Distribution, Composition Profiles and Source Identification of Polycyclic Aromatic Hydrocarbons in Roadside Soil of Delhi, India

Abstract

Distribution, composition profiles and sources of polycyclic aromatic hydrocarbons (PAHs) were evaluated in roadside soils from Delhi, India. PAH determination was made by Sonication extraction and chromatographic clean-up with final analysis by high performance liquid chromatography with ultraviolet-diode array detector (HPLC-UV-DAD).The average concentration of ∑PAHs was 6838.6±3528.4 µg kg -1 and ranged between 81.6 to 45017.4 µg kg -1 . Seven possible carcinogenic PAHs (7c-PAHs) accounted 67.4% to the total PAHs. Diagnostic ratios of individual PAHs and LMW PAHs to HMW PAHs ratio were calculated and applied to assess the possible sources of PAHs which, indicates the mixed pyrogenic activities such as petroleum, biomass and coal combustion are the main contributors. Although, concentrations of individual PAHs were lower than the guideline values but, the concentrations of some high molecular weight PAHs were higher at the locations in the vicinity of industrial areas and there is probable some risk to human health. Keywords: Polycyclic aromatic hydrocarbons (PAHs), HPLC-UV, roadside soil, diagnostic ratio, India