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Hyping Health Risks

Three kids on the same block were diagnosed with leukemia last year. That couldn’t happen just by chance, could it? There MUST be something in the environment that caused it (power lines, the chemical plant down the street, asbestos in their school, iPods, Twinkies?). Quick, let’s measure everything we can think of and compare exposures to other blocks and find an explanation.

That may be the common reaction, and it may seem plausible to the general public, but it’s not good science.

I have just read a book that does a great job of elucidating the pitfalls of epidemiologic studies, the problematic interface between science and emotion-laden public concerns, and the way environmental hazards have been hyped far beyond the evidence. Hyping Health Risks: Environmental Hazards in Daily Life and the Science of Epidemiology by Geoffrey C. Kabat.

He covers the uses, strengths and limitations of epidemiology, discusses the pros and cons of different study designs, and explains how to judge whether an association is causal.

The Ecological Fallacy and Determination of Causality

Ecological studies based on groups rather than individuals can be misleading. Early researchers found a strong correlation between per capita sales of cigarettes and lung cancer; but there was also a strong correlation between sales of silk stockings and lung cancer. They had to look for other types of evidence before they could conclude there was a causal relationship. A study showed a strong correlation between dietary fat consumption and age-adjusted breast-cancer mortality in 41 countries, but that could be due to confounding factors like economic and lifestyle differences. The “ecological fallacy” is

the unwarranted assumption that, just because a given factor is correlated with a disease based on aggregate data, this suggests (1) that the same correlation will hold at the individual level or (2) that the association is indicative of a causal relationship.

Statistical significance is often misunderstood.

Not every finding that is statistically significant is biologically significant, but too often the fact that a given result is statistically significant is used to imply precisely this. More relevant to gauging the importance of a finding is the consistency with existing evidence from other sources and the impact on a population basis.

The following criteria can be used to judge causality:

  • The magnitude of the association
  •  Consistency (same effect shown in different studies carried out in different populations).
  •  Temporal relationship (cause must precede effect)
  •  Coherence of explanation (also known as biological plausibility).
  •  Dose-response relationship.

The relationship between smoking and lung cancer meets all those criteria. Kabat describes four cases in detail where those criteria were not met and where public concern and activism led to bad science and overblown fears.

Does the environment cause breast cancer?

There was a public perception that there was an epidemic of breast cancer in certain areas of the country such as Long Island, and there was a conviction that some form of environmental pollution must play a role. In reality, there was no epidemic, and there is little evidence to support a role for the environment as a cause of breast cancer. Activists got a law passed mandating scientific projects, which were poorly designed and focused on specific pollutants like DDT, and got negative results, disappointing everyone.

Clusters of illness are inevitable. If you spill rice on a grid, there will be squares with lots of grains of rice and squares with none. The challenge is to determine whether a cluster of illness is due to anything more than chance. The public doesn’t understand this, and they demand an explanation for every apparent cluster. In one of Kabat’s examples, a community that had the highest rate of breast cancer one year had the lowest rate the following year.

To put the concern about breast cancer into perspective, any environmental effect is bound to be small, while the rate of lung cancer is 1.5 times that of breast cancer and it is 90% preventable by smoking cessation.

Do Electromagnetic Fields Cause Cancer?

EMF concerns are demolished by an understanding of the physics involved. Any effects of EMF are well below the level of thermal noise. One physicist concluded that

there are good reasons to believe that weak ELF [extremely low frequency] fields can have no significant biological effect at the cell level – and no strong reason to believe otherwise…. He likened concern over weak EMF from power lines to the fear that leaves falling from trees could fracture a person’s skull.

The National Institute for Environmental Health Sciences reviewed the evidence for an association of EMF with cancer, acknowledged that it was all either negative or weak and inconsistent, yet they made a politically cautious decision to classify EMF as a possible carcinogen – a decision that cannot be scientifically justified.

Does residential radon exposure cause lung cancer?

Is there radon in your house? How much? In which rooms? How long have you lived there? How much time did you spend in which rooms? How much radon was in your previous residence? Residential radon studies are hampered by the near impossibility of quantifying an individual’s exposure over time. And most of the studies are flawed by the failure to correct for smoking. The risk of radon exposure to smokers is high; the risk to non-smokers is questionable. The way to reduce lung cancer deaths from radon is not to test everyone’s home and try to lower radon exposure – it is to get people to stop smoking. A 20% increase in risk of lung cancer from radon exposure (including smokers and non-smokers) must be put into perspective with the 2000% increase in risk from smoking.

Does Second-Hand Smoke Cause Lung Cancer and Heart Disease?

This is a little different because we are reasonably sure there is a risk and we know the mechanism. The problem is that the risk is  small and difficult to measure accurately, and Kabat argues that it is practically impossible to quantify an individual’s exposure to second-hand smoke over long periods of time. Studies have compared the spouses of smokers to the spouses of non-smokers, but some smokers bombard their spouses with clouds of smoke while others considerately smoke out on the porch, and we have no way of knowing whether the non-smoking spouses were exposed to smoke at work or elsewhere. Other studies have measured cotinine (a nicotine derivative) in the urine of those exposed to second-hand smoke, but the test only represents one point in time.

The association of heart disease with passive smoking is much weaker than the association with lung cancer, and anti-smoking activists lost all credibility when they extrapolated from poor data and tried to claim that passive smoking caused 50,000 cardiac deaths a year in the US.

99.99% of the Pesticides in Our Diet are Natural and Unavoidable

There is a strong ideological environmental movement that is predisposed to find dangers from artificial chemicals in our environment. They seldom put those fears into perspective with natural and unavoidable chemicals. Bruce Ames, originator of the Ames test, a biological assay to identify carcinogens, co-wrote a paper showing that 99.99% of pesticides in the American diet are chemicals that plants produce to defend themselves. About half of the natural pesticides that have been tested are carcinogenic in rodents. They concluded that “natural and synthetic chemicals are equally likely to be positive in animal cancer tests. We also conclude that at the low doses of most human exposures the comparative hazards of synthetic pesticide residues are insignificant.”

Reading this book will give you a better understanding of what epidemiology can and can’t do, and insight into how the rational scientific process can be perverted by the press, politicians, and grass-roots activists. One unstated take-home lesson from this book is that we should worry less about potential small environmental dangers and do something about the very large and preventable environmental danger of smoking.

Posted in: Book & movie reviews, Science and the Media

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27 thoughts on “Hyping Health Risks

  1. Pingback: Conspirama
  2. storkdok says:

    Thank you for the review! I have often stated this to my patients, and they are shocked at the reality check. I have put the book on my wish list.

  3. Jules says:

    I must read this book.

    Environmentalism is a pet interest of mine, but I often find myself on “green” blogs, explaining why they’re wrong (soy wax candles are “healthier” than paraffin, for instance). I usually limit myself to explaining the facts, but it’s hilarious how often threads die the instant I post.

  4. skeptyk says:

    @ Jules

    And soy wax EAR candles are the bestest!

  5. tmac57 says:

    Don’t forget about silicone breast implants. I would guess most of us non-scientists out there have been lured into over estimating the risks of such threats at times ,in a natural reaction to try to protect ourselves and loved ones.
    Whenever I get tripped up by one, I have a Homer Simpson moment…”Doh!!!”.

  6. hatch_xanadu says:

    “Is there radon in your house? How much? In which rooms? How long have you lived there? How much time did you spend in which rooms? How much radon was in your previous residence? Residential radon studies are hampered by the near impossibility of quantifying an individual’s exposure over time. And most of the studies are flawed by the failure to correct for smoking.”

    Exactly, exactly, exactly. Thank you. Same goes for myriad other environmental “toxins”.

    http://xkcd.com/552/

  7. britrfw says:

    I am reminded of a documentary on Nuclear Power. When confronted by the fact that the nuclear radiation level right next to a reactor was almost un-measurable and much lower than the radiation from radon in his home, a seemingly intelligent but passionate anti nuclear activist replied that the radiation from the reactor was artificially made and dangerous but the radiation from radon was natural and hence safe.

  8. Jules says:

    On the subject of radiation:

    I will never understand the guidelines in place for radiation. I work with tritium. If you swallowed the most concentrated, most radioactive of our compounds, you’d get all the side effects of the compound, and none from the radiation. You’d probably be exposed to more radiation from the CTscan they’d give you to see if they could detect it. You get a bigger badder worser dose of radiation standing outside. At night. Under a new moon. Or standing downwind of my cats’ litter box.

    I also work with some pretty nasty stuff, as far as biological effects go. Modesty prevents me from elaborating, beyond saying that attempts to make these compounds into pharmaceuticals have failed dismally due to awful “side effects” (primary?).

    Guess which one causes a bigger problem if I spill it?

  9. TsuDhoNimh says:

    Definitely read “Dietary pesticides (99.99% all natural)*” by Ames. It’s a PDF here:

    http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=54831&blobtype=pdf

    And cite it heavily to all your vegan and crunchy granola friends.

    Some foods, such as beet root, have so much formaldehyde in them they would be banned if they were a building material, but they are in all the health food stores.

  10. tmac57 says:

    TsuDhoNimh:”Some foods, such as beet root, have so much formaldehyde in them they would be banned if they were a building material, but they are in all the health food stores.”
    Hey, but at least you’d leave behind a well preserved corpse! Poor so and so, he died so young, but doesn’t he look ‘all natural?”

  11. HCN says:

    The first line in this posting, “Three kids on the same block were diagnosed with leukemia last year. ” made be think of something:

    Many cancers are caused by viruses. I sometimes wonder when there are pockets of a specific cancer if the environmental cause was something as “natural” as a virus.

  12. Calli Arcale says:

    Remember also that many cancers share genetic predispositions, and although some people move far away from home, a significant percentage tend to stick close to the place where they grew up — have such studies controlled for family relationships?

  13. Richard says:

    I’m glad you and the author mentioned anti-smoking activism. Although I don’t smoke anymore, I am a passionate (though moderate) social libertarian. By exploiting fears such as second-hand smoke, overzealous activists want to bully people into behaving in ways they approve of.

  14. David Gorski says:

    Secondhand smoke is a legitimate health risk; I also happen to think that Kabat downplays its risk more than the science warrants, particularly given his connection to James Enstrom. The section of the book about secondhand smoke comes across to me in the review as by far the weakest.

    Come to think of it, I’ve been meaning to do a post on secondhand smoke and the scientific evidence. However, it’ll have to wait until I get past this wave of grant season (late April, at the earliest), because that would be a hum-dinger of a post to have to update all my references and see what’s new. That’s a project on par with writing a review article.

  15. Harriet Hall says:

    Bottom line: science is pretty sure second-hand smoke is dangerous, but we don’t know exactly how much. The question of what to do with that imperfect knowledge is not a scientific question. My husband says anyone should have the right to smoke any time anywhere he wants – as long as he does it in a plastic bag. Personal behaviors that interfere with the rights of others are generally considered to be legitimate reasons for government intervention. The debate between individual freedom and government efforts to protect people from harm will never end.

  16. David Gorski says:

    Indeed, although, annoying guy that I am, I can’t help but add that science is much more than “pretty sure” that SHS is a hazard. Not as sure as it is that vaccines don’t cause autism, I’ll admit, but pretty darned sure nonetheless. ;-)

    In any case, social norms change as well. It used to be considered acceptable to smoke pretty much anywhere, with relatively few exceptions. I watch old movies, where smoking is glamorized, and TV shows like Mad Men, which portray the early 1960s or earlier, and marvel at all the ash trays on workers’ desks. It was just how people worked; it was considered perfectly acceptable to smoke while at work. Now it’s not, particularly since people who work in smoky places are forced to breathe it in 40 or more hours a week for years at a time.

    A libertarian once argued to me that SHS is a risk inherent in, for example, the hospitality industry and then likened it to the risk from the coal dust that causes black lung in the mining industry. I retorted that that was a fundamentally flawed argument because it assumes that exposure to SHS is an inherent risk of working in bars and restaurants that workers must simply accept or find work elsewhere. That is, of course, ridiculous. There’s nothing inherent in the work required in bars or restaurants that demands exposure to SHS, other than tradition. In contrast, exposure to coal dust is a risk inherent to working in coal mines that can’t be completely eliminated. You can’t change the properties or location of coal to prevent worker exposure to coal dust. Even so, guess what? We do try to decrease that risk as much as possible.

    In fact, the whole coal dust analogy is actually an excellent argument that OSHA should do more to decrease the unavoidable risks inherent in coal mining as much as possible, not that we as a society should do less to minimize risks to workers not inherent to the job that can be fairly easily decreased in other industries.

  17. ImperfectlyInformed says:

    As far as pesticides and cancer, it might say more about the MTD (maximum tolerable dose) than it does about their carcinogenicity. Further, the concern with pesticides is generally not cancer (although the April EHP issue has an article on pyrethroids and cancer) but neurological illnesses, for which reasonable correlations have been consistently discovered.

  18. gkabat says:

    Maybe David Gorski should read the book before offering an opinion about it based on a brief review. And maybe he should hesitate before making assumptions about me based on my “connection” with James Enstrom. If he had read the book, he would know that I do not consider secondhand smoke to be free of risk. What I point out is that discussion of the relevant scientific evidence is badly skewed. The best studies measuring actual exposure to secondhand smoke in various environments (in the 1970s and 1990s) indicate the average exposure is on the order of a few cigarettes per day. Since these studies were conducted, exposure in the U.S. has decreased due to widespread restrictions on smoking. These crucial studies are rarely cited. Second, the epidemiologic studies are only cited selectively. In fact, the largest cohort studies of spousal smoking in the U.S. – those of the American Cancer Society – show little evidence of an association of spousal smoke exposure with risk of lung cancer or of coronary heart disease, particularly in women (the group with the greatest historical exposure), and do not support the claims of a 25% increase in risk for these diseases, which are treated as gospel. Third, the number of deaths attributed to secondhand smoke exposure (based on these skewed estimates of the relative risk) – on the order of 50,000 deaths per year — are not supported by the epidemiology. Finally, tobacco control activists studiously avoid making the obvious comparison between the effects of active smoking and those of secondhand smoke exposure. This is my point – that we need to put these things in perspective and to cite all of the relevant science, not just that which supports our case.

    I have published dozens of articles on the harmful effects of smoking, and, like Professor Enstrom, I am no friend of tobacco. I have been on record for 25 years as believing that no one should be unwillingly exposed to the “surplus air pollution” of environmental tobacco smoke.

    You don’t advance the discussion by making off-the-cuff, ill-informed judgments about highly technical and highly politicized issues, like passive smoking.

    Geoffrey Kabat, Ph.D.
    Department of Epidemiology and Population Health
    Albert Einstein College of Medicine

  19. David Gorski says:

    I had originally decided against citing these links, as I wasn’t in the mood to provoke controversy in the comments of this post, having caught flak for having done so in other of my co-bloggers’ posts. :-)

    However, since Dr. Kabat has shown up and accused me of making “offhand” comments, perhaps he would be so kind to explain his relationship with Dr. Engstrom and the tobacco funding for the BMJ study. You see, my “offhand” mention was not as “offhand” as Dr. Kabat would like to make it sound, having been based upon, among many others, these sources:

    http://www.sourcewatch.org/index.php?title=James_E._Enstrom
    http://circ.ahajournals.org/cgi/content/full/116/16/1845
    http://no-smoke.org/document.php?id=333
    http://legacy.library.ucsf.edu/tid/iqe07a00
    http://www.nature.com/nature/journal/v446/n7133/full/446242a.html

    Perhaps all these criticisms are unjustified.

    I’m also happy to learn that Dr. Kabat does unequivocably think SHS is a hazard. That being said, I remain puzzled why he is so frequently cited by those trying to fight workplace smoking bans. I’m also puzzled about his statement that he has unequivocally said that SHS is a health hazard, given his publication record. That’s why I went back an did a PubMed search looking for publications by Dr. Kabat that do indeed strongly conclude that SHS is a health hazard. Perhaps he had published some since 2003. All I can find are papers that at every turn conclude that the risk is overblown and “lower than currently believed,” at least once by his having done what I like to call a “competing meta-analysis.” Every paper I found concluded that the degree of health risks from SHS is considerably lower than currently estimated or that the evidence supporting the link between SHS and, for instance, cardiac disease is considerably weaker than advertised, and there were editorials arguing the same thing. In other words, his “unequivocal” statements always seem to be qualified with a huge “however…” Perhaps Dr. Kabat could point me in the direction of these publications that so “unequivocally” condemn SHS as a health hazard, as, I’m afraid, I’m at a loss at the moment. I realize that arguing that the risks are lower than what is believed is not necessarily the same thing as denying them, but when the current estimated risk is on the order of a RR of 1.25 for various health outcomes, it doesn’t take much “downplaying” of the risk to turn into denying it in practice. Moreover, taking him at his word, if Dr. Kabat does truly believe that SHS is a significant health risk, on what scientific basis does he believe this? His own publication record at virtually every turn says that science doesn’t really support SHS being as significant a health risk as currently believed; so one wonders what science he does believe on this issue.

    Perhaps I’m wrong; it wouldn’t be the first time. However, I have been following this issue for a while now and in my sparring with certain libertarians (one in particular) over the years about SHS and the utility of indoor workplace smoking bans, two names are frequently cited: Dr. Engstrom and Dr. Kabat. Clearly the tobacco lobby and opponents of bans on workplace smoking consider Dr. Kabat’s work to be supportive of their position. Are they wrong? I would be very much relieved if that were the case.

  20. gkabat says:

    I spent a lot of time and sweat writing the book to explain how and why the science is quite secondary when these kinds of issues like passive smoking become “causes celèbres.” Reading the book would be a good place to start. Your Web site is devoted to “Science-based medicine,” but you seem to be more interested in pursuing guilt by association and my failure to be on the side of the angels. In every interview I have ever done with a news outlet I have made it clear that I thought – as far back as 30 years ago – that the lack of restrictions on smoking was primitive and that no one should have to breathe other people’s tobacco smoke. And I make the point repeatedly in the book.

    The fact is that you don’t have a first-hand acquaintance with the articles I referred to. It takes many hours to read and understand what a study shows and how all the studies fit together. As I said in my previous comment, because of the highly politicized nature of the issue, few people have the inclination and the necessary background to evaluate these studies. That is what I attempted to do in the long chapter devoted to passive smoking. But it is a thankless task. Because few people really care what the studies show. It is so much easier to accept what the highly politicized consensus reports have to say.

    If you don’t value the distinction between the science and politics, then I question your whole endeavor. There are many issues where the consensus is not the whole story, or is simply wrong. But I understand that people want to believe what they want to believe. And since we all know that smoking cause major mortality and morbidity, all many people are concerned with is not giving the tobacco industry a pass. But the science has nothing to do with this. The science needs to be judged critically, otherwise the whole enterprise is hopeless. For a smart person, you seem to have no awareness of how reputable scientists have been tarred by ignoramuses, hacks, and self-promoters for alleged collusion with the tobacco industry – which has never been substantiated. I am referring to Enstrom, myself, and Roger Jenkins.

    There are people who love to blog and express their opinions at great length and engage in ad hominem innuendo. It’s a lot less glamorous to try to inform oneself about the subject matter before expressing an opinion.

    My view is simply that like many other low-level environmental exposures, environmental tobacco smoke – as present-day methods permit us to measure it – is probably at the limits of what epidemiologic studies can detect. This is totally consistent with the fact that average exposure of a never smoker to ETS in careful studies conducted in many cities in the U.S. and Europe is on the order of 1/1,000th that of the average active smoker.

    By the way, if you had read the book, you would see what Sir Richard Peto had to say about the hazard of passive smoking before a committee of the House of Lords in 2006. He has better things to do than assess the evidence regarding the effects of passive smoking on chronic disease. As someone who focuses on large, important causes of mortality, he doesn’t think it’s worth the time. Nevertheless, his take on passive smoking dovetails with what I have been saying for many years.

    Geoffrey Kabat

  21. David Gorski says:

    You appear to be attributing political motives to me that I have not stated simply because I do not necessarily agree with you on SHS and have a problem with your past associations with Dr. Engstrom and, though him, with the tobacco industry. I have problems with your associations for the very same reason I am always more skeptical of studies funded by big pharma:

    http://www.sciencebasedmedicine.org/?p=192
    http://www.sciencebasedmedicine.org/?p=215
    http://www.sciencebasedmedicine.org/?p=408

    Moreover, associations are relevant when they directly impact an investigator’s research. In that, I am perhaps in the minority here at SBM, at least in terms of the focus I tend to take on this issue. I also note that you have been very assiduously avoided my questions about a conflict of interest, other than to accuse me of using, in essence, only guilt by association. My frequent refrain is that COIs don’t necessarily mean an investigator is wrong (the data, science, and how well an investigator’s conclusions are supported by them determine that), but COIs do make me look more closely and with more skepticism at his studies. I could also retort that I really don’t have a dog in this fight, career-wise, medicine-wise, and science-wise given that I don’t take care of patients with lung cancer and don’t do research on the effects of smoking, but you clearly do.

    You also should know that I’m an equal opportunity offender, so to speak. I have also been known to criticize the very same things you criticized in your book, namely the hyping of dubious environmental risks, for instance, cell phones and cancer, where, right here on this very blog, I was very critical of Dr. Ronald B. Herberman for feeding this hype:

    http://www.sciencebasedmedicine.org/?p=8

    I’m guessing you probably lambasted Dr. Herberman, too, in your book, assuming it hadn’t already gone to press before he released his warning last year.

    There’s also Dr. Raymond F. Palmer trying to hype a link between mercury emissions from coal-burning plants and autism based on truly bad epidemiology:

    http://www.sciencebasedmedicine.org/?p=111

    Heck, I even rip on the ecological fallacy in the post above.

    Believe it or not, I actually share your distaste for the tendency to inflate questionable associations into causes; indeed, I’m especially well known on this particular blog and elsewhere for being particularly harsh on the antivaccine movement and its abuse of epidemiology to try to prove “causation” of autism due to vaccines or mercury in vaccines. Earlier in my online career, when I was a denizen of the Usenet newsgroup misc.health, alternative, I regularly used to tussle with people who believed that silicone breast implants lead to autoimmune diseases and cancer and with people who thought that living near high power lines is a major risk for cancer. It is simply that, on the issue of SHS, I find your critiques that I’ve seen outside of your book far less compelling than in the cases of, for instance, EMF, cell phones, etc. Also contrary to your apparent view of me, I’ve even gone on record as having criticized the excesses of the tobacco control movement, especially the advocacy of outdoor smoking bans, which, IMHO, are completely unjustified on a scientific basis and clearly appear to be based only on ideology. (Actually, for any other purpose than trying to keep the grounds free of cigarette butts, such bans are idiotic, especially if the justification for them is to protect health.) In other words, I’m not the ideologue you seem to think that I am pontificating at length about things I know little about.

    This brings me to your insinuation that I lack “primary” knowledge, which seems (at least to me) to imply that you think that someone who isn’t directly involved doing research in the field has no qualification or right to criticize someone else’s work. That is, quite simply, a canard. One only has to have the scientific background to be able to read and assess the published record in the peer-reviewed literature; in fact, I have read your BMJ paper, as well as a lot of the primary literature. In brief, I have informed myself about this matter over the last few years. As far as your scientific record goes, to me (and most scientists) your work is what you have published in the peer-reviewed literature and presented at meetings. For purposes of discussing the science of SHS, I don’t really care much what you have said or written outside of such arenas, other than how it relates to what you have published in the peer-reviewed literature.

    Next, your point about the “average exposure of a never smoker” is also a non sequitur/red herring in that that is not the point of workplace smoking bans. The point is, rather, how much smoke a worker is exposed to working 40 hours a week in a smoky workplace, like a bar, where the exposure to SHS is much more intense. In other words, your pointing that out is irrelevant to the question of whether SHS is a hazard to workers.

    Finally, your citing Sir Richard Peto is simply the logical fallacy known as the “appeal to authority.” One wonders why, if Dr. Peto (and, I assume, you) have “better things to do” than to look at “lesser causes of mortality,” you, at least, apparently have ample time to try to slap down a little-known, relatively obscure blogger like me who happened to have made an “offhand” comment about you that you didn’t like in the comment section of a blog post containing a favorable review your book (where it’s unlikely that very many people will see my comment, I might add).

    Of course, you could always send me a review copy of your book, or maybe Harriet will send me hers now that she’s done with it. :-)

  22. For what it’s worth, we on SBM are not unanimous in our qualitative estimates of the risks of secondhand smoke. My own view is essentially that of Dr. Kabat, even if I arrived at it by somewhat less rigorous means:

    1. The obvious politicization and the near impossibility of having a calm, rational discussion of the subject with several of my anti-public-smoking friends registered high on my baloney meter several years ago, as first mentioned here;

    2. The dose-response curve for active smoking and disease suggests that the risk is far lower for passive smoking than is typically claimed, unless there is a threshold effect at very low doses, which seems unlikely;

    3. I noticed a similar phenomenon—social and quasi-epidemiologic—in my own field a few years ago, involving alleged health risks of inhaling trace anesthetic gases. My own literature review revealed studies chock full of confounders and biases which even if ignored still resulted in ‘relative risks’ of only 1-1.5, which one or two authors were honest enough to admit might mean nothing—the “limits of what epidemiologic studies can detect.”

    I don’t like to be around cigarette smoke, but I’m not worried about toxin exposure. It’s more an aesthetic than a scientific question.

    KA

  23. David Gorski says:

    For what it’s worth, we on SBM are not unanimous in our qualitative estimates of the risks of secondhand smoke.

    Obviously not. We’re not unanimous about (virtually) anything, and so far it’s looking like it’s two against one here (well, three if we count Dr. Kabat, but he’s not an SBM blogger). :-)

    Moreover, editors and regular contributors here at SBM have near-total editorial freedom, as long as they address issues relevant to the theme and mission of this blog. Sometimes we even butt heads. Sometimes we even butt heads to the point where we each get lumps, metaphorically speaking. Sometimes we even get royally ticked off at one another, but (so far) when that’s happened we’ve always “kissed and made up.” The one thing we are unanimous on, however, is the importance of science-based medicine, which is, of course, why we are not worried about all of us having near editorial freedom. None of us need worry that one of us will start advocating, for instance, that homeopathy is science.

    The obvious politicization and the near impossibility of having a calm, rational discussion of the subject with several of my anti-public-smoking friends registered high on my baloney meter several years ago, as first mentioned here

    Actually, that is not a particularly good reason to doubt the science. Advocates of CAM frequently “notice” that it is “impossible” to have a “calm, rational” discussion with us advocates of science-based medicine and accuse us of being ideologues or “mean.” Does that mean we might be full of “baloney”?

    Wait, don’t answer that….

    But do consider the possibility of selective memory and confirmation bias; we’re all prone to them.

    I don’t like to be around cigarette smoke, but I’m not worried about toxin exposure.

    Nor should you be for brief exposures (unless, perhaps, you have asthma that’s exacerbated by exposure to cigarette smoke), but I bet you would be if you had to work 40 hours a week around it. I would be. (Actually, back when I was in high school, for about a year and a half I did work in a restaurant where the smoke was quite thick and the “nonsmoking” and “smoking” sections didn’t make a difference.) As far as the policy implications of the science behind SHS, that is the real issue. Then there’s the issue of changing social standards and bad arguments against banning indoor smoking, which I spent far more time discussing than my “offhand” comment about Dr. Kabat.

  24. This is a belated response to Dr. Gorski’s unjustified April 4 attacks on Professor Geoffrey C. Kabat, who co-authored with me the May 17, 2003 BMJ paper on environmental tobacco smoke (ETS) and mortality in California (http://www.bmj.com/cgi/content/abstract/326/7398/1057). I am particularly proud that Professor Kabat had the courage and integrity to work with me on a high quality epidemiologic study of ETS, one of the most politically charged issues in public health.

    During the six years since its publication, not a single error has been identified in our paper and with each passing year there is more evidence that our findings accurately describe the relationship of active and passive smoking to mortality in California and the United States. Note: I prefer to identify my co-author as Professor Kabat, because he has held professorships at two prominent medical schools in New York State for the majority of time since 1992, including during the time that we worked together on our BMJ paper.

    For those readers who believe in fairness, objectivity, and honesty in science-based medicine, I request that you read the five references below, which counter the five weblink references that Dr. Gorski cited in his first April 4 email message. I believe that the references below clearly show that Dr. Gorski’s ad hominem criticisms of Professor Kabat and me are unjustified.

    1) October 10, 2007 Epidemiologic Perspectives & Innovations paper “Defending legitimate epidemiologic research: combating Lysenko pseudoscience” by James E. Enstrom (http://www.epi-perspectives.com/content/4/1/11 and http://www.scientificintegrityinstitute.org/EPI101007E.pdf).

    2) “The Controversy Over Passive Smoking: A Casualty of the ‘Tobacco Wars’,” Chapter 6, pages 147-182, in June 10, 2008 book “Hyping Health Risks: Environmental Hazards in Daily Life and the Science of Epidemology” by Geoffrey C. Kabat (http://www.hypinghealthrisks.com/index.html and
    http://www.amazon.com/Hyping-Health-Risks-Environmental-Epidemiology/dp/0231141483)

    3) September 3, 2008 Complaint by James E. Enstrom to District of Columbia Court of Appeals Office of Bar Counsel Against Sharon Y. Eubanks
    (http://www.scientificintegrityinstitute.org/Eubanks090308.pdf and
    http://www.tobacco-on-trial.com/2008/10)

    4) November 3, 2008 PLoS Medicine reader response by James E. Enstrom “Using the Internet to Disclose Competing Interests”
    (http://www.plosmedicine.org/annotation/listThread.action;jsessionid=7904CEFCDFDE8BA0AD7F89E0811BAE33?inReplyTo=info%3Adoi%2F10.1371%2Fannotation%2F2e61a452-1085-4c4d-ba83-8d698e8a6efa&root=info%3Adoi%2F10.1371%2Fannotation%2F2e61a452-1085-4c4d-ba83-8d698e8a6efa)

    5) April 1, 2009 New Scientist article “Have the Tobacco Police Gone Too Far” by David Robson (http://www.newscientist.com/article/mg20227021.300-have-the-tobacco-police-gone-too-far.html)

    James E. Enstrom, Ph.D., M.P.H.
    Research Professor
    University of California, Los Angeles
    jenstrom@ucla.edu
    http://www.cancer.ucla.edu
    http://www.scientificintegrityinstitute.org
    http://www.acsh.org/about/pageID.108/default.asp
    http://www.spiked-online.com/index.php?/inspired/article/1357
    http://www.spiked-online.com/index.php?/innovationsurvey/article/3179

  25. I’ve never contributed to SBM before and will confess to being something of a one-trick-pony in my focus, but having read Dr. Kabat’s book and being intrigued by some of the comments made here I would like to add some thoughts of my own.

    Let me start with Harriet Hall’s review where she notes in reference to ETS causing cancer and heart disease, “we are reasonably sure there is a risk and we know the mechanism.” I would argue that the only “reasonable sureness” comes from a popular perception that there’s been widespread epidemiological support for this contention. However, if one looks at a comprehensive listing of studies concerning just lung cancer up through 2001 I believe one would find that the support is a lot weaker than normally assumed. See:

    http://www.nycclash.com/philly.html

    and note how few of those studies passed even the bare minimum test of statistical significance. Thirty years ago very few medical researchers in the world would have agreed with the statement that “we are reasonably sure there is a risk” and yet the widespread surety of today seems to be based on rather shaky ground.

    I am not arguing that there is NO risk, but I WOULD argue that the risk, particularly in well ventilated and air-filtrated modern environments, is so small that it is misleading to use the word “risk” to describe it. After all, would you say that a parent is subjecting a child to a “risk” of skin cancer by asking that child to bring in the morning paper from the front porch? There are limits to how such words should be used by doctors and scientists when communicating with the public and I believe those limits have clearly been overstepped when it comes to low levels of ETS exposure.

    Kimball Atwood then speaks of a similar “scare wave” of studies involving inhalation of trace quantities of anesthetic gases. Imagine if there was an “Anesthetic Gas Control” movement with a base budget of 900 million dollars a year. That’s the amount that the AMA has listed for “Tobacco Control” money just from US State budgets in its 2001 Tobacco Control Report at: http://www.ama-assn.org/ama/upload/mm/hod_ibot14_doc.doc Think for a moment how many more the anti-anesthetic gas studies would have been produced, with standards involving even more confounders and biases in an effort to please the grantors looking for support for their goals of “Anesthesia Control” if there was that kind of bankroll out there pushing it. And in the case of Tobacco Control we’re not simply talking about researchers being corrupted by grant money but also about them being corrupted by the ideals of producing research “for the greater good.”

    This last concern ties in with David Gorski’s focus on “competing interests.” If you visit the PLoS One journal site at:

    http://www.plosmedicine.org/annotation/listThread.action?inReplyTo=info%3Adoi%2F10.1371%2Fannotation%2F3a22438c-206d-4e3a-8019-f362a1b23203&root=info%3Adoi%2F10.1371%2Fannotation%2F3a22438c-206d-4e3a-8019-f362a1b23203

    you will find some extensive discussion, including an extensive and well-referenced entry by me, of Stanton Glantz’ competing interests in the area of Tobacco Control. In general the vaguest of ties to tobacco funding, even when such funding is given explicitly with “no-strings attached,” seems to always get treated as ultimately damning, while even the strongest of financial ties to the “Tobacco Controllers” is treated as totally innocent. The danger this poses to the academic and research community is clear and I addressed it at some length in an article in the Edmonton Journal a couple of years ago at:

    http://www2.canada.com/edmontonjournal/news/letters/story.html?id=4a64c2d9-4da5-4420-b50b-9e19a8229912

    and the sad, although almost funny, part of that story was that the paper printed a response a week later:

    http://www.canada.com/edmontonjournal/news/letters/story.html?id=540e76a5-28f8-4a19-8342-3be344cbebcf

    where my article was criticized on the basis of my not disclosing my own “affiliations” with suspect organizations with hidden funding. In reality of course those organizations basically HAVE no funding and I sure as certainly didn’t. In terms of Dr. Kabat’s arguable “competing interests” I believe that if you check his writings and research publications in the area of smoking he has always been painstakingly thorough in making them clear… unlike the fellow focused on in the PLoS reference above.

    Finally, a brief note about David Gorski’s statement that, “None of us need worry that one of us will start advocating, for instance, that homeopathy is science.”

    Are you so sure of that? What about Dr. Winickoff’s concerns about “Third Hand Smoke” and such things as the deadly exposure of children to highly radioactive polonium 210? If you don’t think that ranks up there with homeopathy please see my analysis at Columbia Press below Dr. Kabat’s article:

    http://www.cupblog.org/?p=493

    and note that for a child to be exposed to the “deadly dose” highlighted by the New York Times the poor kid would have to lick floors for close to three trillion years (roughly 274 life cycles of the current universe).

    I think I’d call that homeopathy in just about any book. And speaking of books, I read Dr. Kabat’s several months ago, not just a review of it, and thought it was excellent indeed!

    Michael J. McFadden
    Author of “Dissecting Antismokers’ Brains”
    Mid-Atlantic Director, Citizens Freedom Alliance, Inc.
    Director, Pennsylvania Smokers’ Action Network (PASAN)
    Associate Member, The International Coalition Against Prohibition (TICAP)
    http://pasan.TheTruthIsALie.com

    { Note: the ONLY “financial” part of all that stuff happens if someone buys a book. :> }

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