Hydrogeochemistry of arsenic pollution in watersheds influenced by gold mining activities in Paracatu (Minas Gerais State, Brazil)
| Autor: | Ricardo Sierpe, Ricardo Cesar, Edison Dausacker Bidone, Maria Carla Barreto Santos, Marcos Manoel Ferreira, Zuleica Carmen Castilhos |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Arsenic pollution
Gold mining Health Toxicology and Mutagenesis chemistry.chemical_element 010501 environmental sciences Environment Sulfides 010502 geochemistry & geophysics 01 natural sciences Arsenicals Mining Arsenic Water Pollution Chemical Environmental Chemistry Ecotoxicology Humans Groundwater 0105 earth and related environmental sciences Hydrology Minerals business.industry Sorption General Medicine Contamination Pollution chemistry Oxisol Environmental chemistry Gold business Geology Brazil Iron Compounds Water Pollutants Chemical Environmental Monitoring |
| Zdroj: | Environmental science and pollution research international. 23(9) |
| ISSN: | 1614-7499 |
| Popis: | The aim of this study is to evaluate total arsenic (As) concentrations in drinking water (main pathway of human exposure) and its hydrogeochemical controls in the "Morro do Ouro" gold mine region, which is the largest gold mine in Brazil, characterized by gold-arsenopyrite association. Arsenic concentration was generally below the detection limit (LOD 0.5 μg L(-1)). Thus, water ingestion may not be a significant exposure pathway to local population. Low groundwater As concentrations (1 μg L(-1)) are likely due to ore body structural setting, which plunges from 10° to20°, being readily covered by thick phyllites that are poor in As some hundreds of meters away from the mine. Thirty-five percent of As levels in superficial waters (0.5 to 40 μg L(-1)) were10 μg L(-1), which is the maximum permissible value for human ingestion. The highest concentrations were found nearby mine facilities and old artisanal mining areas surrounding the mine, decreasing downstream. Undisturbed watersheds showed As concentrations close to LOD. Hydrogeochemical data stress the sorption (adsorption and co-precipitation) of As role, mainly by Fe oxyhydroxides, as a geochemical filter that retains As, attenuating its concentration in both superficial and groundwater. Such minerals are abundant in the region oxisols, sediments, and phyllites and may form stable mineral complexes with As under the pH (mostly neutral) and Eh (reduced environment) conditions found in the field. It has been demonstrated that As(III) (more toxic) and As(V) co-exist in the analyzed waters and that As(V) predominates in superficial water. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink