Effects of Heavy Metal Contamination Caused by Residual Leachate on Forest Soil in Babol Anjilsi Region, Iran

The heavy metals are a part of the minor elemental elements in the nature. Forest soils directly and indirectly affect public health through the production of nutritional factors on plants and animals in the ecosystem. Pollution in forest soils may lead to disorder in soil structure, interference in the growth of plants and trees, and even soil contamination to heavy metals such as Fe-Hg-Ag-As-Cr-Mn-Co-Cu-Mo-Ni-Zn-Sn-W using various indicators of contamination.

To conduct the study, 40 soil samples from the waste disposal area of Babol (Babol Anjilsi region) were systematically selected harvested and the concentration of metals was measured using an ICP device. The enrichment factor and geo-accumulation index were used to determine the contamination of the study area.

The results of the study showed that Fe-As-Cr-Ni-Co concentration in the study area is higher than the maximum acceptable concentration of the Ericson 2011 standard. The geo-accumulation index was obtained for all metals. The results showed the concentration of metals in the soil relevant to the source of leachate from waste landfill in the area. The values of the Contamination Factor (CF) indicated that most of the samples were in the non-polluted to medium class and the contamination factor for Fe-Cr-W metals was the highest value. In general, about 20% of the data was in the medium to high pollution class.

Geo-accumulation index zonation map analysis showed that the origin of heavy elements of the region is the residual leachate and geological.