The Comparative Distribution of Volatile Aromatic Hydrocarbons in Ambient Air of Hamadan (West of Iran) with Gasoline Stations

Abstract

Transportation sources create a major pollution problem with hydrocarbons in the ambient air of cities and petrol locations. The objective of this study was comparative distribution of volatile aromatic hydrocarbons (VAH) in the ambient air of Hamadan city and petrol stations. For this purpose, 74 samples of large size were obtained with charcoal tube and pump sampling. Samples were taken at eight sites in Hamadan at which traffic flow varied between 100 to 1200 vehicles per hour. Samples were analyzed with gas chromatography equipped with flame ionizing detector.

The mean concentrations of benzene, toluene, m- and p-xylene and o-xylene in gasoline stations were 89.9, 128.6, 61.8 and 25.5μg/m $^3$ respectively. The concentrations depend on density of vehicular traffic per hour. The results of data analyses showed a significant difference between concentration of volatile aromatic hydrocarbons in gasoline locations and ambient air of Hamadan city (P = 0.005). The mean concentrations of volatile aromatic hydrocarbons in ambient air during the spring and the summer were more than during autumn and winter (P = 0.005).

The concentrations of volatile aromatic hydrocarbons in gasoline stations and ambient air are high as compared to other cities in the world that made potential effort to citizens' health. The authorities must decrease the amount of benzene in consumption of gasoline in Iran.