Secondhand Smoke and Health
by Terry Simpson, M.D., F.A.C.S.
Monday, December 3, 2007
The 1964 Surgeon General Report, which declared that the inhalation of cigarettes would likely cause lung cancer and heart disease, had a profound impact in the United States. This report started America thinking that the practice of inhaling cigarette smoke was unhealthy and began a long series of studies, lawsuits, and laws, that changed the face of America from a primary smoking society—where over 60 percent of adults in the U.S. smoked—to a number that is now about 30 percent.
On June 27, 2006, long after the first Report and yet likely based on its long-lasting impact, Surgeon General Richard Carmona issued the following statements regarding secondhand smoke:
(a) The scientific evidence is now indisputable: secondhand smoke
is not a mere annoyance. It is a serious health hazard that can lead
to disease and premature death in children and nonsmoking adults.
(b) Secondhand smoke contains more than 50 cancer-causing chemicals, and is itself a known human carcinogen
(c) There is no risk-free level of exposure to secondhand smoke. Nonsmokers exposed to secondhand smoke at home or work increase their risk of developing heart disease by 25 to 40 percent and lung cancer by 20 to 30 percent.
The Surgeon General also stated that 49,000 deaths per year were caused
by second hand smoke. As a surgeon, I was stunned, because I had never
seen an autopsy report listing secondhand smoke as the cause of death.
Nor had I seen this as a secondary cause of death. So I asked six pathologists
if they had ever listed secondhand smoke as a cause of death – not
one had. In my years of clinical practice, I have seen patients die
from many devastating diseases, and yet I have never seen anyone who
has been disabled by, or has died as a result of, secondhand smoke.
This was my first clue that perhaps there was more hyperbole than science
involved in the reports issuing from the Surgeon General’s Office.
To give a contrast: 33,000 people die per year of pancreatic cancer
– all of the pathologists have listed pancreatic cancer as a cause
Composition of Smoke
Secondhand smoke, also called Environmental Tobacco Smoke (ETS), is a combination of Mainstream Smoke, which is exhaled by smokers and Sidestream Smoke, which is released directly from the burning tip of cigarettes or cigars. Sidestream smoke is the primary constituent of environmental tobacco smoke, providing most of the vapor phase and over half the particles. Hence, at events such as “The Big Smoke”, the majority of particulate matter comes from sidestream smoke. Exhaled mainstream smoke contributes between 15 and 43 percent of the particulate matter in environmental tobacco smoke. Sidestream smoke is generated at lower temperatures and a higher alkalinity than mainstream smoke, and as a result has a different chemical composition.
During environmental tobacco smoke formation, both sidestream smoke
and exhaled mainstream smoke are diluted by many orders of magnitude
and subsequently undergo physical transformation and alterations in
chemical composition. For example, nicotine and many other semi-volatile
compounds of tobacco smoke tend to be present in the particle phase
of inhaled mainstream smoke, but evaporate into the vapor phase as
exhaled mainstream smoke is rapidly diluted during the formation of
environmental tobacco smoke.
Secondhand Smoke and Lung Cancer
If secondhand smoke exposure is a significant risk factor for developing lung cancer, then we should expect to see increased numbers of cancer cases in non-smokers who are exposed to regular doses of secondhand smoke. Has there been an increase in the incidence of lung cancer among nonsmokers over the last 40 years? The answer is quite simply… No.
Data from national mortality studies show that rates of lung cancer among non-smoking women remained stable between the 1950’s to the 1980’s (very few women smoked during those years) and didn’t rise until substantial numbers of women started smoking in more recent years. These non-smoking women were included in numerous studies as control groups for examining lung cancer rates in their smoking spouses. As anti-smoking logic would dictate, the longer one is exposed to secondhand smoke the more we should see a rise in lung cancer. However, when we examine the data from the studies noted above, we do not see such a rise in cancer rates for these non-smoking women.
In 1992, secondhand smoke was labeled a Class A carcinogen: one that causes lung cancer and is responsible for the deaths of 3,000 Americans annually (U.S. EPA, 1993). However, there were no autopsies, no bodies, nor one person that could be claimed as a victim. The EPA did not base their classification on their own independent study but examined over thirty epidemiological studies (i.e., studies that attempt to correlate various risk factors with early death in different populations). Eleven of those studies were done in the United States and of those, just 8 found a positive risk, 3 found a negative risk but none of them were statistically significant (that is, none of the U.S. studies could make the statement that there was a cause-and-effect relationship between secondhand smoke and cancer).
In medical research, a statistical confidence level of 95% means that there is only a five percent chance that a significant finding could be due to chance (i.e., a random result). In their interpretation of the epidemiological studies, the EPA made a critical procedural statistical alteration. They changed the confidence level to 90%. This statistical manipulation made it more likely that their findings would show significant negative health effects of secondhand smoke, but also made more likely the potential for erroneous conclusions. Furthermore, the EPA did not take into consideration the factors independently associated with both the development of lung cancer and exposure to secondhand smoke, factors that certainly could account for the purported relationship between secondhand smoke and early death. Finally, they did not attempt to assure that the subjects were properly identified into the correct experimental group. The EPA left several important questions unanswered such as: Were the exposed cases truly ill with primary lung cancer? Had the subjects been smokers previously? Were they truly exposed to secondhand smoke? And, did the subjects accurately report their exposure levels?
The EPA also classified secondhand smoke as a carcinogen based on chemical “similarities” between inhaled mainstream smoke and environmental tobacco smoke. Their logic was that since inhaled tobacco smoke is a carcinogen, environmental tobacco smoke must also be. Inhaled mainstream smoke, however, contains chemicals at concentrations of up to one million times those found in environmental tobacco smoke (which is a combination of exhaled mainstream smoke and sidestream smoke). Further, deep inhalation affects the degree of exposure to those chemicals, as well as the deposition of those chemicals into the respiratory passages of the smoker. One of the frustrating issues is we do not know the chemical, or chemical compounds responsible for the link to lung cancer and/or heart disease. This leads to another difficult issue – the length of exposure to the chemical might not yield a linear relationship to the formation of cancer (also known as the exposure-risk relationship). Single dose exposure likely does not yield 100 percent incidence of carcinoma. For example, low exposures of materials in drinking water does not yield disease, but higher and longer exposures of materials – such as arsenic, certainly produce disease. Much as a single aspirin may produce the effect of headache relief, a large dose of aspirin will be toxic. What was not evident in many of these studies was a dose-response curve to secondhand (passive) smoking and disease.
At the behest of Congressman Henry Waxman (D-Ca), the Congressional Research Service (CRS) spent two years examining reports and came up with the following conclusions regarding secondhand smoke and lung cancer (Redhead and Rowberg, 1995):
(a) The statistical evidence does not appear to support a conclusion
that there are substantial health effects of passive smoking.
(b) It is possible that very few or even no deaths can be attributed to secondhand smoke.
(c) If there are any lung cancer deaths from secondhand smoke, they are likely to be concentrated among those subjected to the highest exposure levels (e.g., spouses).
(d) The absolute risk, even to those with the greatest exposure levels, is uncertain.
The CRS found that, what was considered an “obvious” conclusion by the EPA was, in fact, flawed. The EPA reasoned that if the smoke inhaled by a smoker was close enough in composition to that which is exhaled, then if one was carcinogenic the other must also be carcinogenic. This assumption is chemically incorrect and was rejected.
The CRS examination of the various studies concluded that someone exposed to significant secondhand smoke—a spouse for example—might increase their risk of dying from lung cancer to 2/10 of one percent, while those who are exposed on the job would have less risk: 7/100 of one percent.
The most devastating opinion about the EPA’s decision to classify secondhand smoke as a class A carcinogen, came from Federal Judge William Osteen who interviewed scientists for four years and in 1998 opined,
The Agency disregarded information and made findings based on selective information… [The EPA] deviated from its risk assessment guidelines; failed to disclose important (opposing) findings and reasons; and left significant questions without answers… Gathering all relevant information, researching and disseminating findings, were subordinate to EPA’s [goal of] demonstrating [that] ETS was a Group A carcinogen… In this case, the EPA publicly committed to a conclusion before research had begun; adjusted established procedure and scientific norms to validate the Agency’s public conclusion, and aggressively utilized the Act’s authority to disseminate findings to establish a de facto regulatory scheme…and to influence public opinion… While doing so, [the EPA] produced limited evidence, then claimed the weight of the Agency’s researched evidence demonstrated ETS causes cancer. (Osteen, 1998)
Because the EPA report was “advisory” and not “regulatory,” Judge Osteen’s indictment was reversed. However, it is important to note that the decision was reversed on a technical distinction, not the merits of the EPA’s report.
In another large-scale study, and in contradistinction to the EPA
conclusions, the World Health Organization International Agency on
Cancer published a report concluding that there was no statistically
significant risk of lung cancer in non-smokers who lived or worked
with smokers (Boffetta, et al, 1998). This study was the product of
ten years of data gathered from seven European countries.
Health Risks of Secondhand Smoke
In a study spanning 16 U.S. cities, the U.S. Department of Energy researchers placed monitors on nonsmoking bartenders and waiters who worked in smoke-filled bars and restaurants to measure the amount of environmental tobacco. The conclusion was that the monitors detected minuscule amounts of tobacco products. (Jenkins, et al, 1999) The harm that might come from such minuscule amounts of exposure was calculated as “none” to “improbable harm”. The anti-tobacco forces have condemned this study because it was partly funded by the R.J. Reynolds Company. Later, a group of individuals visited the establishments and concluded that since they saw few individuals smoking, the study was flawed. In spite of this study being done by Oak Ridge National Laboratories, it was painted with a broad brush because of the funding from the tobacco industry.
Environmental tobacco smoke (ETS) is considered by many authorities to be an important component of indoor air pollution in part because it is often viewed as being equivalent to mainstream cigarette smoke (MS). It has been clearly demonstrated that ETS is not the same as MS. Side stream cigarette smoke (SS) is a major contributor to ETS. Side-stream smoke is generated under different conditions than MS, and as a result, has a different relative chemical composition. Exhaled MS, the second primary contributor to ETS, is a different material from that which leaves the cigarette butt and enters the lungs. Exhaled MS has been substantially depleted in vapor-phase constituents, and the particulate matter is likely to have increased its water content in the high-humidity environment of the respiratory tract. As the cigarette smoke, both SS and exhaled MS, enters the atmosphere, it is diluted by many orders of magnitude and subsequently undergoes both physical transformation and alterations in its chemical composition. Upon standing, or during air exchange from other sources, ETS continues to change… (Guerin, et al, 2000)
The science and chemistry of this field of research are complex, and if the conclusions reached do not meet with current public policy, the research scientist is often stereotyped as being “pro-tobacco”. Because these studies are expensive, and because tobacco companies often supply the grant funds to purchase the supplies, anti-tobacco advocates will often say this is equivalent to bribing the researchers. They sometimes fail to mention, however, the anti-tobacco-funded researchers who personally receive thousands of dollars to vet anti-tobacco research and lend their name to the anti-tobacco movement. One of those individuals, Stanton Glantz, a Ph.D. whose field of expertise is aerospace engineering, attempted to convince the EPA to accept that there were over 50,000 cardiac deaths a year attributed to secondhand smoke. The Congressional Research office examined the statistics related to secondhand smoke and cardiac events and determined that those numbers were implausible (Gravelle and Redhead, 1994)
And yet, the anti-smoking advocates continue to march their cause…
The Occupational Safety and Health Administration (OSHA) withdrew a 12-year-old petition that smoking be banned from all indoor workplaces. The withdrawal was based on a lack of evidence. The decision was taken to court in an attempt to force OSHA to reverse its decision. OSHA stated that it would regulate based on permissible levels of the various ingredients in environmental tobacco smoke, and the lawsuit was withdrawn on the grounds that OSHA would do nothing. (Henshaw, 2001)
It’s no wonder OSHA decided to withdraw its complaint, since even its own people couldn’t agree on a position. In 1997, Acting Assistant Secretary of OSHA, Greg Watchman aired his own view:
Field studies of environmental tobacco smoke indicate that under normal conditions, the components in tobacco smoke are diluted below existing Permissible Exposure Levels (PELS) as referenced in the Air Contaminant Standard (29 CFR 1910.1000). It would be very rare to find a workplace with so much smoking that any individual PEL would be exceeded. (Letter from Greg Watchman, 1997)
As with arsenic content in drinking water, for example, setting scientific numbers to permissible levels would compel the scientific community to make real statements as to levels that are acceptable. Given that science had already answered the question with a number of chemicals in tobacco, such a regulation would be a blow to all anti-smoking advocates and their contention that there is no “safe” level of secondhand smoke.
With no scientific evidence to back his statement, Mayor Bloomberg of New York City proclaimed that bartenders inhale the equivalent of half a pack of cigarettes a day. In fact, a study from the U.K. showed that the average London bartender inhaled the equivalent of six cigarettes annually (about one quarter of a pack). (Matthews and MacDonald, 1998)
Perhaps one of the better studies was published in the British Medical Journal by epidemiologist James Enstrom and Geoffrey Kabat (2003). Their study of 35,000 Californians showed that lifelong exposure to a husband or wife’s smoke produced no increased risk of coronary heart disease or lung cancer among the non-smoking spouses. As with most who oppose the anti-tobacco lobby, Enstrom was forced to defend his study on the basis that it had received funding from a tobacco company. The study was condemned as biased, even though it was published in a peer-reviewed journal, the statistics were not flawed, and the conclusions were sound.
When the cigar lounge at Seattle's El Gaucho restaurant was closed because smoking in public places in the state of Washington became illegal, one of the reasons cited was to “protect the workers”. The premise of this law has no evidence. Suffice it to say, there is far more evidence to ban the sale of alcohol in bars and restaurants than cigar smoking. Every day in every major city there are deaths from people who have consumed alcohol and driven. Alcohol is directly responsible for about 100,000 deaths a year and an estimated 2.3 million years. Alcohol prohibition didn’t work. So why attempt to prohibit tobacco?
The press frequently overlooks inconsistent data when reporting about environmental tobacco smoke. The most recent example was when a group of radiologists noted that one-third of patients who had never smoked, but were exposed to “high levels” of secondhand smoke, showed MRI changes in their lungs similar to the changes seen in smokers. What failed to make the mainstream news was that two-thirds of the patients who were listed as non-smokers, but exposed to “high levels” of second hand smoke, paradoxically, had lower diffusion through the lungs than the “low exposure” group. That is, they showed the opposite of changes seen with heavy smokers. Again, what made the news in most circles was that this was more proof about the negative effects of environmental tobacco smoke. What did not make the news was that the paradoxical report might prove the opposite of their conclusion. (Science Daily, 2007)
The Surgeon General was incorrect. secondhand smoke may be an irritant and an annoyance, but it’s not a cause of death. There are no body bags filled with those who have developed tumors or heart disease as a result of second-hand smoke. The body bags are filled, however, with scientists and physicians who dare go against the anti-smoking lobby and state the obvious—the science isn’t there. As much as they want to ban all smoking in all places, the health risk is grossly overstated. Whenever someone dies of lung cancer, such as Diane Reeves, the late wife of Christopher Reeves, the anti-smoking lobby uses the news as a media circus. They want to relate the unfortunate death to something… even if such a relationship has no basis in solid scientific research.
In 1633, the Catholic church condemned Galileo for asserting that the Earth revolves around the sun. Galileo was forced to recant his scientific findings to avoid being burned at the stake. This was a clear conflict between faith and science.
[Editor’s note: Most of the studies referenced in this article examined the effects of ETS where cigarette smoke was the major contributor. Since cigarette and cigar tobacco, though similar, have some substantive differences, the specific effects of cigar ETS on health await future elucidation. Nevertheless, we believe that the current article identifies the kind of fuzzy logic that is often used by anti-tobacco researchers and demonstrates clearly that current legislation regarding ETS is based on faulty research, faulty logic, or both. Further, the current article has several points that are applicable to cigar smoke, including the fact that inhaled smoke is chemically different than exhaled smoke and that ETS is highly diluted and therefore cannot be compared equally with mainstream smoke.]
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Enstrom, J. E. and Kabat, G. C. (2003, May 17) “Environmental tobacco smoke and tobacco related mortality in a prospective study of Californians, 1960-98.” British Medical Journal, 326(7398): 1057. Available: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=155687
Gravelle, J. G., and Redhead, C. S. (1994, March 23). Congressional Research Office Memorandum “Discussion of Source of Claims of 50,000 Deaths from Passive Smoking.” “in response to request for information on the possible source of an estimated premature 50,000 deaths from passive smoking effects.” Available: http://www.nycclash.com/Cabinet/CRSDiscusses_50000_Deaths.html
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Matthews, R., and MacDonald, V. (1998). "Passive Smokers Inhale
Six Cigarettes a Year." UK News Electronic Telegraph, Issue 1178.
Osteen, W. L., United States District Judge (1998). "Flue-Cured Tobacco Cooperative Stabilization Corporation, et al v. United States Environmental Protection Agency, et al." United States District Court for the Middle District of North Carolina, Winston-Salem Division, 6:93CV00370, 89-90. Available: http://www.forces.org/evidence/epafraud/files/osteen.htm
Redhead, C. S. and Rowberg, R. E. (1995, November 14) CRS Report for Congress. “Environmental Tobacco Smoke and Lung Cancer Risk.” Retrieved November 2007 from the WWW. Available: http://www.forces.org/evidence/files/crs11-95.htm
Science Daily. (November 27, 2007). “Second hand smoke damages lung, MRIs show.” Available: http://www.sciencedaily.com/releases/2007/11/071126104424.htm
U.S. Environmental Protection Agency. (1993) “Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders. ” National Institutes of Health. Monograph 4, NIH Publication No. 93-3605, August 1993.
About the Author
Terry Simpson is a physician - surgeon, writer, and avid cigar smoker.blog comments powered by Disqus