Study on the risk of soil heavy metal pollution in typical developed cities in eastern China

Abstract

Enrichment of heavy metals in urban soils has become a major regional environmental risk. At present, research on the soil heavy metals in cities lacks risk spatial correlation analyses between different heavy metals, and there is a relative lack of assessments of the ecological and health risks. We selected Wuxi, a typical developed city of eastern China, collected and tested the contents of heavy metals in the urban soils of Wuxi in May 2020. Combined with Pb isotope analysis, ecological and health risk assessment, we found that the high heavy metal concentrations in Wuxi are mainly located in the central and western regions, and that the changes in spatial fluctuation are relatively small. The Pb isotopes in the urban soils of Wuxi are distributed in areas, such as those are related to coal combustion, automobile exhaust and urban garbage, indicating that the heavy metals in the urban soils of Wuxi are affected by human activities such as coal combustion and automobile exhaust. The average value of the potential ecological risk index of soil heavy metal Cd is 80.3 (the threshold: 40), which represents a high-risk state. Whether adults or children, the risk of soil heavy metals via ingestion is much higher than that through skin exposure. High health risk values are present in the central area of Wuxi and decrease in a ring-shaped pattern, which is similar to the population distribution of Wuxi and greatly increases the potential risk from soil heavy metals, which should be given close attention. We should develop and use clean energy to replace petroleum fossil fuels, especially in densely populated areas. This study provides technical support for the prevention and control of urban heavy metal pollution.

Recent Developments in Rice Molecular Breeding for Tolerance to Heavy Metal Toxicity

“…Among them, OsHMP37 had a much higher expression level than the other seven HMPs, whereas OsHMP28 was solely expressed in the roots. Only OsHMP09, OsHMP18, and OsHMP22 showed increased expression levels in all tissues, despite the fact that most of the selected OsHMPs were variably expressed in different tissues under varying HM exposures [45]. Approximately 43 putative Fe-S cluster assembly genes have also been identified in the rice (Oryza sativa) genome and the expression of all genes has been validated [59,60].…”

“…An extensive study in eastern China investigated HM levels in urban soils and found that high concentrations of HMs in soil were mainly concentrated in central and western regions with relatively few spatial variations [45]. Municipal solid waste, automobile emissions, combustion of coal, and HM emissions from human activities including vehicle exhaust are all partially responsible for the rise of lead isotopes in urban soils.…”

Spatiotemporal patterns of soil heavy metal pollution risk and driving forces of increment in a typical industrialized region in central China

“…33 This index combines ecology, biochemistry, and other aspects to evaluate the potential ecological hazard of heavy metals. 34 This index is calculated as eqn (7), where EI i is the single potential ecological risk index of heavy metal i, C i is the concentration of heavy metal i, S i is the environmental quality standard of heavy metal i, and T i is the toxicity coefficient of heavy metal i. In this study, the background values of the studied heavy metals were used as the quality standard, and the toxicity coefficients of each heavy metal were Co = 5, Cr = 2, Cu = 5, Mn = 1, Ni = 5, Pb = 5, Zn = 1, and Cd = 30.…”

Sequential Speciation Analysis of Metals in Geological Samples by Mass Spectrometry

“…Heavy metal is one of the most toxic species which exists widely in soil and is closely related to human health [ 31 ]. The heavy metals in soil can further enter drink water and plants, and then enter the human body by diet.…”