Investigation on the Direct Transfer of SVOCs from Source to Settled Dust: Analytical Model and Key Parameter Determination

Settled dust is an important medium for semivolatile organic compound(SVOC) transport indoors. Understanding the mechanism of interaction between SVOCsand settled dust can greatly improve the exposure assessment. This study develops ananalytical model to elucidate the mechanism of direct contact between SVOC sources andsettled dust. The model incorporates the adsorption of SVOCs onto indoor surfaces,which was ignored in previous numerical models. Based on this model, a hybridoptimization method is applied to determine the key parameters of SVOC transport, i.e.,the diffusion coefficient in the dust, the dust-air partition coefficient, and the chambersurface-air partition coefficient. Experiments of direct contact between SVOC sourcematerials containing organophosphorusflame retardants (OPFRs) and settled dust wereconducted in chambers. The key parameters were determined by performing curvefittingusing data collected from the OPFR chamber tests and from the literature on phthalates.The reliability and robustness of the model and measurement method are demonstratedby the highfitting accuracy and sensitivity analysis. The obtained key parameters are moreaccurate than those from correlations in prior studies. Further analysis indicates that dust-air partition coefficient plays an importantrole and the adsorption effect on surfaces cannot be neglected for SVOC transport.

Automated summary

This study develops an analytical model to elucidate the mechanism of direct contact between SVOC sources and settled dust. The key parameters for SVOC transport are determined through experiments and curve fitting, improving the accuracy and reliability of exposure assessment.