The arsenic metabolism in different biological organisms has been studied extensively. However, little is known about protozoa. Herein, we investigated the cell stress responses of the freshwater ciliate Tetrahymena pyriformis to arsenate toxicity. An acute toxicity assay revealed an 18-h EC(50) arsenate concentration of ca. 40 μM, which caused significant changes in the cell shape, growth and organism mobility. Whereas, under exposure to 30 μM arsenate, T. pyriformis could grow reasonably well, indicating a certain resistance of this organism. Arsenic speciation analysis revealed that 94-98% of the total arsenate in cells of T. pyriformis could be transformed to monomethylarsonic acid, dimethylarsinic acid and a small proportion of arsenite after 18 h of arsenate exposure, thus indicating the major detoxification pathway by arsenic oxidation/reduction and biomethylation. Finally, comparative proteomic analysis unveiled significant changes in the expression of multiple proteins involved in anti-oxidation, sugar and energy metabolism, proteolysis, and signal transduction. Our results revealed multiple pathways of arsenate detoxification in T. pyriformis, and indicated that protozoa may play important roles in the biogeochemical cycles of arsenic.
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http://dx.doi.org/10.1016/j.ejop.2012.01.005 | DOI Listing |
J Expo Sci Environ Epidemiol
January 2025
Department of Environmental Sciences & Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Background: Preterm birth (PTB) is a common pregnancy complication associated with significant neonatal morbidity. Prenatal exposure to environmental chemicals, including toxic and/or essential metal(loid)s, may contribute to PTB risk.
Objective: We aimed to summarize the epidemiologic evidence of the associations among levels of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), manganese (Mn), lead (Pb), and zinc (Zn) assessed during the prenatal period and PTB or gestational age at delivery; to assess the quality of the literature and strength of evidence for an effect for each metal; and to provide recommendations for future research.
Materials (Basel)
January 2025
Academic Area of Earth and Materials Sciences, Autonomous University of Hidalgo State, Mineral de la Reforma 42184, Mexico.
Mine tailings are a byproduct of mineral extraction and often pose an environmental challenge due to the contamination of soil and water bodies with dissolved metals. However, this type of waste offers the opportunity for the recovery of valuable metals such as silver (Ag). In the present investigation, an integral analysis of a sample of tailings was carried out, addressing granulometry, elemental composition, neutralization potential (NP), and acid potential (AP), as well as mineralogy, for the dissolution of silver from this type of waste.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, 040 01 Košice, Slovakia.
In Slovakia, there are a number of contaminated sites that have occurred due to intensive mining, mineral processing, metallurgical activities, chemical industry, fossil fuel combustion, and industrial agriculture in the past. This paper summarizes the occurrence, chemistry, toxicity, and mineralogy of arsenic species related to soil and water contamination in Slovakia. Four main localities with arsenic exposure were identified.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
January 2025
Department of Zoology, Faculty of Science, Zagazig University, Zagazig, 44519, Egypt.
The residual concentration of pesticides and heavy metals (arsenic, mercury, selenium, lead, cadmium, and aluminum) was measured in the soil and the cattle egret (Bubulcus ibis) liver from two localities at Sharkia Governorate, Egypt. The pesticide residues have taken the following pattern: chlorpyrifos > metalaxyl > piperonyl butoxide > thiophanate-methyl, in the soil. The residual concentration of pesticides was greater in the soil at Kafr El-Ashraf village (agricultural site) than at El-Qanayat city (garbage site) during the summer season of 2021 compared with the winter season of 2022.
View Article and Find Full Text PDFJ Environ Sci (China)
July 2025
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address:
Arsenic (As) and antimony (Sb), with analogy structure, belong to VA group in the periodic table and pose a great public concern due to their potential carcinogenicity. The speciation distribution, migration and transformation, enrichment and retention, as well as bioavailability and toxicity of As and Sb are influenced by several environmental processes on mineral surfaces, including adsorption/desorption, coordination/precipitation, and oxidation/reduction. These interfacial reactions are influenced by the crystal facet of minerals with different atomic and electronic structures.
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