Pollution Characteristics, Spatial Distribution, and Health Risk Assessment of Soil Heavy Metal(loid)s in Panxi District, Southwest China: A Typical Industrial City

ABSTRACT

This study collected 49 topsoil samples in agricultural soil from Panxi district (Sichuan, China), investigating the contamination status and probabilistic health risk of their heavy metal(loid)s (HMs). The average concentrations (mg/kg) of As, Cd, Cr, Cu, Ni, Pb and Zn were 18.18, 1.66, 294.05, 143.37, 70.18, 31.70 and 139.18, respectively. The pollution index (Pi) of the seven HMs were in the descending order of Cd > Cr > Cu > As > Zn > Ni > Pb, and the comprehensive Nemeiro risk index (PN) was 2.67, indicating that the study area was a moderate pollution by HMs. Meanwhile, Cd showed major contribution to the soil pollution among these HMs. The spatial distribution of HMs revealed that the southwestern part of the study area was the contamination hotspots. The hazard index (Hi) for children and adults were 1.621 and 0.346, respectively, and the total non-carcinogenic risk for children exceeded the threshold of 1. The carcinogenic risks associated with Cr (adults:, children:) and Ni (adults:) far exceeded the safe level of 1E-04; Monte Carlo simulations showed that humans locating in the study area suffered from a relatively significant carcinogenic risk; and the children were at higher risk than the adults. Among the three exposure pathways (ingestion, inhalation, and dermal contact), the ingestion was the most important way for HMs to harm human health. Overall, this study provides a scientific basis for both controlling HMs contamination and reducing the potential health risks in studied soils.

KEYWORDS:

• Panxi
• soil heavy metal(loid)s
• pollution assessment
• health risk assessment
• Monte Carlo simulations

Acknowledgments

The authors would like to thank all those who contributed to this research.

Author contributions

Yi-ping Zhang: Conceptualization, data curation, methodology, software, writing-original draft, writing-review and editing, and formal analysis. ZheWang: Conceptualization, methodology, project administration, writing-review and editing and formal analysis, and funding acquisition.

Zhen-long Zhang: Software and visualization. Qing Sun, Ying Luo, Wen-jing Jia, Qiu-ping Zeng,Zhen-yu Wang, Jia-qian Zhang and Xi-yang Feng: Experimental design, operation and data acquisition. Feng-yu Huang:Writing review and editing and formal analysis. Fa-cheng Yi: Validation and supervision

Data availability

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Ethics approval

In this study, all stages have been performed in accordance with ethical standards.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the National Key Research and Development Program of China, the R&D and Model Construction of Grading and Zoning Comprehensive Prevention and Control Technology System for Typical Non-Ferrous Metal Smelting Slag Field in Southwest China and its Influence Area (SN: 2019YFC1803500); the National Key Research and Development Program of China, a Pollution Risk Assessment and Information Management Platform for the Influence Area of Non-Ferrous Metal Smelting Slag Field (SN: 2019YFC1803504); the Key Research and Development Program of Sichuan Provincial Department of Science and Technology, Research of The Development of Heavy Metal Compound Pollution Passivator for Farmland Soil Based on Solid Waste Resource Utilization, its Passivation Remediation Mechanism and the Effect Demonstration (SN: 2018SZ0298); the National Natural Science Foundation of China (No.41402248); the Open Fund Project of Sichuan Provincial Key Laboratory in Universities for the Development of Characteristic Biological Resources of Dry-hot River Valley(SN:GR-2020-E-02 and SN:JDH-2019-E-01); Science and Technology Planning Project of Panzhihua, The Development Of A Pollution Assessment And Dynamic Monitoring System For Soil Heavy Metal Pollution In Mango Main Producing Area in Panzhihua (SN: 2017CY-N-8); Applied technology research and development fund project of Aba Prefecture in the field of ecological environment protection (SN:20YYJSY0063); and The Longshan Talent Research Project of SWUST, The Assessment and Remediation of Soil Heavy Metal Pollution(SN: 17LZX613; 18LZX638);The Evaluation on the Ecological Restoration Effect of Frangipani in the Dry-hot Valley of the Jinsha River(JDH-2019-E-01);and The Temporal and Spatial Evolution Characteristics, Development Trend Forecast and Ecological Restoration Countermeasures of Ecological Vulnerability in the Dry Valley Region (Maoxian Section) of the Upper Minjiang River(20YYJSYJ0063).