Partitioning of volatile organic compounds to aerosols: A review

Although volatile organic compounds (VOCs) exist mainly in the gas-phase rather than in aerosols, the concentrations of VOCs measured from aerosols are comparable to those of semi-volatile organic compounds, which preferentially partition into aerosols. VOCs that partition into aerosols may raise health effects that are generally not exerted by aerosols or by VOCs alone. So far, only scant reports on VOC/aerosol partitioning are available in the extant literature. In this review, we discuss findings presented in recent studies on the partition mechanism, factors affecting the partition process, existing knowledge gaps, and recommendations to help address these gaps for future research. Also, we have surveyed the different models that can be applied to predict partition coefficients and the inherent advantage and shortcoming of the assumptions in these models. A better understanding of the partition mechanism and partition coefficient of VOCs into aerosols can improve prediction of the global fate and transport of VOCs in the environment and enhance assessment of the health effects from exposure to VOCs.