Benzo(a)Pyrene Equivalency and Source Identification of Priority Polycyclic Aromatic Hydrocarbons in Surface Sediments from Yamuna River

ABSTRACT

Identification of polycyclic aromatic hydrocarbons (PAHs) sources in the environmental compartments is crucial, but there is a need for appropriate management and remediation plan in the environment. PAHs can provide useful information, because they have been utilized for source apportionment. In this study, priority 16 PAHs were determined in sediments from Yamuna River in Delhi for the assessment of their possible sources. Among 16 PAHs, the dominant compounds were fluoranthene, chrysene, fluorine, and pyrene, and their sum accounted for more than 96% of the total 16 priority PAHs. The concentrations of ∑16PAHs at locations between upstream and downstream were not showing any considerable spatial gradient. The concentration of seven probable carcinogenic PAHs ranged 236–6230 µg kg⁻¹ with the mean value of 1897 ± 1740 µg kg⁻¹, and accounted for 40% of the ∑16PAHs. Benzo(a)pyrene toxic equivalent factors (TEFs) used for the quantification of relative toxicity potential of priority PAHs in terms of BaP toxicity equivalency (BaP_TEQ) were presented. Homolog profiles demonstrated the dominance of two-, three-, and four-ring PAHs. Composition profile and selected concentration ratios of PAHs were used as diagnostic tools for the identification of possible emission sources of PAHs. The study suggested the pyrogenic activities of petroleum, coal, and biomass combustions as a major source of PAH contamination in the river. However, marginally petrogenic sources from automobile workshops and accidental spillage cannot be ruled out. The observed levels of total PAHs and their toxicity equivalency in sediments were more or less comparable with similar studies carried out worldwide.

KEYWORDS:

• Priority PAHs
• river sediment
• source apportionment
• toxicity equivalent

Acknowledgment

The authors are thankful to the competent authorities, Central Pollution Control Board, for the support and guidance to conduct this work. The views expressed in this paper are those of authors and do not necessarily reflect the organization's.