Distribution of Polycyclic Aromatic Hydrocarbons and Polychlorinated Biphenyls and their Source Identification in Urban Roadside Soils

摘要

This study deals with distribution and identification of possible sources of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in urban roadside soils of Kurukshetra, a developing city in Haryana, India. The concentration of Σ16PAHs and Σ28PCBs was ranged between 16.1-2538.0 μg kg-1 and 3.33-34.81 μg kg-1. The average concentration of total PAHs, total possible carcinogenic PAHs, total PCBs and dioxin-like PCBs was 631.6±44.5 μg kg-1, 568.8±38.8 μg kg-1, 11.57±2.00 μg kg-1 and 2.85±0.34 μg kg-1, respectively. Carcinogenic fractions of PAHs and PCBs accounted for 90.1% and 34.6% to the total PAHs and PCBs, respectively. Diagnostic ratios of individual PAHs and higher fraction of high molecular weight PAHs indicate the pyrogenic activities such as motor vehicles, biomass and coal combustion as major sources of PAHs. Group homolog pattern shows that lower chlorinated PCBs were higher in concentrations than high chlorinated PCBs. Combustion of mixtures of waste, containing paper, cartons, plastics and painted wood, may be the possible sources of dioxin like-PCBs. Concentrations of PAHs and PCBs observed in this study were compared with available soil quality guidelines, which were lower than the guideline values, and analysed soils may be categorised in non contaminated soils.