Development of a modeling framework to predict indoor air concentrations of semivolatile organic compounds

Conference · Thu Dec 31 04:00:00 EST 1998

OSTI ID:679334

Van Loy, M D; Nazaroff, W W ^[1]; Daisey, J M ^[2]

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1. Univ. of California, Berkeley, CA (United States). Dept. of Civil and Environmental Engineering
2. Lawrence Berkeley National Lab., CA (United States). Environmental and Energy Technologies Div.

Semivolatile organic compounds (SVOCs) are an important but largely unstudied class of indoor air pollutants. SVOCs have been well-studied as outdoor air pollutants, but much less effort has been focused on understanding the factors affecting their concentrations in indoor air. Because of these compounds` low (10-6 to 10 Pa at room temperature) vapor pressures, they readily partition into condensed phases from the gas phase. In outdoor air, this phenomenon is important as a source of secondary organic aerosol and as a mechanism for long range transport and persistence of SVOCs in the atmosphere as particle-phase species. Indoor environments include another potential condensed phase besides the airborne particle phase: surface materials such as carpet, wallboard, upholstery, ceiling tiles, linoleum, and many others. Adsorption to these materials has a markedly different effect on indoor contaminant concentrations because the condensed phase is stationary. Unlike the airborne particle phase, for which ventilation is a significant removal mechanism, the only significant pathway for removal of reversibly sorbed pollutants from the indoor environment is desorption into the gas phase followed by ventilation. Because buildings generally have a large surface area to gas-phase volume ratio, the net removal of SVOCs from the indoor environment via this mechanism is likely to be very slow. Compounds re-emitted from one surface are likely to quickly re-absorb to another. This paper presents an analysis of the factors affecting indoor concentrations of SVOCs including ventilation, gas-particle partitioning, gas phase sorption on indoor surfaces, particle deposition, and oxidative radical chemistry and estimates their relative importance to facilitate simplification of numerical simulations of indoor pollutant concentrations.

• Sponsoring Organization: Environmental Protection Agency, Washington, DC (United States); National Science Foundation, Washington, DC (United States); USDOE, Washington, DC (United States)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 679334
• Report Number(s): CONF-980632--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
54 ENVIRONMENTAL SCIENCES
CARBON SINKS
ECOLOGICAL CONCENTRATION
FORECASTING
INDOOR AIR POLLUTION
MATHEMATICAL MODELS
ORGANIC COMPOUNDS
PHASE STUDIES
VOLATILE MATTER