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Total concentrations and different forms of antimony (Sb) in soils of Laokuang District (LKQ-1, LKQ-2, LKQ-3), Beikuang District (BKQ-4, BKQ-5, BKQ-6) and Nankuang District (NKQ-7, NKQ-8, NKQ-9, NKQ-10) of Xikuangshan, Hunan province, China were analyzed. The soil Sb concentrations in the whole-ore heap of LKQ-1 and the mining land of NKQ-7 were up to 4258 and 3174 mg/kg respectively, which were both 2000 times above the background soil Sb level in China. In terms of vertical distribution, the Sb concentrations gradually declined with the rise of soil depth. Tessier's 5-step sequential extraction method showed Sb mainly existed in stable forms (organic-matter-bound form, residual form), and the available form accounted for 18%. The proportions of different forms ranked as residual form >iron/manganese oxides >organic-matter-bound form >carbonate-bound form > water-soluble form. Vegetation affected the form distribution of Sb in a complex way and may increase the bioavailability of Sb, so ecological restoration of Sb can be realized through the absorption by vegetation. Analysis of the geoaccumulation index and the potential ecological risk index showed that Xikuangshan was under extremely severe Sb pollution and very serious potential ecological risk. The Sb mining and smelting activities of humans aggravated local Sb pollution. [ABSTRACT FROM AUTHOR]

Mining activities have introduced various heavy metals and metalloids to surrounding soil environments, causing adverse impacts to the ecological environment system. The extremely high concentration of various heavy metals and metalloids make the Xikuangshan (Hunan, China) an excellent model to assess their ecological risk. In this study, the soil samples from 26 locations of different land use methods in four areas (smelting area, road nearby ore, mining area, and ore tailing area) in Xikuangshan with different levels of various heavy metals and metalloids (Sb, As, Pb, and Cd) were analyzed; in addition, the index of geo-accumulation and the potential ecological risk index were used to evaluate ecological risk. The results showed that the average contents of Sb, As, Pb, and Cd in all soil samples were 4368.222 mg·kg−1, 40.722 mg·kg−1, 248.013 mg·kg−1, and 40.941 mg·kg−1, respectively, implying serious contamination of compound pollution of heavy metals in soil. The concentration of heavy metals in soil among smelting area, road nearby ore, mining area, and ore tailing area showed significant distribution characteristics of region because different mining activities such as smelting, mining, transportation, and stacking caused different pollution intensity. Moreover, the contents of Sb in soil samples decreased successively in residue field, wasteland, forestland, sediment, grassland, and vegetable field, and the contents of Sb in vegetable-field and ecological restoration grassland were relatively low, which indicate that the method of grassland ecological restoration is an effective method to control antimony pollution in soil. The results of ecological risk assessment showed that the antimony mining area was seriously polluted by Sb, As, Pb, and Cd, and had strong ecological risk, and Sb and Cd were the most important pollution factors, which indicated that the pollution of Sb and Cd should be a major concern of relevant departments of environment and health. [ABSTRACT FROM AUTHOR]

• We summarized and discussed about antimony pollution in water environment and its sources. • Research on toxicity of antimony was documented. • Occurrence and biogeochemistry of antimony in water environment were discussed. Antimony, the compounds of which exhibit toxicity, finds extensive usage in industrial processes for flame retardants, plastics, batteries, electronic components, and mechanical bearings. Consequently, mining and industrial activities contribute to the continuous migration of antimony into aquatic environments, influencing the Earth's biogeochemical cycle. Given China's status as the primary global exporter of antimony, the country confronts the challenge of water pollution arising from intensive antimony mining operations. This paper focuses on the latest advances in research concerning antimony toxicity, identifies potential sources of antimony water pollution, and explores its migration pathways and biogeochemistry. Moreover, the study provides estimations of antimony quantities in different compartments. Finally, we discuss the prospects for enhancing our comprehension of antimony's biogeochemical behavior. [ABSTRACT FROM AUTHOR]

Abstract Increasing attention is being paid to Sb as a primary hazardous substance, and further systematic studies of Sb behavior in freshwater wetlands are required. The plain wetlands in Lake Taihu basin located in lower Yangtze River valley, are heavily populated and economically developed area in China. The plain wetlands receive polluted water from point sources (textile and printing plants). In this study, Sb speciation in plain wetlands was investigated and the potential ecological risk of 8 metal(loid)s (As, Cd, Cr, Cu, Ni, Pb, Zn, Sb) were assessed. The mean Sb concentration in the wetlands water is 7.03 μg L−1, which consist of pentavalent, trivalent, organic Sb dissolved in water and a great part that attached to suspend solids (SS). Statistical analysis indicated that Sb(Ⅲ) is dissolved from SS and then further oxided to Sb(V) accompanied with tailing water discharged into wetlands; presence of organic Sb is related to microorganic in eutrophic environment; precipitation of SS is the dominant factor for distribution of bioavailable Sb in surficial sediment. The toxicity coefficient factor for Sb is proposed as 10 and ambient background of 8 metal(loid)s are set up. The potential ecological risk for plain wetlands was 135, which was low level. As, Cd and Sb were main contributors to the ecological risks. The wetlands are threatened by Sb pollution, which should be restrict by reducing the concentration of SS and Sb in tailing water from local water treatment facilities. Graphical abstract Image 10115 Highlights • Sb's toxicity coefficient of 10 was determined and was used to evaluate potential ecological risk of plain wetlands. • Sb speciation in water and sediment of plain wetlands were performed. • The factors affecting the distribution of Sb species in water were analyzed. • The fate of Sb pollutants from textile mill and printing industries plain wetlands was illustrated. [ABSTRACT FROM AUTHOR]

Xikuangshan is located in Lengshuijiang City, Hunan province, China. With intensive mining and metallurgical activities, large amounts of tailing containing heavy metals (in this study, the term “heavy metals” is used for both metals and metalloids) were introduced to the soils around the mine area. Those heavy metals including antimony and other heavy metals would pose huge risk to human health and ecological environment. With a view to providing information on the extent of contamination and potential ecological risk of heavy metals in the soils of this mine area, the total contents of antimony (Sb), manganese (Mn), zinc (Zn), arsenic (As), cadmium (Cd), and lead (Pb) in the soils were examined. The results revealed that the predominant pollutants in this area were Sb, Cd, and Zn with mean concentrations being 356.58, 9.98, and 486.42 mg kg−1, 119.66, 117.41, and 5.17 times of the corresponding background values respectively. The pollution indices (Ps) indicated that the pollution levels of all sampling zones were serious including the control zones. The ecological risk levels of all heavy metals were very high on all the sampling zones except sampling zone 7 (as considerable), and Sb, Cd, and As were regarded as making great contribution to the risk indices (RI). [ABSTRACT FROM AUTHOR]

Antimony (Sb) persists in environmental media and can be toxic to aquatic organisms and humans. Although China is the primary Sb-producing country, the levels of Sb contamination and their potential risk to water resources remain unclear. This study provides an overview of Sb contamination in surface water and centralized drinking water sources across China and assesses its potential ecological and human health risks. Species sensitivity distribution was used to derive acute and chronic aquatic life criteria for Sb, which were 511.7 μg/L and 148.3 μg/L, respectively. Zooplankton were determined to be the most sensitive species, and fish were the least sensitive. Sb contamination in China is more serious than other countries. Risk quotients were used to assess the ecological risks of Sb. Chronic ecological risk quotients of 0.0013–27.39 were identified for surface water located near Sb mines. The highest values indicate high risk, particularly for zooplankton species. Exposure characteristics for the Chinese population across age group, sex, season, and region were used to assess the non-carcinogenic risk of Sb in centralized drinking water sources in China. Hazard quotients of 0.001–0.99 were found for these centralized drinking water sources. The non-carcinogenic risk posed by Sb was acceptable in the majority of locations, except in Hunan Province, which had the highest hazard quotient (approximately 1). This province contains the main Sb mining area in China, which poses a relatively large threat to human health. The Sb health risk for children was significantly higher than adults, but there was no significant difference in risk between men and women. The Sb drinking water guidance value to protect human health was calculated to be 19.65 μg/L for Chinese population. The results of this ecological and human health risk assessment highlight the importance of clean Sb production to reduce the negative effects of Sb contamination in China. [Display omitted] • Antimony (Sb) constitutes an ecological risk in surface water near mines in China. • Sb poses a high health risk to residents in Southern China. • The acute and chronic Sb criteria for native Chinese freshwater organisms are 511.7 and 148.3 μg/L, respectively. • The Sb drinking water guidance value to protect human health is recommended to be 19.65 μg/L for the Chinese population. [ABSTRACT FROM AUTHOR]

Mining activities have caused heavy metal pollution in Xikuangshan (XKS), China. This work aims to assess heavy metal ecological risk in XKS using a potential ecological risk (PER) index and detect the responses of the soil bacterial community under heavy metal stress at different pH levels. The PER index indicated that antimony (Sb), cadmium (Cd), and arsenic (As) posed the most serious ecological risk at the sampling sites. We compared the effects of heavy metals on the structure of the microbial community under acidic and neutral conditions. Our results suggested significant differences between microbial community responses to heavy metals in acidic and neutral soils. Zinc (Zn) and lead (Pb) were the main heavy metal factors affecting the bacterial community under acidic conditions, whereas the effect of Sb, As, and chromium (Cr) exceeded them in neutral soils. This was possibly due to the different characteristics of heavy metals and their interactions with soil properties. The main genus were positively correlated with Sb, As, Zn, Pb, and Cd in both acidic and neutral soils, which may due to increasing resistance under conditions of long-time pollution. The results of our structural equation modeling indicated that the variations in the bacterial community structure were mainly explained by heavy metals in acidic and neutral soils. The soil nutrients and pH also had significant direct influences on the bacterial community under neutral conditions, as well as indirect effects due to their impact on heavy metals in neutral and acidic soils. Several heavy metal-resistant bacteria can be used for remediation under acid and neutral conditions. [ABSTRACT FROM AUTHOR]