Assessment of Heavy Metal Accumulation in the Roadside Soil and Plants of Robinia pseudoacacia, in Gumushane, Northeastern Turkey

The concentrations of heavy elements were studied in the soils and plants of Robinia pseudoacacia, along a highway passing through Gumushane City Center, Turkey. The aim of this study is to understand heavy metal accumulation due to dense traffic load, industrialization, urbanization, and/or geological features of the region. The assessment of the heavy metal accumulation of the soils is based on the Geoaccumulation Index and Enrichment Factor, and that of plants, is based on the Bioaccumulation Factor. According to the Geoaccumulation Index, soil samples were uncontaminated for Cr, Co, Cu, Rb, and Sr elements, uncontaminated to moderately contaminated for V, Ni, Ba, and Zn, and moderately to heavily-heavy contaminated for As. The contamination of soil samples changes from moderate heavy-extremely contaminated degree for Pb. According to the Enrichment Factor; soil samples show, no enrichment-moderately-severe enrichment for V Considering the Zn element, enrichment is in minor to severe enrichment. On the other hand, element enrichment is severe to very severe enrichment for As and that of Pb is minor to an extremely severe enrichment level. The data revealed that the soil in the study area is significantly contaminated for Zn, As, and Pb. Also, concentration levels of Cu, Fe, Mo, Ni, Sr, and Zn in the shoots of Robinia pseudoacacia at some location were determined as above and/or exceeded the upper limit of the normal range.