Spatial distribution, formation mechanism, and health risk assessment of high-fluoride groundwater at the largest antimony mine in Hunan Province, China

Abstract

To date, few systematic studies have been conducted of the spatial distribution, formation mechanism, and health risks of high-fluoride (F−) shallow groundwater in humid and semi-humid areas of the Xikuangshan antimony mine, Hunan Province, China. In this study, during March and April 2022, a total of 39 shallow groundwater samples were collected and analyzed using factor analysis, principal component analysis, and health risk assessment. F− concentrations in the shallow groundwater were found in the range of 0.08–15.00 mg/L (mean: 1.21 mg/L), with 25.64% of the samples having F− concentrations higher than in the Chinese national standard for drinking water (1.00 mg/L). Principal component analysis revealed that the main source of F− in the shallow groundwater samples is cation exchange, accounting for 73.40%, followed by the dissolution and precipitation of F-bearing minerals (15.10%) and human influence (11.50%). Among different age groups, children had the highest percentage of individuals (36.38%) with an F− intake above the health risk quotient safety limit, followed by adult males (23.12%), teenagers (22.21%), and infants (21.22%). The findings of this study will contribute to devising strategies for the provision of safe drinking water and the management of the geological environment. HIGHLIGHTS The abundance and spatial distribution of F− shallow groundwater in humid and semi-humid areas of the Xikuangshan antimony mine was determined.; The hydrogeochemical behaviors and formation mechanisms that elevate F− levels in shallow groundwater during antimony mining activities were evaluated.; The health risks of high-fluoride (F−) shallow groundwater in humid and semi-humid areas were analyzed.;

Keywords

• fluoride
• formation mechanism
• health risk
• positive matrix factorization (pmf) model