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Comments on: ENVIRONMENTAL TOBACCO SMOKE: A GUIDE TO WORKPLACE SMOKING POLICIES [Draft] EPA 400/6A0/004 Response Addressing: Chapter 1: What Is ETS? Section: Differences Between Mainstream and Sidestream Smoke Section: Chemical Make-up Section: Other Contaminants Prepared by: David W. Eaker, Ph.D. Senior R&D Chemist R.J. Reynolds Tobacco Company October 1990

SUMMARY: The section titled "Chemistry of ETS versus MS/SS" (Chapter 1, part A.2) of the EPA draft document "ETS: A Guide to Workplace Smoking Policies" contains numerous biased statements and is poorly referenced. This makes verification of accuracy extremely difficult, and contributes to a distinct lack of objectivity and thoroughness of the document. Indirect references to selectively prepared "government" publications are cited and relied upon to the virtual exclusion of readily available primary references. This overall slant is reflected in the pervasive low level of understanding of the topic under discussion. Seriously misleading statements regarding ETS constituents and concentrations discerned from information on mainstream and sidestream smoke are prevalent. Discussions of smoke stream production are flawed, with little or no recognition of critical aspects of chemical and physical dynamics involved. Even when it is recognized that this document is to be directed to the lay public, the mantle of scientific validity should not be bestowed via the use of inadequate references and inappropriate distillations of more rigorous information. Comments specific to individual points follow. COMMEIVTARY: Page 7, line 1: The first sentence initiates the naive or purposeful confusion of sidestream smoke and ETS, neglecting the critical distinction of dilution and aging of ETS relative to either MS or SS smoke. Such distinction is crucial to the legitimate consideration of exposure, dose or biological effect [1]. Lines 4-5: In contrast to the statement in the EPA document that "Sidestream smoke (SS) is the smoke emitted ... between and during puffs", it has been reported that the generation of sidestream smoke during puffs is limited and is not typically considered

significant [2,3]. Lines 5-6: The statement 'The stronger a smoker inhales, the more sidestream smoke is emitted.", is not only totally undocumented, but also is contradictory to reported results [3, and references therein]. Line 6: "For the average smoker, ... " The relative amount of tobacco burned between puffs versus puffing as quoted at 55% is again circuitously referenced, but is not unreasonable. The term "making sidestream smoke the largest constituent of ETS" again omits consideration of evolutionary processes by implying SS is maintained unchanged as a part of ETS. Sidestream smoke should more properly be termed a precursor of, or a contributor to ETS. Lines 8-10: The numerical value for percentage of mainstream exhaled is quoted from unpublished material, and is therefore not verifiable. Again, exhaled MS is not a "constituent" of ETS. Values reported for exhaled MS range from 5 to 50%. Paragraph 5: The multi-phasic character of ETS is a physical reality, not a contrivance of scientists for the purposes of study. The statement "Particles that are smaller than one-tenth of a micrometer are called the gas phase" is patently incorrect and exposes the pervasive absence of basic scientific knowledge evidenced in this document. The subsequent estimate of number of components in ETS is in general agreement with smoke 2

chemistry literature, however the indictment of "43 ... are known carcinogens" omits any specifics as to type, evidence for biological potential, parameters of any carcinogenesis studies, relevant concentration versus that found in ETS, etc. Page 8, Line 1: This first sentence is unclear as to the meaning of the phrase "more toxic and carcinogenic chemicals". Does this phrase refer to number of constituents or to their concentration in some unspecified smoke stream? Sidestream smoke is generally considered to be qualitatively similar to mainstream (number of components), with differences in the quantitative yields (primarily increased in sidestream) [3,4]. The second clause also adds to the confusion. Does it refer to exposed or dose "concentrations" being higher in active smokers? Lines 2-7: The ratios of SS/MS yields quoted for "tar" and nicotine are perhaps valid for selected cigarettes, specifically low-"tar" or ultralow-"tar", but are higher than a balanced consideration of most market brands would yield [3,4]. Again, however, the use of such ratios is fraught with hazards [2] as they are primarily influenced by product specific mainstream deliveries. According to Baker and Proctor: The important question is not the ratio of sidestream/mainstream but rather what is the concentration of the constituent in the indoor environment and how does it compare to levels from sources other than ETS. Studies based solely on observations of fresh sidestream, or highly and unrealistically concentrated ETS, should take into account the possible differences between these smokes and ETS found in real-life situations [5]. 3

Sidestream smoke deliveries are generally proportional to the tobacco rod weight, independent of other cigarette construction variables. Consequently, "sidestream-to- mainstream" ratios should not be used to draw conclusions or imply relative exposures/doses of ETS versus mainstream smoke. The last sentence in this paragraph, and the following table selectively represent work of Adams and Hoffmann [4]. A complete representation of their results is neither provided nor cited. Paragraph 2: This paragraph is substantially correct, as per the discussion included immediately above. However, there is little substantiation for the contention "In some cases, it may have actually increased it."; and none is cited. Paragraph 3: The little substantive information in this paragraph is hearsay, relying on such phrases as "it is fairly certain that commercial tobaccos contain up to ...." Paragraph 4: Nothing worthy of comment in this political statement. Perhaps the most troubling aspect of Chapter 1, section A.2 is the use of misleading sidestream smoke concentrations and their comparison to mainstream values to give an exaggerated impression of ETS exposures. Far more relevant to the true situation are measurements of aged and diluted sidestream smoke and exhaled mainstream smoke, which provide data substantially different from those for sidestream smoke. Such measurements properly take into account the complex physics and chemistry of aerosol dynamics, as well 4

as the natural dilution effects occurring with aerosol dispersion [5J. The sidestream smoke "confusion" seems to have been fabricated and perpetuated to accentuate the desired point without addressing critical aspects of E"I'S evolution. RECOMMENDATION: It is recommended that the EPA document be rewritten to accurately define and distinguish smoke stream constituency and concentrations and to put ETS constituent concentrations into proper perspective with analogous concentrations from other sources -L.&. exposures to CO from engine exhaust, TLVs and STELs for individual components (typically well above ETS levels) and relative exposures and "risks". 5

REFERENCES 1) Lofroth, G., Burton, R.M., Forehand, L, Hammond, S.K., Seila, R.L, Zweidinger, R.B., Lewtas, J., "Characterization of Environmental Tobacco Smoke", Environ. Sci. Technol., P 5" 610-614 (1989). 2) Triebig, G., Zober, M.A., "Indoor Air Pollution by Smoke Constituents - A Survey", Prev. Med.. 13 570-581 (1984). 3) Guerin, M.R., Higgins, C.E., Jenkins, R.A., "Measuring Environmental Emissions from Tobacco Combustion: Sidestream Cigarette Smoke Literature Review", A=. Envir.. 2121. 291-297 (1987). 4) Adams, J.D., O'Mara-Adams, K.J., Hoffmann, D., "Toxic and Carcinogenic Agents in Undiluted Mainstream Smoke and Sidestream Smoke of Differeni Types of Cigarettes", Carcinogenesis. $(51, 729-731 (1987). 5) Baker, R. R., Proctor, C. J., "The Origins and Properties of Environmental Tobacco Smoke", Env. Internat., 16 231-245 (1990). 6