Source identification and risk analysis of potentially toxic elements (PTEs) in rainwater runoff from a manganese mine (south central Hunan, China)

Xin Luo,Zhenghua Wang,Bozhi Ren,Ren-Jian Deng,Feng Jiang,Andrew S Hursthouse

doi:10.2166/ws.2020.352

Abstract

Abstract Potentially toxic elements (PTEs) in manganese ore areas are prevalent in rainwater runoff and pose a major threat to human health. In this study, field investigation and geostatistical analysis methods of positive matrix factorization (PMF) and geographic information systems (GIS) were used to systematically study the pollution in rainwater runoff from a manganese mining area in Xiangtan, China, to evaluate source contributions for the health risk assessment of PTEs. The average concentrations (mg/L) of six PTEs were: 0.3357 (Mn), 0.0450 (Ni), 0.0106 (Cu), 0.0148 (Zn), 0.0068 (Cd) and 0.0390 (Pb). The coefficients of variation (CV) for Mn and Zn were &gt;180% and &gt;130%, with the other analytes having values below 70%. The GIS and PMF analysis produced more refined spatial source apportionments, including mining, smelting, transportation, agricultural production and natural sources. The results of the health risk assessment showed that the non-carcinogenic risk was negligible, and the carcinogenic risk was potentially dangerous but acceptable for both adults and children. In addition, the children's total carcinogenic risk value was greater than that of adults, highlighting their vulnerability. This study demonstrates the potential of PMF to provide a framework to spatially prioritize treatment objectives within the mining region to improve environmental conditions.

Highlights

A number of potentially toxic elements (PTEs) have been highlighted as priority contaminants globally and have received widespread attention due to their persistence and toxicity to humans and organisms (Liu et al )
We describe a detailed investigation of PTE content in rainwater runoff from a large-scale manganese mining site using a combination of positive matrix factorization (PMF) and geographic information systems (GIS) mapping
The results show that the mean values of HQingestion, HQdermal, and hazard index (HI) were both

Summary

Introduction

A number of potentially toxic elements (PTEs) have been highlighted as priority contaminants globally and have received widespread attention due to their persistence and toxicity to humans and organisms (Liu et al ). Water Supply | 21.2 | 2021 transportation, there are numerous sources and pathways for wider environmental contamination and the exposure of workers and residents This is evident in the manganese mining area of Xiangtan, south central China, where prolonged exploitation activities have led to the movement of manganese and other PTEs into the soil by a number of routes, resulting in excessive soil pollution (Cao et al ; Ren et al ; Li et al ). Under the action of rainfall, especially in subtropical climate zones, rainwater runoff provides a potentially significant pathway for a wider pollution impact on the local environment and can lead to significant exposure and potential harm to human health (Yang et al ; Tang et al ) Addressing these key issues is an urgent priority, since resolving a wide range of localized cases will support the future phase of national economic and social development

Methods

Results

Conclusion