Effectiveness of Smokeless Ashtrays

Journal of the Air & Waste Management Association ISSN: 1096-2247 (Print) 2162-2906 (Online) Journal homepage: https://www.tandfonline.com/loi/uawm20 Effectiveness of Smokeless Ashtrays David A. Wampler , Shelly Miller-Leiden , William W. Nazaroff , Ashok J. Gadgil , Andres Litvak , K.R.R. Mahanama & Matty Nematollahi To cite this article: David A. Wampler , Shelly Miller-Leiden , William W. Nazaroff , Ashok J. Gadgil , Andres Litvak , K.R.R. Mahanama & Matty Nematollahi (1995) Effectiveness of Smokeless Ashtrays, Journal of the Air & Waste Management Association, 45:6, 494-500, DOI: 10.1080/10473289.1995.10467380 To link to this article: https://doi.org/10.1080/10473289.1995.10467380 Published online: 05 Mar 2012. Submit your article to this journal Article views: 324 View related articles Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=uawm20 ISSN 1047-3289 /. Air & Waste Manage. Assoc. 45: 494-500 TECHNICAL PAPER Copyright 1995 Air & Waste Management Association Effectiveness of Smokeless Ashtrays David A. Wampler, Shelly Miller-Leiden, and William W. Nazaroff University of California, Berkeley, California Ashok J. Gadgil, Andres Litvak, K.R.R. Mahanama, and Matty Nematollahi Lawrence Berkeley Laboratory, Berkeley, California ABSTRACT Most environmental tobacco smoke (ETS) issues from the tips of smoldering cigarettes between puffs. Smokeless ashtrays are designed to reduce ETS exposure by removing particulate and/or gas-phase contaminants from this plume. This paper describes an experimental investigation of the effectiveness of four smokeless ashtrays: two commercial devices and two prototypes constructed by the authors. In the basic experimental protocol, one or more cigarettes was permitted to smolder in a room. Particulate or gas-phase pollutant concentrations were measured in the room air over time. Device effectiveness was determined by comparing pollutant concentrations with the device in use to those obtained with no control device. A lung deposition model was applied to further interpret device effectiveness for particle removal. The commercial ashtrays were found to be substantially ineffective in removing ETS particles because of the use of low-quality filter media and/or the failure to draw the smoke through the filter. A prototype ashtray using HEPA filter material achieved better than 90% particle removal efficiency. Gasphase pollutant removal was tested for only one prototype smokeless ashtray, which employed filters containing activated carbon and activated alumina. Removal efficiencies for the 18 gas-phase compounds measured (above the detection limit) were in the range of 70 to 95%. INTRODUCTION The possible adverse health effects of environmental tobacco smoke (ETS) on nonsmokers have created a growing public IMPLICATIONS Public awareness of the adverse health effects of passive smoking has resulted in many control strategies aimed at reducing nonsmokers' exposure to ETS. Smokeless ashtrays are designed to capture and treat the smoke from a smoldering cigarette prior to release to the environment. Tests of two commercially available smokeless ashtrays revealed them to be substantially ineffective at removing tobacco smoke particles. However, investigation of new prototypes suggests that high removal efficiencies can be readily achieved, both for particles and for volatile organic compounds (VOCs). Nonsmokers' exposure to ETS might be significantly reduced if smokers began using effective smokeless ashtrays whenever they smoked indoors. 4 9 4 Journal of the Air & Waste Management Association desire to reduce nonsmoker exposure to ETS. This desire has resulted in both technology- and policy-oriented control strategies. Technology-oriented controls include increased ventilation in rooms where smoking occurs and the use of portable air filtration devices. Policy-oriented control strategies include local ordinances which may ban smoking in certain buildings or segregate smokers from nonsmokers.1 However, the use of policy-oriented controls is limited. For example, restricting smoking in residential buildings is not feasible, but considerable exposure to ETS can occur to nonsmokers in residences. Spengler et al.2 found that household smoking was a substantial contributor to personal respirable suspended particles. Emmons et al.3 found that the primary site of ETS exposure was the workplace, unless a smoker was in the home, in which case the household was the primary site. Because a large portion of ETS issues from the idling cigarette between puffs,4-6 capturing and removing both gasphase contaminants and particles from this smoke stream could significantly reduce nonsmokers' exposure. Control devices with this aim are commercially available and are known as "smokeless ashtrays." This paper describes chamber experiments that were conducted to determine the effectiveness of four smokeless ashtrays for removing gas-phase and particulate matter from sidestream cigarette smoke. Prior to the chamber experiments, a sensory test was performed for each device under normal operating conditions. A lung deposition model also was applied to the data from the particle experiments to determine the mass of ETS particles that would be deposited in the lungs of a 30-year-old male nonsmoker exposed for one hour following cigarette combustion, with and without the use of a smokeless ashtray. EXPERIMENTAL METHODS Smokeless Ashtrays Four smokeless ashtrays were used in this study. Two commercial ashtrays, denoted SA-1 and SA-2, were purchased from local retailers (retail price: $20 and $39, respectively). The other two devices, SA-3 and SA-4, were prototype ashtrays designed and constructed by the authors. Each ashtray was new when tested, and its filters were not preconditioned prior to the study. Volume 45 June 1995 Wampler, Miller-Leiden, Nazaroff, Gadgil, Litvak, Mahanama, and Nematollahi ,| SA-2 SA-1 smoke was occasionally observed to bypass the filter through narrow cracks that separate the ashtray from the fan. Although no smoke discharge into the room was visible from any of the ashtrays under normal lighting, a strong odor of tobacco smoke emanated during tests of both SA-1 and SA-2 and, to a lesser extent, SA-3. Only a slight odor was detected in the exhaust when SA-4 was tested. When a strong beam of light was cast in an otherwise dark room across the exhaust of each ashtray, smoke was observed being discharged from the exhaust areas for SA-1 and SA-2. No visible smoke was observed under these conditions for SA-3 or SA-4. Particle Experiments —INACTIVATED ALUMINA GRANULAR ACTIVATED CARBON SA-3 SA-4 Figure 1 . Sketches of the four smokeless ashtrays. All four devices share the same conceptual design: a small fan draws the smoke plume from an idling cigarette through one or more filters before discharging the treated air to the room. The device geometry and filter media differ among the four devices. Figure 1 presents schematic diagrams of the ashtrays. The filter for SA-1 is composed of a 10-mm bed of granular activated carbon sandwiched between two 1-mm-thick paper filters. The filter for SA-2 consists of a black fiber filter media with dimensions 6.5 x 6.5 x 0.75 cm. The exact composition of the media could not be determined. Light could easily be seen through the pores of the SA-2 filter, suggesting that the filter's effectiveness for removing submicron smoke particles would be small. Ashtray SA-3 has two glassfiber HEPA filters with 2.5-cm pleats (Flander's Filters). Ashtray SA-4 also has two glass-fiber HEPA filters plus a 2.5-cm layer of granular activated carbon (International Air Filter) and a 1.8-cm layer of granular activated alumina impregnated with 4% potassium permanganate (Unisorb, Mark 2; Applied Air Filter). The carbon and alumina are included for removing gas-phase nonpolar and polar organic compounds, respectively. Sensory Examination The first investigation of the effectiveness of the four ashtrays was based on visual inspection. A commercial cigarette was lit and placed in an ashtray. For SA-2, the rising Volume 45 June 1995 The particle removal effectiveness of ashtrays SA-1, SA-2, and SA-3 was quantified by a series of particle measurement experiments. In each experiment, a smoldering cigarette (Kentucky reference cigarette 1R4F) was placed in the normal position of the functioning ashtray, and airborne particle concentrations were measured in the room as a function of time. In a separate baseline experiment, similar measurements were made with a smoldering cigarette but with no smokeless ashtray in use. The experiments were conducted at the Indoor Air Quality Research House located at the Richmond Field Station of the University of California.7 The floor of the study room is linoleum, and the ceiling and walls are painted sheetrock and plywood. The room has been weatherized to reduce the infiltration rate to less than 0.1 air changes per hour. Figure 2 presents a schematic diagram of the arrangement for the PARTICLE RESEARCH CHAMBER (Volume = 36 cubic meters) Gas chromatograph for sulfur hexafluoride Condensation nucleus counter CZD Differential mobility analyzer Smokeless ashtray Optical particle counter Passive exhaust through hood Figure 2. Schematic of the 36-m3 chamber used for the particle experiments. One cigarette was burned in separate experimental runs involving SA-1, SA-2, SA-3, and for a baseline case. The chamber was ventilated with particle-free air, and the ventilation rate was measured, using SF6 decay, to be in the range 0.7 to 0.9 h"1. Journal of the Air & Waste Management Association 495 Wampler, Miller-Leiden, Nazaroff, Gadgil, Litvak, Mahanama, and Nematollahi particle experiments. To prevent infiltration of particles from the outside and to simulate ventilation rates comparable to a typical home, particle-free HEPA-filtered air was supplied into the room. Prior to each experiment, the particle concentration in the room was reduced by forced air ventilation to less than 1,000 particles cm 3 . Combustion of the cigarette occurred atop a table in the center of the unoccupied room. An aluminum sleeve with an inside diameter equal to the outside diameter of the cigarette encircled the cigarette approximately 5 mm from the filter/tobacco interface and extinguished the cigarette after a constant length (-4.5 cm) had been burned. Initially, a researcher lit the cigarette with a butane lighter, placed the cigarette in the ashtray, left the room, and securely closed the door. Particle emissions resulting from the act of lighting the cigarette were measured and found to be negligible (contributing 0.3 \xg rrr3 to the particle mass concentration in the room). The cigarette smoldered for approximately six minutes in each experiment. Particle Measurements. Particles were sampled through a 3-m length of 0.95-cm I.D. copper tubing. The sampling point was located in the center of the room, approximately 0.3 m above and 1 m to the side of the ashtray. Total particle number concentration was measured with a condensation nucleus counter (TSI Model 3020). Particle size distributions were measured with an optical particle counter (PMS Model LAS-X) and an electrostatic classifier (TSI Model 3071) coupled to an ultrafine condensation particle counter (TSI Model 3025). Ventilation Rate Measurements. The ventilation rate of the room was determined during each experiment by measuring the concentration decay rate of SF6. At the start of a run, a 25-ml aliquot of 17.6% SF6 in helium was injected from outside the study room through an injection port. The SF6 concentration was continuously monitored at three locations in the room by means of a remotely located gas chromatograph with an electron capture detector (HewlettPackard Model 5890). Lung Deposition Model. A lung deposition model, as described by Nazaroff et al.,8 was combined with the particle size distribution data from each of the four particle experiments to predict deposition of tobacco smoke particles in three lung regions: nasopharyngeal (NP), tracheobronchial (TB), and alveolar (Alv). Lung deposition calculations yield deposited dose of particles for one hour of exposure, starting with cigarette ignition. The calculations were conducted for a 30-year old male, breathing through his nose under light exercise conditions (20 breaths per minute with 1.25 L tidal volume, equal inspiration and expiration periods without pause). Nazaroff et al. have shown that the deposited mass of ETS particles per mass of body weight varies little with age and gender.8 Gas-Phase Experiments Ashtray SA-4 was tested for its effectiveness in removing gaseous pollutants. These tests were conducted in a 20-m3 stainless steel environmental chamber at Lawrence Berkeley Laboratory (LBL). In each run, three cigarettes were smoked consecutively inside the unventilated chamber, using a smoking machine. The airborne concentrations of 23 selected gas-phase compounds, including nicotine, three aldehydes, and 19 volatile organic compounds (VOCs), were measured in the chamber air. Three runs were conducted. Two were baseline experiments with no smokeless ashtray present. In the third run, SA-4 was present, and the cigarette's sidestream smoke traveled through the ashtray before being emitted to the chamber. Table 1 gives the Table 1 . Physical parameters and measurement devices used for gas-phase experiments. Physical parameters: Ashtray tested: Room volume: Room surface: Number of cigarettes smoked per experiment: Type of cigarette: SA-4 20 m3 Stainless steel 3, using a smoking machine with a total puff volume of 35 cm3, a frequency of 1 puff mirv1 and a duration of 2 sec per puff 1R4F (Kentucky reference cigarette) Analyte Formaldehyde and acetaldehyde Collection Silica Sep-Pak cartridge impregnated with 2,4-dinitrophenylhydrazine (Millipore Corp.) Analysis High Performance Liquid Chromatography (Series 1090, Hewlett-Packard Co.); Nova-Pak C18 column (Waters chromatography) Detection Diode-array ultraviolet detector (Series 1090, Hewlett-Packard Co.) Nicotine 20/40 mesh XAD-4 Sorbent tubes (SKC West Inc.) Gas chromatography (Shimadzu GC-9A); DB-WAX capillary column (J&W Scientific) Nitrogen-phosphorus detector (DET) VOC Multisorbent bed, Tenax-TA, Caroxene carbon molecular sieve and activated charcoal (Envirochem Inc.) Gas chromatography (Series 5790A Hewlett-Packard Co.); Restek Rtx-5 capillary column (J&W Scientific) Mass selective detector (Series 59970, HewlettPackard Co.) 4 9 6 Journal of the Air & Waste Management Association Volume 45 June 1995 Wampler, Miller-Leiden, Nazaroff, Gadgil, Litvak, Mahanama, and Nematollahi physical parameters of the gas-phase experiments, in addition to the instruments used to obtain and quantify species concentrations. Chamber Configuration. The 20-m3 stainless steel environmental chamber is designed for investigating emissions of pollutants from indoor sources under simulated, controlled indoor environmental conditions. Prior to each experiment, the room was sealed to reduce the air exchange rate to as low a value as possible. In a previous experiment, with no sampling pumps operating, the air exchange rate was determined to be 0.005 h-1 using SF6 as a tracer gas. Adding the air flow caused by the sampling equipment, the overall air exchange rate during these experiments was estimated to be 0.03 h-1. Six small mixing fans, positioned on the walls at various locations inside the chamber, operated for the duration of each experiment and ensured well-mixed conditions. A 20watt fluorescent lamp (Model #90108, Lights of America) was mounted 0.5 m from the wall and operated for the entire 5.5-hour experiment. In previous experiments, the chamber temperature did not change because of the lamp. The average room air temperature, measured in three locations with Type-T thermocouples, was 25 °C. Humidity of the chamber air, monitored continuously with a chilled-mirror dew-point hygrometer (Model 911 Dew-All, EG&G, Inc.), ranged from 40 to 45%. GAS-PHASE RESEARCH CHAMBER (Volume = 20 cubic meters) Sep-Pak Flow Controller Vacuum Pumps ® Multisorbent Samplers 20/40 mesh XAD-4 Sidestream smoke emitted into chamber Solenoid valves remotely controlled Mainstream tobacco smoke exhausted outside chamber Ashtray SA-4 Figure 3. Schematic of the 20-m3 chamber used for the gas-phase experiment involving SA-4. Minor modifications were made for the baseline experiments. For each experiment, three cigarettes were sequentially smoked using a smoking machine, and the sidestream smoke was emitted to the unventilated chamber. Mainstream smoke was exhausted outside the chamber. Volume 45 Jyne 1995 The chamber air also was monitored for CO at one-minute intervals using a diffusion sampler based on electrochemical detection (Draeger Model 190). The monitor was located on the floor in the center of the chamber and was calibrated prior to the experiment, using 0 and 60 ppm CO calibration gases. Cigarette Ignition,, Smoking, and Snuffing. By necessity, the manner in which the three 1R4F reference cigarettes was ignited and extinguished differed slightly between the baseline experiments and the controlled experiment. However, these differences are unlikely to significantly affect the results. In the baseline runs, the three cigarettes were securely mounted in a rotating cylindrical carousel (designed by LBL staff), sequentially ignited, smoked by machine at a rate of one 35-ml puff per minute, and extinguished. Mainstream smoke was exhausted outside the chamber. For the experiment in which SA-4 was used, the three 1R4F cigarettes were placed side-by-side in the base of the ashtray and ignited using small Nichrome wire coils installed through the back wall of the ashtray (see Figure 3). Each coil was wired to a switch and a power supply capable of providing an 8-amp current. Three remotely controlled solenoid valves ensured that the smoking machine always puffed on the lit cigarette. The cigarettes were extinguished in the same manner as used in the particle experiments. Gas Measurement Methods. Sampling ports for VOCs, aldehydes, and nicotine were located approximately 1.5 m above the floor in the middle of the room. In each experiment, the three cigarettes were smoked in the corner of the room. To establish background concentrations for aldehydes and VOCs, samples were collected in the chamber prior to lighting the cigarettes. After the cigarettes were smoked, four successive one-hour samples were collected for VOCs. Two aldehyde samples were collected, using 100-minute sampling periods beginning immediately after cigarette combustion and at 140 minutes after cigarette combustion, respectively. A single four-hour sample was collected for nicotine, beginning immediately after cigarette combustion. The cigarette lengths were measured before and after smoking to determine the total amount of tobacco smoked. For determining removal efficiency, the average concentrations for the controlled experiment were multiplied by the ratio of the average length of tobacco smoked in the baseline experiments, 14.65 cm, to the average length In the controlled experiments, 13.7 cm. Removal Efficiency Removal efficiency for a smokeless ashtray was determined as the difference between the time-averaged concentrations with and without a smokeless ashtray, normalized by the time-averaged concentration without a smokeless ashtray in operation. Journal of the Air & Waste Management Association 497 Wampler, Miller-Leiden, Nazaroff, Gadgil, Litvak, Mahanama, and Nematollahi RESULTS AND DISCUSSION Particle Experiments The particle number concentration in the room is plotted against time in Figure 4 for the three smokeless ashtrays tested. Results for each ashtray are compared to the corresponding result for a smoldering cigarette without a smokeless ashtray. Background particle number concentrations can be seen for the first 20 minutes prior to lighting the cigarette. Background particle mass concentration for each experiment is negligibly small, less than a few tenth 5 of a Hg m 3 . The ventilation rates for these experiments varied from 0.7 to 0.9 h 1 , as shown in Figure 5. Figure 4 shows that the two commercial ashtrays are substantially ineffective at removing tobacco smoke particles on a number basis. For SA-2, the number concentration is even greater with the control device than without it. This increase may reflect the inhibition of particle coagulation in the plume because of dispersion caused by the control device. In contrast, SA-3 showed an order of magnitude reduction in particle number concentration compared to the uncontrolled smoldering cigarette. Smoke particle number distributions obtained using the optical particle counter (OPC) and differential mobility 150 baseline (0.8 IV1) SA-1 (0.9 h"1) 100 50 baseline (0.8 h' 1 ) SA-2 (0.7 h"1) ex 100 r 8 0 baseline (0.8 h"1) SA-3 (0.9 h' 1 ) §en 100 50 10° I io5 0.01 I g •a 1C Figure 5. One-hour time-averaged airborne particle mass distributions from cigarettes smoldering in control devices SA-1, SA-2, and SA-3, respectively, compared to the distribution from an uncontrolled smoldering cigarette (baseline). Sampling began with cigarette ignition. 1Q3 IO 2 § 1.0 Particle diameter (nm) I io4 u 0.1 baseline io 5 4 I „» g 10s 10" 50 100 150 200 250 300 Time (min) Figure 4 . Particle number concentration versus time for three smokeless ashtrays, SA-1, SA-2, and SA-3, compared to an uncontrolled smoldering cigarette (baseline). In each case, the cigarette was lit at t = 0 min and burned for approximately six minutes. 4 9 8 Journal of the Air & Waste Management Association analyzer (DMA) were converted to mass distributions assuming a constant particle density of 1.2 g cm 3 . One-hour and 2.5-hour average mass distributions commencing with cigarette ignition were calculated for each of the four experimental runs. Figure 5 shows the first-hour-since-combustion average particle mass distribution for each of the three ashtrays in comparison with the uncontrolled smoldering cigarette. The mass distribution for SA-1 shows -60% reduction in particle mass for particle sizes greater than 0.1 |im For SA-2, a shift in the particle mass distribution can be seen: there is a greater mass concentration of particles less than -0.2 jj,m with the control device than for the uncontrolled smoldering cigarette. For SA-3, the mass distribution occurs in the same particle size range as the uncontrolled smoldering cigarette, but the mass concentration is an order of magnitude lower. On a mass basis, the overall removal efficiency was 52% for SA-1 and 35% for SA-2. Ashtray SA-3 was expected to have a particle removal efficiency of greater than Volume 45 June 1995 Wampler, Miller-Leiden, Nazaroff, Gadgil, Litvak, Mahanama, and Nematollahi 99% because a HEPA filter was used.9 However, the total mass removal efficiency was determined to be 93%. The discrepancy may result from imperceptible leaks that allowed particles to bypass the filter, from leakage of smoke out of 20- is• NP Region E3 TB Region 110- £1 Alv Region 5- the ashtray opening, or from particle growth downstream of the filter because of condensation of cooled gases. Predictions from the lung deposition model are shown in Figure 6. As expected, the largest mass of deposited cigarette smoke particles occurred for the uncontrolled smoldering cigarette where 15.8 fxg smoke particles would deposit in all three regions of the lung combined. The total mass deposited in the case of SA-1 and SA-2 was 8.8 and 13.7 jig, respectively. Predicted lung deposition for SA-3 is 1.2 jxg, an order of magnitude lower than the other cases. The partitioning of the total deposited mass among the various regions of the lung is similar for each of the four experiments, with approximately 80% of the particle mass depositing in the alveolar region of the lung. The location of deposited mass is important with respect to clearance mechanisms and the occurrence of disease.10 Gas-Phase Results Figure 7 compares, for baseline and controlled experiments, m m the average concentrations of 15 compounds measured in the 20-m3 environmental chamber. Clearly, significant reduction occurred in the concentrations of all species when the smokeless ashtray SA-4 was used. The removal efficiency Figure 8. Predicted total mass deposited in the nasopharyngeal (NP), of SA-4 for these species ranged from approximately 70% tracheobronchial (TB), and alveolar (Alv) regions of the lung during one hour of exposure to emissions from an uncontrolled smoldering to more than 95%. The removal efficiencies for formaldecigarette and for a smoldering cigarette set in each smokeless ashhyde and acetaldehyde were approximately 93 and 77%, tray. Analysis begins with cigarette ignition and applies to the case of respectively; nicotine was removed with an approximate a closed 36-m3 room, with an air exchange rate of 0.7 to 0.9 rr1. 95% efficiency. Eight compounds were analyzed 1,3-butadiene nicotine formaldehyde acetaldehyde acrylonitrile but not included in Figure 7. Five of 400 200 20 40 200 these were at levels below the listed T detection limits for both the baseline 200 100 100 10 20 and controlled experiments: butyraldehyde and 3-methyl-l-butanol (having detection limits of 2.5 jig nv3), 0 0 ethyl acetate, ethyl acrylate, and m,p-xylene o-xylene toluene benzene styrene 80 60 120 30 16 butyl acetate (having detection limits of 0.5 ug nr 3 ). Experimental results for acrolein are suspected to be invalid. 40 30 60 15 Pyrrole and 3-vinylpyridine are omitted because they are of interest only 0 0 as markers of ETS exposure. phenol pyridine m,p-cresol o-cresol 2-butanone During each run, four VOC 12 40 60 120 samples, two aldehyde samples, and T one nicotine sample were collected. 30 20 60 Each sample was separately analyzed, and the individual species concentraex ND ND 9$ ND ' tions were determined. The average 0 species concentrations reported in Figure 7 reflect arithmetic average valFigure 7. Mean gas-phase concentrations (jxg rrr3) of 15 species generated from the ues for all valid samples, and error bars sidestream smoke of three cigarettes which were smoked sequentially in an unventilated 20indicate one standard deviation in inm3 chamber. The hatched bars represent results without a smokeless ashtray in use. The dividual samples. The error bars for open bars represent results with the cigarettes placed in smokeless ashtray SA-4. Error bars represent one standard deviation from the mean. the cresols and phenol are relatively I I Volume 45 Jun@1§§§ 1 I 1 Journal of the Air & Waste Management Association 499 Wampler, Miller-Leiden, Nazaroff, Gadgil, Litvak, Mahanama, and Nematollahi large as a result of observed systematic decreases in concentration over the 250-minute sampling period. These compounds may react with the chamber walls, causing a reduction in airborne concentrations during the experiment. Because of an experimental error, the VOC data for the first baseline experiment were judged invalid and not used. However, nicotine and aldehyde data from this run were valid and showed reproducibility with data from the second baseline run. For example, the four-hour average nicotine concentrations for the two baseline experiments were 137 and 149 |ig nv3, respectively. Carbon monoxide generated during the combustion of cigarettes is difficult to remove, and the sorbent media used in SA-4 was not expected to significantly affect CO emissions. Indeed, CO measurements between the baseline and controlled experiments did not differ; in each case, the peak concentration in the chamber was 12 ppm. a reliable, high-efficiency, low-cost smokeless ashtray is within reach. ACKNOWLEDGMENTS We thank Al Hodgson and Joan Daisey at Lawrence Berkeley Laboratory (LBL) for use of the LBL chamber and Thu Phan at LBL for gas-phase sample analysis. Also, we thank Flander's Filters, Applied Air Filters, and International Air Filter for supplying materials. This research was supported by funds provided by the Cigarette and Tobacco Surtax Fund of the State of California through the Tobacco-Related Disease Research Program of the University of California, Grants Number RT 666 and RT 299. Additional support was provided by the National Science Foundation through Grant BCS-9057298 and from the National Heart, Lung and Blood Institute through Grant 5R01HL4249004. REFERENCES SUMMARY AND CONCLUSIONS The results from both the sensory examination and the chamber experiments provide firm evidence that currently available smokeless ashtrays are relatively ineffective at removing tobacco smoke particles from a smoldering cigarette. We have shown that particle removal efficiencies can be substantially improved by replacing low-efficiency filters with high-efficiency filters and by not allowing tobacco smoke to bypass the filter. In addition, we have shown that substantial reductions in gas-phase contaminants can be achieved by adding effective sorption media for removing both polar and nonpolar organic compounds from sidestream smoke. It is important to emphasize that the results reported in this article represent device effectiveness only when challenged by a smoldering cigarette. In practice, the overall reduction of ETS concentrations resulting from smokeless ashtray use would be somewhat less than the device effectiveness reported here because of the uncontrolled contributions of (1) sidestream emissions while the cigarette is being held and (2) exhaled mainstream smoke. Further experiments of the type conducted here—but with human smokers using the device—would more directly provide the information needed to assess the expected reduction in ETS concentration. Field tests of the impact of device use on ETS concentrations in normal indoor settings would also be valuable. Efforts to develop effective smokeless ashtrays should be viewed as complementary to other ETS control measures, rather than as a substitute. Clearly, prohibiting smoking in a public building has a greater potential to reduce ETS exposure than implementing any source-control technology. However, legislative regulation of smoking in private residences appears completely impractical; thus, alternative means to control ETS exposure should be considered in these settings. The commercial devices we tested are not very effective. Yet, the performance results for the prototype devices indicate that the challenge of providing 5 0 0 Journal of the Air & Waste Management Association 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Lambert,W.E.; Samet, J.M.; Spengler, J.D. "Environmental tobacco smoke concentrations in no-smoking and smoking sections of restaurants," Am. ]. Pub. Hlth. 1993, S3, 1339. Spengler, J.D.; Treitman, R.D.; Tosteson, T.D.; Mage, D.T.; Soczek, M.L. "Personal exposure to respirable particulates and implications for air pollution epidemiology, "Environ. Sci. Technol. 1985,19, 700. Emmons, K.M.; Abrams, D.B.; Marshall, R.J.; Etzel, R.A.; Novotny, T.E.; Marcus, B.H.; Kane, M.E. "Exposure to environmental tobacco smoke in naturalistic settings," Am. J. Pub. Hlth. 1992, 82, 24. National Research Council. Environmental Tobacco Smoke: Measuring Exposures and Assessing Health Effects; National Academy Press: Washington, DC, 1986. Muller, W.J.; Hess, G.D.; Scherer, P.W. "A model of cigarette smoke particle deposition," Am. Ind. Hyg. Assoc. J. 1990, 51, 245. Byrd, J.C.; Shapiro, R.S.; Schiedermayer, D.L. "Passive smoking: A review of medical and legal issues," Am. /. Pub. Hlth. 1989, 79, 209. Offermann, F.J.; Sextro, R.G.; Fisk, W.J.; Grimsrud, D.T.; Nazaroff, W.W.; Nero, A.V.; Revzan, K.L.; Yater, J. "Control of respirable particles in indoor air with portable air cleaners," Atmos. Environ. 1985, 19, 1761. Nazaroff, W.W.; Hung, W.Y.; Sasse, A.G.B.M.; Gadgil, A.J. "Predicting regional lung deposition of environmental tobacco smoke particles," Aerosol. Sci. Technol. 1993, 19, 243. American Society of Testing and Materials. 1993 Annual Book ofASTM Standards, 14.02, F1471-93:904; 1993. Martonen, T.B., "Deposition patterns of cigarette smoke in human airways," Am. Ind. Hyg. Assoc. J. 1992, 53, 6. About the Authors D.A. Wampler, M.S., is a recent graduate of the Department of Civil Engineering, Environmental Engineering Program, 631 Davis Hall, University of California, Berkeley, CA 94720-1710. S. Miller-Leiden, M.S., is pursuing her Ph.D. in the same department. W.W. Nazaroff, Ph.D., is an associate professor in that department. A.J. Gadgil, Ph.D., is a staff scientist with the Indoor Environment Program, Energy and Environment Division, Lawrence Berkeley Laboratory, Berkeley, CA 94720. A. Litvak, a doctoral student at LASH ENTPE in France, is presently conducting research at Lawrence Berkeley Laboratory. K.R.R. Mahanama, Ph.D., is a staff scientist and M. Nematollahi is a research assistant at Lawrence Berkeley Laboratory. Volume 45 June 1995