Tobacco Documents Online

The assumption (statement) made in the last paragraph on p. 80 (and later in the chapter) that "the averaRe...=!*cyer...emit about 22 mg of RSP per cigarette" is totally unjust:Lfied. This reviewer must assume that the IARC reference gives an average sidestream 'tar' of 22 mg/cigt (which is not unreasonable). How is it possible to justify the equation that 22 mg SS 'tar' = 22 mg ETS RSP? Even the author recognizes the fact that "almost all nicotine shifts from the particulate phase in MS and fresh SS smoke to the vapor phase in ETS". It must be assumed thai: this same phenomenon occurs for other tobacco-smoke constituents. The weight of ETS RSP must be substantially less than the 22 mg predicted from SS 'tar'. However, it is not known what the r.^latiunship is. p. 81 - It is only correct to state that "Nonsmokers are exposed to ETS in indoor spaces" where smoking occurs. statement accordingly. Please modify p. 84 - The author states that "The utility cf Eq. 4 depends on the assumption of an air exchange rate" when in reality Eq. 4 depends on many more assumptions (no. of smokers, R:;P/cigt., sinks, etc.) The appropriateness and limitations of these assumptions are never clearly defined and they impact heavily on the usefulness of the proposed models. Gb (Z This reviewer fails to see how the example presented "illustrates -1 ~ the utility of models". Having data from one experiment which are N ~ 17, then fit to a model which has been adjusted Eor variables measured -1 11

in the experiment can in no way be used as validation of the general applicability of the model. Even i:n this case, when the actual air exchange is used, the model predicts 130% of the RSP actually determined. Combined with the observation that, on * average, RSP overestimates ETS by an additional 50% [T0;110],these facts severely hinder the general applicability of this model. The second example is equally flawed. The entire difference between daytime and evening RSP concentrations is erroneously attributed to ETS. The impact of persona]. activity other than smoking on the daytime RSP concentration i,s completely ignored. This so-called "pig-pen" effect (espoused pr:imarily by the authors of C hapter 6) should be explained as a further conforndcr of these data. The author "implies that ETS may diffuse throughout a large office building, exposing nonsmokers even in private offices" and offers * the data of Williams, 1985 [123]; as "support". The data of Williams et al., in fact, do not support t:ais implication. The results (Williams et al.) were miscalcu:lated and originally published incorrectly; corrections to the calculations were made * and subsequently published [34]. These corrected data were overlooked or ignored by the author and actually refute the observation. Assuming the analytical method of Williams et al. is sound, tneir data suppor` ey.:eedingly clean air in the office complex surveyed. p. 85 - The author states that from "li:mited field tests of * "[]" refers to Chaps. 5-8 Index. 12

the...model...it is clear that both models and observations based ,r1 on...monitoring...yield consistent results". This could not be further from the }~ ~t::- Simpl l stated, this; model has certainly not been validated and has yet to be used in even one incidence to provide reliable data in advance of actual air monitoring. p. 86 - What is the relevance of the narrative concerning the Mormons and the Seventh Day Adventists? p. 88 - The author correctly states that "In the •absence of...data...exposures can be estimated by models or by extrapolation from biological markers". The key word here is ~a "estimate" and it needs to be realized that the existing models have' yet to provide any indication of -re:producible, reliable estimates. In other words, the quality of these estimates is still ~ very much in question among scientists. This reviewer reiterates the comment provided to p. 79. ETS exposures can be assessed by air monitoring but only estimated by modeling, questionnaires, and the like. The statement "there are models in use...which can predict the concentrations of RSP from ETS to a reasonable degree of accuracy" is the opinion of the author and is not a generally held opinion. p. 89 - The author (inadvertently?) providea further evidence of the inappropriateness of calculated exposurEas- by stating "it has been calculated that a nonsmoker would inhale volatile nitrosamines 13

equivalent to...35 filter cigarettes." What evidence exists that this magnitude of exposure has, in fact, occu:cred? What the author alsc fails to include is the f?^_t that "no ep;c?emiological data exist linking human respiratory cancers to volatile nitrosamines." * ([g]; see also comment to Chapter 6, p. 71) The author makes further statements based on "the assumption that formation of cotinine...and clearance from the body does not differ substantially from smokers to nonsmokers". It is known, however, that formation of cotinine and clearance from the body do differ * substantially [2,45]. What is the relevance of the :.ote ddded regarding the RSP/nicotine ratio and the resulting calculated RSP? RSP/nicotine ratios are known to vary from 2:1 up to 100:1 across normal environments. This calculation serves no useful purpose. If you want to know RSP with any degree of confidence, you must measure it. This note should be deleted. p. 90 - The author presents a one-sided viewpoint ("may substantially underestimate") on the ability :)f nicotine absorption to predict exposure to other ETS constituents. It is at least equally likely (and never mentioned by this author) that nicotine absorption would overestimate exposure to other ETS constituents k,aGFc'. on possibilities of nicotine in the di.et: (see comment to p. 80) and of a detectable nicotine background in the absence of other ETS constituents (see comment to p. 58 [Ch. 5]). * "[]" refers to Chaps. 5-8 Index. 14

The author attempts to support his view of the appropriateness of RSP measurements for ETS exposure with a reference to the Surgeon General's report: "...*_:±e relationships of RUSP mea=»rPneTt.z to ETS are quite accurate". This comment is taken out of context and appears to be slanted solely for the author's purpose. The actual quotation from the Surgeon General's report is "At a practical level, the technology for measuring nicotine levels and RSP levels is available and accurate." The author should strive to remain objective in presentation of the relevant issues. p. 91 - It is not a consensus among researchers in the field that RSP is the best atmospheric marker of ETS exposure. This is the author's opinion. It is incorrectly stated that the cotinine measures reflect the actual dose of an ETS constituent. The confounding factors (diet, background nicotine) were never presented. The statement that cotinine measures "may substantially underestimate exposures to other constituents of ETS" is totally unfounded. As stated previously, it is equally likely (if not more so) that these measures will overestimate actual ETS exposures. It is presented as an advantage that RSP-based estimates are model- based_ In reality, this is its second most serious drawback (the first being that,RSP 41 ._ not specific to ETS). In discussing the GE) Qn drawbacks, the author fails to point out these limitations or the .~ .~ fact that RSP in nonsmokers is not absorbed in the same manner as N ~ 4D it is in smokers [2]. ~-A 15