Implications of ASHRAE s Guidance On Ventilation for Smoking-Permitted Areas

Transcription

1 Copyright 24, Aerican Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. This posting is by perission fro ASHRAE Journal. This article ay not be copied nor distributed in either paper or digital for without ASHRAE s perission. Contact ASHRAE at Iplications of ASHRAE s Guidance On Ventilation for -Peritted Areas By Stanton A. Glantz, Ph.D., and Suzaynn Schick, Ph.D. T he issue of how to deal with secondhand soke has been a subject of debate within ASHRAE for any years. 1 This debate has centered around ANSI ASHRAE Standard 62, Ventilation for Acceptable Indoor Air Quality, whose stated purpose is to specify iniu ventilation rates and indoor air quality that will be acceptable to huan occupants and are intended to iniize the potential for adverse health effects. Acceptable indoor air quality is defined as air in which there are no known containants at harful concentrations as deterined by cognizant authorities and with which a substantial ajority (8% or ore) of the people exposed do not express dissatisfaction. In 1981, ASHRAE first recognized that tobacco soke posed probles inside buildings by revising indoor air quality Standard 62 to require ventilation rates two-to-five ties higher in soking areas than in non-soking areas of buildings. Standard said, higher ventilation rates are specified for spaces where soking is peritted because tobacco soke is one of the ost difficult containants to control at the source and that the standard is developed so that indoor air quality does not ipair health. This approach alared the tobacco industry because, as Philip Morris noted, it would effectively double the costs for heating and cooling in areas which allow soking. 1 This increased ventilation cost becae a reason for building owners to ake buildings soke-free, and these soke-free policies reduce cigarette consuption by 29% by aking it easier for people to cut down or stop soking. 2 As a result, the tobacco industry, working both directly and through the hospitality and gaing industries, 1,3 has ounted a continuous capaign to have ASHRAE Standard 62 provide for soking in buildings. On June 26, 22, the ASHRAE Board of Directors voted that that the following sentence be added to the target title, purpose and scope of its ventilation and indoor air quality standard, Standard 62, This standard does not address spaces where soking is expected to occur. 4 This decision was based on a recoendation fro the Board Policy Coittee that recognized that The title of Standard 61 is Ventilation for Acceptable Indoor Air Quality. If suppleental guidance for spaces where soking is peritted was included in the standard, such inclusion would be contrary to the title of the standard. There is evidence About the Authors Stanton A. Glantz, Ph.D., is professor of edicine at the University of California, San Francisco. Suzaynn Schick, Ph.D., is a postdoctoral fellow at the University of California, San Francisco. 54 ASHRAE Journal ashrae.org March 24

2 that acceptable air quality cannot be achieved where soking is peritted. 5 Nevertheless, the Board also voted to support the developent of an Inforative Appendix, Appendix I (part of Addendu 62o) that provides Guidelines for Ventilation in -Peritted Areas. While Appendix I was deleted fro Standard 62 at ASHRAE s Winter Meeting this January, the principle of ore ventilation reains in Standard 62 Section 6.5, while the SSPC considers its deletion in forthcoing addenda.* Despite this deletion, aterial siilar to it can be expected to appear in the new ETS design guide being developed under contract to ASHRAE that can be expected to effectively define the procedures for ventilating soking-peritted areas. The stated purpose of forer Appendix I (which was still available on ASHRAE s Web site at the tie of this writing) was to provide satisfaction with respect to odor and sensory irritation, not health. This paper exaines the iplications of Appendix I and the forthcoing ETS design guide for the odor, irritation and health aspects of indoor air quality due to the presence of tobacco soke. Pollution Levels Under Appendix I It is possible to estiate the additional respirable suspended particulate load above background fro secondhand soke levels that will occur in each of the scenarios in Appendix I using the relationship C RSP = G ( P V ) sr Q where C RSP = respirable suspended particulates fro second-hand soke, G = effective RSP eissions per cigarette (adjusted to account for the effects of deposition), (P/V) = occupancy in people/volue, s = percentage of occupants who are sokers, r = rate of soking (cigarette/sokertie), and Q = ventilation rate (air changes/tie). This equation is the sae steady state ass balance proposed and validated by Repace and Lowry 6 and Ott et al. 7,8 written in ters of the variables in Table I-3 of Appendix I. Table 1 suarizes the results of these calculations of the increases in RSP due to secondhand soke above any background levels that were present for other reasons, based on the inforation in Table I-3 of Appendix I (Occupancy, Proportion of Sokers, Rate, and Total Ventilation Rate). G = 14 g/ cigarette. 8,9 The ceiling heights are assued. The equation assues, as does Appendix I, that there is perfect ixing. These levels of RSP are well above the 4.4 µg/ 3 levels two-thirds of the healthy subjects Junker, et al. 1 found considered unacceptable air quality in a ore recent, well-designed study than the 2-year-old study 11 ASHRAE relied upon to develop Appendix I. Are these Levels Cofortable? The cofort standard in Appendix I was based on a 1983 study by Cain et al., participants of unspecified gender, 3% of who were active sokers and were allowed to take soking breaks during their evaluations, participated in the study. Air fro a chaber, where people were soking a controlled nuber of cigarettes under various ventilation conditions, was delivered to a sniff box. Before testing the soke, participants first sniffed eight concentrations of 1-butanol to establish an intensity scale. Then they selled varying concentrations of diluted cigarette soke fro the sniff box over the course of an hour, atching the apparent odor intensity to the reebered 1-butanol intensity scale. At the end of an hour of testing, the participants were asked to also describe the final condition as acceptable or unacceptable in a binary choice. *Stanton Glantz, a coauthor of this paper, subitted a change proposal to SSPC 61 to delete Appendix I, with a rationale siilar to that found in this article. The coittee agreed to delete the appendix. However, the principle of ore ventilation reains in Section 6.5, while the SSPC considers its deletion in forthcoing addenda, and work on the ETS design guide is continuing. March 24 ASHRAE Journal 55

3 In contrast to the real world situation that Standard 62 and Appendix I were designed to address, these assessents were not based on odor easured at the tie cigarettes were actually being soked. The easureents were recorded after soking had ceased and the cigarettes had been extinguished. The study did not find any ventilation rates that et the requireent of 8% acceptability when soking was actually occurring in the soking chaber, even though sokers were over-represented in the study group. Moreover, Cain, et al. noted, None of the (ventilation) conditions in the present study would satisfy even two-thirds of nonsokers. A newer, ore rigorous study published in 21 by Junker, et al., 1 reports the results of two sets of experients. One set, using nonsoking woen as subjects, establishes the odor threshold for sidestrea soke at.6 4 µg/ 3 SHS-PM25. The second set of experients assayed odor acceptability, with 24 nonsoking woen as participants. Each participant sat in a sall Plexiglas exposure chaber and assessed four different diluted sidestrea soke concentrations presented in a rando order alternating with clean air. The assessent began with a clean air zero condition and during each of the eight conditions participants were given a startle stiulus test, followed by a questionnaire to fill out and - Peritted Application Roo 1 Roo 2 Casino 1 Casino 2 Conference Roo Gae Arcade Bowling Alley (Seating Area) an eye blink count. Acceptability was assessed by arking a line on a scale fro 1 (unacceptable) to 1 (acceptable). Positive values greater were scored as acceptable and negative as unacceptable. Each set of secondhand soke scores was copared to the values for the clean air condition preceding it. At the highest dilution tested, equivalent to 32,3 ft 3 (3 3 ) clean air per cigarette, the air was judged acceptable by only 33% of the participants. (92% found the clean air condition that preceded the secondhand soke condition acceptable.) Junker, et al. report that the detection of the arousing (secondhand soke) odor alone was sufficient to create dissatisfaction. These results indicate that sidestrea cigarette soke has one of the lowest odor thresholds of any known copound and causes sensory irritation at concentrations very near the threshold concentrations,.6 4 µg/ 3 SHS-PM25. Thus, it appears that the guidance in Appendix I does not appear to eet its stated design objective of satisfaction with respect to odor and sensory irritation. Health Iplications While Appendix I was careful not to ake any health clais, it is iportant to note that all the levels of RSP calculated using the ethodology described above exceed the 15 µg/ 3 Occupancy (People Per 3 ) Proportion Rate Total Ventilation of Sokers, (Cigarettes/ Rate (L/s C RSP SM Soker-h), Per Adapted SR Person) µ g/ Ceiling Height Office annual arithetic ean level of PM5 specified by the U.S. EPA National Abient Air Quality Standard. 12 (These size particles are siilar to those generated by secondhand soke.) These levels also are well above levels that would be considered to pose an acceptable risk for lung cancer based on federal standards. 13 It is appropriate to use the annual exposure levels for coparisons because people exposed to secondhand soke in workplaces such as offices, restaurants, and bars are consistently exposed. While ost attention on secondhand soke has been devoted to lung cancer, secondhand soke also increases the risk of heart disease. Soe of these changes, in particular effects on blood platelets and vascular endothelial function (which affects the ability of the arteries in the heart to expand and increase blood flow when the heart needs ore blood) occur within less than 3 inutes of secondhand soke exposure in realistic environents These changes both increase the iediate risk of a heart attack and do long ter daage to the heart and blood vessels. In addition, short ter exposure to RSP in secondhand soke reduces heart rate variability 17 (sall rando fluctuations in heart rate around the basic rate). While the precise echaniss have not been elucidated, a reduction in heart rate variability 56 ASHRAE Journal ashrae.org March µ / 59 µ / 19 µ / 29 µ / 59 µ / 63 µ / 53 µ / 5 µ / 37 µ / 45 µ / 29 µ / Table 1: Respirable suspended particulate levels associated with Standard 62-21, Appendix I.

4 increases the risk of a heart attack. One experient involved having volunteers sit in the soking lounge (RSP = 78 µg/ 3 ) for two hours at the Salt Lake City airport. 17 This exposure to secondhand soke RSP was associated with a consistent and significant reduction in heart rate variability associated with about a 1% increase in risk of a heart attack. No one yet has deterined how quickly this effect occurs or how low a concentration of secondhand soke is required to trigger this effect, but it will occur at soe of the levels of RSP present in spaces designed in accordance with the guidelines in Appendix I, even under the assuptions that bias the results to low levels of RSP. The Assuptions Used in 62o for Cofort Since the guidelines in Appendix I noinally sought to provide cofort, it is necessary to have soe easure of the level of tobacco soke pollution that will create discofort. Appendix I was based on a 21-year-old study 11 (prepared by an individual who did consulting work for the tobacco industry 18,19 ) that sought to identify the level that would be acceptable to 8% of experiental subjects in a chaber study. There are several probles with using this study as the basis for engineering decisions in 24. First, one-third of the experiental subjects were sokers, uch higher than the 23% of the adult population than sokes today. 2 - Peritted Application Roo 1 Roo 2 Casino 1 Casino 2 Conference Roo Gae Arcade Bowling Alley (Seating Area) Occupancy (People Per 3 ) Ceiling Height Proportion of Sokers, SM Rate (Cigarettes/ Soker-h), SR Total Ventilation Rate L/s-Person cf/ person 7 3 9,5 2, , 4, ,85 6, ,333 13, ,19 4, , ,8 8, ,85 6, , , ,615 Office ,615 Table 2: Additional ventilation rates required to obtain a secondhand soke respirable suspended particulate level (C RSP ) of.6 µg/ 3 using conservative engineering assuptions. The fact that there was a high proportion of sokers in the test group biases the levels of ventilation necessary for acceptable air quality down. Indeed, this paper 11 also reported that None of the conditions in the present investigation [including the level of ventilation used in Appendix I] would satisfy even two-thirds of nonsokers. 11 Appendix I did not reflect a uch newer (21) and ore carefully done study, 1 which concludes that Odor thresholds of sets obtained fro the olfactory experients showed that a edian odor sensation was perceived at very low concentrations equivalent to an ETS-PM25 concentration of approxiately.6 4 µg/ 3. 1 At about 4.4 µg/ 3 only one-third of subjects found the quality of the air acceptable. 1 All the experiental subjects were healthy nonsokers; including individuals with edical conditions such as astha would have lowered further the level of acceptability. Appendix I also included other assuptions that bias the recoended ventilation rates toward lower values. The assued soking prevalence (proportion of sokers) is low in several cases. Appendix I assues that only 25% of occupants are sokers in a Bar Cocktail and Casino 1 (Table 1). Several of the other environents ( Roo 1, Casino 2, Conference Roo, Gae Arcade, Bowling Alley, and Office) assue that only 2% of people soke, less than the prevalence of soking in the adult population (23%). 2 The assued soking rates are low. For exaple, they assue only one cigarette soked per hour per sokers in a bar or cocktail lounge, 5 cigarettes per hour in casinos. These are environents where sokers would be expected to soke ore than average, yet no objective data are presented to support this assuption. The assued level of.6 cigarettes/hour in workplaces also is low. While designers relying on Appendix I and the anticipated ETS design guide could and should adjust the percentage of sokers and cigarette consuption rate to the correct values for the space that they are designing, there is a strong likelihood that designers who are not tobacco-use epideiologists will siply assue that the nubers there are typical and follow the exaples given there. In addition, acceptable ventilation levels in soking lounges and heavy soking bars are based on adapted people only, who have accliatized to the pollution due to the secondhand soke, which hides the higher ventilation quantities that would March 24 ASHRAE Journal 57

5 be required in these places even if one accepts the other assuptions in Appendix I. None of the calculations in Appendix I allow for particularly sensitive people, such as people with astha, allergies, lung or heart disease, or children, even though such people are likely to be in roos with secondhand soke designed according to the recoendations in Appendix I. All these assuptions bias the results to lower the ventilation rates (and higher levels of secondhand soke pollution) that will be deeed acceptable. In addition, the results are strongly dependent on the assuptions that are ade. For exaple, using an average soking prevalence of 23% 2 (rather than the low 2% assued in Appendix I) and a soking rate of two cigarettes/hour per soker 6,11 (rather than the very low rate of.6 cigarettes/hour assued in Appendix I) raises the RSP levels for Roo 1 and Office fro 29 µg/ 3 to 112 µg/ 3. Advertiseent in the print edition forerly in this space. Thus, none of the pollution levels achieved eet cofort, uch less health, design objectives. This procedure is not consistent with good engineering design principles; norally any assued values are selected to represent high end inputs to ensure that the syste will respond effectively in real world conditions and be suitable for sensitive people. Even as a iniu ventilation recoendation, it is not good practice to bias all of the assuptions toward the lower end. An Alternative Approach Appendix I did not purport to develop its recoendations based on health considerations, but rather cofort (odor control). 21 If one accepts this design goal of cofort rather than health, a ore direct way to approach specification of ventilation requireents would be to ake conservative assuptions about soking levels and rates, then copute the ventilation levels necessary to achieve the design objective level of RSP. For exaple, suppose we set a design objective at the odor threshold of.6 µg/ 3 based on the newest available inforation on sensory perception of secondhand soke. 1 Note that, in ters of odor, even this level only represents the lower end of the edian odor threshold, eaning that half the population would detect odors below this level. (Even this design objective does not reach de inius levels of cancer, 13 but it coes uch closer than Appendix I.) We assue 25.5% soking prevalence, the 75th percentile of soking prevalence aong the 5 states. 2 (The highest prevalence is 3.9%, in Kentucky. 2 ) The soking rates are also adjusted upward to ore reasonable estiates. The resulting ventilation levels (Table 2) are uch higher than in Appendix I (Table 1), ranging fro 3,4 to 4,2 cf/person (1615 to 19 L/s per person). These levels are so high that it ight be argued that they put ASHRAE in the uncofortable position of recoending unfeasible solutions to the proble of secondhand soke. These values, however, follow fro conservative engineering assuptions and procedures cobined with ass balance. Conclusion Given the high levels of ventilation required to eet even a cofort design goal based on odern evidence, cobined with the deand for guidance encouraged by the tobacco industry and its allies, 1 what is ASHRAE to do? There are two broad ASHRAE policies that are relevant: On June 9, 22, The Board of Directors affir[ed] the iplied policy that ASHRAE standards shall consider health ipacts where appropriate ( & ) and the ASHRAE Code of Ethics states in part: Our efforts shall be directed at all ties to the enhanceent of the public health, safety and welfare. 22 As noted, spaces designed in accordance with the guidelines in Standard Appendix I can lead to levels of RSP that are not consistent with public health, safety, and welfare. These policies would see at odds with recoendations in Standard Appendix I, which are based on unrealistic assuptions, which bias recoendations to lower ventilation rates. In any ways, Appendix I was siilar to a civil engineering society developing recoendations for bridge construction based on liberal assuptions about strength of building aterials, while assuing that the nuber of vehicles on the bridge was low. While such guidance ight serve econoic needs of contractors who wish to cut corners, it could be viewed as violating basic engineering principles and ethics. Since ASHRAE sees unwilling to develop a standard based on de inius risk, 1,13 perhaps it would be best to siply include a stateent in Standard 62, as the Board Policy Coittee did in its report to the ASHRAE Board of Directors on June 25, 22, that There is evidence that acceptable air quality cannot be achieved where soking is peritted, 5 delete Section 6.5, the stateent in the standard about the need for additional ventilation or air cleaning when soking is peritted, drop the forthcoing ETS design guide, and leave it at that. 58 ASHRAE Journal ashrae.org March 24

6 Acknowledgents This work was supported by the National Cancer Institute (CA-6121 and CA-87472). References Bialous, S.A. and S.A. Glantz. 2 ASHRAE Standard 62: tobacco industry s influence over national ventilation standards. Tob. Control 11(4): Fichtenberg, C.M. and S.A. Glantz. 2 Effect of soke-free workplaces on soking behaviour: systeatic review. BMJ 325(7357):188. Dearlove, J.V., S.A. Bialous and S.A. Glantz. 2 Tobacco industry anipulation of the hospitality industry to aintain soking in public places. Tob. Control 11(2): ASHRAE. 2 Excerpts fro BOD Minutes June 22, Motion 32; June ASHRAE Board Policy Coittee. 2 Recoendations Regarding Inclusion of ETS in Standard 6 June 6. Repace, J.L. and A.H. Lowrey Indoor air pollution, tobacco soke, and public health. Science 28(4443): Ott, W., L. Langan and P. Switzer. 199 A tie series odel for cigarette soking activity patterns: Model validation for carbon onoxide and respirable particles in a chaber and an autoobile. Journal of Exposure Analysis and Environental Epideiology 2(Suppl 2): Klepeis, N., W. Ott and P. Switzer A ultiple-soker odel for predicting indoor air quality in public lounges. Environ. Sci. Technol. 3: Ozkayanak, H., J. Xue, B. Weker and J. Spengler The Particle Tea (PTEAM) Study: Analysis of the Data. EPA Draft Final Report, Volue III. Boston, MA: Harvard School of Public Health. Report No.: Prepared under Contract Junker, M., B. Danuser, C. Monn, and T. Koller. 2 Acute sensory responses of nonsokers at very low environental tobacco soke concentrations in controlled laboratory settings. Environental Health Perspectives 19: Cain, W., B. Leaderer, R. Isseroff, L. Berglund, R. Huey, E. Lipsitt, et al. 198 Ventilation requireents in buildings I. Control of occupancy odor and tobacco soke odor. Atospheric Environent 17(6): U.S. Environental Protection Agency. 2 National Abient Air Quality Standards Nov. 15.( Accessed: June Repace, J.L. and A.H. Lowrey. 199 An enforceable indoor air quality standard for environental tobacco soke in the workplace. Risk Analysis 13(4): Glantz, S.A. and W.W. Parley. 2 Even a little secondhand soke is dangerous. JAMA 286(4): Glantz, S.A. and W.W. Parley Passive soking and heart disease. Mechaniss and risk. JAMA 273(13): Glantz, S.A. and W.W. Parley. 199 Passive soking and heart disease. Epideiology, physiology, and biocheistry. Circulation 83(1): Pope III, C.A., D.J. Eatough, D.R. Gold, Y. Pang, K.R. Nielsen, P. Nath, et al. 2 Acute exposure to environental tobacco soke and heart rate variability. Environ. Health Perspect. 19(7): R.J. Reynolds Docuent Collection Access Date: July 3, 2 Bates No Cain, W. and G. DiMarco. Consulting contract with R.J. Reynolds. July 8,1987. Access Date: July 3, 2 Bates No. legacy.library.ucsf.edu/tid/ejc97c. U.S. Centers for Disease Control and Prevention. 2 Prevalence of current cigarette soking aong adults and changes in prevalence of current and soe day soking United States, MMWR 52(14): ASHRAE. 2 Addendu 62o to ANSI/ASHRAE Standard 62-21, Ventilation for Acceptable Indoor Air Quality. standards/62-21_o.pdf. Accessed: July 3, 2 2 ASHRAE. Code of Ethics. frae.asp?about/1about.ht. Accessed: July 3, 2 Advertiseent in the print edition forerly in this space. March 24 ASHRAE Journal 59