Document Type : Article
Authors
1
Faculty of Civil & Environmental Engineering Tarbiat Modares University
2
Transportation Research Institute Mimistry of Road and Urban Development
Abstract
The purpose of this study is to practically determine an appropriate sampling area for identification of pollution from the exploitation of roads in Iran. To fulfill this objective, after field study, the classification of roads, based on environmental priorities, was carried out. Then, monitoring and assessing the environmental impact resulting from the exploitation of the roads was undertaken. To achieve this, four roads under different climate conditions were selected and various parameters of water, soil and air were evaluated, according to the corresponding traffic load, in two separate periods of time. Based on examination, the values of most investigated parameters, except soil parameters, were below the standard limits. Although there is no rational and meaningful relation between traffic load and the obtained values in soil samples, more attention should be paid to the source of some basic pollutants, such as total petroleum hydrocarbon, ands nickel and vanadium, which, in some cases, violate standards. Asphalt, tires, and vehicle fuel are the main sources of nickel, vanadium and TPH in road transportation. Even though concentration of these contaminants in the water and air samples of the road margin was insignificant, in his tudy, hemaximumconcentration of 14 mg/kg of TPH in soil was observed. Nickel concentration in the three cases was even higher than standard levels, and concentration of 90 mg/kg of soil, which is about twice the standard level, has been recorded for this contaminant. The maximum concentration of 162 mg/kg of vanadium, which is nearly three times the standard level, was also measured in the soil. High concentrations of soil pollutants, in comparison to other environments such as water and air, can be related to its ability to retain contaminants. Therefore, in order to assess the impact of emissions from the exploitation of roads on the physical environment, the soil bed is a better location in comparison with the air and water resources of rim roads.
)