Pollution and health risk assessment of potentially toxic elements in sediments of International Hamoun Wetland, Iran

Abstract

This study evaluated the ecological and health risks of potentially toxic elements (PTEs) in sediments of the Hamoun International Wetland, southeastern Iran. Twenty surface sediments were collected and PTEs concentrations were detected using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The ecological risk of 15 elements was investigated using the Improved Weighted Index (IWI) as a new approach, and Principal Component Analysis (PCA). The determination of the level of risk to human health from seven PTEs was assessed with the Hazard Index (HI) and carcinogenic risk (CR). The mean concentrations of all PTEs, except As (37.7 mg/kg), Cd (0.4 mg/kg), and Cs (5.2 mg/kg), were lower than the mean values of the Earth. The IWI ranged from 0.83 to 2.70 (mean: 1.84), classifying 10% of the study sites as uncontaminated and 90% of the study sites as moderately or slightly contaminated. Based on PCA, 56% of the elements were of natural origin. The probable origin of As was anthropogenic sources, and for Cr and Cd, two sources (natural and anthropogenic) were identified. The total HI values for adults were 0.53 and for children 0.88. The highest and lowest CR were obtained for As (1.37 × 10^–4), and Pb (3.21 × 10^–7), respectively. These values did not indicate a potential health risk to humans. To reduce the risk of As, controlling pollutant inputs and implementing effective management strategies to decrease potentially toxic elements (especially As) are essential for improving the sediment quality of the Hamoun Wetland.