Muhandisī-i Bihdāsht-i Muḥīṭ (Mar 2023)
Assessment of Potentially Toxic Element Pollution in Groundwater Resources Using MI and PoS Indices (Case Study: City of Sonqor)
Abstract
Background & Objective: In the dry and semi dry regions of the world, due to almost 90% of their required water is provided from groundwater resources, these resources are vital. Therefore, this study was conducted to assessment of potentially toxic elements (As, Pb, Cd and Cu) pollution in groundwater resources of city of Sonqor, Kermansah Province, west of Iran in 2022 using MI and PoS indices. Materials & Methods: In this descriptive cross-sectional study, a total of 36 groundwater samples were collected randomly from 12 sampling sites during summer and autumn seasons. The value of some qualitative parameters including T, pH, EC and TDS were determined insitu. After samples preparation, the contents of As, Pb, Cd and Cu were determined using ICP-OES. Also, the metal (MI) and the PoS indices were computed for qualitative assessment of groundwater resources. Moreover, all statistical analyses were done using SPSS version 19.0 Results: Based on the results obtained, the mean contents of the analyzed elements (µg/l) in groundwater samples collected in the summer season were found to be 4.22 for As, 0.125 for Pb, 0.387 for Cd and 0.598 for Cu, while the mean levels of As, Pb, Cd and Cu in groundwater samples of the autumn season were 2.98, 0.137, 0.213 and 0.610, respectively. Also, in comparison, the mean concentrations of the analyzed elements in the groundwater samples of both seasons were lower than the maximum permissible concentrations (MPCs) established by WHO, EPA and Iran DOE. Besides, the MI and PoS indices of the summer season with mean values of 1.00 and 203, respectively, showed that the quality of groundwater resources of the study area was classified as 'slightly affected' and 'low quality degradation level'. Whereas, in the autumn season the mean values of MI with 0.830 and PoS with 144, showed that the quality of groundwater resources of the study area was classified as 'pure' and 'none–low quality degradation level', respectively. Conclusion: Although based on the findings, the quality of the groundwater resources of the study area was desirable during the implementation of this research, the overuse of agricultural inputs particularly phosphorus and urea fertilizers and also heavy metal-based pesticides (e.g. arsenical pesticides/herbicides), could be pose to decrease of the quality of groundwater resources, and cause irreversible damages in this area. Therefore, regular and periodic monitoring of groundwater quality for environmental and human health maintenance is recommended.
