Evaluation of the ecological risk index (Er) of heavy metals (HMs) pollution in urban field soils

Abstract

This study presents the importance of urban field soils for producing vegetable crops. This study was conducted in the three local areas of Isfahan (first region), Falavarjan (second region), and Natanz, Feridan, and Golpayegan (third region) to evaluate transfer factor (TF), contamination factor, ecological risk (Er) and potential ecological risk index (RI) which were employed to investigate the Pb, Cu, Co, Cd, and Cr pollution of the urban field soils affecting vegetable to reveal the potential hazards of HMs pollution for the first time in Isfahan city in Iran. To measure the pollution of such heavy metals (HMs) as Pb, Cu, Co, Cd, and Cr, the related soil samples were collected and their pollution and ecological risk indices were assessed. The results showed the highest pollution of Pb and Cr in the field soils of the first (127.37 and 112.65 mg kg −1) and second (6.94 and 4.61 mg kg −1) regions, respectively, which were greater than the amounts recommended by Iran's Environmental Protection Agency. The high TF of Cr (0.56 mg kg −1), Cd (0.23 mg kg −1), and Co (0.30 mg kg −1) from the soils to the tubers were found to mostly involve leafy and fruity vegetables. The highest contamination factor (PF) of Cr (12.46 mg kg −1) in the first region was in the class of very high pollution. The highest Er of Cd in first and second regions was 264.0 and 214.9 mg kg −1 , respectively, which were considered in the high-risk class. These indices revealed possible increases in potential ecological RI in the mentioned regions (up to 330.8 and 272.4 mg kg −1 , respectively), which were classified in the classes of high and moderate pollution risk. Principal component analysis indicated that the pollution of the HMs in Isfahan and Falavarjan was overlapped. Cr in PC1 and Cd and Co in PC2 had the highest distributions and impacts representing enhancing transfer factor from the soils to onions, potatoes, and basil.

Heavy Metal Analysis and Health Risk Assessment of Potato (Solanum tuberosum L.) Cultivars irrigated with Fly Ash-Treated Acid Mine Drainage

“…In order to assess the non-carcinogenic human health risk from the consumption of vegetables contaminated by heavy metals, the target hazard quotient (THQ) values were estimated. The THQ values (Table 4) of the local population due to the consumption of contaminated vegetables were calculated using Equation (4) as described by [44][45][46].…”

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“…Based on the classifications of ERF in Table 2 all the trace metals except Cd are in the low contamination class. The mean ERF values for Cd during the dry and wet seasons were in the considerable risk category 44,45 . The high ERF values of Cd reported in this study is similar to that obtained by Wang et al [77].…”

“…Toxic response factors for the metals are Mn (1.00), Fe (0.00), Cu (5.00), Zn (1.00), Pb (5.00), and Cd (30.00), [41]. The different categories of ecological risk factor based on the classifications of Mahabadi et al [44] and Rostami et al [45].…”

Distribution and assessment of the environmental risk of heavy metals in Aguada Blanca reservoir, Peru

“…The potential ecological risk index (RI) is commonly used as a diagnostic tool to determine contamination in sediments, soils and waters due to the presence of metals in the environment. The RI is defined as the sum of the ecological risk index (RE) of each heavy metal, for which Equations 3 and 4 are shown (Hakanson, 1980;Miranzadeh Mahabadi et al, 2020;Sun, 2017).…”