In the Main Ethiopian Rift (MER) area, rural populations often use water that exceeds the World Health Organization thresholds for fluoride (F–) and arsenic (As), two elements that are hazardous for human health. In this study, twenty-nine water samples were collected from lakes and hot and cold springs in southern MER to investigate source(s) and health-risk of the F– and As contamination. According to major ion and trace element analyses, only cold spring water is safe for consumption, whereas hot spring water is the most contaminated. Leaching tests performed with the MER rhyolitic volcanic rocks and their weathered products (fluvio-lacustrine sediments) demonstrate that the main cause of the F– and As release is geogenic, i.e., not related to anthropogenic activities. The weathering of volcanic glass and minerals (apatites, clays, hydro-oxides) by CO2-bearing alkaline water induces the mobilisation of F– and As from solid to liquid phase. This process is particularly fast, when fluvio-lacustrine sediments are involved, and can be further enhanced by hot groundwater leaching. This study, investigating the distribution, sources, and mechanisms of F– and As release in MER water, could be of interest also for other sectors of the East African Rift and other similar volcano-tectonic settings.

Origin of fluoride and arsenic in the main ethiopian rift waters / Bianchini G.; Brombin V.; Marchina C.; Natali C.; Godebo T.R.; Rasini A.; Salani G.M.. - In: MINERALS. - ISSN 2075-163X. - ELETTRONICO. - 10:(2020), pp. 453-453. [10.3390/min10050453]

Origin of fluoride and arsenic in the main ethiopian rift waters

Natali C.;
2020

Abstract

In the Main Ethiopian Rift (MER) area, rural populations often use water that exceeds the World Health Organization thresholds for fluoride (F–) and arsenic (As), two elements that are hazardous for human health. In this study, twenty-nine water samples were collected from lakes and hot and cold springs in southern MER to investigate source(s) and health-risk of the F– and As contamination. According to major ion and trace element analyses, only cold spring water is safe for consumption, whereas hot spring water is the most contaminated. Leaching tests performed with the MER rhyolitic volcanic rocks and their weathered products (fluvio-lacustrine sediments) demonstrate that the main cause of the F– and As release is geogenic, i.e., not related to anthropogenic activities. The weathering of volcanic glass and minerals (apatites, clays, hydro-oxides) by CO2-bearing alkaline water induces the mobilisation of F– and As from solid to liquid phase. This process is particularly fast, when fluvio-lacustrine sediments are involved, and can be further enhanced by hot groundwater leaching. This study, investigating the distribution, sources, and mechanisms of F– and As release in MER water, could be of interest also for other sectors of the East African Rift and other similar volcano-tectonic settings.
2020
10
453
453
Bianchini G.; Brombin V.; Marchina C.; Natali C.; Godebo T.R.; Rasini A.; Salani G.M.
File in questo prodotto:
File Dimensione Formato  
minerals-10-00453-v2.pdf

accesso aperto

Tipologia: Pdf editoriale (Version of record)
Licenza: Open Access
Dimensione 9.37 MB
Formato Adobe PDF
9.37 MB Adobe PDF

I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1224397
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 25
  • ???jsp.display-item.citation.isi??? 22
social impact