Assessment of Soil Contamination Status in Selected Agricultural Lands in Dhi Qar Province, Southern Iraq, Using Pollution Indices

Document Type : Original Article

Authors

1 Soil Science department

2 عضو هیات علمی

3 Urmia University

4 Department of Soil Science

5 University of Sumer, College of Agriculture

10.30466/asr.2026.56244.1889

Abstract

The accumulation and pollution of heavy metals in agricultural soils pose a serious global issue due to their toxicity, abundance of pollution sources, non-degradability, and persistence in the environment. The aim of this study is to assess the potential contamination of heavy metals in agricultural lands in Dhi Qar Province, southern Iraq, using pollution indices. In order to assess the pollution status of soils in the study area, 50 surface soil samples were collected from lettuce (Lactuca sativa) cultivated fields. The total concentrations of metals including copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), chromium (Cr), and nickel (Ni) were measured in the soil samples. To quantify the risk of soil contamination by heavy metals, the geo-accumulation index (Igeo), contamination factor (CF), and ecological risk potential (Er) were also applied. The results showed that the average concentrations of Cu, Zn, Pb, Cd, Cr, and Ni in the soils were 1198, 2964, 332, 18, 171, and 11 mg kg-1, respectively. The levels of heavy metals—Cu, Zn, Pb, Cd, and Cr—exceeded acceptable limits in the study area. Based on the Contamination Factor (CF), Cd and Cr were classified as having high contamination levels (CF > 6), while Ni showed low contamination (CF ≤ 1). According to the Igeo index, Cd was in class six, indicating an extremely high contamination level, and it also had the highest ecological risk potential among the heavy metals studied. Analysis of the spatial distribution maps of the contamination factor indices showed that the highest concentrations of heavy metals occurred in the northern, central, southeastern, and parts of the southwestern regions. Therefore, regular monitoring of heavy metal concentrations and identification of pollution sources in the region’s soils are recommended to reduce and manage environmental and health risks.

Keywords

Main Subjects


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Articles in Press, Accepted Manuscript
Available Online from 14 June 2026
  • Receive Date: 03 June 2025
  • Revise Date: 14 July 2025
  • Accept Date: 26 July 2025