RESUMO
A total of 58 surface dust samples were collected in urban area of Xi'an City. High Performance Liquid Chromatography (HPLC) was used to analyze the concentrations of six phthalic acid esters (PAEs) listed as priority pollutants by United States Environmental Protection Agency (U.S. EPA). Composition, distribution, environmental sources and exposure characteristics of PAEs in the surface dust were further studied. All analyzed PAEs were detected in the surface dust. The concentration of individual PAE compounds varied from not detectable to 183.19 mg·kg-1 and their mean concentrations decreased in the order of DEHP>DnBP >>DEP >DMP >BBP >DnOP. The total concentration of six PAEs (∑6PAEs) ranged from 0.87 to 250.30 mg·kg-1 with an average of 40.48 mg·kg-1, and followed the order of parks >traffic area >mixed business and traffic area >residential area >educational area >industrial area. The ∑6PAEs presented the decreasing trend along the main urban area - the second ring road - the third ring road. The results of correlation analysis, principal component analysis and cluster analysis showed that PAEs in surface dust of Xi'an City were related to the application of plasticizers, the emission of cosmetics and personal care products along with building materials and home decoration materials. The dose order of human exposure to PAEs in surface dust was the direct ingestion by hand and mouth >>dermal adsorption >inhalation via mouth and nose. Meanwhile, the intake dose of children was higher than that of adults. However, the intake dose of DnBP, DEHP, DBP and BBP was lower than the tolerable daily intake (TDI) suggested by European Union Scientific Committee for Toxicity, Ecotoxicity and the Environment (EU CSTEE) and the reference doses (RfD) proposed by U.S. EPA.