Characterization and Health Risk Assessment of Human Exposure to PAHs in Dust Deposited on Leaves of Street Trees in Egypt

AbstractDust deposited on leaves of trees can be effectively used as monitors of polycyclic aromatic hydrocarbons (PAHs). Sixteen EPA priority PAHs concentrations in deposited dust on leaves of the street trees (leaves dust) at 14 sampling sites at traffic and residential areas in Cairo, Egypt were measured. The health risk of the 16 PAHs to humans were estimated and calculated. Results indicate that the predominant PAHs were high molecular weight-PAHs, with higher contribution 83%, whereas low molecular weight-PAHs were the less lower contribution 17%. Higher concentrations of ΣPAHs recorded at traffic areas (18,223 ± 4,172) mg/kg, whereas lower levels were found in residential areas (8,261 ± 2,006) mg/kg. The diagnostic ratios and total indexes of PAHs compounds indicate that traffic emissions and incomplete combustion were the major sources of PAHs in deposited dusts on leaves of street trees of Greater Cairo. The health risk assessment focused on ΣPAHs in leave dust, which were related to health impac...