Soil Contamination by Arsenic in Urban Areas: A case study of Arak City

Arsenic contamination is of great environmental concern due to its toxic effects as a carcinogen. In order to assess soil arsenic contamination and its distribution patterns, surface soil samples collected from the urban areas of Arak were analyzed. Totally, 62 surface soil samples were collected from depth of 0–20 cm of different locations including parks, green spaces, agricultural, roadsides, and squares of Arak City. The spatial distribution of arsenic in soil was mapped using GIS and kriging method. The concentration of arsenic in the surface soil of Arak City was between 2.2- 10.8 mg/kg (average: 5.78 mg/kg). Spatial analysis showed that arsenic contamination enhances in the city center and there was an increasing trend from south to north. In addition, the mean arsenic concentration in the urban topsoil samples from Arak was lower compared with mean concentration for other cities around the world. It seems that arsenic in soil is controlled by natural and anthropogenic factors. The highest concentrations of arsenic in center and the north areas reflected arsenic loading is originated from anthropogenic sources such as vehicles and industrial processes.