Major ion compositions, sources and risk assessment of karst stream under the influence of anthropogenic activities, Guizhou Province, Southwest China

Tianhao Yang; Qixin Wu; Yanling An; Jiemei Lv

doi:10.7717/peerj.15368

Major ion compositions, sources and risk assessment of karst stream under the influence of anthropogenic activities, Guizhou Province, Southwest China

PeerJ. 2023 May 18:11:e15368. doi: 10.7717/peerj.15368. eCollection 2023.

Authors

Tianhao Yang^{1

2}, Qixin Wu^{2

3}, Yanling An^{2

4}, Jiemei Lv^{2

3

4}

Affiliations

¹ School of Public Health, The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, Guizhou Medical University, Guiyang, China.
² Key Laboratory of Karst Geological Resources and Environment, Ministry of Education, Guizhou University, Guiyang, China.
³ The College of Resources and Environmental Engineering, Guizhou University, Guiyang, China.
⁴ The College of Resources and Environmental Engineering, Guizhou Institute of Technology, Guiyang, China.

Abstract

To explore the influence of different types of anthropogenic activity on the rivers, we investigate the major ion composition, sources and risk assessment of the karst stream (Youyu stream and Jinzhong stream), which are heavily influenced by mining activities and urban sewage, respectively. The chemical compositions of the Youyu stream water, which is heavily influenced by mining activities, are dominated by Ca²⁺ and SO₄²^-. However, the chemical compositions of the Jinzhong stream water, which is heavily influenced by urban sewage, are dominated by Ca²⁺ and HCO₃^-. The Ca²⁺, Mg²⁺ and HCO₃^- in Jinzhong stream are mainly derived from rock weathering, while the Youyu stream is affected by acid mine drainage, and sulfuric acid is involved in the weathering process. Ion sources analysis indicates that the Na⁺, K⁺, NO₃^-, and Cl^- in the Jinzhong stream mainly derive from urban sewage discharge; but NO₃^- and Cl^- of the Youyu stream mainly derive from agricultural activities, and Na⁺, K⁺ are mainly from natural sources. The element ratios analysis indicates the ratio of SO₄²^-/Mg²⁺ in Youyu stream (4.61) polluted by coal mine is much higher than that in Jinzhong stream (1.29), and the ratio of (Na⁺+K⁺+Cl^-)/Mg²⁺ in Jinzhong stream (1.81) polluted by urban sewage is higher than Youyu stream (0.64). Moreover, the ratios of NO₃^-/Na⁺, NO₃^-/K⁺, and NO₃^-/Cl^- in the agriculturally polluted Youyu stream were higher than those in the Jinzhong stream. We can identify the impact of human activities on streams by ion ratios (SO₄²^-/Mg²⁺, (Na⁺+K⁺+Cl^-)/Mg²⁺, NO₃^-/Na⁺, NO₃^-/K⁺, and NO₃^-/Cl^-). The health risk assessment shows the HQ_T and HQ_N for children and adults are higher in Jinzhong stream than in Youyu stream and the total HQ value (HQ_T) of children was higher than one at J1 in the Jinzhong stream, which shows that children in Jinzhong stream basin are threatened by non-carcinogenic pollutants. Each HQ value of F^- and NO₃^- for children was higher than 0.1 in the tributaries into Aha Lake, indicating that the children may also be potentially endangered.

Keywords: Health risk assessment; Major ion composition; Mining activities; Small karst stream; Sources; Urban sewage discharge.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Anthropogenic Effects*
Child
China
Humans
Risk Assessment
Rivers*
Sewage
Water

Substances

Sewage
Water

Grants and funding

This research was funded by the National Natural Science Foundation of China (41863004), and the Guizhou Science and Technology Support Program ([2021]465). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.