smokers’ rights partisans. I may be completely wrong about this, but I can’t help but speculate that perhaps he’s become a little more enamored than is good for him of his chosen role of watchdog over scientific claims made by the antismoking movement which he has come to view as hopelessly corrupt:

In essence, the role that I am now playing is one that the tobacco industry used to play, albeit for a different reason. The tobacco industry played a watchdog role because they wanted to discredit tobacco control and undermine its public credibility. I am now playing this watchdog role because I want to restore the scientific integrity of the movement and save its public credibility. Nevertheless, the role that I am playing is very similar to what the tobacco industry used to do.

To some extent, it is surprising to me that the tobacco companies have not made more of a public display over the outright misrepresentation of science by anti-smoking groups. I suppose they feel that if they just lay back, the movement will destroy its own credibility. This may be a wise strategy, since it seems that every day, the claims get more and more absurd.

So, what am I to think of Mike Siegel? Four months after discovering his blog, I still don’t know. All I can do is to cheer him on when he’s right, as he was in criticizing ASH’s ludicrous statement and in destroying the ridiculous claim that 340 young people die every day from seeing smoking in the movies. And when he’s in the wrong, as in my opinion he was in touting the McFadden and Kuneman study on his blog before it was published in a peer-reviewed journal and, in my opinion, in generalizing cases of exaggeration or misrepresentation of the science behind SHS into blanket declarations that the “tobacco control movement has lost its scientific integrity,” there should be no hesitation to call him out on it.

Just like the tobacco control scientists that Dr. Siegel seems to love to castigate so much.

By Orac

Orac is the nom de blog of a humble surgeon/scientist who has an ego just big enough to delude himself that someone, somewhere might actually give a rodent's posterior about his copious verbal meanderings, but just barely small enough to admit to himself that few probably will. That surgeon is otherwise known as David Gorski.

That this particular surgeon has chosen his nom de blog based on a rather cranky and arrogant computer shaped like a clear box of blinking lights that he originally encountered when he became a fan of a 35 year old British SF television show whose special effects were renowned for their BBC/Doctor Who-style low budget look, but whose stories nonetheless resulted in some of the best, most innovative science fiction ever televised, should tell you nearly all that you need to know about Orac. (That, and the length of the preceding sentence.)

DISCLAIMER:: The various written meanderings here are the opinions of Orac and Orac alone, written on his own time. They should never be construed as representing the opinions of any other person or entity, especially Orac's cancer center, department of surgery, medical school, or university. Also note that Orac is nonpartisan; he is more than willing to criticize the statements of anyone, regardless of of political leanings, if that anyone advocates pseudoscience or quackery. Finally, medical commentary is not to be construed in any way as medical advice.

To contact Orac: [email protected]

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