Spatio-Temporal Variations in the PAH Concentrations in the Soil Samples Collected from Functional Brick Kilns Locations in Balochistan, Pakistan

Abstract

The current study aimed to envisage the spatial and seasonal distribution of the six polycyclic aromatic hydrocarbons (PAHs) in the soil samples collected in the proximity of the brick kilns in Balochistan, Pakistan. Soil samples were collected in four directions with the increasing distance of 100, 300 and 500 m away from each brick kiln at all study sites. The concentration of the PAHs was determined through high-performance liquid chromatography (HPLC). The results of the current study report that all six PAH compounds were detected in the soil samples and the concentration of the studied PAHs varied with increasing distance from the source and with directions. Total PAHs (∑PAHs) concentration at study sites ranged from 2.74 to 4.51 µg/g and 1.05 to 1.13 µg/g in summer and winter seasons, respectively. The maximum concentrations of the PAHs were found in the summer as compared to the PAHs detected in winter. The soil was dominated by low molecular weight (LMW) PAH compounds in the summer whereas, in the winter soil was dominated by high molecular weight (HMW) PAH compounds. The concentration levels of all detected PAHs also varied among the studied sites. Carcinogenic potency of PAHs in studied samples was less than 1 except the soil samples from Mastung. No correlation was noticed between physiochemical properties and ∑PAHs. It is recommended that the soil near the brick kilns be regularly monitored for the presence of PAHs due to their high potential of carcinogenicity.