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This investigation focused on the potential sources of polycyclic aromatic hydrocarbons (PAHs) in different matrices and their temporal variations surrounding a coal-fired thermal power plant in India. Samples were collected in different seasons for 1 year. Gas chromatography-mass spectroscopy (GC-MS) was used to perform the measurement of 16 priority PAHs. Average PAH concentrations were ranged from 0.71 to 2.99 ng/m 3 in air and 1.59-22.7 ng/g in soil respectively. High levels of PAHs were found in soil compared to air, which indicated deposition in soil. This could be because of the fallout of high-molecular-weight compounds. During the monsoons, PAH concentrations in the air were the lowest compared to the other seasons because of the dilution effect. Phenanthrene, fluoranthene, and pyrenes were dominant in the air, contributing up to 32.5%, 22.7%, and 19.2% of total PAHs, respectively. On the other hand, soils contained fluoranthene (12.3%), pyrene (10.7%), benzo[b]fluoranthene (10%), chrysene (9.82%), and indeno[123-c,d]pyrene (9.64%) compounds. The occurrence of indeno[1,2,3-cd]pyrene (9.14 ng/g) indicated that the soil is contaminated from fly ash and diesel emissions from the thermal power plant and vehicular emission. The diagnostic ratios, thematic maps, and principal component analysis revealed that the fly ash, diesel emissions from the thermal power plant, vehicles, and biomass burning were the probable sources of PAHs in the study area. The human health risk assessment studies reveal that the soil samples are more prone to carcinogenicity than air samples. As per our knowledge, this is the first report on the impact of PAHs on air and soil in this region.

Polyaromatic hydrocarbons (PAHs) utilizing bacteria were isolated from soils of seven sites of Mathura refinery, India. Twenty-six bacterial strains with different morphotypes were isolated. These strains were acclimatized to utilize a mixture of four polycyclic aromatic hydrocarbons, i.e., anthracene, fluorene, phenanthrene, and pyrene, each at 50 mg/L concentration as sole carbon source. Out of total isolates, 15 potent isolates were subjected to 16S rDNA sequencing and identified as a member of diverse genera, i.e., Bacillus, Acinetobacter, Stenotrophomonas, Alcaligenes, Lysinibacillus, Brevibacterium, Serratia, and Streptomyces. Consortium of four promising isolates (Acinetobacter, Brevibacterium, Serratia, and Streptomyces) were also investigated for bioremediation of PAH mixture. This consortium was proved to be efficient PAH degrader resulting in 40-70 % degradation of PAH within 7 days. Results of this study indicated that these genera may play an active role in bioremediation of PAHs.