Results from survey of environmental tobacco smoke in offices in Ottawa, Ontario

Distribution analysis of airborne nicotine concentrations in hospitality facilities

A number of publications report statistical summaries for environmental tobacco smoke (ETS) concentrations. Despite compelling evidence for the data not being normally distributed, these publications typically report the arithmetic mean and standard deviation of the data, thereby losing important information related to the distribution of values contained in the original data. We were interested in the frequency distributions of reported nicotine concentrations in hospitality environments and subjected available data to distribution analyses. The distribution of experimental indoor airborne nicotine concentration data taken from hospitality facilities worldwide was fit to lognormal, Weibull, exponential, Pearson (Type V), logistic, and loglogistic distribution models. Comparison of goodness of fit (GOF) parameters and indications from the literature verified the selection of a lognormal distribution as the overall best model. When individual data were not reported in the literature, statistical summaries of results were used to model sets of lognormally distributed data that are intended to mimic the original data distribution. Grouping the data into various categories led to 31 frequency distributions that were further interpreted. The median values in nonsmoking environments are about half of the median values in smoking sections. When different continents are compared, Asian, European, and North American median values in restaurants are about a factor of three below levels encountered in other hospitality facilities. On a comparison of nicotine concentrations in North American smoking sections and nonsmoking sections, median values are about one-third of the European levels. The results obtained may be used to address issues related to exposure to ETS in the hospitality sector.

Urinary mutagenicity and thioethers in nonsmokers: role of environmental tobacco smoke (ETS) and diet

The urinary excretion of mutagens and thioethers was investigated in a controlled diet study and in two field studies. A diet containing charcoal-broiled meat and other items rich in mutagenic compounds increased the urinary mutagenicity as assessed in Salmonella typhimurium strain TA98 with metabolic activation approximately 46-fold compared to a diet low in mutagens. The excretion of thioethers after ingestion of the diet rich in mutagens also increased significantly when compared to the diet low in mutagens. The increase was associated with the content of preformed thioethers in the diet. In the first field study with 21 nonsmokers, urinary mutagenicity as assessed in Salmonella typhimurium strain TA98 and excretion of thioethers showed no relation to either the self-reported exposure to environmental tobacco smoke (ETS) or to serum cotinine concentrations used as an objective marker for ETS exposure. In the second field study, urinary mutagenicity was determined with a tobacco-smoke sensitive Salmonella typhimurium strain YG1024 with metabolic activation. No correlation was found between the mutagenic activity in urine and ETS exposure duration, nicotine on the personal sampler, cotinine in saliva and cotinine in urine. Our results suggest that real-life ETS exposure does not measurably increase either urinary mutagen or urinary thioether excretion. Furthermore, diet seems to be the most important source for both urinary mutagen and thioether excretion in nonsmokers.

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.

Mainstream and environmental tobacco smoke

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.