Past investigations have shown that accumulation of heavy metals in soils is an environmental problem in many areas. Several factors including industrial and agricultural activities have caused soil ontamination at different levels. The purpose of this research was to determine the spatial variability of Zn and Ni in soils under three different land uses: agricultural, industrial and urban, around the city of Mashhad , Northeast of Iran. Topsoil samples (0-10 cm) were collected from 151 sites in an area of 600 km2. The location of each sampling site and its land use were recorded by GPS. Total metal concentrations were measured by atomic absorption spectroscopy. Soil contamination was mapped using GS+ and Surfer Software and Kriging. The result showed that the concentrations of Zn and Ni were higher in industrial and urban compared to agricultural soils. In some parts of the studied area, the concentrations of Ni and Zn in industrial and urban soil samples were higher than maximum permissible limits. Zn concentration in 4% of soil samples was higher than 150 mg kg–1 and in 11% of soil samples was more than 100 mg kg-1. Ni concentration in 23% of soil samples was above the suggested threshold (50 mg kg-1). It seems that Ni and Zn concentrations in soils have been affected by industrial activities and parent materials. Generally, it was concluded that some parts of the studied area were polluted by selected heavy metals; therefore, a monitoring program should be planned for this area.

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