Distributions of Some Heavy Metals in Agricultural Soil and Their Environmental Impacts in Chamchamal District, Sulaymaniya Governorate, Northeastern Iraq

Abstract

Soil samples were collected from Sangaw, Qadir Karam, and Takiat Gabbary sites of Chamchamal agricultural soil Sulaymaniya Governorate, Northeastern Iraq. The heavy metals Co, Cr, Cu, Ni, Cd, Zn, Pb, As, and Mn. in Eighteen soil samples were studied and used as an indicator for pollution by using many indices such as the contamination factor (CF), enrichment factor (EF), geo-accumulation index (Igeo), pollution load index (PLI), pollution ecological risk (Er), and risk index (RI). The results showed that the heavy metal concentration values were as follows: Mn> Ni> Zn> Cr> Cu> Pb> Co> As> Cd. The CF data showed that the soil in the study area has low contamination with Co, Cr, Cu, and Mn and moderate contamination with Ni, Pb, Zn, and As. Also, the soil samples are considerably contaminated by Cd and As in the Qadir Karam site. According to the results of Igeo, the soil was unpolluted for Co, Cr, Ni, Cu, Pb, Zn, and Mn, while being unpolluted to moderately polluted for Cd and As. The EF calculation results indicated that Co, Cr, Cu, and Mn have deficient to minimal enrichment, and have moderate enrichment for Ni, Pb, and Zn, while, for Cd and As is significant enrichment. According to the Er values, all the heavy metals in the studied sites reflect a low potential ecological risk. The risk index (RI) value is classified as moderate ecological risk for heavy metals in all sampling sites.