There is an increasing demand for the development of brick kilns area in Iran, which emit a considerable amount of pollutants to environment. The present study aimed to investigate the extent of soil contamination by heavy metals around the brick kiln area in Aran-o-Bidgol city. The correlation coefficients, analysis of variance, principal component analysis, cluster analysis, soil contamination indices and interpolation technique were utilized to investigate the soil contamination and pinpoint the possible sources of contamination. The Results showed the average concentration of all heavy metals were greater than background values and soils were contaminated by heavy metals to some extent. Results also indicated that copper, nickel and zinc had simultaneously emanated from anthropogenic including agricultural activities and urban emissions while the sources of cadmium and lead could mostly be attributed to different anthropogenic activities including brick kilns and related transportation. The distribution maps revealed that the brick kilns emissions had only affected the concentrations of cadmium and lead to some degree.

Heavy metals usually accumulate and migrate in soil environment due to human activities and this in return poses potential ecological and health risks. A total of 135 surface soil samples were collected from Aran-o-Bidgol City, Iran and were analyzed for their Cd, Pb, Ni and Cu concentrations to determine these elements' spatial distribution and potential ecological risks. To this end, interpolation mapping was conducted using Ordinary Kriging. The mean concentrations of Cd, Pb, Ni and Cu in the samples were 0.72, 11.41, 29.87 and 14.82 mg kg(-1), respectively, which were all higher than their background values. The spatial variation in the concentration of heavy metals could be attributable to point sources and vehicle emissions. Considering the severity of the potential ecological risks of metals, the descending order of contaminants' concentrations was Cd > Cu > Ni > Pb. The Potential Ecological Risk Index (RI) suggested that approximately 40 % and 59 % of the samples posed high and significantly high potential ecological risks, respectively. Moreover, ecological risk decreased progressively going from southwest to northeast over the under-study area. Considering the background values and RI, this area presented a relatively high level of contamination.

Soil is a non-renewable dynamic natural resource that is essential to human life and serves as the most important sink for toxic ingredients like trace elements (1,2). There have been great concerns about the contamination of hazardous elements due to rapid industrialization and urbanization during the recent decades (3-6). Trace elements via urban soils can intake into the human body through three ways, ingestion, inhalation and dermal absorption, accumulate in fatty tissues, and subsequently affect the nervous, endocrine and immune system; also, hematopoietic function and normal cellular metabolism (7,8). In evaluating anthropogenic contaminations, more attention should be paid to understanding the status, quantity and dispersion of the pollution in the ecosystem. There is the need for more detailed information about the accumulation and levels of human exposure to

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