Heavy metal pollution near an abandoned mercury-bearing waste recovery enterprise in southwestern China: Spatial distribution and its sources in soil and plants

Jianbo Guo; Liyuan Liu; Qinzhong Feng; Camillus Uchenna Okonkwo; Xiujin Zhang; Jun Chen; Shitong Yang; Chen Yang

doi:10.1016/j.envres.2024.118694

Heavy metal pollution near an abandoned mercury-bearing waste recovery enterprise in southwestern China: Spatial distribution and its sources in soil and plants

Environ Res. 2024 Mar 21;252(Pt 1):118694. doi: 10.1016/j.envres.2024.118694. Online ahead of print.

Authors

Jianbo Guo¹, Liyuan Liu², Qinzhong Feng¹, Camillus Uchenna Okonkwo¹, Xiujin Zhang¹, Jun Chen³, Shitong Yang¹, Chen Yang⁴

Affiliations

¹ College of Resources and Environment, University of Chinese Academy of Sciences, 100049, Beijing, China.
² College of Resources and Environment, University of Chinese Academy of Sciences, 100049, Beijing, China. Electronic address: liuliyuan@ucas.ac.cn.
³ Chongqing University of Science and Technology, 401331, Chongqing, China.
⁴ College of Resources and Environment, University of Chinese Academy of Sciences, 100049, Beijing, China. Electronic address: chenyang@ucas.ac.cn.

PMID: 38521357
DOI: 10.1016/j.envres.2024.118694

Abstract

The contribution of smelting of nonferrous metals to heavy metals in surface soil have become increasingly important over the past decade. In this study, the distribution of heavy metals around an abandoned mercury-bearing waste recovery enterprise were investigated. Soil (14) and plant (18) samples were collected in the surrounding area. The total concentration of heavy metals and methyl mercury content were measured by ICP-MS and HPLC-ICP-MS. The results show that the average contents of Cd, Cr, Pb, Hg and As in all soil samples are higher than the second-level values of Soil environmental quality-Risk control standard for soil contamination of development land (GB 36600-2018). Hg in the leaves ranged from 0.003 to 0.174 mg kg^-1. Besides, the Pearson correlation analysis results indicate that Hg has a different environmental behavior compared to the other heavy metal under certain environmental or geographical conditions. But the mantel test statistical analysis results show that the Cr (P < 0.01), Cu, Pb, and Fe (P < 0.05) in the soil may have similar pollution sources with carbonate-bound mercury and iron-manganese oxide-bound mercury. The Hg concentrations show no correlation among plant leaves and soil, but significantly influenced by the distance and wind direction. These findings suggest that Hg in plant leaves may be derived from the deposition of atmospheric mercury from secondary mercury plant. The results will supplement those for relevant policy making for mercury-bearing waste recovery enterprises to improve urban environmental quality and human health.

Keywords: Heavy metals; Mercury speciation; Mercury-bearing waste recovery enterprise; Methyl mercury.