Identification of sources and their potential health risk of potential toxic elements in soils from a mercury‑thallium polymetallic mining area in Southwest China: Insight from mercury isotopes and PMF model

Xiaohui Zhang; Kang Tian; Yimin Wang; Wenyou Hu; Benle Liu; Xuyin Yuan; Biao Huang; Longhua Wu

doi:10.1016/j.scitotenv.2023.161774

Identification of sources and their potential health risk of potential toxic elements in soils from a mercury‑thallium polymetallic mining area in Southwest China: Insight from mercury isotopes and PMF model

Sci Total Environ. 2023 Apr 15:869:161774. doi: 10.1016/j.scitotenv.2023.161774. Epub 2023 Jan 25.

Authors

Xiaohui Zhang¹, Kang Tian², Yimin Wang³, Wenyou Hu², Benle Liu², Xuyin Yuan³, Biao Huang⁴, Longhua Wu²

Affiliations

¹ Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
² Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
³ Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes of Ministry of Education, College of Environment, Hohai University, Nanjing 210098, China.
⁴ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. Electronic address: bhuang@issas.ac.cn.

PMID: 36708830
DOI: 10.1016/j.scitotenv.2023.161774

Abstract

Identification of potential toxic element (PTE) sources and their specific human health risk is critical to the management of PTEs in soils. In this study, multi-medium were collected from a mercury‑thallium polymetallic mining area in Southwestern China. Hg isotope technique together with positive matrix factorization (PMF) model was used to identify PTE sources and assess their source-oriented health risk. Results showed that among the studied PTEs, this study area presented high pollution of Hg, Tl and As, with higher concentrations than their corresponding background values of Guizhou province, yet their average concentrations in covering soils were significantly lower than those in the natural soils. The Tl in coix grains should also be paid more attention due to its high concentration. Both natural and covering soils had different Hg isotope composition with tailings, while sediments have similar Hg isotope fractionation with covering soils. According to the PMF model, three sources in both natural and covering soils were apportioned and Hg, Tl and As were mainly influenced by the historical mining activities, which also confirmed by their Hg isotope signatures. The contributions of historical mining activities accounted for 40 % and 20 % of the PTEs in natural and covering soils, respectively. The assessment of source-specific health risks suggested that the non-carcinogenic risk of Hg, Tl and As was much higher than other elements. Historical mining activities were regarded as the major contributor to health risks (79 % and 76 % for natural soils and 50 % and 59 % for covering soils, respectively). This indicated that the restoration of coveing soils indeed decreased the health risk in this study area. These findings thus highlight the importance of ongoing monitoring of covering soils in the polymetallic mining area, which is imperative for preferably assessing the health risk of PTEs in similar mining area worldwide.

Keywords: Mercury isotope signatures; Multi-medium; Non-carcinogenic risks; Source identification; Tl.

MeSH terms

China
Environmental Monitoring / methods
Humans
Mercury Isotopes
Mercury* / analysis
Metals, Heavy* / analysis
Risk Assessment
Soil
Soil Pollutants* / analysis
Thallium

Substances

Mercury
Thallium
Mercury Isotopes
Soil
Soil Pollutants
Metals, Heavy