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CRITIQUE OF THE REPORT ENTITLED Environmental Tobacco Smoke:. A Compendium of Technical Information U.S. Environmental Protection Agency Chapters 5-8 Prepared by: Mark J. Reasor, Ph.D. , L 7 Ii I received the B.S. (1967) and M.A. (1969) degrees in Biochemistry from Purdue and Duke Universities, respectively. I received the Ph.D. degree in Biochemical _Toxi-cology from <the.-Johns =Hopkins--Univers~.ty in 1975. In 1975-76, I performed postdoctoral work in pharmacology- at the National Institute of Environmental Health Sciences, North Carolina. I then became an Assistant Proi:essor of Pharmacology and Toxicology at West Virginia University in 1976, and achieved tenure at that institui:ion in 1984. I am certified in general toxicology by the American Board of Toxicology. Since 1969, I have published 66 research articles in the fields of pharmacology and toxicology. I am an Editorial Board member of Toxicology and Applied Pharmacology, an .official journal of the Society of Toxicology, and am an Associate Editor of Journal of Toxicology and Environmental Health. I have published one book chapter and one review article on environmental tobacco smoke: (1) Biological markers in assessing exposure to environmental tobacco smoke. In: Environmental Tobacco-Smoke: Proceedings_.of the

- 2 - International Symposium at..McGi11 UniversiLy (D. Ecobichon-.and J.M. Wu, eds.), Lexington Books, Lexington, MA, pp. 69-77, 1990; (2) The composition and dynamics-of environmental tobacco smoke. J. Environ. Health 50: 20-24, 1987. A copy of my curriculum vitae is attached. I have been asked to review Chapters Five through Eight of an EPA draft compendium of technical literature on environmental tobacco smoke. OVERVIEW •As•presented, the four chapters addressing aspects of exposure to ETS do not effectively present the issues associated with this topic. This is due, in part, to the omission of cer,tain information and redundancy among the chapters. One way to remedy this situation would be to reorganize this section with the addition of another chapter. A suggested framework for this reorganization is presented in this introductory overview. The remaining sections of this critique will provide specific comments on individual chapters. The first chapter in the series on exposure should be concerned with the chemical compositiorr of ETS. This chapter would provide a basis for discussing the issues related to exposure. Without an appreciation of the problems inherent in analyzing the composition and properties of ETS, a discussion of the assessment of exposure cannot be fully evaluated. Aspects of composition are sczttered throughout - ob. T ~ N ~ rA ~A

- 3 - r i J LI the four chapters-; thus. the -reader never- iecei-ves :a comprehensive analysis of the subject. Azeas that should be- discussed include the-results and limitations-of controlled laboratory studies examining sidestream smoke as a surrogate for ETS, a critique of the use of mainstream to sidestream smoke ratios in the comparison of exposure to ETS with active smoking, and field studies on the composition of ETS. The role of aging in determining the chemical composition and particle sizes of ETS should also be carefully considered. A chapter examining the significance of ETS in indoor air pollution-should be the second chapter in the series. This chapter should include a more general discussion of indoor air pollution, in which the overall contribution of ETS is put in a proper perspective.. Chapter 6, "Exposure to Air Pollutants," does not succeed in this respect; the chapter's singular focus on ETS gives the reader the impression that it is the only significant: source of indoor air pollution. The chapter on "Measuring Exposure to Environmental Tobacco Smoke" would follow, expanded to provide an in-depth discussion of the problems inherent in specifically measuring exposure to ETS. Considerations of poteni:ial airborne markers and their limitations, proper experimenta:L design, and appropriate equipment to measure the various ETS constituents should be included. At present, Chapter !i does only a fair job on part of this topic.

- 4 - f- I Next, the Compendium-,might- include--a-chapter- on - mathematical modeling, which may present a usefuI approach to exposure estimation under appropriate.cirtumstances:- However,-. the contribution of this approach to a better understanding of ETS exposure can only be assessed if the limitations of modeling are clearly discussed. At present, Chapter 7 fails to address these limitations, particularly the heavy reliance on existing data and the necessity of making certain assumptions of questionable validity. As presented, Chapter 7 should be retitled to more correctly reflect the nature of the material_presented. -For example, a title of "Assessment of Exposure to ETS: Use of Mathematical Mode!ls" is more - descriptive of the author's presentation. The final chapter of this section would discuss the use of biological markers for assessing exposure to ETS. The present Chapter 8 provides a good general overview of the subject, but the evaluation of the literature could be more comprehensive. Overall, I found the chapters superficial in places, somewhat redundant (particularly regardin(.1 the composition of ETS and the use of biological markers),*contradictory on certain topics (use of carbon monoxide as a marker for ETS: Chaps. 5 & 6; use of cigarette equivalents: Chaps. 6 & 8), and not very effective in achieving the goal stated in the title of the document. The individual chapters were of widely varying quality, and except for Chapter 5 and parts of Chapter 8, did a poo-r job- of present-ing,a balanced==ana1_ys-is.-of- the--

- 5 - issues. At the least, each :chapter- shoul9.=contain-.a. section..- dealing with future needs to give the rea9er an idea of where deficiencies exist and how-they can-be ad3ressed.-.With these general comments in.mind, the following.discussion-will focus on the problems associated with each chapter. Suggestions for improvements will be made where appropriate. The page on which an item of attention is located will be noted in brackets, e.g., [p.54]. Additional relevant references will be cited at the end of the discussion of each chapter. C<~S

- 6 - Chapter 5 Measuring Exposure to Environmental Tobacco Smoke Br.ian P. Leaderer In general, Dr. Leaderer presents a reasonably balanced analysis of this topic. In particular, he is careful to list the limitations associated with the use of certain substances as markers for ETS. The author should discuss and reference recent studies from the laboratcry of Dr. Delbert Eatough (Eatough et al., 1989, 1990; Tang et al., 1988) that - have-, examined:tobacco-specific chemicals Euch as solanesol, 3-ethenylpyridine, and particulate phase ricotine, for_use as markers. These are significant studies ir this field, and should be thoroughly reviewed in any chapter on exposure. Eatough et al. utilized 'the annular denuder system for measuring vapor phase nicotine; therefore, in light of the discussion on this technique [p.62], the <<uthor should be familiar.with this research. Ultraviolet particulate matter (UV-PM) may have value in monitoring the particulate phase of ETS (Carson and Erikson, 1988). The use of tobacco-specific nitrosamines as markers For ETS would be of particular value because of their potential health effects, However, they have not been detected in room air (Klus et al,, 1985). - Personal monitoring can provide an integrated measure of an•individual's exposure since all of the material collected by a sampler is retained for analysis. In contrast to what the author states [p.54], biomarkers- are not

- 7 - necessarily effective in providing= an--integrated-measure of - exposure. Since biomarkers decay with time from tissue and fluids, a person heavily exposed to an airborne contaminant- may show no detectable level of the biomarker if sampling occurs long after exposure is terminated. In this circumstance, an integrated measure of exposure would be impossible to obtain. In general, statements made by the author could be better referenced. For example, in Table 1, it would be valuable to provide citations of studies ahere these --techniques formeasur-ing-RSP have been used. This would enable the interested reader to evaluate the statement that all of the methods have been used with success in chamber and field studies [p. 60-61]. By referencing articles, it would be possible to obtain more detailed technical information on the technique. A general problem throughout the chapter in evaluating statements was that no references were included in the copy I received. REFERENCES Carson JR and Erikson CA: results from survey of environmental tobacco smoke in offices in Ottawa, Ontario. Environ. Tech. Lett. 9: 501-508, 1988. Eatough DJ, Benner CH, Bayona JM, Richards G, Lamb JD, Lee ML, Lewis EA, and Hansen LD: Chemical composition of. environmental tobacco smoke. I. Gas--phase acids and - bases. Environ. Sci. Technol. 23:, 679-687, 1989. Eatough D.J.,•Hansen LD, and Lewis EA: The chemical characterization of environmental tobacco smoke in Environmental Tobacco Smoke, Proceed'.ngs of the International Symposium at McGill Un:.versity of 1989, Ecobichon DJ and--Wu-JM, edi-tors-, Lex'..ngton--Books, DC-- Health and Co., Lexington, Mass., pp,. 3-50, 1990

- 8 - Klus H, Begutter H, Nowak A, Pinterits= G, -Ult-sch-, •and •Wihli~dal- H: Indoor air pollution due to tobacco smoke under real conditions. Preliminary results. Tokai J. Exp. Med. 10: 331-340, 1985. Tang H, Richards G., Gunther K, Crawford J, Lee ML, Lewis EA, and Eatough DJ: Determination of ga:>-phase nicotine and 3-ethenylpyridine and particulate phase nicotine in environmental tobacco smoke with a collection bed capillary gas chromatography system. J. High Resol. Chromat. Chromat. Commun. 11: 775-782, 1988. ~..

- 9 - I i Chapter..6 Exposure to Air Pollutants John McCarthy,_ Elizabeth Miesner,.arid -John Spengler.- This chapter does not present a balanced picture of the subject. The title of the chapter is misleading; the authors do not discuss exposure to air pollutants, rather they limit their presentation to ETS. The reader does not obtain an impression of the relationship of ETS to the overall problem of indoor air pollutants. In fact:, as Dr. Spengler has discussed in a previous publication (;tpengler and Sexton, 1983),.indoor.air pollution,can arise from a multitude of sources. The authors should be encouraged to discuss this relationship in an effort to provide a more balanced pre- sentation of the topic. The authors do not discuss the ].imitations or qualifications associated with the statements they make on a number of issues. For example, their discussion of the composition of ETS [p. 76] is much too siriplistic and misleading. The studies and values cited in Table 3 relate to freshly generated sidestream smoke and noi: to ETS. It is also important to point out that these values were generated under .standardized laboratory conditions and may have little relationship to ETS as it exists in the arabient environment. The-reasons for this include: 1) ETS is composed of both sidestream smo,ke and exhaled mainstream smoke, the latter of which has not been characterized. The re:lative contribution of each of these types.of-smoke to ETS-has not-been.measured - c.r

under laboratory or ambient_conditions; and 2) the process of= aging markedly affects the composition-of ETS, making simple sidestream smoke. values -difficult, if not impossible-,--to interpret. The aging of ETS should be discussed in detail, since an appreciation of this process is essential in -evaluating da,ta on ETS. For example, Pritchard et al., (1988) reported that a significant fraction of the particulate matter in ETS evaporates under ambient conditions. Benner et al., (1989), reported that particles in ETS -coagulate as they age. Tang et al., (1988),•=demonstrated that constituents of ETS decay at different rates in a ventilated indoor laboratory. Also, ultraviolet light caused marked changes in the phase distribution of nicotine in ETS. Vu Duc and Huynh (1987) observed that the half-lives of particles from sidestream smoke vary as a function of size. It should follow that an additional problem is the use and interpretation of ratios of sidestream smoke to mainstream smoke to compare levels of chemicals in each type of smoke. Considering the problems of using sidestream smoke as a surrogate for ETS, such values are virtually meaningless. Furthermore, the amounts of each type of smoke generated are dependent on the smoking patterns of individuals; the deeper the inhalation (leading to increased deposition) and the more frequent the puff ( leading to increased production.of mainstream smoke), the less ETS will be generated from a cigarette. I