The toll due to secondhand smoke

Given that I’ve dedicated my life to treating cancer and researching the biology of cancer, the ultimate goal being to use that knowledge of cancer biology to develop ever more effective treatments directed at the specific molecular derangements that lead to cancer, it’s not surprising that I’m very much anti-tobacco. After all, arguably there is no known behavior that causes more cancer-related deaths than smoking tobacco. It’s not just lung cancer, either. Smoking causes a wide variety of cancers, chronic obstructive pulmonary disease (COPD), and cardiovascular disease, all of which result in huge numbers of deaths among smokers each and every year. Clearly, smoking tobacco is so harmful due to a variety of health problems that it can cause that it is rare to find anyone who tries to argue otherwise. Unfortunately, there are estimated to be over 1 billion smokers in the world, and the toll of their addiction includes cancer, lung disease, and heart disease, and it’s estimated that during the 20th century over 100 million people worldwide died due to tobacco-related diseases.

While it is clear that smoking tobacco is deadly to those who actually become addicted to it, what has also becoming increasingly clear is that secondhand smoke is also a health hazard. It turns out that I’ve dealth with this topic before, mostly in the context of dealing with those who would argue against the contention that secondhand cigarette smoke increases the risk of cardiovascular disease (and cardiac events in those with preexisting cardiac disease), chronic lung problems, and lung cancer. For instance, denialists like to try to argue that epidemiology can never demonstrate a relative risk less than two, a contention that no reputable epidemiology organization accepts and a contention that, if accepted, would force us to deny a whole range of health risks, including the relative risk of myocardial infarction due to, for example, Avandia. Indeed, six years ago Tim Lambert ably described the origin of the claim that epidemiology can’t confirm a relative risk of a magnitude less than two. Not surprisingly, this claim originated with Philip Morris as a strategy to downplay the risk due to secondhand smoke.

I may have left my blog (mostly) inactive during the recent Thanksgiving holiday weekend, but there was a story describing a study that appeared on the Friday after Thanksgiving and tries to come up with an estimate of the death toll worldwide that can be attributed to secondhand tobacco smoke:

Secondhand smoke kills more than 600,000 people worldwide every year, according to a new study.

In the first look at the global impact of secondhand smoking, researchers analyzed data from 2004 for 192 countries. They found 40 percent of children and more than 30 percent of non-smoking men and women regularly breathe in secondhand smoke.

Scientists then estimated that passive smoking causes about 379,000 deaths from heart disease, 165,000 deaths from lower respiratory disease, 36,900 deaths from asthma and 21,400 deaths from lung cancer a year.

Altogether, those account for about 1 percent of the world’s deaths. The study was paid for by the Swedish National Board of Health and Welfare and Bloomberg Philanthropies. It was published Friday in the British medical journal Lancet.
“This helps us understand the real toll of tobacco,” said Armando Peruga, a program manager at the World Health Organization’s Tobacco-Free Initiative, who led the study. He said the approximately 603,000 deaths from secondhand smoking should be added to the 5.1 million deaths that smoking itself causes every year.

Upon reading the story, I had to wonder: Does this study actually show that secondhand smoke results in such a large number of deaths worldwide? So, as usual, over the weekend I decided to go to the source, namely the World Health Organization study that was published online in The Lancet entitled Worldwide burden of disease from exposure to second-hand smoke: a retrospective analysis of data from 192 countries. The study, supported by the Swedish National Board of Health and Bloomberg Philanthropies, sought to estimate the global burden of disease due to secondhand smoke.

Before we look at risks due to secondhand smoke, it should be pointed out that this study found that large numbers of people worldwide are exposed to secondhand smoke. For instance, it was estimated that, worldwide, approximately 40% of children (aged 0-14 years for purposes of this study), 33% of male non-smokers, and 35% of female non-smokers were regularly exposed to second-hand smoke. In this case “regularly” was defined differently for children as for adults. For children the definition of secondhand smoke exposure included having one or both parents who smoked indoors or having another person living with them who smoked. These estimates were obtained mainly from the global youth tobacco survey (GYTS), which is a school-based survey of children aged between 13 years and 15 years that covers more than 120 countries. For adults, the definitions of exposure were based on either having a spouse who smokes or regular exposure to tobacco smoke at work and could be further characterized by the number of cigarettes smoked by the spouse, the duration of exposure, or the frequency of exposure in number of days per week. Overall, the highest proportions of the population exposed to secondhand smoke were found in Europe, the western Pacific, and parts of southeast Asia, with more than 50% of some population groups exposed.

Next, the investigators attempted to estimate the burden of disease from secondhand smoke as deaths and disability-adjusted life-years (DALYs) for children and adult non-smokers. The basis of these calculations were relative risk estimates for specific diseases and area-specific estimates of the proportion of people exposed to secondhand smoke, using comparative risk assessments using data from 192 countries. Specific diseases and conditions were chosen based on recent reviews that judged the evidence to be sufficient to infer a causal association with secondhand smoke and if national incidence statistic were available. Ultimately, the health outcomes chosen for children were:

  • Lower respiratory infections (relative risk 1.55)
  • Asthma onset (relative risk 1.32)
  • Acute otitis media (relative risk 1.38)

For adults, the health outcomes studied were:

  • Adult-onset asthma (relative risk 1.97)
  • Lung cancer (relative risk 1.55)
  • Heart disease (relative risk 1.21)

There are a number of other adverse health outcomes that have been linked with secondhand smoke, but investigators either didn’t have adequate data to study these outcomes or deemed the existing evidence not to be strong enough to support a causal relationship.

Once these outcomes were decided upon, the attributable burden of disease, in deaths or DALYs, was estimated for every outcome by multiplication of the population attributable fraction by the total burden attributable to that disease. To put it more simply, the attributable risk is the difference in the incidence of a condition between an exposed population and an unexposed population. Similarly, the attributable burden of disease is the incidence of disease that can be–as you might guess–attributed to the exposure to secondhand smoke. When it was all put together, the authors estimated:

This exposure was estimated to have caused 379,000 deaths from ischaemic heart disease, 165 000 from lower respiratory infections, 36 900 from asthma, and 21,400 from lung cancer. 603 000 deaths were attributable to second-hand smoke in 2004, which was about 1·0% of worldwide mortality. 47% of deaths from second-hand smoke occurred in women, 28% in children, and 26% in men. DALYs lost because of exposure to second-hand smoke amounted to 10·9 million, which was about 0·7% of total worldwide burden of diseases in DALYs in 2004. 61% of DALYs were in children. The largest disease burdens were from lower respiratory infections in children younger than 5 years (5,939,000), ischaemic heart disease in adults (2,836,000), and asthma in adults (1,246,000) and children (651,000).

One aspect of the results of this study that were particularly disturbing is that deaths due to secondhand smoke were skewed toward poor and middle-income countries, where children tended to die of lower respiratory infections associated with secondhand smoke. In Europe’s high-income countries, only 71 child deaths were recorded for this study, while 35,388 deaths were in adults. In contrast, in Africa, there were an estimated 43,375 deaths potentially attributable to secondhand smoking in children compared with 9,514 in adults. This is very much like the case with infectious diseases, where the death toll in poor African countries is much higher than in wealthier, more developed countries.

By any stretch of the imagination, these are huge numbers. However, although there’s little doubt that secondhand smoke is an indoor pollutant that has the potential to result in health problems in nonsmokers, just how good are these estimates? Part of the problem with this study is that these estimates rely on a number of assumptions. These include the accuracy of the meta-analyses used to estimate the relative risk for each disease due to secondhand smoke and assuming that the fatality rate for each condition associated with secondhand smoke was the same as the mean case fatality rate for the disease in general. This latter assumption I found particularly troubling, not because it isn’t a relatively reasonable assumption in most conditions but because making such an assumption over 192 nations may not be valid. One reason is that fatality rates for each disease might be very different depending upon the nation, given the large differences that exist in access to health care and the quality of that health care in all these countries.

Other uncertainties in epidemiological studies of this type also include problems with the underlying health data available for analysis; inaccuracies in the exposure data used; the choice of the population under study; the effect sizes and whether they are transferable to other populations and exposure conditions; the burden of active smoking (deduced from the total burden before estimation of the burden from secondhand smoke); and the susceptibility of ex-smokers. The investigators performed various sensitivity analyses, in which they tested the effects of changing different variables on the the final estimates for the total number of deaths attributable to secondhand smoke. For example, making changes in these assumptions could lower the death toll estimate by as much as 28% or increase it by as much as 30%. One aspect of this study that is somewhat reassuring is that the estimates don’t vary by that much depending upon changes in major assumptions and that the estimates of attributable risk due to secondhand smoke in this study are in line with similar estimates from other studies.

With over 1 billion people smoking, the global burden of disease due to tobacco is staggering, even if secondhand smoke were perfectly safe. However, there has been a body of evidence growing over the last 30 years implicating secondhand tobacco smoke as a significant health risk. Because it’s primarily epidemiological in nature, it’s full of flaws and potential biases such that no single study can demonstrate definitively the relative risk of death due to secondhand smoke. That’s why one has to assess at the totality of evidence in coming to conclusions, and that totality of evidence clearly points in the direction of secondhand smoke being a major health risk. The question that follows from data such as this study is: What should we do about it?

Comments

  1. #1 novalox
    January 2, 2011

    @194, 195

    How utterly predictable, instead of backing up her positions with actual facts, carol goes to the ad hominem route.

  2. #2 Carol
    January 2, 2011

    Prometheus – That is another fraudulent misrepresentation of the issue to pretend that it is necessary to prove that HPV causes 100% of lung cancers, in order to object to the anti-smokers deliberately committing scientific fraud by ignoring more than 50 studies, which implicate HPV in at least a quarter of NSCLCs. This isn’t the last word on the percentage, either, because the various studies to date didn’t all use the latest techniques or look for all the necessary types of HPV.

    This fraud doesn’t just inflate the number of deaths blamed on smoking. It is also entirely probable that different rates of HPV infection between non-smokers exposed and not exposed to secondhand smoke entirely account for your claims that secondhand smoke causes lung cancer in non-smokers. You are guilty of scientific fraud for refusing to consider this reasonable alternative explanation, solely because it contradicts your pre-drawn conclusions and hinders your social engineering agenda. Remember, secondhand smoke is what this discussion is supposedly about. So quit trying to change the subject.

    As I said, the most likely explanation of those negative studies you cherry-picked is that they’re playing the same games of denial that they played with Epstein-Barr virus and nasopharyngeal carcinoma. However, unintegrated HPV genome maintained as a nuclear plasmid in the infected cervical epitheliumis is fully capable of expressing both the E6 and E7 proteins. It doesn’t need to replicate.

  3. #3 Carol
    January 2, 2011

    Chemmomo, if most people thought that tobacco smoke was vile and obnoxious, it would not have been necessary fo you to ban smoking. Furthermore, you anti-smokers would have been able to keep your smoke-free establishments in business, without outlawing competition from those who allow smoking. Your own actions prove that you are a liar.

  4. #4 Chemmomo
    January 3, 2011

    Carol, we live in a democracy. Your conspiracy theories notwithstanding, the laws were passed by the majority of people who consider tobacco smoke vile and obnoxious. A single smoker can offend hundreds of people.
    The fact that “nonsmoking” sections of restaurants and airplanes existed before the bans (although essentially ineffective) attest to this fact.
    And Carol, please specify how my finding tobacco smoke offensive makes me a “liar.”

  5. #5 ildi
    January 3, 2011

    Ohio’s statewide smoking ban passed with 58 percent of the votes. I must say, all the smokers standing outside provide great cover for the ‘smokers’, nudge, nudge, wink, wink…

    I’m sure you’re an avid supporter for the right to smoke all types of materials wherever one wants, right, Carol? I’d sure hate to have to categorize you as one of the subhuman garbage.

  6. #6 Todd W.
    January 3, 2011

    @Carol

    The lie that I claimed “that smoking has nothing to do with lung cancer” is a fraudulent misrepresentation of my position, which is in kind with anti-smokers’ lack of scientific ethics. And YOUR pretense that I agree with Chris is another fraudulent misrepresentation of my position, likewise designed to try to evade my point.

    Okay, I’m confused. So, if we say that you claim that smoking has nothing to do with lung cancer, we’re being fraudulent. Yet, if we say that you claim that smoking does have something to do with lung cancer, we’re still fraudulent? Which is it, then? Do you say that smoking is not related or that it is related to lung cancer? Please do try to be clear.

    Also, you didn’t answer the question: what benefit do you derive from smoking? I’m really quite curious.

  7. #7 Chris
    January 3, 2011

    Carol:

    Chemmomo, if most people thought that tobacco smoke was vile and obnoxious, it would not have been necessary fo you to ban smoking.

    That is because you are addicted. Yes, private properties can be smoke free if they want. I just don’t want smoke on public buses, their shelters and other public enclosed spaces. Before most restaurants became smoke free, we were at a small neighborhood restaurant that was smoke free. An addicted smoker was incensed that he could not smoke in there and did not like it when the waiter told him that no one ever wanted to sit in their former smoking section so it was a business decision.

    Carol:

    This fraud doesn’t just inflate the number of deaths blamed on smoking.

    Investigators say ashes from cigarettes or pot may have sparked fatal Redmond fire:

    Authorities say they are investigating whether a fire that swept through a Redmond apartment building early Saturday, killing a 32-year-old man and four young boys, was caused by ashes left smoldering in the bathroom.

  8. #8 Carol
    January 3, 2011

    Chemmomo – This is not a “democracy,” any more than Communist Russia was a democracy. It doesn’t represent the people, it represents the will of theocratic oligarchy, who control the politicians and the mass media, and and trying to impose a compulsory state religion, which is based on scientific fraud, on everyone else. The laws were NOT passed by a majority of the people, they were passed by crooked politicians, at the instigation of lying media. They made sure that the people only heard the anti-smokers’ point of view, versus the anti-smoker-approved misrepresentation of our point of view, namely that Big Lie of falsely framing the issue as “freedom versus public health” instead of “anti-smoker scientific fraud.” They prevented anyone from exposing the anti-smokers’ frauds and acts of political corruption, such as the “EPA” report on ETS. The fact that those 50-plus studies have never been mentioned by the mass media, in stark contrast to the propaganda blitzkrieg that began with the very first quack study blaming secondhand smoke for causing lung cancer in non-smokers, is proof of their conspiracy.

    And quit pretending that you’re entitled to violate any of rights that you please, just by whining that you don’t like the smell, and falsely pretending to speak on behalf of everyone in the country. These are our INALIENABLE rights that yuou are violating, our rights to the equal protection of the laws and to freedom of religion, that you are violating. And we have NO OBLIGATION WHATSOEVER to submit peacefully to it, because the government was instituted specifically to protect those rights, and if it fails to do so, it has the consent of the governed no longer, and no right to demand our allegiance.

  9. #9 Carol
    January 3, 2011

    ildi, your referendums are as fraudulent as Communist elections, for the reasons cited above. Remember those 50-plus studies of HPV and lung cancer that your mass media accomplices keep the public ignorant about, while lying that the issue is “freedom versus public health.”

  10. #10 JohnV
    January 3, 2011

    Ah yes, the inalienable rights: life, liberty, and being an asshole smoker who rages on blogs and spews incoherence and toxic smoke with every breath. Voltaire would be proud.

    Extra credit for threatening violent revolt over your ability to consume cancer sticks in public places.

  11. #11 Caro
    January 3, 2011

    Todd W, you’re living proof that anti-smokers are psychopathic criminals who ought to be rounded up and put in prison. How many times do I have to repeat it? Your ilk are guily of flagrant scientific fraud for deliberately using defective studies in order to falsely blame tobacco for diseases that are really caused by infection.
    Your ilk are guily of flagrant scientific fraud for deliberately using defective studies in order to falsely blame tobacco for diseases that are really caused by infection. Your ilk are guily of flagrant scientific fraud for deliberately using defective studies in order to falsely blame tobacco for diseases that are really caused by infection. Ignoring those 50-plus studies of HPV and lung cancer is the most glaring proof.

  12. #12 Todd W.
    January 3, 2011

    @Carol

    Still waiting on your answer to two questions:

    1) Is smoking related to lung cancer or is it not related to lung cancer, in your opinion? (A brief “yes it is related” or “no it isn’t related” will do.)

    2) What benefits do you derive from smoking?

    Thanks, in advance.

  13. #13 Todd W.
    January 3, 2011

    Wow. Ask a couple simple questions and get labeled as a psychopathic criminal. You’re quite amusing, Carol.

  14. #14 Scottynuke
    January 3, 2011

    I’d almost call Poe, but you’re right Todd — Carol’s much too amusing.

  15. #15 Calli Arcale
    January 3, 2011

    Carol — just a quick question. So HPV may cause some specific forms of lung cancer. That doesn’t surprise me; HPV is known to cause cancer in other parts of the body, after all. (Hence its name.) The question is: how does this absolve cigarettes, given that there is more than one kind of lung cancer?

    Corollary question: if HPV-triggered lung cancer absolved cigarettes in your mind, what is your opinion on lung cancer due to radon gas exposure?

  16. #16 Chris
    January 3, 2011

    Scottynuke:

    I’d almost call Poe, but you’re right Todd — Carol’s much too amusing.

    Though at this point I get uncomfortable deriving amusement from someone who is obviously mentally ill.

  17. #17 Scottynuke
    January 3, 2011

    Chris: While Carol’s aversion to reality is certainly obvious, we’ll never know if it’s an act or not.

    “If we couldn’t laugh we would all go insane,” as Mr. Buffett once sang.

  18. #18 Vicki, Chief Assistant to the Assistant Chief
    January 3, 2011

    I’ve seen suggestions (though not recently, so they may not have panned out) that some percentage of cigarette smokers are in fact self-medicating for schizophrenia. The other meds for that still aren’t great (either), and at least some of those people started smoking decades ago.

    That said, just as nicotine patches are less harmful than smoking, I suspect that it should be possible to figure out which bits of tobacco are having the useful effect, and provide them in some other way. I have a partner who smoked for a long time, quit for a decade, then smoked for most of another. He’s been off tobacco again for about a year and a half, a chunk of that using nicotine patches and such. Nicotine isn’t exactly the bodies friend, but the patches did less damage than the cigarettes, as well as not smelling bad. A nicotine patch doesn’t risk causing fires, and it doesn’t damage the user’s sense of smell.

  19. #19 Chemmomo
    January 3, 2011

    Carol @208

    These are our INALIENABLE rights that yuou are violating, our rights to the equal protection of the laws and to freedom of religion

    So smoking is a religion? That explains a lot.

  20. #20 ildi
    January 3, 2011

    I’ve seen suggestions (though not recently, so they may not have panned out) that some percentage of cigarette smokers are in fact self-medicating for schizophrenia.

    … and many self-medicate with weed to manage the side-effects of the antipsychotics. I totally advocate for Carol’s inalienable right to get stoned! Maybe she would be less scary…

    Most people I know who voted for the smoking ban did so because it fricking STINKS, Carol, and they wanted to be able to go to a bar or restaurant without having their clothes and hair reek afterward. They also voted for the ban because people who work in a bar should have the right to do so without being exposed to the stink and negative health effects of smoking – not illusory, as much as you wish to think so. I can shoot pool and have a drink without risk of triggering an asthma attack.

    I also had smoking friends who felt almost as strongly as you regarding their god-given right to stink up any place they were to satisfy their cravings. The reason bans have to be voted in place is because courtesy seems to take a back seat to addiction.

    One of my coworkers has been hospitalized several times the past couple of winters for bronchitics/pneumonia, the last time because her left lung collapsed. She now sneaks a block away and hides in a doorway to smoke.

  21. #21 Prometheus
    January 3, 2011

    Carol – turning it up to 11 – claims:

    “These are our INALIENABLE rights that yuou [sic] are violating, our rights to the equal protection of the laws and to freedom of religion, that you are violating.”

    Not being a Constitutional scholar, I went to the US Constitution and the ammendments commonly referred to as the Bill of Rights. I failed to find a guaranteed right to smoke tobacco (or other herbs). Perhaps Ms. Thompson could point me to the section she is referring to.

    Equal protection under the law also seems a bit of a stretch, since the laws about smoking in public places, airliners, etc. apply equally to all. Granted, smokers will have their lifestyles affected the most by them, but even I – a life-long non-smoker – cannot light up in a public place, were I to choose to take up the habit.

    Freedom of religion? For starters, the “establishment clause” and “free exercise clause” (as in “Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof…”) do not give people free reign to do whatever they like so long as they claim it is a religious practice. Laws against marijuana smoking, bigamy and human sacrifice have withstood “free exercise of religion” challenges. (OK, I was kidding about that last one)

    I believe that certain Native American tribes have obtained a religious exception to federal drug laws to allow the use of peyote in their religious practices, but I doubt that tobacco smokers would be able to do the same. On the other hand, who knows what the courts might decide?

    Then Carol goes full-canvas-jacket (#211):

    “…anti-smokers are psychopathic criminals who ought to be rounded up and put in prison.”

    I think that Ms. Thompson is showing us that she’s not ready for an adult debate on the merits of her argument.

    Prometheus

  22. #22 Carol
    January 3, 2011

    Promotheus – Once again: The issue is ANTI-SMOKER SCIENTIFIC FRAUD. And when your ilk use the government to commit scientific fraud to deprive us of our liberty, that automatically violates our rights to the equal protection of the laws, just as much as throwing innocent people in prison. You think that you can violate other peoples’ freedom just because it’s more pleasant or convenient for YOU, so you’re criminals.

    And when you pretend that you’ve supposedly settled the health issue for once and for all, and that you have no obligation to look at any scientific evidence other than what furthers your agenda, then your garbage is theology, not science, and you are violating our rights to freedom of religion by ramming it down our throats.

    So take your little pettifogging crap of pretending that if something isn’t listed in the Constitution as protected, that’s means it’s fair game for you to persecution. The freedom to smoke is just as much Constitutionally-protected as anything else, meaning that you have no right to take it away without a valid reason. And you have valid reason, so your charlatans committed fraud.

  23. #23 Carol
    January 3, 2011

    The last line is supposed to say, “And you have NO valid reason, so your charlatans committed fraud.”

  24. #24 Todd W.
    January 3, 2011

    @Carol

    Since you still haven’t answered, here it is again…

    Still waiting on your answer to two questions:

    1) Is smoking related to lung cancer or is it not related to lung cancer, in your opinion? (A brief “yes it is related” or “no it isn’t related” will do.)

    2) What benefits do you derive from smoking?

  25. #25 ildi
    January 3, 2011

    You think that you can violate other peoples’ freedom just because it’s more pleasant or convenient for YOU, so you’re criminals.

    So, you’re admitting to being a criminal? After all, you insist on violating other peoples’ freedom to breath clean air with your noxious fumes and exhalations just because it’s convenient for you…

  26. #26 Chance Gearheart, AAS, NREMT-P
    January 3, 2011

    @Carol

    I’ve got some questions for you:

    1) What proof do you have that research into disease caused by or influenced by second hand smoke is fraudulent or only based upon “lifestyle questionares”, keeping in mind a cursery search of PubMed’s public abstract database has hundreds of articles on the topic ranging from upregulation of Alpha-Nicotinic receptors on Breast Cancer cells, to studies that link the exposure to secondhand smoke with everything from childhood developmental delay, an increased rate of IUGR and birth defects, and increased risk of heart disease and COPD.

    2) What purported benefits are there to smoking in terms of health?

    3) You frequently equate people who are against public smoking, despite the overwhelming mountain of evidence, as legal facists or Nazis. What legal presidence do you have that public smoking is a protected right of all Americans? (keeping in mind, there is no law against lighting up in private or in designated areas.)

    4) Can you provide documented, reliable proof of the conspiracy against smokers you assert?

  27. #27 andrew
    August 18, 2011

    I am a passive smoke victim. I am due to be reprieved in December when I get to move, and this gives me 4 months of passive smoking with two smokers, one of whom is a chain smoker who smokes all night in the room directly below me. I identify the feeling of poison inside me as a result and correlated that with the feeling at work of methanal poisoning by a careless teacher..
    In fact I stated that methanal was in cigarettes before I discovered this fact for myself, purely by a feeling that I had been poisoned by this compound 5 years previously.
    I am suffering daily from symptoms of stress and a feeling of being poisoned. I cannot understand how the people around me can stand inhaling this stuff day in day out. Every night I sellotape myself into my room and put a wet shirt under the door to prevent smoke getting in my room.
    I know that the smaller organic compounds such as methanal will get through this and so I must keep my windows wide open overnight.. As I write I am feeling the symptoms of being poisoned as I do again and again… there is no dount I will outlive my housemates, mainly by moving away as soon as I am able to, only then the daily symptoms will finally cease. But it is going to be a long 4 months!!

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