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1.
Environmental tobacco smoke (ETS), also referred to as secondhand smoke (SHS), is a major threat to public health and is increasingly recognized as an occupational hazard to workers in the hospitality industry. Therefore, several countries have implemented smoke-free regulations at hospitality industry sites. In Portugal, since 2008, legislation partially banned smoking in restaurants and bars but until now no data have been made available on levels of indoor ETS pollution/exposure at these locations. The aim of this study was to examine the occupational exposure to ETS/SHS in several restaurants in Lisbon, measured by indoor fine particles (PM(2.5)) and urinary cotinine concentration in workers, after the partial smoking ban in Portugal. Results showed that the PM(2.5) median level in smoking designated areas was 253 μg/m3, eightfold higher than levels recorded in canteens or outdoor. The nonsmoking rooms of mixed restaurants exhibited PM(2.5) median level of 88 μg/m3, which is higher than all smoke-free locations studied, approximately threefold greater than those found in canteens. Importantly, urinary cotinine concentrations were significantly higher in nonsmoker employees working in those smoking designated areas, confirming exposure to ETS. The proportion of smokers in those rooms was found to be significantly positively correlated with nonsmoker urinary cotinine and indoor PM(2.5) levels, establishing that both markers were occupational-ETS derived. The use of reinforced ventilation systems seemed not to be sufficient to decrease the observed ETS pollution/exposure in those smoking locations. Taken together, these findings demonstrate that the partial restrictions on smoking in Portuguese venues failed to provide adequate protection to their employees, irrespective of protective measures used. Therefore, a smoke-free legislation protecting individuals from exposure to ETS/SHS in all public places and workplaces is urgently needed in Portugal.  相似文献   

2.
1. The determination of personal exposures to environmental tobacco smoke (ETS) and respirable suspended particles (RSP) for housewives, and fixed site monitoring of their homes, have been undertaken by these authors throughout Europe, South East Asia and Australia. Median 24 h time weighted average (TWA) concentrations for ETS particles and nicotine were found to be significantly higher for housewives living in smoking households compared with those living in nonsmoking households. For Europe, median TWA concentrations of 4.1 and <0.26 microg/ml for ETS particles and 0.63 and < 0.08 microg/m3 for nicotine were found for housewives living in smoking and nonsmoking households respectively. 2. In addition to the measurement of RSP, ETS particles and nicotine, saliva cotinine concentrations were determined using a radioimmunoassay method with a limit of quantitation of 1 ng/ml. Median saliva cotinine concentrations of 1.4 and <1 ng/ml were determined for European housewives living in smoking and nonsmoking households respectively, which reflected the poor limit of quantitation of this methodology. A chromatographic method utilising tandem mass-spectrometric detection was developed and validated for the determination of both cotinine and 3-hydroxycotinine, two of the main metabolites of nicotine, with lower limits of quantitation of 0.05 and 0.10 ng/ml respectively. This method was applied to samples collected from subjects with a known ETS exposure history and median cotinine concentrations of <0.05 ng/ml for self-reported unexposed nonsmokers, 0.65 ng/ml for nonsmokers reporting some ETS exposure and 1.28 ng/ml for nonsmokers living with smokers were found. 3. In conclusion, the measurement of RSP and ETS concentrations derived from personal or fixed site monitors for housewives may provide some indication of potential exposures to dependent children. The recent development and application of a highly sensitive assay for the determination of cotinine in saliva has provided evidence to suggest that concentrations determined at sub-nanogram levels may be used as a biomarker for ETS exposure. This improved methodology, coupled with non-invasive sampling for saliva, may be of significance when considering the application of cotinine as a biomarker for ETS exposure in children.  相似文献   

3.
1. In order to elucidate the role of exposure to environmental tobacco smoke (ETS) in various acute and chronic illnesses in children, it is important to assess the degree of exposure by suitable methods. For this purpose, we determined the exposure to ETS in 39 children (4-15 years) and 43 adults (16+ years) by questionnaires, personal diffusion samplers for nicotine, and cotinine measurements in saliva and urine. In addition, the influence of the smoking status and the location of the home (urban or suburban) on the benzene exposure of the children was investigated. 2. On average, the 24 children living in homes with at least one smoker were exposed to ETS for 3.1 h/d. This is significantly longer (P<0.001) than the daily exposure time of the 15 children from nonsmoking homes (0.3 h/d). The nicotine concentrations on the personal samplers worn over 7 days were 0.615 and 0.046 microg/m3 for children from smoking and nonsmoking homes, respectively (P<0.001). Average salivary cotinine levels were 1.95 ng/ml in children from smoking homes and 0.11 ng/ml in children from nonsmoking homes (P< 0.01). The corresponding urinary cotinine levels were 29.4 and 4.5 ng/mg creatinine (P< 0.001). There was no difference in the extent of ETS exposure between children and adults from smoking households. Adults from nonsmoking homes tended to have higher ETS exposure than children from nonsmoking homes. 3. Exposure to benzene, which was determined by means of personal samplers, measurements of benzene in exhaled air and of the urinary benzene metabolite trans, trans-muconic acid, was not significantly related to the smoking status of the home but primarily dependent on the location of the home.  相似文献   

4.
A new analytical procedure was developed for the quantitation of nonsmoker salivary cotinine. Small volumes of saliva were diluted with water, fortified with cotinine-d3 (internal standard), then passed through small extraction columns. The analyte and internal standard were eluted with 0.1% (v/v) acetic acid/acetonitrile. Aliquots of each extract were analyzed directly, without chromatographic separation, using chip-based (NanoMate) nanospray tandem mass spectrometry. The calculated detection limit was 0.49 ng cotinine/mL saliva. This method was used to quantify salivary cotinine collected from nonsmoking human subjects living in one of three environmental tobacco smoke (ETS) exposure categories or "cells": 1. smoking home/smoking workplace; 2. smoking home/nonsmoking workplace; and 3. nonsmoking home/smoking workplace. Samples were collected during five sequential days, including Saturday, as part of a larger study to evaluate potential variability in exposure to ETS. Salivary cotinine measurements were made for the purpose of excluding misclassified smokers and for comparison with known levels of exposure to airborne nicotine in each exposure category. The concentrations observed were consistent with those reported from other large studies reported elsewhere. A non-parametric statistical test was applied to the data within each cell. No statistically significant differences were found between the mean cotinine concentrations collected on a weekday as compared to those collected on a weekend day. When the non-parametric test was applied to the three cells, a statistically significant difference was observed between cell 1 compared to cells 2 and 3. The salivary cotinine concentrations were thus statistically invariant over a five-day exposure period, and they were greatest under the conditions of smoking home and smoking workplace.  相似文献   

5.
AIM: To measure the relation between workplace smoking policies and exposures to Environmental Tobacco Smoke (ETS) of workers in bars and restaurants. METHODS: 114 workers in Wellington and Auckland were questioned about sources of exposure to ETS and smoking habits, and details of the smoke-free policy in their work place were recorded. A hair sample was collected from each participant and tested for nicotine. RESULTS: Among non-smoking workers, hair nicotine levels varied strongly according to the smoke free policy at their place of work (Kruskall-Wallis, chi2 = 26.38, p < 0.0001). Those working in 100% smoke free restaurants had much lower levels than staff working in bars with no restrictions on smoking, and levels were intermediate for staff working in places with a partial smoking ban. These findings were not changed when adjustments were made for other sources of ETS exposure. Hair nicotine levels among nonsmokers working in places with no restriction on smoking were similar to hair nicotine levels of active smokers. CONCLUSION: The present New Zealand Smoke Free Environment Act does not protect workers in the hospitality industry from exposure to ETS. The findings from this study highlight the substantial levels of exposure of bar and restaurant staff from patrons' smoking.  相似文献   

6.
Lee PN  Hamling J 《Inhalation toxicology》2006,18(14):1053-1070
Recent authoritative reviews consider smoking has no effect on breast cancer risk, but some studies report an increase from environmental tobacco smoke (ETS). We reviewed the overall evidence on ETS and breast cancer in nonsmoking women. We extracted details of available studies, derived relative risk (RR) estimates with confidence intervals (CIs) for various ETS exposure indices and conducted meta-analyses. Using an index for each study most closely equivalent to "spouse ever smoked," a weak, but significant, association was seen (random-effects RR = 1.12, 95% CI = 1.02-1.24, n = 22). However, the estimates were heterogeneous: close to 1.0 for prospective, North American and larger studies, and those adjusting for many potential confounders, but significantly (p < .05) elevated in case-control, European, and smaller studies, and those accounting for fewer potential confounders. Risk was increased in premenopausal women (RR = 1.54, 95% CI = 1.16-2.05, n = 10), but not postmenopausal women. Dose-response findings were similarly heterogeneous. No significant increase was seen for ETS in childhood or the workplace or from the spouse specifically, but an increase was seen for total exposure (RR = 1.54, 95% CI = 1.17-2.04, n = 6). Increases mainly derive from case-control studies asking detailed ETS histories, where RRs depend heavily on who is classified in the totally unexposed reference group, and may be prone to recall bias. Results from prospective studies using similar histories are needed. Study weaknesses and possible publication bias also limit interpretation. Because of the inherent implausibility that ETS exposure might cause breast cancer, given the similar risks of smokers and nonsmokers, one cannot confidently conclude ETS exposure increases risk in nonsmokers.  相似文献   

7.
Recent authoritative reviews consider smoking has no effect on breast cancer risk, but some studies report an increase from environmental tobacco smoke (ETS). We reviewed the overall evidence on ETS and breast cancer in nonsmoking women. We extracted details of available studies, derived relative risk (RR) estimates with confidence intervals (CIs) for various ETS exposure indices and conducted meta-analyses. Using an index for each study most closely equivalent to “spouse ever smoked,” a weak, but significant, association was seen (random-effects RR = 1.12, 95% CI = 1.02–1.24, n = 22). However, the estimates were heterogeneous: close to 1.0 for prospective, North American and larger studies, and those adjusting for many potential confounders, but significantly (p < .05) elevated in case-control, European, and smaller studies, and those accounting for fewer potential confounders. Risk was increased in premenopausal women (RR = 1.54, 95% CI = 1.16–2.05, n = 10), but not postmenopausal women. Dose-response findings were similarly heterogeneous. No significant increase was seen for ETS in childhood or the workplace or from the spouse specifically, but an increase was seen for total exposure (RR = 1.54, 95% CI = 1.17–2.04, n = 6). Increases mainly derive from case-control studies asking detailed ETS histories, where RRs depend heavily on who is classified in the totally unexposed reference group, and may be prone to recall bias. Results from prospective studies using similar histories are needed. Study weaknesses and possible publication bias also limit interpretation. Because of the inherent implausibility that ETS exposure might cause breast cancer, given the similar risks of smokers and nonsmokers, one cannot confidently conclude ETS exposure increases risk in nonsmokers.  相似文献   

8.
Substance abusers are more likely to smoke cigarettes than the general population. Yet, in most drug treatment programs smoking cessation receives little attention. The purposes of this study were to: (1) examine substance abuse counselors' attitudes toward and practices related to nicotine addiction and smoking cessation treatment; and (2) describe barriers to smoking cessation treatment and smoking policies in substance abuse treatment facilities. A total of 254 substance abuse counselors in Kentucky completed mailed questionnaires (53% response rate). Almost one-fourth were current smokers. Smoking and nonsmoking counselors differed in their attitudes toward nicotine addiction, barriers to treatment, and satisfaction with smoking cessation training. Few counselors routinely followed the clinical preventive guidelines with nicotine-dependent clients. However, they were receptive to providing smoking cessation treatment. Over half of the drug treatment programs banned indoor smoking, but permitted smoking on facility grounds. Implications for policy change by national addiction certification and licensing organizations and state accreditation authorities are discussed.  相似文献   

9.
《Substance use & misuse》2013,48(1-2):51-58
This study evaluated State of California alcohol license records as a measure of businesses selling alcohol for consumption on premise. In 2008, researchers attempted to visit all 799 licensed restaurants, bars, and pubs in six medium-sized cities near San Francisco. Surveys collected detailed business characteristics for a subsample of 151 bars or restaurants that included a separate bar area. Results suggest inaccuracies of official records regarding license locations and types (bar/pub vs. restaurant). Analyses also indicate that establishment characteristics are related to local alcohol outlet densities. Study implications and limitations are discussed.  相似文献   

10.
Environmental tobacco smoke (ETS) exposure was measured among 242 children with asthma who live in homes where at least one person smokes. Subjects were identified through clinics, schools, community agencies, and hospitals serving low-income, medically underserved communities in Los Angeles. Parents were surveyed about smoking behaviors in the household, children's ETS exposure, and attitudes towards smoking and smoking behavior change. Validation measures included urine cotinine for the child with asthma and passive air nicotine monitors placed in the subjects' homes. Overall reported levels of household smoking and ETS exposure were low, with a significant amount of household smoking taking place outside rather than inside the home. Over 47% of the respondents reported absolute restrictions against smoking in the home, and these restrictions were associated with lower reported levels of smoking, ETS exposure, and air nicotine and urine cotinine concentrations.  相似文献   

11.
Six volunteer female habitual smokers were exposed during a 2-wk experimental period to cigarette smoke, both actively and passively, in an exposure chamber (volume 10 m3, average air exchange rate 6.8 times/h), where the ambient carbon monoxide, particle, and aldehyde concentrations were monitored. Three of the six subjects were smoking at the time, 2 cigarettes (filtered, self-burning low tar brand) per person per hour, 30 cigarettes altogether during each of the 5-h experimental days in the chamber. Samples of blood and urine were taken from each subject after 3 nonsmoking days and after each day of active or passive smoking. Among the parameters tested, blood carboxyhemoglobin, plasma cotinine, and urinary mutagenicity were higher in samples taken after active smoking than after nonsmoking periods. Although the exposure conditions were similar for all subjects, the parameters measured showed quite high interindividual variation. Thioethers and thiocyanates were not significantly elevated in the active smoking samples; neither were there any differences during this short experimental period in the sister chromatid exchange frequencies. The only parameters showing an increasing trend after passive exposure, as compared with nonsmoking samples, were urinary mutagenicity and plasma cotinine, the main metabolite of nicotine.  相似文献   

12.
Published reports document 20-40% lower mean serum clozapine concentrations in smokers compared with nonsmokers due to enzyme induction. Despite the increase in nonsmoking psychiatric facilities in the United States, previous studies have not tracked individual changes in serum clozapine levels after smoking cessation. Clozapine level changes were analyzed in 11 patients at Oregon State Hospital who were on stable clozapine doses, before and after implementation of a hospital-wide nonsmoking policy. A mean increase in clozapine levels of 71.9% (442.4 ng/ml +/- 598.8 ng/ml) occurred upon smoking cessation (p < .034) from a baseline level of 550.2 ng/ml (+/- 160.18 ng/ml). One serious adverse event, aspiration pneumonia, was associated with a nonsmoking serum clozapine level of 3066 ng/ml. Elimination of statistically extreme results generated a mean increase of 57.4 % or 284.1 ng/ml (+/- 105.2 ng/ml) for the remaining cases (p < .001) and permitted construction of a linear model which explains 80.9% of changes in clozapine levels upon smoking cessation (F = 34.9;p = .001): clozapine level as nonsmoker = 45.3 + 1.474 (clozapine level as smoker). These findings suggest that significant increases in clozapine levels upon smoking cessation may be predicted by use of a model. Those with high baseline levels should be monitored for serious adverse events.  相似文献   

13.
Cadmium concentrations in milk and blood of smoking mothers   总被引:1,自引:0,他引:1  
Cadmium concentrations were measured by flameless atomic absorption spectrometry in blood and mature milk of 15 nonsmoking and 56 smoking mothers during the nursing period. Both blood and milk concentrations increased with increasing cigarette consumption. The median blood and milk concentrations in nonsmokers were 0.54 and 0.07 microgram/l, respectively; these values rose to 1.54 and 0.16 micrograms/l in blood and milk of mothers smoking more than 20 cigarettes per day. Milk concentrations of cadmium were approximately 10% of corresponding blood concentrations. The cadmium exposure of infants nursed by nonsmoking as well as by smoking mothers was far below the exposure of formula-fed infants or the provisional acceptable weekly intake level set by the WHO.  相似文献   

14.
Summary To test the hypothesis that involuntary smoking can result in increased drug metabolism, five nonsmoking healthy male volunteers (21–36 y old) were enrolled in a study of single-dose theophylline pharmacokinetics before and after intense environmental tobacco smoke (ETS) exposure. Exposure was provided by spending 3 h/day for five consecutive days in a small room with a smoking apparatus that burned four cigarettes simultaneously, at a rate of 20 cigarettes/h.Measurement of urine cotinine concentration demonstrated that significant absorption from ETS occurred in all subjects. However, pre- and post-exposure pharmacokinetic parameters for theophylline did not differ significantly: VZ=0.438 vs 0.4401·kg–1; t1/2=9.19 vs 9.69 h; CL=34.4 vs 32.6 (ml·kg–1·h–1), respectively. Similarly, 24-hr urinary excretion of theophylline and its metabolites was unchanged by ETS exposure.We conclude that intense short-term passive smoking does not affect theophylline disposition. The possibility of chronic ETS exposure causing alterations in drug metabolism cannot be excluded.Supported by an Institutional Research Grant from the University of Texas Health Science Center at San Antonio  相似文献   

15.
Mainstream and environmental tobacco smoke   总被引:1,自引:0,他引:1  
Environmental tobacco smoke (ETS) is derived from cigarette smoldering and active smoker exhalation. Its composition displays broad quantitative differences and redistributions between gas and respirable suspended particulate (RSP) phases when compared with the mainstream smoke (MSS) that smokers puff. This is because of different generation conditions and because ETS is diluted and ages vastly more than MSS. Such differences prevent a direct comparison of MSS and ETS and their biologic activities. However, even assuming similarities on an equal mass basis, ETS-RSP inhaled doses are estimated to be between 10,000- and 100,000-fold less than estimated average MSS-RSP doses for active smokers. Differences in effective gas phase doses are expected to be of similar magnitude. Thus the average person exposed to ETS would retain an annual dose analogous to the active MSS smoking of considerably less than one cigarette dispersed over a 1-year period. By contrast, consistent epidemiologic data indicate that active smoking of some 4-5 cigarettes per day may not be associated with a significantly increased risk of lung cancer. Similar indications also obtain for cardiovascular and respiratory diseases. Since average doses of ETS to nonsmoking subjects in epidemiologic studies are several thousand times less than this reported intake level, the marginal relative risks of lung cancer and other diseases attributed to ETS in some epidemiologic studies are likely to be statistical artifacts, derived from unaccounted confounders and unavoidable bias.  相似文献   

16.
Workers in the catering industry are at greater risk of exposure to secondhand smoke (SHS) when smoke-free workplace policies are not in force. We determined the exposure of catering workers to SHS in Hong Kong and their risk of death from heart disease and lung cancer. Nonsmoking catering workers were provided with screening at their workplaces and at a central clinic. Participants reported workplace, home, and leisure time exposure to SHS. Urinary cotinine was estimated by enzyme immunoassay. Catering facilities were classified into three types: nonsmoking, partially restricted smoking (with nonsmoking areas), and unrestricted smoking. Mean urinary cotinine levels ranged from 3.3 ng/ml in a control group of 16 university staff through 6.4 ng/ml (nonsmoking), 6.1 ng/ml (partially restricted), and 15.9 ng/ml (unrestricted smoking) in 104 workers who had no exposures outside of work. Workers in nonsmoking facilities had exposures to other smoking staff. We modeled workers' mortality risks using average cotinine levels, estimates of workplace respirable particulates, risk data for cancer and heart disease from cohort studies, and national (US) and regional (Hong Kong) mortality for heart disease and lung cancer. We estimated that deaths in the Hong Kong catering workforce of 200,000 occur at the rate of 150 per year for a 40-year working-lifetime exposure to SHS. When compared with the current outdoor air quality standards for particulates in Hong Kong, 30% of workers exceeded the 24-h and 98% exceeded the annual air quality objectives due to workplace SHS exposures.  相似文献   

17.
During a period of eight years from 1977, pupils in F primary school in S ward, Tokyo were monitored each year with a general medical check-up to identify and eliminate any children with urine abnormalities and then the hydroxyproline: creatinine ratio (HOP ratio) in the urine of 4,375 children chosen at random was measured. The children's area of residence was classified, according to distance, into three areas. In addition, the children were classified into four groups depending on their estimated degree of exposure to Environmental Tobacco Smoke (ETS). The relationship between ETS and the HOP ratio was observed annually. The HOP ratio was greatest in schoolchildren living in the area nearest the main roads. The influence of ETS also tended to increase when ventilation rates in their rooms were lowered. The strength of these associations was considered significant depending on the magnitude of the HOP ratio, the correlation coefficient, a two-way layout and relative risk (R.R.). In addition, the consistency and coherence observed in measurements each year suggested a causal relationship. The influence of ETS and area distinctions on the HOP ratio was totally independent and showed virtually no interaction. However, the changes in patterns of indoor smoking from 1980 onwards were not sufficiently accounted for by the previous interview and questionnaire surveys so we introduced an additional bias, namely misclassification of pupils. Subsequently, the possibility of underestimation of the influence of ETS was considered, thereby establishing the need for a revision of the relevant questionnaires.  相似文献   

18.
Despite inititatives to reduce tobacco consumption, smoking remains a primary cause of death for both smokers and nonsmokers exposed to environmental tobacco smoke (ETS). The characteristics of some specific groups can make them more exposed to ETS or limit the benefit of prevention measures. This study investigated determinants of ETS in a population of young adult students, considered at higher risk of exposure due to their specific lifestyle. This cross-sectional study involved 90 students aged 20 ± 1.7 years, from the University of Luxembourg, prior to the smoking ban enforcement in public places in the country. Participants reported their tobacco consumption and exposure to ETS at home and/or in public places, and provided a hair sample analyzed for nicotine and cotinine. Nicotine and cotinine were significantly higher in smokers than in nonsmokers' hair in general (median: 2.6 vs. 0.9 ng/mg and 87.1 vs. 22.5 pg/mg respectively). However, nonsmokers exposed to ETS at home and in public places had comparable concentrations to smokers (nic = 2.2 ng/mg; cot = 56.2 pg/mg), whereas unexposed nonsmokers presented significantly lower values (nic = 0.4 ng/mg, cot = 8.5 pg/mg). Nonsmokers exposed to ETS only at home presented higher values than nonsmokers only exposed in public places (nic: 1.3 vs. 0.8 ng/mg, cot: 70.4 vs. 15.0 pg/mg). The study shows the widespread exposure to ETS in this population, the importance of exposure assessment, and the relevance of hair analysis for this purpose. Results suggest that ETS can lead to equivalent exposure to active smoking and that exposure at home can highly contribute to ETS, which is not solved by smoking ban in public places.  相似文献   

19.
Smokers are highly reactive to smoking-related cues that are directly linked, or most proximal, to actual smoking behavior (e.g., lit cigarettes). However, over the course of smoking, proximal cues may not be the only stimuli to become strongly associated with smoking. Distal cues, such as the environments in which smoking occurs (e.g., bar) might also gain associative properties and come to evoke robust reactivity from smokers. To test this, a pilot study was first conducted to develop standard pictorial stimuli of smoking and nonsmoking environments, all of which were completely devoid of proximal smoking cues. A comparison set of smoking and nonsmoking proximal cues was then created. Using the 12 total pictorial cues developed, 62 adult smokers participated in a cue-reactivity study during which they viewed and rated pictorial smoking and nonsmoking environment and proximal cues. Results demonstrate that, similar to proximal cues, environments associated with smoking can alone function as stimuli capable of evoking strong subjective reactivity from smokers. This work supports a broader conceptualization of drug-related cues in cue-based research and treatment development that includes proximal and distal cues as distinct categories. (PsycINFO Database Record (c) 2008 APA, all rights reserved).  相似文献   

20.
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.  相似文献   

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