Source profile and carcinogenic risk assessment of pahs found in aerial deposited road particles

PAHs are a cluster of significant environmental contaminants that have aroused substantial attention due to their ubiquitous occurrence and biological toxicity. Thirty locations from five different land use zones were selected to analyze USEPA's priority 16 PAHs in the aerial deposited road particles of Guwahati by Gas Chromatography-Mass Spectrometry. The findings revealed that the high molecular weight PAHs were the significant constituents, and their concentrations were highest near National Highways (8601 ng/g) and lowest in Residential areas (2081 ng/g), reflecting the impacts of commercialization-industrialization protocols on PAH emission. Benzo[a]pyrene equivalent (BaPeq) toxicity and Incremental Lifetime Cancer Risk (ILCR) were utilized to estimate the possible hazards to human health that PAHs in the road particles may pose. The most significant BaPeq toxicity was found at the National Highway sites (921.5 ± 21.54 ng BaPeq/g) and lowest in the Sensitive areas (242.6 ± 11.74 ng BaPeq/g). The combined hazard levels due to the PAHs in aerial deposited road dust were in the range of 10^-6 to 10^-4, indicating a significant risk of cancer to the adults (1.39E-05) and children (1.26E-05) in Guwahati through ingestion and dermal exposure. The potential sources of PAHs were identified using Positive Matrix Factorization (PMF) and diagnostic ratio determination, which showed that traffic emissions from automobiles fueled by petrol and diesel, industrial incinerator boiling, and coal/wood burning are essential factors in regulating the proliferation of PAHs in aerial deposited road particles of Guwahati.