Environmental Tobacco Smoke Constituents Research Articles

The botanical biofiltration of volatile organic compounds and particulate matter derived from cigarette smoke

Despite the growing use of control measures, environmental tobacco smoke (ETS) remains a significant pollutant source in indoor air in many areas of the world. Current control methods for reducing ETS exposure are inadequate to protect public health in environments where cigarettes are smoked. An alternative solution is botanical biofiltration which has previously been shown to lower concentrations of volatile organic compounds (VOCs) and particulate matter (PM) from a range of polluted air streams. This study is the first to assess the potential of a botanical biofilter with the species Spathiphyllum wallisii (Peace Lily) for the removal of cigarette-derived VOCs and all size fractions of PM. Single pass removal efficiencies of 43.26% for total VOCs and 34.37% for total suspended particles were achieved. The botanical biofilter reduced the concentrations of a range of harmful ETS chemicals including nicotine, limonene, and toluene. Evaluation of the re-emission of ETS constituents filtered by the botanical biofilter revealed no particle resuspension or off gassing. The results demonstrate the potential of botanical biofilters to reduce public ETS exposure, although further research is needed to improve upon and ensure the efficiency of these systems for practical applications.

Role of Mouse Cytochrome P450 Enzymes of the Cyp2abfgs Subfamilies in the Induction of Lung Inflammation by Cigarette Smoke Exposure.

Many constituents of tobacco smoke (TS) require bioactivation to exert toxic effects; however, few studies have examined the role of bioactivation enzymes in the adverse effects of TS exposure. This knowledge gap is a major source of uncertainty for risk assessment and chemoprevention efforts. Our aim is to test the hypothesis that cytochrome P450 (P450) enzyme-mediated bioactivation is essential to the development of TS exposure-induced lung toxicity, by determining the contributions of P450 enzymes in the mouse Cyp2abfgs gene subfamilies to environmental tobacco smoke (ETS)-induced lung inflammation. Adult female wildtype (WT) and Cyp2abfgs-null mice (both on C57BL/6J background) were exposed to filtered air or ETS, intermittently, for 1 or 2 weeks. Lung inflammation was assessed by quantification of inflammatory cells, cytokines, chemokines, and proteins in bronchoalveolar lavage fluid (BALF) and histopathological analysis. Glutathione (GSH) conjugates of 2 ETS constituents, naphthalene (NA), and 3-methylindole (3MI), were measured in mice exposed to ETS for 4 h. Persistent macrophagic and neutrophilic lung inflammation was observed in ETS-exposed WT mice; the extent of which was significantly reduced in ETS-exposed Cyp2abfgs-null mice. Levels of proinflammatory cytokines and chemokines, along with the total protein concentration, were increased in cell-free BALF from ETS-exposed WT mice, but not Cyp2abfgs-null mice. Additionally, GSH conjugates of NA and 3MI were detected in the lungs of WT, but not Cyp2abfgs-null, mice following ETS exposure. These results provide the first in vivo evidence that the mouse Cyp2abfgs gene cluster plays an important role in ETS-induced lung inflammation.

Environmental Tobacco Smoke and Cardiovascular Disease.

Environmental tobacco smoke (ETS) and its sequelae are among the largest economic and healthcare burdens in the United States and worldwide. The relationship between active smoking and atherosclerosis is well-described in the literature. However, the specific mechanisms by which ETS influences atherosclerosis are incompletely understood. In this paper, we highlight the definition and chemical constituents of ETS, review the existing literature outlining the effects of ETS on atherogenesis and thrombosis in both animal and human models, and briefly outline the public health implications of ETS based on these data.

The impact of commonly used air filters in eliminating the exposure to secondhand smoke constituents.

Exposure to secondhand tobacco smoke (SHS) also known as environmental tobacco smoke (ETS) has been well established scientifically as a human health hazard. Despite this and warnings from health agencies, concerns over the economic impact of smoke-free bans have limited political resolve to enact these regulations. Arguments against smoke-free bans include the contention that air filters can eliminate the health risks from SHS exposure. In this study, we assessed the effectiveness of air filters (MERV 4 and MERV 8) commonly used in homes and businesses in reducing the concentrations of total suspended particulates, fine particles and carbon monoxide from SHS as a measure of their potential to reduce the toxicity associated with SHS exposure. Our results demonstrate that these filters are not effective at reducing carbon monoxide levels or PM 2.5, which have been correlated with human health toxicity/disease. Thus, our findings, from a public health perspective, do not support the use of common air filters as a viable alternative to smoke-free bans.

Determination of thiocyanate (biomarkers of ETS) and other inorganic ions in human nasal discharge samples using ion chromatography

Environmental tobacco smoke (ETS) is a mixture of air and tobacco smoke containing more than 4000 chemical substances. In view of the health risks of many of these substances, studies are needed to determine biomarkers of exposure to ETS constituents in people who actively or passively are exposed to the toxic compounds. The methodologies for determining most biomarkers from saliva, urine and blood samples are known, but methods for analyzing these compounds in nasal discharges are not available. The objective of this work was to develop an analytical procedure for the determination of thiocyanate and other biomarker compounds in samples of nasal discharge using ion chromatography.

Environmental Tobacco Smoke: Exposure, Health Effects, and Analysis

Tobacco smoke contains more than 4,000 chemicals, and 44 compounds have been classified as human carcinogens. Toxicity can be both mainstream smoke as well as the constituents of environmental tobacco smoke. In the light of this evidence, work is intensifying on assessing exposure on the basis of the results of tests performed to quantify the amounts of suitable environmental tobacco smoke constituent biomarkers in samples of biological materials taken from humans. The authors present information on the composition of tobacco smoke and its toxicity to humans, and also data on the methodologies applicable in the analysis of biological material samples for their biomarker content.

Analysis of Markers of Exposure to Constituents of Environmental Tobacco Smoke (ETS)

Tobacco smoke is a complex mixture of more than 4000 chemical compounds, many of which are harmful to human health. These compounds belong to various chemical classes, including amides, imides, lactams, carboxylic acids, aldehydes, ketones, alcohols, phenols, amines, hydrocarbons, ethers, and inorganic compounds. There are three types of tobacco smoke streams: the mainstream, the sidestream, and environmental tobacco smoke (ETS). In view of the threat to human health resulting from exposure to either of these tobacco smoke streams or to ETS, it has become necessary to monitor levels of substances characteristic of tobacco smoke, i.e., “biomarkers,” The biomonitoring of toxic substances involves the analysis of biological materials taken from human subjects (urine, saliva, placenta, sweat, blood) for the presence of selected biomarkers. This article presents information on sample preparation techniques and analytical methodologies applicable in the analysis of biological materials for the presence of biomarkers and also on the levels of biomarkers present in samples of biological material taken from people exposed to various degrees to the harmful actions of substances present in tobacco smoke.

Influence of relative humidity and gaseous ammonia on the nicotine sorption to indoor materials

Sorption of nitrogen-containing organic constituents of environmental tobacco smoke may be influenced by ammonia, a common indoor gas, and relative humidity (RH). We quantified sorption kinetics and equilibria of nicotine with stainless steel, cotton-polyester curtain, and polypropylene carpet at 0%, 50%, and 90% RH and in the presence of ammonia using a 10-l stainless steel chamber. Nicotine was introduced into the chamber by flash evaporating 50 μl of pure liquid. Kinetic sorption parameters were determined by fitting a mass balance model to experimental results using a nonlinear regression. Results show that an equilibrium partition coefficient, k(e) , of nicotine tended to increase as the RH increased for the curtain and carpet. Adsorbed water may contribute to an increase in available sites for nicotine sorption on the surface. In the presence of 20- and 40-ppm NH(3) , the values of k(e) for carpet were decreased by 14-40% at 50% and 90% RH, but the effect of NH(3) was not observed at 0% RH. The values of k(e) ranged from 54 to 152 m. Our findings indicate the relative importance of nicotine sorption to surfaces is dependent on the relative humidity and the presence of ammonia. This research demonstrates that relative humidity and gaseous ammonia can influence nicotine sorption to common indoor surfaces, i.e., curtains and carpets. Increasing the relative humidity from dry to modest appears to enhance the sorptive capacity. Presence of the typical range of gaseous ammonia concentrations can reduce the nicotine sorption in a humid environment but does not affect the sorptive capacity in the absence of added water. Thus, studies on the dynamic sorption of other alkaloids or amine constituents of environmental tobacco smoke to indoor surfaces should consider the impact of water vapor concentration because of the interaction of water with the surface and sorbates. Furthermore, the mixture of gaseous amines may participate in adsorption site competition.

Comparison of Environmental Tobacco Smoke (ETS) Concentrations Generated by an Electrically Heated Cigarette Smoking System and a Conventional Cigarette

Smoking conventional lit-end cigarettes results in exposure of nonsmokers to potentially harmful cigarette smoke constituents present in environmental tobacco smoke (ETS) generated by sidestream smoke emissions and exhaled mainstream smoke. ETS constituent concentrations generated by a conventional lit-end cigarette and a newly developed electrically heated cigarette smoking system (EHCSS) that produces only mainstream smoke and no sidestream smoke emissions were investigated in simulated “office” and “hospitality” environments with different levels of baseline indoor air quality. Smoking the EHCSS (International Organisation for Standardization yields: 5 mg tar, 0.3 mg nicotine, and 0.6 mg carbon monoxide) in simulated indoor environments resulted in significant reductions in ETS constituent concentrations compared to when smoking a representative lit-end cigarette (Marlboro: 6 mg tar, 0.5 mg nicotine, and 7 mg carbon monoxide). In direct comparisons, 24 of 29 measured smoke constituents (83%) showed mean reductions of greater than 90%, and 5 smoke constituents (17%) showed mean reductions between 80% and 90%. Gas–vapor phase ETS markers (nicotine and 3-ethenylpyridine) were reduced by an average of 97% (range 94–99%). Total respirable suspended particles, determined by online particle measurements and as gravimetric respirable suspended particles, were reduced by 90% (range 82–100%). The mean and standard deviation of the reduction of all constituents was 94 ± 4%, indicating that smoking the new EHCSS in simulated “office” and “hospitality” indoor environments resulted in substantial reductions of ETS constituents in indoor air.

Environmental tobacco smoke (ETS) evaluation of a third-generation electrically heated cigarette smoking system (EHCSS)

This sub-study of a randomized, controlled, forced-switching, open-label, parallel-group, clinical study compared environmental tobacco smoke (ETS) produced when 60 male and female adult smokers switched to a third-generation electrically heated cigarette smoking system (EHCSS), continued to smoke a conventional cigarette (CC), or stopped smoking (No-smoking). Concentrations of air constituents including respirable suspended particulate (RSP), carbon monoxide (CO), ammonia and total volatile organic compounds (TVOCs) and ETS markers including solanesol-related particulate matter (Sol-PM), ultraviolet absorbing particulate matter (UVPM), fluorescent particulate matter (FPM), nicotine and 3-ethenyl pyridine (3-EP) were measured in a ventilated, furnished conference room over a 2-h period on separate occasions for each smoking condition. When the EHCSS was used, concentrations of CO and most ETS markers were in the same range as during no-smoking. Concentrations of ammonia were reduced by 41% and concentrations of other selected constituents of ETS were reduced by 87–99% in the air of a room in which EHCSS cigarettes were smoked as compared to concentrations in the same room when conventional cigarettes were smoked. Switching from conventional cigarette smoking to the EHCSS resulted in substantial reductions in concentrations of several markers of environmental tobacco smoke.

Environmental Tobacco Smoke: Incomplete Research or Author Bias?

Environmental Tobacco Smoke: Incomplete Research or Author Bias?

Exposure to environmental tobacco smoke in German restaurants, pubs and discotheques

In contrast to other countries, there is an on-going debate but still no smoke-free legislation in Germany. Exposure to environmental tobacco smoke (ETS) in hospitality venues is assumed to be high, but air quality data are lacking. Therefore, the aim of our study was to perform a comprehensive exposure assessment by analysing the indoor air concentration of toxic or carcinogenic ETS compounds in restaurants, pubs, and discotheques. Active sampling of indoor air was conducted for 4 h during the main visiting hours in 28 hospitality venues. Polycyclic aromatic hydrocarbons (PAH), volatile organic compounds (VOC), aldehydes/ketones, and cadmium were analysed. In addition, particle mass concentration was assessed with two different methods and particle number concentration (PNC) was determined. Median nicotine levels were 15 microg/m(3) in restaurants, 31 microg/m(3) in pubs, and 193 microg/m(3) in discotheques. Across these three sampling site categories median levels of 3-ethenylpyridine ranged from 3 to 24 microg/m(3), median levels of benzene from 8 to 20 microg/m(3), median levels of cadmium from 3 to 10 ng/m(3), and median levels of the sum of 16 PAH according to US-EPA from 215 to 375 ng/m(3), respectively. Median PM(2.5) mass concentration assessed gravimetrically varied between 178 and 808 microg/m(3) and PNC between 120,000 and 210,000 particles per cm(3) in restaurants, pubs, and discotheques. The majority of the particles had a size of 0.01-0.5 microm. Concentrations of ETS compounds were always highest in discotheques. The strong correlation between ETS-specific markers (nicotine, 3-ethenylpyridine) and PM(2.5), PAH, VOC, aldehydes/ketones, and cadmium indicated ETS as main source of these toxic or carcinogenic substances. In conclusion, indoor air concentrations of ETS constituents were high in German hospitality venues and represented a substantial health threat. Effective measures to protect patrons and staff from ETS exposure are necessary from a public health point of view.

Environmental Tobacco Smoke Exposure in German Discotheques: Measurement of Particulate Matter, Volatile Organic Compounds and Polycyclic Aromatic Hydrocarbons

P-292 Introduction: Environmental tobacco smoke (ETS) is by far the most significant indoor air quality issue in health terms and has been classified as carcinogenic to humans. In contrast to other European countries, in Germany smoking in public places is not restricted. The aim of our study was to assess the extent of exposure to constituents of environmental tobacco smoke in discotheques as an important public exposure site for adolescents. Methods: Active sampling of indoor air was performed during 4 hours at night in 10 discotheques in two German cities. Airborne fine particulate matter (PM2.5) was measured either cumulatively by gravimetry using a medium volume sampler or continuously as PM mass concentrations by using an aerosol spectrometer. Vapour phase samples were analysed for volatile organic compounds (VOC) using thermodesorption and a gas chromatograph/mass spectrometer (GC/MS). Aldehydes in air were sampled with XPoSure™ sampler and analysed by high pressure liquid chromatography (HPLC). Gaseous/particulate polycyclic aromatic hydrocarbons (PAH) were determined in extracts of PM2.5 filter and PU-foam by GC/MS. Concentrations are given as geometric means (GM) of the values of 10 discotheques with geometric standard deviation (GSD). Results: Geometric mean concentrations of those VOCs known as gas phase markers of ETS were for nicotine 203 μg/m3 (GSD 1.2) and for 3-ethenyl pyridine 20 μg/m3 (GSD 1.2). The values of relevant carcinogens as constituents of ETS ranged between 12 and 50 μg/m3 in case of benzene (GM 22, GSD 1.2) and between 83 and 570 μg/m3 in case of acetaldehyde (GM 185, GSD 1.2). The geometric mean concentration of the sum of those 16 PAHs indicated as priority pollutants by the U.S. EPA was 391 ng/m3 (GSD 1.1). PM2.5 concentrations assessed either by gravimetry or by aerosol spectrometry correlated very well (pearson correlation coefficient r=0.97, p<0.001). The geometric mean concentration of PM2.5 measured by aerosol spectrometry was 884 μg/m3 (GSD 1.3) and of PM10 1005 μg/m3 (GSD 1.3). Levels of nicotine correlated with levels of 3-ethenyl pyridine (r=0.80, p<0.01), benzene (r=0.84, p<0.01), PM2.5 (r=0.67, p<0.05) and PM10 (r=0.66, p<0.05). Discussion: Though it is known that the exposure to ETS in discotheques is elevated compared to other public places such as restaurants or pubs, our study demonstrated concentrations of ETS-specific and of ETS-related compounds which were considerably higher than those levels reported before even for discotheques in several countries. Conclusion: Exposure to ETS in German discotheques is intense and represents a health threat.

Gas- and particulate-phase specific tracer and toxic organic compounds in environmental tobacco smoke

Cigarette smoke constituents are worthy of concern and characterized as carcinogens. Different experiment conditions may affect the environmental tobacco smoke (ETS) constituents. A study was undertaken in a 75.5-m 3 spare office to evaluate ETS constituents in a real environment. Thirty-four volatile organic compounds (VOCs) including three ETS tracers: nicotine, 2,5-dimethylfuran and 3-ethenylpyridine (3-EP), 19 carbonyl compounds, 54 semi-volatile compounds (24 polycyclic aromatic hydrocarbons (PAHs) and 30 alkanes) as well as CO and total particulate matter (TPM) from 15 leading commercial brands were determined. ETS constituents did not increase with increasing cigarette tar. ETS tracers nicotine and 3-EP were affected greatly due to more sorption and surface reactions in real world compared to other studies conducted in chamber, which resulted in 2–5 times lower. Benzene, toluene, ethylbenzene, xylenes, acrolein, 2-butanone and the high molecular weight compounds exhibited little affect. Pearson correlation analyses show that gas-phase and particulate-phase ETS tracers did not show significant correlation, but within each homologue many of compounds correlated significantly. Indole and cholesta-3,5-diene were also detected in ETS. These results may be useful in efforts to better understand the health effect of ETS exposure and source apportionment.

Inhibition of Neovascularization by Environmental Agents

The formation of new blood vessels, neovascularization, occurs by two unique processes: vasculogenesis, the de novo assembly of blood vessels from angioblast precursors, and angiogenesis, the formation of new capillary sprouts from preexisting vessels. There are many potential targets by which environmental pollutants may inhibit neovascularization and thus there are many possible phenotypic outcomes. Two examples of environmental pollutants that have been demonstrated to inhibit neovascularization include 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a prototypical halogenated aromatic hydrocarbon, and constituents found in environmental tobacco smoke. Studies have shown that TCDD disrupts neoangiogenesis by inhibiting the expression of angiogenic stimuli as well as by reducing the responsiveness of endothelial cells to those stimuli. Additionally, studies have shown that constituents of environmental tobacco smoke, including pyradine and pyrazine derivatives, can potently inhibit the angiogenic process of branching as well as the vasculogenic process involved in capillary plexus formation. Further, the inhibition of neovascularization by either TCDD or environmental tobacco smoke constituents is associated with reduced endothelial cell proliferation and altered expression of extracellular matrix proteins. Future research that identifies the specific angiogenic signaling pathways that are disrupted by these pollutants will improve our ability to assess their risk to human health. Finally, it is likely that many other environmental pollutants impact neovascularization; however, very few have been studied in sufficient detail. Thus, additional research also is needed to identify those environmental agents that mediate their toxicity by disrupting neovascularization.

Biomarkers in maternal and newborn blood indicate heightened fetal susceptibility to procarcinogenic DNA damage.

Polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene (BaP) are widespread air contaminants released by transportation vehicles, power generation, and other combustion sources. Experimental evidence indicates that the developing fetus is more susceptible than the adult to carcinogenic effects of PAHs, although laboratory studies in rodents suggest that the dose to fetal tissues is an order of magnitude lower than that to maternal tissues. To assess fetal versus adult susceptibility to PAHs and environmental tobacco smoke (ETS), we compared carcinogen-DNA adducts (a biomarker associated with increased cancer risk) and cotinine (a biomarker of tobacco smoke exposure) in paired blood samples collected from mothers and newborns in New York City. We enrolled 265 nonsmoker African-American and Latina mother–newborn pairs in New York City between 1997 and 2001 (estimated average ambient air BaP concentrations < 0.5 ng/m3). Despite the estimated 10-fold lower fetal dose, mean levels of BaP-DNA adducts as determined by high-performance liquid chromatography–fluorescence were comparable in paired New York City newborn and maternal samples (0.24 adducts per 108 nucleotides, 45% of newborns with detectable adducts vs. 0.22 per 108 nucleotides, 41% of mothers with detectable adducts). However, by the Wilcoxon signed-rank test, the levels in newborns were higher (p = 0.02). Mean cotinine was higher in newborns than in mothers (1.7 ng/mL, 47% detectable vs. 1.28 ng/mL, 44% detectable). Consistent with our prior study in a Caucasian Polish population, these results indicate increased susceptibility of the fetus to DNA damage and reduced ability to clear ETS constituents. The findings have implications for risk assessment, given the need to protect children as a sensitive subset of the population.

Gas-phase organics in environmental tobacco smoke: 2. Exposure-relevant emission factors and indirect exposures from habitual smoking

Abstract Sorption of emitted gas-phase organic compounds onto material surfaces affects environmental tobacco smoke (ETS) composition and exposures indoors. We have introduced a new metric, the exposure relevant emission factor (EREF) that accounts for sorptive uptake and reemission to give the mass of individual ETS constituents available for exposure over a day in which smoking occurs. This paper describes month-long experiments to investigate sorption effects on EREFs and potential ETS exposures under habitual smoking conditions. Cigarettes were smoked in a 50-m3 furnished room over a 3-h period 6–7 days per week, with continuous ventilation at 0.3, 0.6, or 2.1 h−1. Organic gas concentrations were measured every few days over 4-h “smoking”, 10-h “post-smoking” and 10-h “background” periods. Concentration patterns of volatile ETS components including 1,3-butadiene, benzene and acrolein were similar to those calculated for a theoretical non-sorbing tracer, indicating limited sorption. Concentrations of ETS tracers, e.g. 3-ethenylpyridine (3-EP) and nicotine, and lower volatility toxic air contaminants including phenol, cresols, and naphthalene increased as experiments progressed, indicating mass accumulation on surfaces and higher desorption rates. Daily patterns stabilized after week 2, yielding a steady daily cycle of ETS concentrations associated with habitual smoking. EREFs for sorbing compounds were higher under steady cycle versus single-day smoking conditions by ∼50% for 3-EP, and by 2–3 times for nicotine, phenol, cresols, naphthalene, and methylnaphthalenes. Our results provide relevant information about potential indirect exposures from residual ETS (non-smoker enters room shortly after smoker finishes) and from reemission, and their importance relative to direct exposures (non-smoker present during smoking). Under the conditions examined, indirect exposures accounted for a larger fraction of total potential exposures for sorbing versus non-sorbing compounds, and at lower versus higher ventilation rates. Increasing ventilation can reduce indirect exposures to very low levels for non-sorbing ETS components, but indirect routes accounted for ∼50% of potential nicotine exposures during non-smoking periods at all ventilation rates.

An international survey of indoor air quality, ventilation, and smoking activity in restaurants: a pilot study.

During a pilot study of indoor air quality in restaurants, a survey was performed in 34 medium-priced restaurants in six countries in Asia, Europe, and North America using a uniform protocol. The concentration of selected constituents of environmental tobacco smoke (ETS) present in occupied areas was determined during lunch and dinner periods by measuring the levels of four particulate-phase markers and two gas-phase markers. The particulate-phase markers determined were respirable suspended particles, ultraviolet particulate matter, fluorescing particulate matter, and solanesol particulate matter. The gas-phase markers were nicotine and 3-ethenylpyridine (3-EP). Correlation between the markers was investigated to explore an improved monitoring approach. It was concluded that at least one marker in each phase was necessary to describe adequately the ETS load. An assessment was made of the ventilation system in each restaurant, and effective ventilation rates were determined based on CO(2) measurements. Smoking activity was also monitored. These data were used to model nicotine and 3-EP concentrations that resulted in a satisfactory prediction of their levels, especially at the higher concentrations. A total number of 1370 questionnaires were returned by the restaurant patrons in five countries. In some countries, dissatisfaction rates above 20% were observed for draft, freshness of air, and noise. The dissatisfaction rates related to tobacco smoke were less than 20%, which is lower than would be predicted based on measured ETS levels. Based on the results of this international pilot study, recommendations are given for future studies of this type.

Environmental tobacco smoke removal capability of activated carbon

Removal of gaseous and vapor constituents of environmental tobacco smoke (ETS) by activated carbons in a packed bed arrangement was studied under dynamic conditions and was compared with that by silica gel and molecular sieve 13X. ETS is a mixture of sidestream smoke and exhaled mainstream smoke, and it consists of various organic and inorganic compounds, trace heavy metals, and particulate matters. Due to the complex nature of ETS-air mixture, its removal from indoors is a challenging task. For experimentation in a laboratory, the ETS was produced from a specially designed smoking apparatus that simulated the puffng of a cigarette by a person. Air containing ETS was passed through a bed containing about 25 grams of activated carbon at room temperature. The flow rate of air-ETS mixture through the bed was 4000 cm3/min. The relative humidity of the air was 50% and contained about 35 to 40 ppm of hydrocarbons as measured as methane-equivalent. The number of particles in the inlet air stream were in the range of 30,000 to 35,000 particles/cm3. About 60% of hydrocarbons present in ETS were removed at these operating conditions for a period of about 70 hours. Based on 15 adsorption and regeneration cycles, it was noted that the carbon bed did not loose its capacity for ETS significantly as indicated by the BET surface area and water adsorption data. At the beginning of an adsorption cycle, the carbon bed captured a significant number of particles. However, the bed rapidly lost its particle capture effciency as the experiment progressed. The number of particles in the outlet air stream was found to be the same as that of the inlet stream within five minutes.

Gas-phase organics in environmental tobacco smoke. 1. Effects of smoking rate, ventilation, and furnishing level on emission factors.

We measured the emissions of 26 gas-phase organic compounds in environmental tobacco smoke (ETS) using a model room that simulates realistic conditions in residences and offices. Exposure-relevant emission factors (EREFs), which include the effects of sorption and re-emission over a 24-h period, were calculated by mass balance from measured compound concentrations and chamber ventilation rates in a 50-m3 room constructed and furnished with typical materials. Experiments were conducted at three smoking rates (5, 10, and 20 cigarettes day(-1)), three ventilation rates (0.3, 0.6, and 2 h(-1)), and three furnishing levels (wallboard with aluminum flooring, wallboard with carpet, and full furnishings). Smoking rate did not affect EREFs, suggesting that sorption was linearly related to gas-phase concentration. Furnishing level and ventilation rate in the model room had little effect on EREFs of several ETS compounds including 1,3-butadiene, acrolein, acrylonitrile, benzene, toluene, and styrene. However, sorptive losses at low ventilation with full furnishings reduced EREFs for the ETS tracers nicotine and 3-ethenylpyridine by as much as 90 and 65% as compared to high ventilation, wallboard/aluminum experiments. Likewise, sorptive losses were 40-70% for phenol, cresols, naphthalene, and methylnaphthalenes. Sorption persisted for many compounds; for example, almost all of the sorbed nicotine and most of the sorbed cresol remained sorbed 3 days after smoking. EREFs can be used in models and with ETS tracer-based methods to refine and improve estimates of exposures to ETS constituents.