Polycyclic Aromatic Hydrocarbons in House Dust Samples : Source Identification and Apportionment

House dust is a heterogeneous matrix, consisting of a variety of inorganic, organic and biological materials. Once pollutants are adsorbed onto house dust particles, they either do not degrade at all or degrade at rates that are relatively slower than their ambient counterparts. Thus house dusts are useful reservoirs for chronic exposure to indoor pollutants. In this study, house dust samples from suburban houses in Brisbane, Australia were collected in summer 2004 and winter 2005. Given the growing need to understand the potential risks of indoor pollutants and to develop appropriate control strategies, the objective of the study was to use receptor-oriented models to estimate the number of sources, their compositions and the contribution of each source to the samples. Thus the polycyclic aromatic hydrocarbon (PAH) composition data were analyzed with advanced factor analysis models. Four factors were required to reproduce the summer data well and each factor had distinctive compositions that suggested that natural gas utilities, cooking, vehicle emissions and miscellaneous combustion processes are the main sources of PAHs in the samples. The implications of the results and of the observed correlation between the building characteristics and the PAH profiles on the quality of these indoor microenvironments and the development of control strategies are discussed