Identification of polycyclic aromatic hydrocarbons in roadside leaves (Ficus benghalensis) as a measure of air pollution in a semi arid region of northern, Indian city-A smart city

Abstract

Abstract In this work, the semi-arid region of northern India was selected to observe the contamination levels, scattering pattern, seasonal distribution, the ratio of low and high molecular density carcinogenic PAHs (Polycyclic Aromatic Hydrocarbons) in the roadside plants (Ficus benghalensis). Total 48 samples [DAV College Jalandhar (inside city) as well as CT Group of Institutions Jalandhar (outside city)] were collected during the year 2017 (within four varying seasons). In order to understand the distribution pattern of PAHs we applied, Principal Component Analysis (PCA) and Cluster Analysis with Multivariate Linear Regression (MLR). The major resources of PAHs on roadside plants were the source of Petrogenic and Pyrogenic. Involvements of Coal Combustion Products (CCPs), automobiles exhaust emission and trickles of lubricate products (Petrogenic) were the key contributors with 36%, 36% and 28% using PCA/MLR, respectively. The mean concentration of total (low and high molecular weight) PAHs (Inside city) were 5.77 and 6.99 ng/m3 (1:1.44) whereas at outskirts of the city was 4.59 and 6.99 ng/m3 (1:1.93), respectively. Total PAHs mean concentration of PAHs (Inside city) was 105.81ng/m3, whereas in the outskirts of the city it was 97.34 ng/m, 3 respectively. The results of total PAHs concentrations (Inside city), indicated that the 4-ringed carcinogenic PAHs were at alarmingly surpassing concentrations (i.e., 30.35 ng/m3), whereas, at city outskirts 4, 5, and 6-ringed hydrocarbons were found in elevated concentration (i.e., 28.49, 25.59, and 23.46 ng/m3). The Two-tailed t-test, ring distribution pattern and toxic equivalency factor were applied for the statistics significance of results.