Release of volatile organic compounds from textile floor coverings in higher temperatures

The effect of temperatures 23 degrees C, 29 degrees C, and 50 degrees C on emission of 4-phenylcyclohexene (4-PC), styrene, total volatile organic compounds (VOCs) and formaldehyde from textile floor coverings with textile backing and styrene/butadiene latex precoat was examined. Tested coverings didn't show emission of styrene and formaldehyde. At 23 degrees C and 29 degrees C two tested coverings showed emission of 4-PC on low level. The higher emission was observed from all coverings at 50 degrees C. VOCs emission from coverings increased with increasing of temperature, especially at 50 degrees C. In conclusion some of new textile floor coverings can cause contamination of indoor air after application of sub-floor heating. Contamination, however, will decrease with time.     

室内材料中挥发性有机物释放模式的研究进展

室内材料中释放的挥发性有机化合物（ＶＯＣｓ）是造成室内空气污染的主要原因之一。ＶＯＣｓ的释放特性是室内空气质量研究的重要组成部分。可精确控制条件的暴露小室技术已成功地用于ＶＯＣｓ释放特性的研究。该技术可用于建立ＶＯＣｓ释放浓度随时间变化的模式，进而也可建立ＶＯＣｓ释放率随时间变化的模式。本文综述了室内材料中挥发性有机化合物的释放模式，阐述了释放过程的基本原理、影响参数和不同释放模式的应用进展。从目前的研究状况来看，单纯挥发模式、稀释模式及蒸汽压模式由于没有考虑到室内普遍存在的吞吐效应的影响，故其应用受到限制。吞吐效应模式是一种比较全面的释放模式，能够较好地描述室内材料中ＶＯＣｓ的释放特性，具有广泛的应用前景。     

Concentrations of volatile organic compounds at a building with health and comfort complaints

For four separate periods over a 1-yr span, the concentrations of volatile organic compounds (VOCs) have been measured at a facility with a history of occupant complaints. The reported symptoms were characteristic of "sick building syndrome." This study was initiated to determine if VOC levels were higher than those measured in "complaint-free" buildings and, if so, to identify sources and other factors that might contribute to the elevated concentrations. VOCs were collected with passive samplers, using a sampling interval that lasted from 3 to 4 weeks. Following collection, the samplers were extracted, and the compounds in the extract were separated and identified using standard gas chromatographic-mass spectrometric procedures. Over 40 different organic compounds with concentrations in excess of 1 microgram/m3 were identified; several species had values greater than 100 micrograms/m3. For each of the first three sampling periods, the total concentration of VOCs detected using this methodology was in excess of 3 mg/m3. Sources of the identified compounds included cleaning products, floor wax, latex paints, and reentrained motor vehicle exhaust. However, the dominant source was the hydraulic system for the buildings' elevators. Compounds were volatilizing from the hydraulic fluid used in this system. Neither the elevator shafts nor the mechanical room housing the fluid reservoirs were vented to the outside. The problem was compounded by the relatively small amount of outside air used for ventilation at this facility (less than 6 L/sec [12 cfm]/occupant or about 1/4 air change/hr). At such low ventilation rates, compounds with strong sources can achieve high steady-state concentrations within the facility. Recommendations have been made to reduce the VOC levels at this site. Although implementing the recommendations will be costly, even a slight improvement in employee productivity will offset these costs.     

Sources of air pollutants indoors: VOC and fine particulate species.

The average concentrations of a large number of fine particle aerosol and VOC species measured in ten Boise, Idaho, residences in wintertime have been apportioned according to their contributions from all inside sources and all outside sources, regarded as two composite source categories. Air change rates for the residences were in the range 0.2-0.8 hr-1. None of the residences had obvious major indoor sources (smokers, woodburning appliances, etc.). The two category apportionment was accomplished through use of the single chamber mass balance indoor air quality model given by Dockery and Spengler. The method depends on the availability of average concentrations measured outside each residence during the same sampling periods used for the inside measurements, and on the ability to identify one or more species that have negligible indoor sources. Calculated infiltration factors (the indoor/outdoor ratio in the absence of indoor sources) for fine particle species averaged 0.5, and varied in a reasonably way with measured air change rates, essentially independent of species. Infiltration factors for the VOCs were indistinguishable from unity. The relative importance of indoor and outdoor sources to measured indoor concentrations showed great variation between species and between residences. In most homes the indoor source contribution was dominant for fine particle Si, Ca, and Fe, while the infiltration contribution was dominant for S, K, Pb, Zn, mass, and extractable organic matter. Indoor contributions to individual VOCs were frequently very large at a few residences and negligible at the others.     

Changes in immunological and hematological parameters of female residents exposed to volatile organic compounds in the city of Kaohsiung, Taiwan

The objective of this study was to assess the effects, if any, of volatile organic compounds (VOCs) in the ambient air of Kaohsiung, Taiwan, on certain hematological and immunological parameters of 153 female study participants. The major source of VOCs was vehicle emissions. The participants were selected from three areas, each area at a different distance from a freeway. Results indicated that total concentrations of VOCs and a subgroup of 25 VOCs (VOC25) ranged from 250 to 335 ppb and 89 to 113 ppb, respectively. The distribution of VOC concentrations did not correlate with distance from the freeway. The participants living in the area with higher VOC concentrations had significantly higher abnormalities of white blood cells (WBC) and hemoglobin (Hb). In addition, IgG and IgA counts were significantly lower for the participants in the area with higher VOCs than for participants in the area with lower VOCs. This finding indicates that VOCs in ambient air may suppress immunological variables.     

Asthmatic symptoms and volatile organic compounds, formaldehyde, and carbon dioxide in dwellings.

OBJECTIVES--As a part of the worldwide European Community respiratory health survey, possible relations between symptoms of asthma, building characteristics, and indoor concentration of volatile organic compounds (VOCs) in dwellings were studied. METHODS--The study comprised 88 subjects, aged 20-45 years, from the general population in Uppsala, a mid-Swedish urban community, selected by stratified random sampling. Room temperature, air humidity, respirable dust, carbon dioxide (CO2), VOCs, formaldehyde, and house dust mites were measured in the homes of the subjects. They underwent a structured interview, spirometry, peak expiratory flow (PEF) measurements at home, methacholine provocation test for bronchial hyperresponsiveness, and skin prick tests. In addition, serum concentration of eosinophilic cationic protein (S-ECP), blood eosinophil count, and total immunoglobulin E (S-IgE) were measured. RESULTS--Symptoms related to asthma were more common in dwellings with house dust mites, and visible signs of dampness or microbial growth in the building. Significant relations were also found between nocturnal breathlessness and presence of wall to wall carpets, and indoor concentration of CO2, formaldehyde, and VOCs. The formaldehyde concentration exceeded the Swedish limit value for dwellings (100 micrograms/m3) in one building, and CO2 exceeded the recommended limit value of 1000 ppm in 26% of the dwellings, showing insufficient outdoor air supply. Bronchial hyperresponsiveness was related to indoor concentration of limonene, the most prevalent terpene. Variability in PEF was related to two other terpenes; alpha-pinen and delta-karen. CONCLUSION--Our results suggest that indoor VOCs and formaldehyde may cause asthma-like symptoms. There is a need to increase the outdoor air supply in many dwelling, and wall to wall carpeting and dampness in the building should be avoided. Improved indoor environment can also be achieved by selecting building materials, building construction, and indoor activities on the principle that the emission of volatile organic compounds should be as low as reasonably achievable, to minimise symptoms related to asthma due to indoor air pollution.     

Migration of volatile organic compounds from attached garages to residences: a major exposure source

Vehicle garages often contain high concentrations of volatile organic compounds (VOCs) that may migrate into adjoining residences. This study characterizes VOC concentrations, exposures, airflows, and source apportionments in 15 single-family houses with attached garages in southeast Michigan. Fieldwork included inspections to determine possible VOC sources, deployment of perfluorocarbon tracer (PFT) sources in garages and occupied spaces, and measurements of PFT, VOC, and CO(2) concentrations over a 4-day period. Air exchange rates (AERs) averaged 0.43+/-0.37 h(-1) in the houses and 0.77+/-0.51 h(-1) in the garages, and air flows from garages to houses averaged 6.5+/-5.3% of the houses' overall air exchange. A total of 39 VOC species were detected indoors, 36 in the garage, and 20 in ambient air. Garages showed high levels of gasoline-related VOCs, e.g., benzene averaged 37+/-39 microg m(-3). Garage/indoor ratios and multizone IAQ models show that nearly all of the benzene and most of the fuel-related aromatics in the houses resulted from garage sources, confirming earlier reports that suggested the importance of attached garages. Moreover, doses of VOCs such as benzene experienced by non-smoking individuals living in houses with attached garages are dominated by emissions in garages, a result of exposures occurring in both garage and house microenvironments. All of this strongly suggests the need to better control VOC emissions in garages and contaminant migration through the garage-house interface.     

Personal exposure meets risk assessment: a comparison of measured and modeled exposures and risks in an urban community

Human exposure research has consistently shown that, for most volatile organic compounds (VOCs), personal exposures are vastly different from outdoor air concentrations. Therefore, risk estimates based on ambient measurements may over- or underestimate risk, leading to ineffective or inefficient management strategies. In the present study we examine the extent of exposure misclassification and its impact on risk for exposure estimated by the U.S. Environmental Protection Agency (U.S. EPA) Assessment System for Population Exposure Nationwide (ASPEN) model relative to monitoring results from a community-based exposure assessment conducted in Baltimore, Maryland (USA). This study is the first direct comparison of the ASPEN model (as used by the U.S. EPA for the Cumulative Exposure Project and subsequently the National-Scale Air Toxics Assessment) and human exposure data to estimate health risks. A random sampling strategy was used to recruit 33 nonsmoking adult community residents. Passive air sampling badges were used to assess 3-day time-weighted-average personal exposure as well as outdoor and indoor residential concentrations of VOCs for each study participant. In general, personal exposures were greater than indoor VOC concentrations, which were greater than outdoor VOC concentrations. Public health risks due to actual personal exposures were estimated. In comparing measured personal exposures and indoor and outdoor VOC concentrations with ASPEN model estimates for ambient concentrations, our data suggest that ASPEN was reasonably accurate as a surrogate for personal exposures (measured exposures of community residents) for VOCs emitted primarily from mobile sources or VOCs that occur as global "background" source pollutant with no indoor source contributions. Otherwise, the ASPEN model estimates were generally lower than measured personal exposures and the estimated health risks. ASPEN's lower exposures resulted in proportional underestimation of cumulative cancer risk when pollutant exposures were combined to estimate cumulative risk. Median cumulative lifetime cancer risk based on personal exposures was 3-fold greater than estimates based on ASPEN-modeled concentrations. These findings demonstrate the significance of indoor exposure sources and the importance of indoor and/or personal monitoring for accurate assessment of risk. Environmental health policies may not be sufficient in reducing exposures and risks if they are based solely on modeled ambient VOC concentrations. Results from our study underscore the need for a coordinated multimedia approach to exposure assessment for setting public health policy.     

Validation for a recirculation model

Recent Clean Air Act regulations designed to reduce volatile organic compound (VOC) emissions have placed new restrictions on painting operations. Treating large volumes of air which contain dilute quantities of VOCs can be expensive. Recirculating some fraction of the air allows an operator to comply with environmental regulations at reduced cost. However, there is a potential impact on employee safety because indoor pollutants will inevitably increase when air is recirculated. A computer model was developed, written in Microsoft Excel 97, to predict compliance costs and indoor air concentration changes with respect to changes in the level of recirculation for a given facility. The model predicts indoor air concentrations based on product usage and mass balance equations. This article validates the recirculation model using data collected from a C-130 aircraft painting facility at Hill Air Force Base, Utah. Air sampling data and air control cost quotes from vendors were collected for the Hill AFB painting facility and compared to the model's predictions. The model's predictions for strontium chromate and isocyanate air concentrations were generally between the maximum and minimum air sampling points with a tendency to predict near the maximum sampling points. The model's capital cost predictions for a thermal VOC control device ranged from a 14 percent underestimate to a 50 percent overestimate of the average cost quotes. A sensitivity analysis of the variables is also included. The model is demonstrated to be a good evaluation tool in understanding the impact of recirculation.     

Development of a combined real time monitoring and integration analysis system for volatile organic compounds (VOCs)

A combined integration analysis and real time monitoring (Peak Capture System) system was developed for volatile organic compounds (VOCs). Individual integration analysis and real time monitoring can be used to qualitatively and quantitatively analyze VOCs in the atmosphere and in indoor environments and determine the variation in total VOC (TVOC) concentration with time, respectively. In the Peak Capture System, real time monitoring was used to predict future elevations in the TVOC concentration (peak), and this was used an indicator of when to collect (capture) ambient air samples for integration analysis. This enabled qualitative and quantitative analysis of VOCs when the TVOC concentration was high. We developed an algorithm to predict variation in the TVOC concentration, and constructed an automatic system to initiate air sampling for integration analysis. With the system, auto-sampling and analysis of VOCs in a conventional house were conducted. In comparison with background concentrations, the results of peak analysis enabled identification of compounds whose concentration rose. This also enabled an evaluation of possible VOC emission sources.     

Indoor air quality and health problems associated with damp floor coverings

Objectives To study the relationship between a high incidence of bronchial asthma among employees working in an office building and an indoor air problem related to the degradation of polyvinyl chloride (PVC) floor coverings in the building. The indoor air measurements and results of renovations are also described.Methods Employees symptoms were surveyed by a questionnaire, and the incidence of asthma was calculated from the medical records for 1997–2000. The quality of indoor air was assessed by microbial sampling and by investigation of the building for possible moisture damage. Indoor air was sampled for volatile organic compounds (VOCs) through Tenax adsorbent tubes. In situ volatile emission measurements from the concrete floor were performed via the field and laboratory emission cell (FLEC) method.Results In an office with approximately 150 employees, eight new cases of asthma were found in 4 years. In addition, the workers complained of respiratory, conjunctival and nasal symptoms. Emissions indicating the degradation of plastic floor coverings (e.g. 2-ethyl-1-hexanol, 1-butanol) were found in the indoor air and floor material samples. The plastic floor coverings, adhesives and the levelling layers were carefully removed from 12 rooms. The VOCs had diffused into the underlying concrete slabs. The concrete was warmed to remove the diffused VOCs from these areas. After the repairs the concentrations of the VOCs indicating the degradation of PVC, decreased, as did the prevalence of the employees symptoms and several asthma patients need for medication.Conclusions The workers in the office building complained of several respiratory, conjunctival and dermal symptoms. The incidence of adult-onset asthma was approximately nine-times higher than that among Finns employed in similar work. The most probable single cause of the indoor air problem was the degradation of the plastic floor coverings.     

Occurrence and potential human-health relevance of volatile organic compounds in drinking water from domestic wells in the United States

BACKGROUND: As the population and demand for safe drinking water from domestic wells increase, it is important to examine water quality and contaminant occurrence. A national assessment in 2006 by the U.S. Geological Survey reported findings for 55 volatile organic compounds (VOCs) based on 2,401 domestic wells sampled during 1985-2002. OBJECTIVES: We examined the occurrence of individual and multiple VOCs and assessed the potential human-health relevance of VOC concentrations. We also identified hydrogeologic and anthropogenic variables that influence the probability of VOC occurrence. METHODS: The domestic well samples were collected at the wellhead before treatment of water and analyzed for 55 VOCs. Results were used to examine VOC occurrence and identify associations of multiple explanatory variables using logistic regression analyses. We used a screening-level assessment to compare VOC concentrations to U.S. Environmental Protection Agency maximum contaminant levels (MCLs) and health-based screening levels. RESULTS: We detected VOCs in 65% of the samples; about one-half of these samples contained VOC mixtures. Frequently detected VOCs included chloroform, toluene, 1,2,4-trimethylbenzene, and perchloroethene. VOC concentrations generally were < 1 microg/L. One or more VOC concentrations were greater than MCLs in 1.2% of samples, including dibromochloropropane, 1,2-dichloropropane, and ethylene dibromide (fumigants); perchloroethene and trichloroethene (solvents); and 1,1-dichloroethene (organic synthesis compound). CONCLUSIONS: Drinking water supplied by domestic wells is vulnerable to low-level VOC contamination. About 1% of samples had concentrations of potential human-health concern. Identifying factors associated with VOC occurrence may aid in understanding the sources, transport, and fate of VOCs in groundwater.     

Occupational exposure to volatile organic compounds and mitigation by push-pull local exhaust ventilation in printing plants

The extensive use of multiple organic solvents in offset lithographic printing causing high emissions of volatile organic compounds (VOCs) indeed poses a serious risk to printing workers' health. In this study, indoor air quality (IAQ) assessments were carried out in seven printing plants and the main objectives were to understand the effect of VOC emissions on IAQ and develop effective mitigation measures to protect workers. The thorough gas chromatography/mass spectrometry (GC/MS) measurements showed that although a variety of VOCs were presented in the indoor air, none of them was found close to individual 8-h time-weighted average (TWA) of the occupational exposure limit (OEL). The additive effect was also found below the critical value of unity. However, short-term personal exposure to total volatile organic compounds (TVOCs) was exceedingly high when a print worker carried out blanket and ink roller cleaning procedures. Therefore, the occupational health risk was mainly due to repeated short-term exposures during intermittent VOC-emitting procedures rather than long-term exposure to background VOCs. Push-pull local exhaust ventilation (LEV) was identified as an effective mitigation measure. Computational fluid dynamics (CFD) analysis was conducted to study the push-pull LEV operation. It was found that there existed a threshold LEV air flow rate for an abrupt reduction in the worker's exposure to VOCs. The reduction was less sensitive when the LEV airflow was further increased beyond the threshold. These phenomena, consistent with experimental results reported by other investigators, were explained by detailed CFD analysis showing the competition between the general ventilation and the push-pull LEV to become the dominating driving force for the resultant local flow pattern.     

Indoor air pollution due to 2-ethyl-1-hexanol airborne concentrations, emission sources and subjective symptoms in classroom users

OBJECTIVE: 2-Ethyl-1-hexanol (2E1H) is a volatile organic compound (VOC) which seldom attracts attention in Japan. This study aimed at clarifying changes in its concentration over time, emission sources, and students' symptoms in classrooms of a university building where indoor air was found to be markedly polluted with 2E1H. METHODS: From March 2001 through September 2002, we measured VOC concentrations in Building A, constructed in 1998, as well as Building B (Sept. 2002), constructed over 30 years ago and considered as a control. Airborne concentrations of 13 carbonyl compounds were quantified with diffusive samplers and high-performance liquid chromatography, and those of 41 other VOCs with an active sampling method using charcoal tubes and a gas chromatograph with a mass spectrometer (GC-MS). In August 2002, we also measured VOC emissions from the floors using double-cylinder chambers and the airborne concentrations of phthalate esters by filtration sampling, both by GC-MS. Subjective symptoms in 315 student classroom users in Building A and 275 in Building B were surveyed in July 2002 with anonymous self-administered questionnaires. RESULTS: 2E1H concentrations in Building A, which exceeded the Japanese recommended threshold of total VOCs (400 microg/m3) in some measurements, tended to be lower in winter and higher in summer, and did not show any tendency for decrease over time. No association was found between indoor concentrations of phthalate esters and those of 2E1H. The concentrations clearly differed between rooms, related to emission rates from the floors. Carpeting materials had been placed directly on the concrete floors in rooms with higher emission levels, whereas the carpeting materials and the concrete floor did not make contact in the room where emission was lower. The odds ratio for subjective symptoms with students in classrooms in Building A was not higher than in Building B where the 2E1H concentrations were low. However, a few students limited to Building A did complain of problems with the nasal passages, throat and lower airways. CONCLUSION: Compounds containing 2-ethyl-1-hexyl moiety are presumably hydrolyzed to emit 2E1H when the backing of carpeting material is in contact with concrete floors. Although no significant difference was observed in symptoms between the student groups in the two buildings, this was possibly due to the small sample size. Measures to prevent 2E1H emission and dose-response relationships in sensitive individuals should be studied further.     

Unmetabolized VOCs in urine as biomarkers of low level exposure in indoor environments

This study aimed to test the possible use of unmetabolized volatile organic compounds (VOCs) in urine as biomarkers of low-level indoor environmental exposure. Twenty-four subjects in 13 dwellings in a prefecture of Japan participated in this study. Air samples of the breathing zone were collected in the living room and bedroom, along with spot urine samples (before bedtime and first morning voids). Toluene, ethylbenzene, xylene isomers, styrene and p-dichlorobenzene in the air and urine samples were measured by gas chromatography/mass spectrometry. For the 21 subjects without solvent exposure at work, there were significant correlations between the time-weighted average air concentrations in the bedroom and morning urinary concentrations for toluene, o-xylene, total xylene and p-dichlorobenzene (correlation coefficients of 0.54, 0.61, 0.56 and 0.84, respectively). Multiple linear regression analysis showed only air VOCs in the bedroom influenced the morning urinary VOC concentrations. We concluded that unmetabolized VOCs in the urine can provide a reliable biological indicator for air VOC exposures in non-occupational environments.     

The Los Angeles TEAM Study: personal exposures, indoor-outdoor air concentrations, and breath concentrations of 25 volatile organic compounds.

The U.S. Environmental Protection Agency and the California Air Resources Board studied the exposures of 51 residents of Los Angeles, California, to 25 volatile organic chemicals (VOCs) in air and drinking water in 1987. A major goal of the study was to measure personal, indoor, and outdoor air concentrations, and breath concentrations of VOCs in persons living in households that had previously been measured in 1984. Other goals were to confirm the marked day-night and seasonal differences observed in 1984; to determine room-to-room variability within homes; to determine source emission rates by measuring air exchange rates in each home; and to extend the coverage of chemicals by employing additional sampling and analysis methods. A total of 51 homes were visited in February of 1987, and 43 of these were revisited in July of 1987. The results confirmed previous TEAM Study findings of higher personal and indoor air concentrations than outdoor concentrations of all prevalent chemicals (except carbon tetrachloride); higher personal, indoor, and outdoor air concentrations in winter than in summer; and (in winter only) higher outdoor concentrations at night than in the daytime. New findings included the following: (1) room-to-room variability of 12-hour average concentrations was very small, indicating that a single monitor may be adequate for estimating indoor concentrations over this time span; (2) "whole-house" source emission rates were relatively constant during both seasons, with higher rates for odorous chemicals such as p-dichlorobenzene and limonene (often used in room air fresheners) than for other classes of chemicals; (3) breath concentrations measured during morning and evening were similar for most participants, suggesting the suitability of breath measurements for estimating exposure in the home; (4) limited data obtained on two additional chemicals-toluene and methylene chloride-indicated that both were prevalent at fairly high concentrations and that indoor air concentrations exceeded outdoor concentrations by a factor of about three.     

Comparison of outdoor and indoor mobile source-related volatile organic compounds between low- and high-floor apartments

The current study examined the hypothesis that there may be vertical variation in mobile source-related volatile organic compound (VOC) concentrations in high-rise apartment buildings. One hundred twelve homes in 56 high-rise apartment buildings with 10 or more stories participated in the study. Both the outdoor and the indoor air concentrations of three VOCs [methyl-tertiary butyl ether (MTBE), benzene, and toluene] were significantly higher for the low-floor apartments than for the high-floor apartments (P < 0.05). The median outdoor concentrations were 5.4, 6.8, and 29.1 microgram/m3, respectively, for the low-floor apartments, yet 4.4, 4.3, and 21.9 microgram/m3, respectively, for the high-floor apartments. Meanwhile, the median indoor concentrations were 6.3, 9.4, and 44.8 microgram/m3, respectively, for the low-floor apartments, yet 5.1, 7.6, and 38.8 microgram/m3, respectively, for the high-floor apartments. These findings indicate that residents of low-floor apartments are exposed to elevated residential levels of mobile source-related VOCs compared to high-floor apartment residents. The indoor concentrations of the target VOCs, except for MTBE, were significantly higher than the outdoor air concentrations for both the low and high floors (P < 0.05). Plus, the outdoor and indoor VOC concentrations were significantly different between the daytime and nighttime data sets for both low- and high-floor apartments, with a P value of less than or close to 0.05.     

Exposures to multiple air toxics in New York City

Efforts to assess health risks associated with exposures to multiple urban air toxics have been hampered by the lack of exposure data for people living in urban areas. The TEACH (Toxic Exposure Assessment, a Columbia/Harvard) study was designed to characterize levels of and factors influencing personal exposures to urban air toxics among high school students living in inner-city neighborhoods of New York City and Los Angeles, California. This present article reports methods and data for the New York City phase of TEACH, focusing on the relationships between personal, indoor, and outdoor concentrations in winter and summer among a group of 46 high school students from the A. Philip Randolph Academy, a public high school located in the West Central Harlem section of New York City. Air pollutants monitored included a suite of 17 volatile organic compounds (VOCs) and aldehydes, particulate matter with a mass median aerodynamic diameter 相似文献   

An evaluation of the indoor air quality in bars before and after a smoking ban in Austin, Texas

This study assessed differences in the indoor air quality and occupancy levels in seventeen bars due to a city-wide smoking ban that took effect on September 1, 2005 in Austin, Texas, USA. We measured the following in each venue before and after the smoking ban: mean number of occupants, mean number of lit cigarettes, temperature, relative humidity, room volume, and PM(2.5), CO, and CO(2) concentrations. Additionally, VOC measurements were conducted at three of the venues. There was not a statistically significant change in occupancy, but the best estimate PM(2.5) concentrations in the venues decreased 71-99%, a significant reduction in all venues, relative to the pre-ban levels; CO concentrations decreased significantly in all but one venue; and concentrations of VOCs known to be emitted from cigarettes decreased to below the detection limit for all but two common compounds. These results suggest that the smoking ban has effectively improved indoor air quality in Austin bars without an associated decrease in occupancy.