Environmental Tobacco Smoke Concentrations Research Articles

Fourteen-day inhalation study in rats, using aged and diluted sidestream smoke from a reference cigarette: I. Inhalation toxicology and histopathology

Sprague-Dawley rats were exposed 6 hr per day for 14 consecutive days to aged and diluted sidestream smoke (ADSS), used as a surrogate for Environmental Tobacco Smoke (ETS), at concentrations of 0.1 (typical), 1 (extreme), or 10 (exaggerated) mg of particulates per cubic meter. Animals were exposed nose-only, inside whole-body chambers, to ADSS from the 1R4F reference cigarette. End-points included histopathology, CO-oximetry, plasma nicotine and cotinine, clinical pathology, and organ and body weights. The only pathological response observed was slight to mild epithelial hyperplasia and inflammation in the most rostral part of the nasal cavity, in the high-exposure group only. No effects were noted at medium or low exposures. The minimal changes noted were reversible, using a subgroup of animals kept without further treatment for an additional 14 days. Overall, the end-points used in the study demonstrated that there was no detectable biological activity of ADSS at typical or even 10-fold ETS concentrations and that the activity was only minimal at very exaggerated concentrations (particle concentrations 100 times higher than typical real-world concentrations).

Fourteen-day inhalation study in rats, using aged and diluted sidestream smoke from a reference cigarette: II. DNA adducts and alveolar macrophage cytogenetics

The chemical constituents of cigarette smoke are greatly diluted in environmental tobacco smoke (ETS). In the typical indoor environment where cigarettes are smoked, the mean value of respirable suspended particles is approximately 0.1 mg/m 3. In this study, we used aged and diluted sidestream smoke (ADSS) of 1R4F University of Kentucky research cigarettes as a surrogate for ETS and exposed Sprague-Dawley rats nose-only to 0, 0.1, 1.0, and 10 mg wet total particulate matter (WTPM)/m 3 for 6 hr per day for 14 consecutive days. DNA from lung, heart, larynx, and liver was tested for adduct formation after 7 and 14 days of exposure and after 14 days of recovery. In addition, alveolar macrophages from animals exposed for 7 days were examined for chromosomal aberrations. Exposure-related DNA adducts were not observed in any of the animals at 0.1 or 1.0 mg WTPM/m 3, which represent ambient and 10-fold exaggerated ETS concentrations, respectively. Slight diagonal radioactive zones, characteristic of adducts observed in human smokers and in animals exposed to mainstream smoke, were observed, but only in lung and heart DNA of animals exposed to the highest concentration of ADSS (10 mg WTPM/m 3), a 100-fold exaggeration of typical field measurements of ETS. The mean relative adduct labeling values (±SE) were 8.7 (±0.2) adducts per 10 9 nucleotides for lung DNA and 5.7 (±0.7) adducts per 10 9 nucleotides for heart DNA after 14 days of exposure. No elevation in chromosomal aberrations was observed in alveolar macrophages. These results indicate a no-observed-effect-level (NOEL) of 1.0 mg/m 3 for DNA adduct formation in lung and heart and a NOEL of at least 10 mg/m 3 for the induction of chromosome aberrations in alveolar macrophages under the conditions of this study.

Respiratory irritation from environmental tobacco smoke.

Acute physiological and chronic pathological responses of the respiratory tract to environmental tobacco smoke (ETS) are reviewed briefly. This study excludes discussion of the possible risk of lung cancer and the known impact of carbon monoxide on the fetus and adult. In some environments, the dose of particulate matter and the concentrations of irritant vapors absorbed on the ETS particles reach a level for which a physiological response may be expected, not only in the nose but also the bronchi. However, direct measurements indicate only small increases of nasal and bronchial resistance if normal subjects are exposed to maximal, likely concentrations of ETS. ETS is readily detected by the nonsmoker, but there is no strong evidence that pulmonary reactions have a psychogenic basis. The condition of approximately 20% of asthmatic patients is exacerbated by ETS exposure. Further study is needed to clarify the likelihood that adults will progress from a minor physiological response to pathological reactions, e.g., chronic obstructive lung disease. In young children (who are less able to escape from ETS), the association between exposure and an increase in respiratory disease is stronger than in adults. Exacerbation of asthma and an increase of respiratory disease are further arguments for legislation to guarantee smoke-free air to the nonsmoking public.

Environmental tobacco smoke: current assessment and future directions.

Scientific information on environmental tobacco smoke (ETS) is critically reviewed. Key areas addressed are: differences in chemical composition between mainstream smoke, sidestream smoke, and ETS; techniques for measurement of ETS; epidemiology; in vitro and in vivo toxicology; and chamber and field studies of perceptual or physiological effects. Questions concerning estimation of ETS exposure, suitability of various biomarkers, calculation of lifetime dose, control of confounding variables, use of meta-analysis, and the relationship between ETS concentrations and human responses all emphasize the need for additional research in order to assess potential effects of ETS on health or comfort.

Fourteen-Day Inhalation Study in Rats, Using Aged and Diluted Sidestream Smoke from a Reference Cigarette

Sprague-Dawley rats were exposed 6 hr per day for 14 consecutive days to aged and diluted sidestream smoke (ADSS), used as a surrogate for Environmental Tobacco Smoke (ETS), at concentrations of 0.1 (typical), 1 (extreme), or 10 (exaggerated) mg of particulates per cubic meter. Animals were exposed nose-only, inside whole-body chambers, to ADSS from the 1R4F reference cigarette. End-points included histopathology, CO-ox-imetry plasma nicotine and cotinine, clinical pathology, and organ and body weights. The only pathological response observed was slight to mild epithelial hyperplasia and inflammation in the most rostral part of the nasal cavity, in the high-exposure group only. No effects were noted at medium or low exposures. The minimal changes noted were reversible, using a subgroup of animals kept without further treatment for an additional 14 days. Overall, the end-points used in the study demonstrated that there was no detectable biological activity of ADSS at typical or even 10-fold ETS concentrations and that the activity was only minimal at very exaggerated concentrations (particle concentrations 100 times higher than typical real-world concentrations).

Acute Symptom Responses to Environmental Tobacco Smoke in Asthmatic and Nonasthmatic Individuals

Acute responses to 65 min exposures to environmental tobacco smoke (ETS) were tested in 24 healthy non-asthmatic nonsmokers and 16 asthmatic nonsmokers, using an environmental chamber. Each subject was exposed to air (sham), and machine-generated cigarette smoke containing 17 ppm and 31 ppm carbon monoxide (CO). Nonasthmatic subjects exercised intermittently (mean respiratory minute volume (VE) of 44 l/min during each of two 15–min exercise bouts); asthmatic subjects remained at rest. After completion of the exposure, subjects made a 0–5 rating of the severity of symptoms, as well as rating the overall severity of exposure on a 0–100 scale. Both symptoms and exposure severity rating were significantly related to CO concentrations. Ratings for a given ETS exposure tended to be higher for asthmatic than for nonasthmatic subjects. Overall exposure severity rating was significantly (p < 0.05) related to four symptom scores for the asthmatics and three for the nonasthmatic subjects. Symptoms common to both groups included unpleasant odour, and nasal discharge; shortness of breath was unique for nonasthmatics and eye irritation for asthmatk subjects. Although the nonasthmatic subjects were exercising intermittently, and thus received both a higher respiratory exposure (calculated from a CO-based index of ETS concentration, VE, and time) and biological exposure (calculated independently using a rebreathing estimate of the increment in carboxyhemoglobin level), the asthmatic subjects appeared to be more adversely affected by the ETS exposures in terms of their subjective responses.

Assessment of Cadmium and Lead Released from Cigarette Smoke.

Cigarette smoke, which contains many harmful compounds, affects not only the smoker's health but also indoor air quality. To evaluate indoor air contamination by cadmium (Cd) and lead (Pb), we measured Cd and Pb contained in the mainstream and sidestream smoke exhaled by experimental smoking of Japanese cigarettes and also determined urinary and blood Cd and Pb levels in smokers and non-smokers and air Cd and Pb levels in smoky environments. 1. One cigarette of each of 7 Japanese brands contained about 1 microgram each of Cd and Pb, of which about 50 ng each was released to the mainstream and 250 ng of Cd and 50 ng of Pb to the sidestream by smoking. 2. The blood Cd level in the smokers was significantly higher than that in the non-smokers. The urinary Cd level in the smokers was slightly higher than that in the non-smokers. The blood Cd level was related to the number of cigarettes smoked daily. Blood and urinary Pb levels did not differ between the smokers and non-smokers, but the blood Pb level was also related to the number of cigarettes smoked daily. 3. The air Cd levels in smoky places such as the smoking car of the special express train, an office, and a pachinko parlor were markedly higher than that in outdoor air. The air Cd concentration was well correlated with the environmental tobacco smoke concentration. On the other hand, the air Pb level was slightly higher in the above smoky places than outdoors. The mean air Pb concentration was not correlated with the environmental tobacco smoke concentration but was higher at higher environmental tobacco smoke concentration in each place.

Assessing Exposures to Environmental Tobacco Smoke

The combustion of tobacco indoors results in the emission of a wide range of air contaminants that are associated with a variety of acute and chronic health and comfort effects. Exposures to environmental tobacco smoke (ETS) are assessed for epidemiologic studies and risk assessment and risk management applications. An individual's or population's exposure to ETS can be assessed by direct methods, which employ personal air monitoring and biomarkers, and indirect methods, which utilize various degrees of microenvironmental measurements of spaces, models, and questionnaires in combination with time-activity information. The major issues related to assessing exposures to ETS are summarized and discussed, including the physical-chemical nature of ETS air contaminants, use of proxy air contaminants to represent ETS, use of biomarkers, models for estimating ETS concentrations indoors, and the application of questionnaires.

Sequential box models for indoor air quality: Application to airliner cabin air quality

In this paper we present the development and application of a model for indoor air quality. The model represents a departure from the standard box models typically used for indoor environments which has applicability in residences and office buildings. The model has been developed for a physical system consisting of sequential compartments which communicate only with adjacent compartments. Each compartment may contain various source and sink terms for a pollutant as well as leakage, and air transfer from adjacent compartments. The mathematical derivation affords rapid calculation of equilibrium concentrations in an essentially unlimited number of compartments. The model has been applied to air quality in the passenger cabin of three commercial aircraft. Simulations have been performed for environmental tobacco smoke (ETS) under two scenarios, CO 2 and water vapor. Additionally, concentrations in one aircraft have been simulated under conditions different from the standard configuration. Results of the simulations suggest the potential for elevated concentrations of ETS in smoking sections of non-air-recirculating aircraft and throughout the aircraft when air is recirculated. Concentrations of CO 2 and water vapor are consistent with expected results. We conclude that this model may be a useful tool in understanding indoor air quality in general and on aircraft in particular.