Pollution indices of heavy metals (Zn, Cu, Cd, Pb, Ni and Fe) in surface soils of Zanjan province

Due to increasing the heavy metal pollution and its related diseases in society [۱-۲], distribution analysis and calculation of the health risk of this pollution in the human environment are very important. Therefore in the present study, the concentration levels of heavy metals such as Zn, Cu, Cd, Pb, Ni and Fe in soil samples collected from ۳۵۷ sampling locations around Zanjan Province, Iran were analyzed. To interpret and to evaluate the pollution status and distribution of heavy metals in soil, metal pollution parameters such as enrichment factor (EF), geoeaccumulation index (Igeo), pollution factor (CF), potential ecological risk index (RI) and pollution Load index (PLI) and geospatial distribution patterns were used. Results indicated that the mean concentrations of Cd and Pb exceeded the world crustal average. Statistical analysis results showed that Zn, Cd and Pb levels in the investigated region were highly influenced by anthropogenic inputs such as metal extraction and mining activities. According to the health risk assessment model introduced by USEPA to evaluate the human health risks, the none-carcinogenic risk for children was above adults. Total potential carcinogenic health risks for both children above the threshold level and for adults in the study area were in acceptable range.