Sources and dynamics of semivolatile organic compounds in a single‐family residence in northern California

Abstract

Semivolatile organic compounds (SVOCs) emitted from building materials, consumer products, and occupant activities alter the composition of air in residences where people spend most of their time. Exposures to specific SVOCs potentially pose risks to human health. However, little is known about the chemical complexity, total burden, and dynamic behavior of SVOCs in residential environments. Furthermore, little is known about the influence of human occupancy on the emissions and fates of SVOCs in residential air. Here, we present the first‐ever hourly measurements of airborne SVOCs in a residence during normal occupancy. We employ state‐of‐the‐art semivolatile thermal‐desorption aerosol gas chromatography (SV‐TAG). Indoor air is shown consistently to contain much higher levels of SVOCs than outdoors, in terms of both abundance and chemical complexity. Time‐series data are characterized by temperature‐dependent elevated background levels for a broad suite of chemicals, underlining the importance of continuous emissions from static indoor sources. Substantial increases in SVOC concentrations were associated with episodic occupant activities, especially cooking and cleaning. The number of occupants within the residence showed little influence on the total airborne SVOC concentration. Enhanced ventilation was effective in reducing SVOCs in indoor air, but only temporarily; SVOCs recovered to previous levels within hours.

Surface reservoirs dominate dynamic gas-surface partitioning of many indoor air constituents

“…However, this explanation for the slower response times seems unlikely, given the open design of the house and the very high internal mixing rates (see Materials and Methods). A response time of several hours was observed for SVOCs in a residence in California (8). The longer response time for the SVOCs may suggest that, for these SVOCs, gasphase mass transfer is not rate limiting for air-surface exchange.…”

Characterizing Airborne Phthalate Concentrations and Dynamics in a Normally Occupied Residence

“…Considering the residence's average air-exchange period of 2.2 h, the DEHP phase-partitioning system may be far from equilibrium for larger particles but is expected to be at or near equilibrium for smaller particles. 48,50,54 Experimentally, the F p values were determined only for particles smaller than 2.5 μm, the SV-TAG particle-size cutoff. In addition, the stated PM2.5 concentrations do not include particles with diameters smaller than 250 nm that were not quantified by the Grimm 11-A OPC.…”

The atmospheric chemistry of indoor environments

“…The temporal responses of gas-phase species to enhancedventilation (usually by opening doors and windows) within genuine indoor spaces have also been monitored. 21,144,145 Gasphase mixing ratios of most gas phase species (i.e. VOCs, HONO, NH 3 ) drop signicantly upon enhanced ventilation because the outdoor air is typically cleaner than that indoors, and the mixing ratios then rebound to their previous steady state values upon closing the doors and windows.…”