Contamination and Health Risk Assessment of Heavy Metals in the Soil of Major Cities in Mongolia

Abstract

Using the case of Ulaanbaatar, Erdenet, and Darkhan cities from Mongolia, the study aimed to assess the contamination level and health risk assessment of heavy metals (As, Cr, Pb, Ni, and Zn) in urban soil. A total of 78 samples was collected from a variety of functional areas. The geoaccumulation index (Igeo) and integrated pollution index (IPI) were used in pollution assessment, while the health risk was scored using a hazard quotient (HQ) and health index (HI) for non-carcinogenic heavy metals, as well as a lifetime average daily dose (LADD) for carcinogenic heavy metals. The results show that the concentration of heavy metals in the soil samples taken from Darkhan city, which presented “uncontaminated” values in terms of Igeo for all metals, was relatively lower than other cities within the contamination assessment. Furthermore, the Igeo value signified “uncontimated to heavily contaminated” soil in the Ulaanbaatar and Erdenet cities. Typically, as for the IPI that observed similar trends with Igeo, the mean IPI values in Ulaanbaatar, Erdenet, and Darkhan were 1.33 (moderate level of pollution), 1.83 (moderate level of pollution), and 0.94 (low level of pollution), respectively. In terms of the assessment of potential health risk, there was a particular or different level of ingestion, dermal contact, and inhalation exposure pathway for human health. Among these three different pathways, the ingestion was estimated by the main contributor for health risk. Each value of HQ and HI indicated that soil heavy metals of studied cities were at a safe level (<1) or had the absence of a significant health risk there. In addition, the potential health risk for children was greater than for adults, where heavy metal values of HI for children had a high value compared to adults. We estimated carcinogenic risks through the inhalation exposure, and as a result, there were no significant risks for human health in the studied cities from three elements (As, Cr, and Ni).

Impact of Abattoir Wastes on Trace Metal Accumulation, Speciation, and Human Health–Related Problems in Soils Within Southern Nigeria

“…34-37 The availability of trace metals in soil and human health–related problems are usually examined using health risk assessment models. 38-40 However, previous studies on abattoirs in Akwa Ibom state did not assess the impact of abattoir wastes on the physicochemical properties of soil, metal speciation, the actual sources of trace metals, and human health–related problems. 7,9,41…”

Application of Geostatistical Analysis and Random Forest for Source Analysis and Human Health Risk Assessment of Potentially Toxic Elements (PTEs) in Arable Land Soil

“…After PTEs enter the soil, they take different chemical forms through dissolution, precipitation, complexation, and adsorption [ 37 ]. The complexation of soil organic matter with PTEs ions has an extremely important effect on the fixation and migration of PTEs ions in soil and water [ 38 ].…”

Screening of Heavy Metal-Immobilizing Bacteria and Its Effect on Reducing Cd2+ and Pb2+ Concentrations in Water Spinach (Ipomoea aquatic Forsk.)

“…is a dominant global vegetable [5]. Excessive Cd 2+ and Pb 2+ accumulation in water spinach can reduce yields and cause potential threats to human health through the food chain [6][7][8]. Therefore, to ensure the safety of agricultural products, it is urgent that we carry out the bioremediation of farmland to remove medium and light heavy metals exceeding standard levels [9,10].…”