Abstract

Polycyclic Aromatic Hydrocarbons (PAHs) formed as a result of unfinished burning of organic compounds which may cause toxic, carcinogenic, mutagenic and teratogenic harm. PAHs can be found in industrial wastes, garbage, cigarette smoke, pesticides and flue gases and can contaminate air, water, soil and food. Although more than 100 PAH compounds are detected in nature out of which at least 16 PAHs compound have more harmful effects. The soil is a long-term sink for airborne PAHs and the concentrations of PAHs are influenced by a wide variety of environmental factors i.e. changes in emissions with traffic volume. To observe the spatial variation in the concentration of PAHs in soil the PAHs were detected in roadside soil collected from different distances i.e. 1m, 5m, and 10m from roadside during winter season. The samples were extracted with hexane by ultrasonic agitation. The extracts were then fractioned on a silica-gel column and the aromatic fraction was subjected to HPLC-UV for analysis of 14 priority PAH pollutants specified by Environment Protection Agency (EPA). The total mean concentrations of PAHs were 15.34, 9.25, and 6.45μg g^-1 at 1m, 5m and 10m respectively. The results show negative correlation coefficient between concentration of PAHs and distances from the road. The carcinogenic potencies associated with the total B(a)P exposure was also calculated by using Potency Equivalent Factor (PEFs) and found to be 1.34, 0.93 and 0.42μg g^-1 at 1m, 5m and 10m from the roadside respectively. Factor analysis suggests that at roadside motor vehicle exhausts are the dominant source of PAH in the soil of Agra.

Keywords: Polycyclic aromatic hydrocarbon; Roadside soil; HPLC; Semi-arid region