Impact of agricultural activities on accumulation of Cadmium, Cobalt, Chromium, Copper, Nickel and Lead in soil of Hamedan province

Document Type: Research Paper



Use of chemical fertilizers, pesticides and sewage sludge in agriculture lands have
increased soils trace metals concentration in many parts of the world. In This article we
report the results of a study on impacts of agricultural activities on soil accumulation of
Cadmium, Cobalt, Chromium, Copper, Nickel and Lead and risk of metal contamination in
Hamedan Province using contamination factor. The soil samples were collected
systematically from agriculture fields with cultivation period of 65, 35 and 20 years. The
results showed the mean concentration of Cd, Co, Cr, Cu, Ni and Pb in the soils was
increased with the cultivation period and a significant difference was seen between the
concentrations of metals, except for Pb, in the soil under different cultivation periods. The
trend of soils trace metal accumulation of Cd, Co, Cr and Cu was exponential, whereas for
Ni and Pb, it was quadratic and linear, respectively. Also, based on the calculated
contamination factors, the soils classified as none and none to medium class pollution were
generally found in lands with more length of cultivation. The increase of trace metals
concentration in the soil followed the increase in the use of fertilizers in the region. The
cultivated soils thus provide a way for entrance of trace elements in the human’s food
chain. Therefore, monitoring contaminated soils is necessary to control and prevent the
risks from contaminated soils.