Halogenated Polycyclic Aromatic Hydrocarbons in Soil and River Sediment from E-waste Recycling Sites in Vietnam

Abstract

We have determined halogenated polycyclic aromatic hydrocarbons (XPAHs) in 40 samples of surface soil (n = 32) and river sediment (n = 8) collected around the E-waste recycling area in Bui Dau, northern Vietnam. Thirty-one target compounds including 21 chlorinated PAHs (ClPAHs) and 10 brominated PAHs (BrPAHs) were quantified by gas chromatography-high resolution mass spectrometry (HRGC-HRMS). The highest concentrations of XPAHs in surface soils (3,960 pg/g dry wt) and river sediments (3,930 pg/g dry wt) were detected from samples near an open burning site and an E-waste recycling workshop. Composition ratios of BrPAHs to total XPAHs in this study were higher than those in fly ash of waste incinerators (12% and 29%), because E-waste in this study contained a large amount of brominated flame retardants (BFRs). These results suggested that XPAHs occurred in E-waste recycling activities and they contaminated the surrounding soil and sediment. A large number of peaks of unidentified isomers of XPAHs, such as X_nPhe/Ant (n = 1 − 4) were observed based on the isotope patterns of molecular ions [M, M+2, M+4] by HRGC-HRMS analyses. These unidentified isomers should be an important factor in the risk assessment for XPAHs.