Distribution of Nickel, Manganese and Cadmium in Soil and Crops in the Mobarakeh Steel Plant Region

Soil pollution and accumulation of heavy metals in crops in industrial areas are the most important bioenvironmental problems that threaten the life of plants, animals and humans. The objective of this study was to determine Ni, Mn and Cd distribution in soil and crops shoots around the Mobarakeh Steel Plant. In this study, we separated 50 zones based on soil utility maps taking into consideration the dominant wind direction (south-western to north- eastern). In each zone, soil was sampled at 0-5, 5-10, 10-20 and 20-40 cm depths (200 samples) and DTPA-extractable concentrations of Ni, Mn and Cd were determined in soil samples. Also 36 plant samples from shoots of 18 main crops were collected in the region and the concentrations of heavy metals were determined in crop samples. Results showed that maximum DTPA-extractable concentrations of Ni and Mn were in the northeast of the region in the 0-5 cm layer (4.2 and 312 mg/kg.soil, respectively) and decreased in 5-10,10-20 and 20-40 cm layers (2.7,2.7,2.1 and 200,212,146 mg/kg.soil, respectively). The concentrations of Ni and Cd in shoots of crops were undetectable with atomic absorption method. The concentration of Mn in rice shoots was 716.6 mg/kg.dry.m. It was higher than USEPA standards (15-100 mg/kg.dry.m). .