ETS Exposure


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(This section presents two excerpts from Dissecting Antismokers’ Brains.  The first excerpt is from the main body of the book while the second is the “conclusion” section from one of the Appendices.   Combined they should give you a good feel for both the type of information found throughout the work and for the contrasting styles of detail in the main body and in the Appendices.  I would like to apologize if the formatting is a bit primitive here: I am not highly skilled at web formatting.)

Secondary Smoke

The great enemy of the truth is very often not the lie - deliberate, contrived, and dishonest - but the myth - persistent, persuasive, and unrealistic.

-- John F. Kennedy


Secondary smoke is usually termed “second-hand smoke” by those seeking its elimination: the image of smoke already used and then being foisted off on others is distasteful and compelling.  The fact that we are all breathing a good quantity of second hand air in public places is never thought of.  A more neutral designation sometimes used is Environmental Tobacco Smoke (ETS).  A third term, “secondary smoke,” is less pejorative than the former term and more concise and widely understood than the latter and as such is used here.

The next few pages will digress from the concentration on the psychological aspects of the Crusade to take a brief but hard look at what secondary smoke actually is and what exposure to it means.  The reason for this digression will be made clear afterwards when we examine how Antismokers have used the concept of secondary smoke to create unreasonable fears.


The Chemistry of Secondary Smoke

As noted earlier in the chapter on Language, about 90% of secondary smoke is composed of water and ordinary air with a slight excess of carbon dioxide.  Another 4% is carbon monoxide, a gas that can act as a poison when in sufficient quantity by reducing the amount of oxygen your red blood cells can carry.  The last 6% contains the rest of the 4,000 or so chemicals supposedly to be found in smoke… but found, obviously, in very small quantities (1989 Report of the Surgeon General  p. 80).

Most of these chemicals can only be found in quantities measured in nanograms, picograms and femtograms.  Many cannot even be detected in these amounts: their presence is simply theorized rather than measured.  To bring those quantities into a real world perspective, take a saltshaker and shake out a few grains of salt.  A single grain of that salt will weigh in the ballpark of 100 million picograms! (Allen Blackman. Chemistry Magazine 10/08/01).

To refer back to our earlier example of arsenic, a nonsmoker would have to work with a smoker 8 hours a day, 5 days a week, 50 weeks a year, for well over a hundred years to be exposed to a quantity of arsenic equal to one grain of salt.    While a lot of waitresses and bartenders may feel as if they’ve worked a hundred years at their jobs, there really aren’t too many who actually have.

And, again as noted earlier, far from all 4,000 of those chemicals are normally labeled as toxic in the first place, with the 1989 Surgeon Generals’ Report only noting that “some” are… without reference to how many or to what amounts would be considered toxic.  One of the most basic principles of scientific toxicology is that “The Dose Makes The Poison.”… a fact always ignored by Crusaders.

When speaking of secondary smoke many Antismokers will also refer to the “40 carcinogenic compounds” it supposedly contains.  In reality only six of those have in fact been classified as “known human carcinogens” (1989 Report of the Surgeon General. pgs. 86-87).  Most of the rest of the 40 compounds have shown insufficient evidence of being human carcinogens and many are commonly found in foods, coffee, and the general environment (Science, 258: 261-265 (1992). The exposure of nonsmokers to the six actual human carcinogens is usually so minuscule as to be almost imaginary in nature and is sometimes far less than other everyday environmental exposures.

Secondary smoke is the mix of all of the smoke that enters the air in a room where someone is smoking, both the smoke exhaled by the smoker and the smoke coming off the tip of the cigarette.  You’ve heard the claim that secondary smoke is twice as bad as what the smoker gets?  In a way this is true: if you held your nose a quarter inch above the burning end of a cigarette and inhaled a slow deep breath through your nostrils you’d be getting a concentration of smoke and its chemicals twice as great as what the smoker is pulling into his or her mouth.

In the real world no one does that.  Even the most hardened of smokers would generally be reduced to paroxysms of coughing from such concentrated inhalation.  The secondary smoke that a nonsmoker comes in contact with is usually an extremely diluted mixture of exhaled smoke and the smoke produced directly from the cigarette’s tip.

Something that’s usually forgotten in the rush of concern about the nonsmoker is that the smoker is also breathing all the secondary smoke produced, and, given the closer proximity to the source, the smoker is inhaling it in far greater quantities and concentrations than most nonsmokers ever would! If the concerns about the dangers of secondary smoke were really true it would make perfect sense for a smoker with a smoking guest to insist that the guest go outside to smoke even if they were both smoking at the same time.  Indeed, smokers would want to rush outside themselves out of fear of their own secondary smoke!

The exact chemical composition of secondary smoke depends largely upon how many seconds it’s been in the air. Just as happens in the case of most combustion products, the chemicals change and break down very quickly, and some elements will tend to settle toward the floor or deposit themselves on walls or curtains.   In pursuit of some arguments Antismokers want to assume from the start that secondary smoke is carcinogenic: this is when they will claim that it’s chemically very similar to mainstream smoke.  However, when they want to argue that comparing secondary smoke exposure to “cigarette equivalents” is unfair  (This method generally produces very low measures of exposure… sometimes as low as six cigarettes per year even for bartenders), they will claim that it’s chemically very different than mainstream smoke and can’t be compared in that way!

No, I am not kidding… this is an example of the type of doublethink that I call the “Catch 22” argument later on.  It’s very useful as an argumentation technique unless the opponent both notices it and has the time available to fully show how both sides of the street are being straddled by the shape-shifting opponent.   The later chapter on Fallacious Argumentation looks at this verbal scamming tool in more detail.

In examining what risk there could be to a nonsmoker we need to develop and accept an estimate as to how much smoke a nonsmoker is likely to inhale when around one or more smokers.  Rather than go into mathematical detail here, the supporting figures are presented in Appendix B.  Those figures will show that, in most reasonably ventilated situations, whether a private home with one or two smokers, or a bar with dozens or hundreds of them, a nonsmoker will usually be exposed to the equivalent of about a thousandth of a cigarette or less per hour.

It could well be argued that anyone concerned at all about secondary smoke shouldn’t be in such a Free-Choice bar or restaurant to begin with, since there are many venues that have already banned smoking on their own; but Crusading activists generally insist that even if 95 out of 100 businesses are “smoke-free” that smokers should not have the right to keep those last five places to themselves and their friends. This is not in any sense an exaggeration or misrepresentation: Antismokers call it “leveling the playing field” and it has served as the basis for many legislated universal bans. 

The need for such leveling arises because, despite Crusaders’ claims to the contrary, restaurants and bars that accommodate both smokers and nonsmokers almost invariably do better business than ones with total bans.  Nonsmokers want an atmosphere that is comfortable, clean, and well ventilated: they are usually quite happy to accompany their smoking friends to establishments that meet those criteria while allowing those friends to smoke without being forced outside.  The only exceptions to this rule occur when an establishment is truly one of the few in its geographic/economic niche that has such a ban: in that case there can often be enough of a specialty demand to make up for other losses.

To return to the chemistry of smoke, let us look at the 6 elements in tobacco smoke that IARC (The International Agency for Research on Cancer) classifies as Class A (Human) carcinogens.  One of those is arsenic, which we looked at earlier.  You’ll remember that you’d have to sit in a room with a smoker smoking 165,000 cigarettes to be exposed to as much arsenic as you would get from a large glass of water.

What about the other five carcinogens though?  Are nonsmokers likely to be exposed to enough of those to have them correctly perceived as threats?  While most of them occur in even smaller quantities than arsenic (naphthylamine, aminobi-phenyl, vinyl chloride and chromium average only about fifteen nanograms apiece), let’s look at the one with the largest quantity present so as to clearly make the case that is least favorable to our own argument.  This is benzene: a human carcinogen that cigarettes produce in quantities not measured in picograms nor even in nanograms, but in micrograms, a unit that is one million times larger than a picogram, but still only one one-millionth of a single gram (1989 Report of the Surgeon General.  p.87)

The average cigarette produces roughly 300 micrograms of benzene (1986 Report of the Surgeon General.  p.130).  If the estimates of smoke exposure for the average nonsmoker in Appendix B hold true, then such exposure would equal roughly three tenths of a microgram per hour of sharing a space with a reasonable number of smokers in a decently ventilated public indoor setting.

Benzene is normally found in fruits, fish, vegetables, nuts, dairy products, beverages, and eggs. The National Cancer Institute estimates that an individual may safely ingest up to 250 micrograms in their food per day, every single day of the year.  Thus, the “safe” exposure to benzene from one day of a normal diet is roughly equal to the exposure experienced by a nonsmoker sharing an airspace with smokers for over 750 hours.  Another way of looking at it would be to compare it to the normal work exposure of a waiter in a decently ventilated Free-Choice restaurant: the waiter would have to work there for four months to receive the equivalent benzene dosage ingested in one day of a “safe” diet.

In 1994, the Air Resources Board of California estimated that California vehicles emitted close to 50 million pounds (i.e. about 23 billion grams) of benzene per year into the atmosphere of California.   At 300 micrograms per cigarette, it would take 70 trillion cigarettes to produce what California\'s vehicles produce in a single year.  Try to imagine all the smokers of the entire world, with each and every one of them smoking well over two hundred cigarettes a day, and all crowded into California, and you’ll have a rough comparison to California’s normal vehicle emissions.

During the course of New York and Philadelphia City Council hearings on vastly enlarging existing smoking bans, Crusaders trotted out the claim that the recently enacted smoking bans in California had reduced the lung cancer rate there by 14%.  The claim seemed impressive unless one realized several things.  First of all, smoking related lung cancer generally has a time lag of between 20 and 40 years, while the total indoor bans in California were only in place about three years when the claims were being made.  Secondly, California has led the country in the past thirty years in reducing vehicle emissions and correcting its air pollution problems.  And thirdly, the age composition and immigration patterns for the state have changed enormously over the past few decades.

By picking one particular statistic however, and ignoring all the background variables, confounders, and other scientific factors, testifying Crusaders were able to mount a convincing and seemingly powerful argument to City Councilors in both cities.  Of course they also helped their case by not mentioning that they got the figure from a study that ended two years before California’s universal smoking ban was enacted! (Master Plan For a Smoke-Free California: /documents/ TobaccoMasterPlan2003.pdf)

The other four human carcinogens in the smoke from a cigarette, all added together, equal less than a single microgram, thus contributing to an exposure for the average nonsmoker in a smoking environment of roughly one nanogram or one one-billionth of a gram per hour (1986 Report of the Surgeon General p. 130, 1989 Report of the Surgeon General p. 87, and Appendix B). Such a level of contact would never be considered as a “risk” for any substance not associated with tobacco smoke.

It’s not just carcinogens that Antismokers worry about though.  There’s now a push to put a label on packs that will warn folks that “cigarettes contain formaldehyde, used in preserving corpses.”   Now isn’t that a pleasant thought?   Of course the Crusaders never want to mention the amount of formaldehyde produced (less than one third of a single thousandth of a gram) or the fact that cooking a healthy vegetarian dinner at a gas stove puts roughly 100 times this amount into the air for your family to breathe (Huber et al. \"Smoke and Mirrors.\" Regulation 16:3:44. 1993).

The situation is the same for almost all the compounds in smoke that the Antismokers point their fingers at.  Upon examining the amounts of the substances involved and checking the values of OSHA and EPA safe concentrations for them, you would find that you’d have to be locked up in a small unventilated bar with hundreds, thousands, or even millions of smokers before even approaching levels thought to be unsafe by actual government standards.  Appendix B presents a number of examples in a well-formatted table.  You’ll note that in the real world significant concentrations of any of the supposedly dangerous elements in secondary smoke would never actually occur.


Appendix B: Secondary Smoke Exposure Conclusion

The different models examined above yield different results, but it seems fair to say that the average exposure in today’s environments mixing smokers and nonsmokers is likely to be a good deal closer to 1/1000th of a cigarette equivalent per hour than to 1/100th.  Thus that is the figure that was used in the main body of Dissecting Antismokers’ Brains in any discussion of exposure to secondary smoke.  In the past air change rates of 10 or 15 times an hour would have been relatively rare.  Today they are seen as necessary in maintaining an atmosphere in which nonsmokers will be content in sharing space with smokers.

Even without such high levels of ventilation, concerns about contact with the “poisons” in tobacco smoke are obviously greatly exaggerated.  It would be extremely difficult for any of the elements in secondary smoke to reach levels that the EPA or OSHA normally consider to be of concern.  Such levels, called Threshold Limit Values (TLVs) or Permissible Exposure Limits (PELs) would never even be approached in real world situations.  The table below illustrates this by looking at a number of these chemicals of concern in an old-fashioned and poorly ventilated small neighborhood bar.

Our model here will be only half the size of our previously used bar model: just 15 feet wide, 60 feet long, with a 12 foot ceiling -- a small bar with a total volume of just 400 cubic meters.  We’ll set the ventilation very low, far lower than would normally be found in any modern establishment concerned with ventilation, smoke, and customer comfort: just three air changes per hour.  Thus our 400 cubic meter bar will average a total air volume of 1200 cubic meters of air each hour.

There are many elements in tobacco smoke that could be measured and are possibly of concern for people’s health.  To show that I have not simply selected ones that support my case I have deliberately chosen seven of the more commonly cited chemicals that begin with the letter A and added three others often given a high profile by Antismoking groups in their literature and TV ads. 

The ones I have chosen have all been assigned Threshold Limit Values (TLVs) or Permissible Exposure Limits (PELs).  TLVs and PELs are the cut-off points at which government agencies such as OSHA believe there first begins to be a health concern for workers exposed to such levels eight hours a day, five days a week, for their entire working lives.  Measurements of chemicals below these values are considered to be below levels where threats to health or safety exist.

Chemical Permissible Exposure Limit (PEL) or Threshold Limit Value (TLV) Total Emitted

Per Cigarette, Side-stream and mainstream

Number of Cigarettes needed per hour to reach TLV or PEL In the air of a small  tavern
Acetaldehyde 45 mg/m3 4 mg 13,500
Acetone 1780 mg/m3 1.7 mg 1,256,470
Acetonitrile 70 mg/m3 .6 mg 140,000
Acrolein 250 mcg/m3 634 mcg 473
Ammonia 18 mg/m3 5.7 mg 3751
Aniline 7,600 mcg/m3 11.2 mcg 814,286
Arsenic 10,000 ng/m3 32 ng 375,000
Cyanide 5,000 mcg/m3 716 mcg 8,380
Formaldehyde 940 mcg/m3 856 mcg 1317
Toluene 188 mg/m3 .7 mg 322,286

Table 1 has four columns.

The first column is the chemical name.

The second column shows the TLV or PEL for each chemical.  Most TLV/PEL figures come from the State of California website at:, and express the concentration of chemical safely allowed per cubic meter of air, or m^3.

The third column shows the total amounts of the chemicals emitted, both sidestream and mainstream, by standard cigarettes as noted in the 1999 Massachusetts Benchmark Study and the 1979 and 1986 Surgeon Generals Reports.  Those figures are measured in thousandths of a gram (mg), millionths of a gram (mcg), and billionths of a gram (ng). The abbreviations stand for milligrams, micrograms, nanograms.

Finally, the fourth column shows the number of cigarettes that would need to be smoked in our small bar each and every hour before the levels of that chemical reached the TLV or level of concern for that chemical.  You’ll see that the numbers here are so large as to be outright ridiculous in any real-world scenario.   

It should be noted that if our model neighbourhood bar were a modern yuppie establishment the ventilation figure would be more like twelve air changes per hour than three.  In such a bar we’d have to jam about 5 million smokers through the doors to reach the safety limit for some of the elements cited above!  Remember the dimensions of the bar: 60 feet long by just 15 feet wide.  In such a bar 40 people would be considered more than a good crowd.  Even if five times that number were somehow crammed in and they were ALL heavy smokers, we still wouldn’t reach the permissible exposure limit of even one of the above compounds --- not even at the poorer ventilation level.

 In addition, it’s worth remembering that the values in Table 1 are based upon continuous eight hour a day, five day per week worker exposure.  OSHA standards regularly allow for these limits to be safely exceeded for certain periods during a workday (such as might occur during a heavy crowding at a bar.)

The concept for the table above came from a similar modeling of a closed 100 cubic meter chamber outlined in a paper by Gori and Mantel available at However the particular elements chosen, the incorporation of air exchanges and real world modeling, and all mathematical computations are mine.


A final humorous note on secondary smoke exposure: a cigarette puts off a bit less than 40 micrograms of cholesterol in both sidestream and mainstream smoke.  At 1,000th of a cigarette per hour a nonsmoker would have to work with smokers for over 600 years for in order to get one day’s recommended dietary value of 600 milligrams.       

I’d recommend a good prime rib instead… provided no one’s made it illegal.