where Cm is the concentration of metals in polluted soil and Cr is the concentration of metals in remediated soil.
Enrichment Factor (EF) of soil samples was also calculated to assess the impacts of anthropogenic or natural activities in soil. EF value less than 2 indicates low enrichment and less influence of anthropogenic activities. EF value between 2 and 5 shows a moderate enrichment while EF value greater than 5 is significantly enriched [27]. EF was calculated as the double ratio of the concentration of a measured element to the reference element in soil and the earth crust [28]. Calculation of EF is expressed in Eq. (2).