The effect of ventilation on indoor exposure to semivolatile organic compounds

Abstract

A mechanistic model was developed to examine how natural ventilation influences residential indoor exposure to semivolatile organic compounds (SVOCs) via inhalation, dermal sorption, and dust ingestion. The effect of ventilation on indoor particle mass concentration and mass transfer at source/sink surfaces, and the enhancing effect of particles on mass transfer at source/sink surfaces are included. When air exchange rate increases from 0.6/h to 1.8/h, the steady-state SVOC (gas-phase plus particle phase with log KOA varying from 9 to 13) concentration in the idealized model decreases by about 60%. In contrast, for the same change in ventilation, the simulated indoor formaldehyde (representing volatile organic compounds) gas-phase concentration decreases by about 70%. The effect of ventilation on exposure via each pathway has a relatively insignificant association with the KOA of the SVOCs: a change of KOA from 10(9) to 10(13) results in a change of only 2-30%. Sensitivity analysis identifies the deposition rate of PM2.5 as a primary factor influencing the relationship between ventilation and exposure for SVOCs with log KOA = 13. The relationship between ventilation rate and air speed near surfaces needs to be further substantiated.

The effect of ventilation on the indoor air concentration of PCB: An intervention study

“…The interventions presented here did not investigate the effect of the ventilation on the concentration caused by emissions from primary sources, as opposed to the model in Thomas et al (2012) [20] where the source of emissions is highly contaminated caulks. Further the results show a different behaviour than predicted in the model by Liu et al (2014) [18] expecting a 60% decrease at a threefold increase of the air exchange rate. Their model predicts the effect of ventilation on the air concentration in a naturally ventilated room.…”

“…In this study particles were not determined. Also the model in Liu et al (2014) [18] investigates SVOCs with Log K oa of 9, 11, and 13, whereas for the PCB congeners detected in this study Log K oa varies between 8 and 10 [19]. It should be mentioned that the model by Liu et al [18] might not be directly comparable with this particular study.…”

“…The modelling of indoor air concentrations done by Liu et al (2014) [18] and Thomas et al (2012) [20] does not consider changes in temperature over time. However, temperatures are known to affect concentrations significantly.…”

“…In the case of PCBs (SVOCs) transport mechanisms depend on a range of factors like source/sink capacity and their concentrations, air concentrations, presence of airborne particles, ventilation, indoor and outdoor temperatures [4,16,17]. Liu et al (2014) [18] made a mass balance model describing the fate of SVOCs (e.g. PCBs) in indoor air of a model room with highly contaminated flooring.…”

Occurrence of triphenylphosphine oxide and other organophosphorus compounds in indoor air and settled dust of an institute building

“…Quite a few experimental studies were conducted based on dynamic measurements. Dynamics of airborne particles can strongly influence the transportation of chemicals that are bound to particles [24][25][26][27]. Under typical indoor conditions, kinetic constraints could influence the partitioning of SVOCs, particularly for those having a high octanol-air partition coefficient (K oa ) values [28].…”