Comparison of the predicted concentration of outdoor originated indoor polycyclic aromatic hydrocarbons between a kinetic partition model and a linear instantaneous model for gas–particle partition

Polycyclic aromatic hydrocarbons (PAHs) of outdoor origin can enter indoor environment via infiltration or ventilation, and lead to human exposure. This study presents a kinetic partition model for the prediction of indoor PAH concentrations that are of outdoor origin. The model was verified with the previous published measurement conducted in a chamber. Indoor gas-phase, particle-phase and airborne concentrations (the sum of the gas- and particle-phases concentrations) of 16 species of PAHs listed by United States Environmental Protection Agency (EPA) as priority pollutants were calculated over a two-year period by the kinetic partition model. The predicted concentrations were compared with those calculated using a simple linear instantaneous model. Uncertainty in the differences between the predicted results by these two models caused by uncertain parameters was further conducted. For some PAHs, remarkable differences existed between the predicted indoor gas- and particle-phases concentrations of outdoor originated PAHs by the kinetic partition model and by the linear instantaneous model. The average relative differences of gas-phase PAHs ranged from 3.60 × 10−6 to 6.31 × 101 while those of particle-phase PAHs were between 5.47 × 10−2 and 9.15 × 10−1. However, there was no obvious average relative difference between the predicted airborne concentrations, which maximized to 6.52 × 10−2. The average relative differences for both the gas- and particle-phases PAHs were even larger when particle deposition rate was at its maximum.