Environmental Tobacco Smoke Measuring Exposures and Assessing Health Effects (1986) / Chapter Skim
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5 Assessubg /Exposures to Environmental Tobacco Smoke in the External Environment
5 Assessubg /Exposures to Environmental Tobacco Smoke in the External Environment
Pages 69-100
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From page 69... ...
environment, including the suitability of proposed tracers or proxy air contaminants that would be representative of ETS, available data on ETS exposure from personal monitoring and monitoring of 69
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From page 70... ...
Most studies to date have been less than ideal because the component that was measured did not meet all the following criteria for an ETS tracer. A marker or tracer for quantifying ETS concentrations should be: and ~ unique or nearly unique to the tobacco smoke so that other sources are minor in comparison, ~ a constituent of the tobacco smoke present in sufficient quantity such that concentrations of it can be easily detected in air, even at low smoking rates, similar in emission rates for a variety of tobacco products, in a fairly consistent ratio to the individual contaminant of interest or category of contaminants of interest (e.g., suspended particulates)
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From page 71... ...
Chamber and field studies have indicated that, under realistic smoking conditions that would be encountered in residences or offices, the typical smoking and ventilation rates would produce CO levels well within the levels observed in the outdoor air or in the indoor air generated from the indoor sources, such as kerosene heater, gas stove, etc. Consequently, it is difficult to factor out the contribution of CO from ETS in any specific, uncontrolled situation.
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From page 73... ...
73 ~In us ~ ~ ~2 cad s" ~¢)
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From page 74... ...
74 c: _ 0 ~ _ on c: _ cut on A ._ ~ ; 0 ~ ._ ~ ~ c.> .° :e ~ 2: ._ ~ ~ c, {: =, x ·_ i_ cut 0 .m c' £ c., .
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From page 75... ...
Research efforts need to be directed toward identifying a tracer or proxy air contaminant for ETS that meets the four criteria outlined above. At present, RSP is widely used as a general measure of ETS exposure indoors, particularly if the measurements are Ignited to locations where the levels of RSP from other sources
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From page 76... ...
PERSONAL MONITORING Measurements of concentrations of air contaminants in the immediate breathing zone of an individual provide information on personal exposure. Persona]
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From page 77... ...
40 80 t20 160 200 240 RESPIRABLE PARTICULATE CONCENTRATION (,ug/m3) FIGURE 5-1 Cumulative frequency distributions of RSP concentrations from central site ambient and personal monitoring of smoke-exposed and nonsmoke-exposed individuals.
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From page 78... ...
They may be useful in establishing ETS exposures, in a background of confounding air contaminants, associated with short-term effects. A variety of sample collection and analysis methods has been used to monitor individual constituents and categories of contaminants found in ETS for both personal monitoring and air monitoring of spaces.
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From page 79... ...
In interpreting measured concentrations of ETS constituents, one must recognize the potential for pronounced spatial and temporal variations. CONCENTRATIONS OF ENVIRON~NTAI, TOBACCO SMOKE IN INDOOR ENVIRONMENTS Various Environmental Tobacco Smoke Constituents There is a sizable body of literature reporting on measurements of various constituents (acrolein, aromatic hydrocarbons, carbon monoxide, nicotine, etc.)
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From page 80... ...
a major general category of ETS contaminants and is produced in concentrations that are easily measured in occupied spaces where smoking occurs. In a survey of more than 80 homes in six U.S.
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From page 81... ...
Tobacco combustion is a major source category that affects the quality of the air indoors. The air-e ontamma~t concentrations in an enclosed space resulting from tobacco combustion, and hence human exposures, are the result of a complex interaction of several interrelated variables (Figure 4-1)
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From page 82... ...
Dynamic and equilibrium models are useful in laboratory studies; equilibrium models are best suited to evaluating and predicting ETS concentrations in field studies, particularly when average concentrations over a period of days or longer are of interest. Equilibrium Models for RSP I,aboratory and field studies typically utilize some form of a single-compartment equilibrium mode} to evaluate the input parameters to the mass-balance equation, to evaluate field-study data, and to project RSP concentrations from ETS indoors.
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From page 83... ...
It should be emphasized that this equation assumes equilibrium conditions, and, to the extent that any of the generation or removal terms are intermittent (e.g., smoking rate) or variable (e.g., ventilation rate)
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From page 84... ...
Using a 2~mg/cigarette em~ssion rate, the estimated total RSP emissions from the intermittent source, i.e., 52 mg/hour, would be represented as being emitted uniformly over a 1-hour period for the full averaging time considered. In large occupied spaces where smoking is permitted, such as nonindustrial occupational environments, estimates (Bridge and Corn, 1972; Jaffe, 1978; Repace and Lowrey, 1980)
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From page 85... ...
or by mfiItration (uncontrolled movement of air through cracks and unintentional openings in the building envelope) serves to reduce the levels of air contaminants generated by an indoor source.
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From page 86... ...
In 1981, ASHRAE adopted Standard 62-81 (Ventilation for Acceptable Indoor Air Quality) , which also recommended ventilation rates for various residential and commercial spaces on an occupa~cy-density basis but distinguished between smoking and nonsmoking occupancy.
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From page 87... ...
A range of 0.4 to 1.5 ach would seem reasonable. Removal by Surfaces Next to ventilation, the major mechanism for removal of suspended particulate matter Is surface deposition.
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From page 88... ...
(a) Average seasonal infilitration of 312 recently constructed houses; the median value is 0.5 air changes per hour (achy.
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From page 89... ...
The results of this study indicate that a particle deposition rate of 0.2 to 0.S h-i for ideal mixing might typically be encountered in occupied spaces. Mixing Once released into an enclosed space, air contaminants move through it by dispersion.
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From page 90... ...
Predicting Environmental Tobacco Smoke Exposures from Tobacco Combustion Utilizing Equation ~1, expected RSP concentrations indoors from ETS can be estimated for a range of the input parameters that realistically can be expected under normal smoking occupancy. Figures 5-4 and 5-5 allow for the easy calculation of RSP levels due to ETS as a function of smoking rate, ventilation, sink rate, mixing, and volume of the space (see the example outlined in the legends of these figures)
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From page 91... ...
The calculated ETS RSP mass determined from this figure serves as an input to Figure 5-5 to determine the ETS respirable suspended particulate mass concentration in any space in ,ug/m3. Smoking rates (diagonal lines)
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From page 92... ...
Figures 5-4 and 5-5 highlight the large effect that small variations in the input parameters can have on the predicted RSP concentration.
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From page 93... ...
It Is also clear from Figures 5-4 and 5-5 that, for the vast majority of conditions, RSP levels due solely to ETS can be expected to equal or exceed levels specified in National Ambient Air Quality Standards for the total suspended particulates (Cocle of Federal Regulations, 1985~. These standards are health-based and reflect different averaging times as well as levels of exposure.
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From page 94... ...
Additional field testing of the Repace and I.owrey model, as well as a better understanding of the variability of the input parameters, either estunated or measured for use in Equation 5-3, is needed. SUMMARY AND RE C OMMENDATIONS ~ investigating the adverse health and comfort impact of air contaminants, it is important to specify the exposure to a specific air contaminant or a class of air contaminants on the time scale corresponding to the health or comfort effect being evaluated.
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From page 95... ...
These models are typically single-chamber models that assume steady-state or equilibrium conditions to estimate RSP levels and require as input parameters an RSP-emission rate for tobacco combustion, number of cigarettes consumed, ventilation or infiltration rates, removal rates by surfaces, air mixing in the space, and volume of the space. Information on the current or past distribution of these input parameters in the range of m~croenvironments in which individuals spend the majority of their time (residences, offices, etc.)
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From page 96... ...
3. information on current or past distributions of the input parameters for the mass-balance models of RSP concentrations is
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From page 97... ...
4. When levels of various constituents of ETS are measured in field situations, data should be gathered on input parameters such as smoking rates or volume so that a detailed field evaluation of the equilibrium mode!
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From page 98... ...
Collection and analysis of nicotine as a marker for environmental tobacco smoke in personal samples. Atmos.
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From page 99... ...
Tomita. Estimation of personal exposure to tobacco smoke with a newly developed nicotine personal monitor.
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From page 100... ...
Acute effects of environmental tobacco smoke.
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