Ecological Risk Assessment of Heavy Metals in Surface Soil of Qinghai Lake Area Based on Occurrence Forms

Abstract

In this paper, the content and speciation of Cd, Cr, Pb, As, Cu, Zn and Ni in 87 groups of soil samples collected by grid method were determined by Inductively Coupled Plasma-Atomic Emission Spectrometry, to explore the speciation characteristics and ecological risk status of heavy metals in surface soil around Qinghai Lake. The results show that: Cd and Pb, compared with Cr, As, Cu, Zn and Ni, in the surface soil around Qinghai Lake are the most seriously polluted, Heavy metal speciation analysis showed that the proportion of weak acid soluble components of Cd was relatively high, with strong mobility and high environmental risk. The reducible components of Zn and Pb account for a relatively high proportion, while the oxidizable components of Cu, Cd and Pb account for a relatively high proportion. The high percentage of residual Cr, Ni and As indicates that they are relatively stable. The extractable content of Cd, Pb and Zn is relatively high, and their activities are strong, which have a great impact on the food chain. The results of Inductively Coupled Plasma-Atomic Emission Spectrometry and the ratio of secondary phase and primary phase showed that Cd and Pb had more serious ecological risk than other heavy metals. According to the results of soil speciation and ecological risk assessment of heavy metals around Chinese and foreign lakes, although the speciation characteristics of heavy metals are different, the pollution of Cd is relatively large. To sum up, heavy metal pollution in soil around Qinghai Lake area has occurred, and there is a serious ecological risk, so it is urgent to take corresponding monitoring and formulate treatment plan.

Heavy Metal Contamination and Health Risk Assessment of Groundwater Sources to Waste Dumpsites in Port Harcourt

“…Also, the adult concentration value of EDIM for Mn, As, and Hg during the wet season ranged from 6.000E-4 to 1.771E-3 mg/kg/person/day, 7.000E to 2.067E-3 mg/kg/person/day, 1.400E-5 to 4.133E-3 mg/kg/person/day; 1.114E-4 to 1.457E-4 mg/kg/person/day, 1.300E-4 to 1.753E-4 mg/kg/person/day, 2.600E-4 to 3.400E-4 mg/kg/person/day; and 9.429E-6 to 1.657E-5 mg/kg/person/day, 1.100E-5 to 1.733E-5 mg/kg/person/day, 2.200E-5 to 3.867E-5 mg/kg/person/day, respectively (Table 2). The obtained values of the expected daily intake of metals (EDIM) in this study generally were low and lower than the regulatory permissible limit prescribed by [25,26,27,28]. Thus, the result defined that all the EDIM computed during both seasons was lower than unity as recommended by standards (Table 1 and 2).…”