Survey of Soil Pollution of Zahedan City Landfill by Heavy Metals (Chromium, Cadmium, Lead and Arsenic) Using Pollution Load Index and Ecological Risk

Soil pollution and accumulation of heavy metals in soil are one of the most important environmental issues that threaded the life of plants, animals and humans. Heavy metals due to their toxicity, stability and bioaccumulation are the serious environmental pollutions. This study aimed to evaluate heavy metals pollution of landfill soil of Zahedan city in Sistan and Baluchestan province.Measurement of heavy metals performed in April 2016 at 10 sites based on common standards, by using of random sampling method. 20 composite samples were collected from surface and depth of the soil. After sample preparation, total amount of Chromium, Cadmium, Lead and Arsenic in the soil samples were extracted by nitric acid and for statistical analysis used the SPSS software version 23.The results of ANOVA on samples of the surface and depth of the soil for these elements have been suggested that there is a significant difference at different stations. The results of PLI study showed that the soil of landfill of Zahedan with PLI value less than 2, has low pollution and the highest pollution in surface and depth of the soil is respectively related to station 2 and 1. The results also showed that heavy metals, Chromium, Cadmium, Lead and Arsenic in surface and depth of the soil with Ecological Risk 203.855 and 236.93 respectively which is located in the category of moderate contamination of Ecological Risk.