Indoor Pollutants (1981) / Chapter Skim
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V. Factors that Influence Exposure to Indoor Air Pollutants
V. Factors that Influence Exposure to Indoor Air Pollutants
Pages 225-258
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From page 225... ...
The emphas is of the second section of this chapter is on geographic vat iations in outdoor pollution and their impact on indoor pollution . Building construction techniques, as they vary geographically, and their of feet on pollution inf titration rates are particularly important.
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From page 226... ...
~ ~ ~ ~ s 2 7 ° Ott S ~ discussed the literature on activity patterns in the context of estimation of exposure to air pollution. The Multinational Comparative Time Budget Research Project, launched in September 1964 by a small group of social scientists from eastern and western countries, used common principles for sampling, interviewing, and data coding and tabulation on an international basis .
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From page 227... ...
227 TABLE V-1 Time Spent in Various Locations in 12 Countries (Average Hours per Day ja .
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From page 228... ...
4 h ~ . Although the estimates in Tables V-1 and V-2 are useful for determining the total amount of time spent in various locations, they give little information about the time of day when persons are present in each location.
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230 100 80 he G 60 40 20 ~ Sl - P I Work // ~ // {~/ / O ~1 1 1 1 it 0.00 2.00 4.00 6.00 8.00 10.00 12.00 2.00 4.00 6.00 8.00 1 0.00 12.00 MIDNIGHT 6 AM NOON 6 PM MIDNIGHT \ ,: / and Family~\ ~ ,~7'J,>? ;/~1~ Tdev''ion \\ TIME 4.00 6 00 FIGURE V-1 Diurnal profiles showing percentage of employed men in United States (44 cities ~ engaged in nine types of activities as a faction of time of day (weekdays only)
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This study, called the Nationwide Personal Transportation Study, was based on home interviews and covered individual activities in considerable detail.
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232 o o 0 e ~ 0 ~ Ck Cut e IS 0 ~ k to ot CL Cut ~0 ¢ E" At: lo 3 D o O V 0 C E" :^ v Cut to .
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From page 234... ...
The available data base i" not large enough to support statistical conclusions, but there is little doubt that the variations in indoor pollutant concentrations correlate with variation" in outdoor concentrations. Thus, it is expected that a city with high outdoor pollutant concentrations will have high indoor concentrations, unless control strategies are used .
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From page 235... ...
57EU. ~ Outdoor O ~ · - IN I ~ he ~ coo _ star d - ~~c cad r FIGURE V-3 Annual nitrogen dioxide concentration outside and inside electric- and gas-cooking homes ~ averaged across each community' ~ indoor and outdoor network (May 1973-April 1978)
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From page 236... ...
of this document address ventilation rates of large buildings, and the discussion of the geographic distribution of air-infiltration rates in this section focuses on residences. Typically, the sir-infiltration rate for American residences is assumed to be O.S-1.5 ach.
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From page 237... ...
FIGURE V-4 Histograms of measured natural air-infiltration riles for three cities. Reprinted with permission from Grot and Clark.
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From page 238... ...
238 TABLE V-4 Distribution of Residential Energy Consumption by Fuel Type ant Region, 1970 (Single-Family Detached Homes ) a Diseribueior of Fuel Use ~ X Gas Oi 1 Region Electricity Northeast New England 20 76 3 1 Middle Atian~cic 46 45 3 6 North central East north central 71 23 2 4 West north central 7 6 20 2 2 South South Atlantic 41 39 13 7 East south central 60 4 20 16 West south central 93 4 3 West .
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239 TABLE V-5 Estimated Stock of Year-Round Occupied Mobile Homes at End of 1977 No. Mobile ~ of No.
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From page 240... ...
Thus, although the exact nature of the impact on indoor air quality is not known, it is fair to expect the heat island to have an impact on the indoor environment that is likely to be adverse. Also, the variations due to mechanical ventilation, structural differences, and air infiltration may vary within a neighborhood as a function of much factors as house orientation, tree barriers, and terrain roughness.
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241 o ~ - ~ So om o O" ~ ~ · ~ - .
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The functional relationship between air infiltration and indoor air quality has not been fully established, nor have the distribution patterns of indoor air quality in the urban, suburban, and neighborhood areas. Further research is warranted to study the cause-and-effect relationship between air inf titration and air quality and to formulate the best
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From page 243... ...
. 1 7 11~1 1.240 1.259 0.853 0.738 0.860 0.498 FIGURE V-6 Effects of orientation and wind barriers on air infiltration in tc~wnhc~use units.
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From page 244... ...
In addition, the General Electric study made ~ number of recommendations that are relevant to air quality, its relationship to neighborhood building planning, and specific efforts to reduce indoor pollutant concentrations: lower floors of high-rise buildings must be specially sealed from traffic-generated pollutants; building entrances should be placed so that prevailing road winds are parallel to them, convection paths inside building. should be minimized; Eleanor control rooma at roof level should be force-ventilated to reduce pollutant
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From page 245... ...
This null hypothesis was rejected in more cases than it was accepted ine Comparison of the observed range and calculated differences led to the conclusion that, although corresponding hourly indoor pollutant concentrations are not uniform throughout a residence, the differences between sampled sites are small and Drobablv~ of minimal health importance. — ~ ~ , In an extensive analytic study of indoor air quality, Shair and Beitner.t assumed that there are no pollutant gradients in the indoor environment.
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246 Cal ' Cal o Cal , 0 ID O Z O A ~e ~ O Y .
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From page 247... ...
me source location wan the living room; adjacent locations were the kitchen and the ball. Episodic release of this inert gas in 24 residences was followed by uniform indoor distributions within 30 min..' .' The one-zone concept does not require instantaneous mixing, because it is based on the behavior of hourly average pollutant concentrations.
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From page 248... ...
Ben o A.= _: = ~ Marc' . FIGURE V-8 Episodic release of sulfur hg~afluoride gas.
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From page 249... ...
Designing and controlling building factors may prove to be an effective mechanism for acbleving desirable indoor air quality. SITE CHARACTERISTICS The characteristics of a building site that influence indoor air quality are addressed as three related subjected air flow around buildings, proximity to major sources of outdoor pollution, and type Of utility service available.
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From page 250... ...
The use of Yaglou's early work on the relationship between occupant density and detectable body odor in determining necessary ventilation rates is discussed elsewhere. Occupancy acbedules and associated building use may affect the type, concentration, and time and space distribution of indoor pollutants.
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From page 251... ...
lout, higher wind pressures drive air through existing openings, referred to as ~leakage,. increasing the infiltration rate.
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From page 252... ...
The control of indoor pollutants depends on floor layout, pollutant concentrations. emission rates of Sources, and type of ventilation system.
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From page 253... ...
Department of Transportation, Federal Highway Administration, Of f ice of Highway Planning, 1974 .
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S . Department of Transportation, Federal Highway Administration, Of f ice of Highway Planning, 1973.
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Department of Transportation, Federal Highway Administration, Office of Highway Planning, 1972.
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U.S. Department of Transportation, Federal Highway Administration, Office of Highway Planning.
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From page 257... ...
Department of Transportation, Federal Highway Administration, Off ice of Highway Planning, 19.t2.
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From page 258... ...
L - whence Berkeley Laboratory Report LBL-9937 . Berkeley , Cal.: Lawrence Berkeley Laboratory, 1979.
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