Exposure of passive smokers to tobacco smoke constituents

Summary In an unventilated room (with or without the presence of ten volunteers) the atmosphere was polluted with sidestream smoke from cigarettes or with the gasphase or constituents of the gasphase of sidestream smoke. One control experiment with no intended air pollution was performed.The air concentrations of carbon monoxide, carbon dioxide, nitrogen oxides, cyanide, acrolein, other aldehydes, nicotine, and total particulate matter were measured.By intermittent addition of freshly generated smoke over the three hour experimental period a constant air concentration of 20 ppm carbon monoxide was sustained. When no persons were present, the air concentration of the other measured tobacco smoke constituents remained constant. When persons were present, however, air concentrations of both gasphase and particulate phase constituents decreased during the experimental period.A considerable variation in the degree of exposure of the passive smokers to the various tobacco smoke constituents was found.In some of the experiments questionnaires concerning subjective annoyance, eye-, nose- and throat irritation were completed by the subjects. Stay in a gasphase polluted atmosphere was found equally annoying as in an atmosphere polluted with whole sidestream smoke. Air pollution with acrolein caused considerably less discomfort and this did not differ from the annoyance caused by staying in the closed, unventilated room with no intended air pollution.It is pointed out that in spite of an often considerable subjective discomfort, exposing non-smokers to tobacco smoke under realistic conditions will not cause inhalation of such amounts of the components of tobacco smoke traditionally considered harmful, that a lasting, adverse health effect in otherwise healthy, grown-up individuals seems probable.This work was supported by a grant from Forschungsgesellschaft Rauchen and Gesundheit. D-2000 Hamburg. Federal Republic of Germany     

An experimental study on irritation and annoyance due to passive smoking

Forty subjects were exposed to cigarette smoke produced by a smoking machine in a climatic chamber. The degree of air pollution due to cigarette smoke corresponded to 2.5 and 1.3 ppm delta CO. The concentrations of particulate matter, NO and NO2, were measured. The effects on subjective irritation, annoyance and eye blinking rate were determined. All measured effects increased with increasing smoke concentration as well as with exposure duration. Based on these effects, a tolerable limit in the range between 1.5 and 2.0 ppm delta CO is proposed.     

A passive tobacco smoke exposure system for laboratory animals

A simple passive tobacco smoke exposure system was developed for laboratory animals. The system consisted of a tobacco smoke generator and an exposure chamber. Performance testing was conducted using Fischer 344 rats. The rats were exposed to passive tobacco smoke generated by 20 cigarettes per day for 3 months. The concentration of the cigarette smoke aerosol (particle phase) in the chamber can be kept almost constant during exposure. The daily average mass concentration was 10.0 +/- 4.3 mg/m3 and the carbon monoxide was 79 +/- 22 ppm during exposure.     

Environmental carbon monoxide from cigarette smoking—a critique

It is often asserted that tobacco smoke in the atmosphere of public places constitutes a health hazard to exposed nonsmokers because of the environmental carbon monoxide generated during the burning of a cigarette. Cigarette smoking is an insignificant source of carbon monoxide in the overall atmosphere as compared with other natural and man-made sources. Even in tightly closed spaces with a large percentage of smokers, only rarely is it possible to build up concentrations which would exceed the established threshold limiting values for extended exposures. Examples include meeting rooms, houses, buses, and aircraft. Carboxyhemoglobin levels in nonsmokers resulting from carbon monoxide in environmental tobacco smoke are below the amount needed to produce the maximum allowable limit of 4% carboxyhemoglobin in the blood, as suggested by the World Health Organization. No strong evidence has been found indicating adverse effects in healthy individuals from concentrations of carboxyhemoglobin at or below these levels.     

A study of air pollution in the smoking hall

We investigated the air pollution in the student smoking hall from February 1st in the winter season, and during 8 days in the middle of April in the spring season. The student smoking hall was in an open, draught location. Moreover, the concentration of pollutants were measured in three time periods: break, lecture and lunch times. The pollutants measured were nitrogen monoxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), suspended particulate matter (SPM) and polynuclear aromatic hydrocarbon (PAH). The concentrations of pollutants measured during the break times were of a relatively higher level than those during the lecture and lunch times. However, the concentration of pollutants were not influenced by ventilation operation in the smoking hall, which is not a closed place. SPM and CO2 concentrations during the break time were instantaneously investigated above Building Sanitation Standards Management, Japan (SPM: 0.15 mg/m3, CO2: 1,000 ppm). Especially, the SPM concentration was recognized to be strongly influenced by tobacco smoke.     

Passive smoking in experimental and field conditions.

In a first study subjects were exposed for 1 hr to constant cigarette smoke concentrations corresponding to 5 or 10 ppm CO. Annoyance, subjective eye irritations, and eye blink rate increase in both conditions during the first 30 min of exposure. Respiratory frequency and heart rate variability are not altered. In a second study the air pollution due to tobacco smoke and its irritating effects were investigated in four restaurants. ΔCO as well as ΔNO—expressing the differences between indoor and outdoor concentrations—showed to be adequate parameters to evaluate the air pollution due to tobacco smoke. Subjective irritations of guests show a dose-response relation to ΔCO values. From the results of both investigations, it can be concluded that a degree of air pollution due to tobacco smoke corresponding to less than 2 ppm ΔCO can be considered as low and tolerable for healthy people. This conclusion however is not valid for small children, elderly people, or for individuals with impaired health, e.g., asthmatics and chronic bronchitics, whose sensitivity to tobacco smoke may be greater or different.     

A Community Approach to Respiratory Disease

The pulmonary retention of certain volatile compounds and particulate matter in cigarette smoke was studied in humans. A smoke-dosage apparatus delivered a standard puff which was inhaled and subsequently exhaled into cold traps. Acetaldehyde, isoprene, acetone, acetonitrile, toluene, particulate matter, and carbon monoxide were measured and compared with the amounts found in noninhaled smoke. A 86% to 99% retention was found for all compounds except carbon monoxide of which 54% was retained. These findings stress the importance of using methods which approximate actual smoking conditions when evaluating the biological effect of tobacco smoke.     

Passive smoking: Irritating effects of the total smoke and the gas phase

Summary In a ventilated climatic chamber 32 subjects (in groups of two or three) were exposed in one experiment to the total sidestream smoke of cigarettes and in another experiment to the gas phase of cigarette smoke, which was obtained by filtering out the particulate matter. The degree of air pollution corresponded to 10 ppm CO in both experiments. The concentrations of the particulate matter, CO, NO, NO₂ and HCHO were recorded. With a questionnaire, we determined the degree of annoyance and of subjective irritations of the eyes, nose and throat; eye blink rate was measured, as an objective indicator of eye irritation.Both exposures of air pollution produced nearly the same degree of annoyance, which indicates that the gas phase is to a large extent responsible for the annoyance due to cigarette smoke. On the other hand the objective and subjective eye irritation was very much lower with the gas phase than with the total smoke. This indicates that the particulate phase is to a very large extent responsible for the irritating effects.     

Effect of individually diversified smoking habits on carbon monoxide retention in the respiratory tract of active smokers and validation of results based of environmental categories

Cigarette smoke, treated as smoke inhaled by active smokers, was generated using self-made smoking-machine and with application of formerly established parameters of individual smoking process. Carbon monoxide was analysed in generated smoke. It was concluded, that diversified smoking process is very individual (different volume and duration time of puff and intervals between puffs) and therefore influences levels of carbon monoxide in MS (from 3.5 to 17.5 mg/cigarette). Simultaneously, carbon monoxide was analysed in exhaled air by active smokers just after each puff. Difference between inhaled and exhaled dose of carbon monoxide was treated to calculated individual retention of carbon monoxide in active smoker's respiratory tract. Mean relative retention was 57.6% and differences between single values were lower than in the cases of CO levels in MS and absolute retention. Estimation of carbon monoxide inhaled doses was proceeded according to environmental standards. Forecasted blood concentration of HbCO after smoking of twenty cigarettes equals 2.3 to 10.4%. These results are similar to the situation that people would inhale air containing CO with concentration 1.2 to 5.5-times higher than limiting value.     

Effect of exposure to 0.5 ppm hydrogen cyanide singly or combined with 200 ppm carbon monoxide and/or 5 ppm nitric oxide on coronary arteries,aorta, pulmonary artery,and lungs in the rabbit

Summary Exposure of rabbits to 0.5 ppm hydrogen cyanide alone or in combination with 200 ppm carbon monoxide for one and four weeks or combined exposure to 0.5 ppm hydrogen cyanide, 200 ppm carbon monoxide, and 5 ppm nitric oxide for two weeks did not cause morphological changes in lungs, pulmonary arteries, coronary arteries, or aorta. The need for selective toxicity studies with tobacco smoke constituents is stressed.Supported by a grant from the Forschungsgesellschaft Rauchen und Gesundheit, Hamburg, Federal Republic of Germany     

Measuring Indoor Air Quality of Hookah Lounges

Many states have implemented smoke-free workplace laws to protect employees and customers from exposure to secondhand smoke. However, exemptions in these laws have allowed indoor tobacco smoking in hookah lounges to proliferate in recent years. To describe the amount of secondhand smoke in hookah lounges, we measured the indoor air quality of 10 hookah lounges in Oregon. Air quality measurements ranged from “unhealthy” to “hazardous” according to Environmental Protection Agency standards, indicating a potential health risk for patrons and employees.Hookahs are pipes used to smoke flavored, sweetened tobacco. Hookah tobacco smoke contains tar, carbon monoxide and other toxins found in cigarette smoke, and in a typical hookah session, smokers inhale more than 40 times the volume of smoke produced by a cigarette.1–3 Hookah lounges are businesses that provide an indoor environment for hookah smoking and sell hookah tobacco in dozens of candy and fruit flavors.4 Indoor smoking in hookah lounges can expose employees and customers to secondhand smoke. Many states have implemented comprehensive smoke-free workplace laws that protect employees and patrons from exposure to secondhand smoke.5 Whereas some laws ban all tobacco use, others include exemptions which have allowed hookah lounges to proliferate.6,7Tobacco smoke is a mixture of chemical compounds that are bound to aerosol particles or are free in the gas phase.8 The concentration of particulate matter in the air is a strong indicator of pollution from tobacco smoke. Studies have measured particulate matter from cigarette smoke in bars and restaurants that allow indoor smoking, revealing employees and customers were exposed to hazardous levels of air pollution.9–11 Hookah smoke contains many of the same toxins as cigarette smoke2,3 and has been associated with lung cancer, respiratory illness, low birth weight, and periodontal disease.12 Laboratory studies have measured the chemical components of hookah smoke, and carbon monoxide levels have been measured in patrons exiting a hookah lounge.1–3,13 However, no study to date has described the concentration of particulate matter in the air inside hookah lounges. This study fills a research gap by analyzing the air quality inside hookah lounges in Oregon.     

WHERE THERE'S SMOKE…CARBON MONOXIDE EXPOSURES IN SMOKING AND SMOKE-FREE WORKPLACES

Comparisons of expired air carbon monoxide levels in non-smoking staff in six licensed clubs (a smoking workplace) were made with those of non-smoking staff of a large public hospital (a smoke-free workplace). There was a significant difference between clubs and hospital in levels of CO at end of work. The average concentration of club workers was 8.7 ppm (Hospital, 5.3 ppm). Approximately one third of these non-smokers in licensed clubs exceeded 10 ppm putting them in the ‘light smoker’ category according to the manufacturer of the monitoring equipment. Club workers increased their CO level during work time by four times the increase of Hospital staff. This study suggests that there are significant gains to be made in reduction of intake of harmful passive-smoking products by removing tobacco smoke from workplaces.     

Luftverunreinigung durch Tabakrauch in Gaststätten

Summary In four restaurants we studied the degree of air pollution due to tobacco smoke and its annoying effects on 360 guests. The concentrations of carbon monoxide (CO), nitrogen monoxide (NO), nitrogen dioxide (N0₂), sulfur dioxide (S0₂) and acrolein (CH₂CHCHO) were determined. It appeared, that the differences = indoor concentration — outdoor concentration for CO and NO can be used as indicators to estimate the degree of air pollution due to tobacco smoke.In three of the analysed restaurants we measured very low tobacco induced values of CO and NO (mean values: 0 to 1.1 ppm CO and 0 to 69 ppb NO). These concentrations are harmless to the health of the guests. Higher values were measured in a badly ventilated tavern (mean values: 3.3 ppm CO and 156 ppb NO). These values, too, may be considered harmless. With these exposures, however, other substances caused irritations and annoyance (12 % of the 360 guests indicated moderate to strong eye irritations).     

Validation of self-reported smoking status by simultaneous measurement of carbon monoxide and salivary thiocyanate

OBJECTIVE: The objective of this study was to determine the validity of tobacco questionnaires when using as gold standard either a single biomarker or a combination of two biomarkers. METHODS: The methods were self-reported smoking compared with salivary thiocyanate and expired carbon monoxide in a 1996, population-based, Swiss survey of 552 men and 565 women. RESULTS: Sensitivity of self-reported smoking relative to salivary thiocynate or carbon monoxide alone was low (38.2% for salivary thiocyanate > or = 100 mg/L, 56.4% for salivary thiocyanate > or = 150 mg/L and 62.6% for carbon monoxide > or = 9 ppm). When defining true positive smokers as people with high concentration of both salivary thiocyanate and carbon monoxide, overall, sensitivity was 88.6% and specificity was 87.2%. In women, sensitivity increased from 85 to 89% when removing subjects exposed to passive smoking. When excluding heavy smokers, sensitivity decreased to 63% in men and to 71% in women. Older women had tendency to misreport smoking. CONCLUSIONS: This comparison of questionnaire data with the simultaneous measurement of salivary thiocyanate and expired carbon monoxide indicates that valid responses can be obtained for self-reported, current smoking in population-based surveys. However, the validity of questionnaires can be underestimated if the gold standard (of exposure to tobacco smoke) is either high levels of carbon monoxide or high levels of salivary thiocyanate.     

Ambient air pollution and preterm birth in the environment and pregnancy outcomes study at the University of California, Los Angeles

The authors conducted a case-control survey nested within a birth cohort and collected detailed risk factor information to assess the extent to which residual confounding and exposure misclassification may impact air pollution effect estimates. Using a survey of 2,543 of 6,374 women sampled from a cohort of 58,316 eligible births in 2003 in Los Angeles County, California, the authors estimated with logistic regression and two-phase models the effects of pregnancy period-specific air pollution exposure on the odds of preterm birth. For the first trimester, the odds of preterm birth consistently increased with increasing carbon monoxide exposures and also at high levels of exposure to particulate matter less than or equal to 2.5 microm in diameter (>21.4 microg/m(3)), regardless of type of data (cohort/sample) or covariate adjustment (carbon monoxide exposures of >1.25 ppm increased the odds by 21-25%). Women exposed to carbon monoxide above 0.91 ppm during the last 6 weeks of pregnancy experienced increased odds of preterm birth. Crude and birth certificate covariate-adjusted results for carbon monoxide differed from each other. However, further adjustment for risk factors assessed in the survey did not change effect estimates for short-term pollutant averages appreciably, except for time-activity patterns, which strengthened the observed associations. These results confirm the importance of reducing exposure misclassification when evaluating the effect of traffic-related pollutants that vary spatially.     

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.     

Transient decrease of exhaled nitric oxide after acute exposure to passive smoke in healthy subjects

Nitric oxide (NO) is produced and detected in the exhalate from the respiratory tract where it plays important regulatory functions. Exhaled nitric oxide (eNO) concentrations are reduced in active cigarette smokers between cigarettes and in nonsmoking subjects during short-term exposure to environmental tobacco smoke. In this study, the authors evaluated eNO before and after an acute exposure to environmental tobacco smoke in healthy, nonsmoking subjects (n = 12). Baseline eNO levels were measured by chemiluminescence at baseline (1 hr before exposure), shortly after the end of exposure, and 10 and 30 min after the end of exposure. Mean room air NO concentration increased from 3 ppb to 4 ppm (range, 560 ppb-8.5 ppm) during the exposure period. Carboxyhemoglobin levels were assessed before and after the exposure with spectrophotometry. All subjects had decreased eNO with exposure to environmental tobacco smoke (mean +/- standard error of the mean: 16.65 +/- 1.35 ppb to 13.86 +/- 1.33 ppb; p < .001). These concentrations remained significantly decreased at 10 min and recovered within 30 min. No modifications in airway resistance or increase in carboxyhemoglobin levels were observed. Exposure to environmental tobacco smoke transiently--but consistently--decreased eNO concentration in healthy, nonsmoking subjects, suggesting that second-hand smoke can directly affect NO in the airway environment.     

Aortic intimal injury in rabbits. An evaluation of a threshold limit.

Sixty-one rabbits were exposed to carbon monoxide, and aortae were then examined by light microscopy and transmission and scanning electron microscopy. The CO concentration in ambient air and the exposure time were varied to estimate the threshold limit for CO-induced focal intimal edema. A significantly higher incidence (P less than .0001) of focal intimal changes was present in rabbits exposed to 180 ppm of CO for four hours or more than in rabbits given a shorter or weaker exposure. The present study, as well as recent reports on the effect of low-level CO exposure on the cardiovascular system, suggests that the CO content in tobacco smoke and in heavily polluted atmospheric air may be deleterious to the arterial wall and enhance atherogenesis. A reevaluation of the recommended threshold limit for industrial CO exposure is proposed.     

Characterization of tobacco products: a comparative study of the tar, nicotine, and carbon monoxide yields of cigars, manufactured cigarettes, and cigarettes made from fine-cut tobacco

Yields of tar, nicotine, and carbon monoxide were compared in selected Canadian brands of manufactured and hand-rolled cigarettes, and small and large cigars. To control for varying volumes of smoke delivery per cigarette or cigar, standardized comparisons in milligrams of toxic substance per liter of smoke were made. The mean deliveries per liter of smoke and tar, nicotine, and carbon monoxide were highest for small cigars, followed by hand-rolled and manufactured cigarettes; large cigars had the lowest deliveries. Five out of six brands of cigarettes handmade from fine-cut tobacco delivered significantly more tar, nicotine, and carbon monoxide per cigarette or per liter than did the identically named manufactured brand.     

Passive smoking at work

Summary Air pollution due to tobacco smoke and its effects on employees were investigated in 44 workrooms. For this purpose, the concentrations of CO, NO, NO₂, nicotine, and particulate matter were determined, and 472 employees were interviewed about annoyance and irritations.The mean values of the concentrations of the components due to tobacco smoke are: CO = 1.1 ppm, NO = 32 ppb, NO₂ = 24 ppb, nicotine = 0.9 g/m³, particulate matter = 133 g/m³. One third of the measured CO values exceeds a critical threshold of 2 ppm CO due to tobacco smoke.One quarter of the persons reports eye irritations at work. One third of the employees qualifies the air with regard to smoke at the workplace as bad. Forty percent of the interviewed persons are disturbed by smoke. The majority of the employees is in favor of a separation into smoking and nonsmoking rooms. This seems to be the most appropriate preventive measure for the protection of nonsmokers at work.Supported by the Swiss National Science Foundation, grant no. 3.912-0.78