بررسی میزان فلزات سنگین خاک منطقه صنعتی و محل دفن زباله شهرستان قائم‌شهر

Background and purpose: Irrational discharge of toxic waste in environment leads to contamination of water, soil and agricultural fields. The aim of this study was to evaluate the contamination levels of cadmium, zinc, copper, lead, arsenic, and iron in the soil of two landfill area in Ghaemshahr, Mazandaran province. Materials and methods: Soil sampling was carried out in a waste burying area and around Tabarestan steel factory in Ghaemshahr from 0 to 20 cm depth of soil in December 2014. The concentrations of heavy metals in soil samples were assayed after drying and acid digestion according to the No. 8523 method of Iran national standards using the atomic absorption spectrophotometer. Results: Comparison of heavy metals concentration indicated that the arsenic levels in both areas and the copper in waste discharging area were higher than the standard levels. Evaluation of contamination index showed that zinc contamination was high and copper and arsenic contaminations were moderate in landfill area. Also, arsenic and zinc contaminations were moderate in the soil around the Tabarestan steel factory. Conclusion: The concentrations of zinc, copper and arsenic in studied areas were higher than standard levels. Moreover, possible harmful effects of heavy metals accumulation in nature and biological systems calls for appropriate planning for toxic waste discharge in these areas.