Arsenic cycling in the Earth’s crust and hydrosphere: interaction between naturally occurring arsenic and human activities

Masuda, Harue

doi:10.1186/s40645-018-0224-3

Cited by 97 publications

(39 citation statements)

References 87 publications

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“…Trace amounts of the elements Ti, As, and Sr are observed as well: Ti is a very common element on Earth, 45 Sr is known to be present in carbonates, 46 and As has been associated with hydrothermal activity and weathering. 47 These elements are identified within first 10-140 ablation layers at the uppermost sample subsurface but were not found in the aragonite host phase (Figure 8B (Figure 8c).…”

Section: Micrometer Inclusions Embedded In An Aragonite Crystal Phasementioning

confidence: 97%

Isotope abundance ratio measurements using femtosecond laser ablation ionization mass spectrometry

et al. 2020

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Accurate isotope ratio measurements are of high importance in various scientific fields, ranging from radio isotope geochronology of solids to studies of element isotopes fractionated by living organisms. Instrument limitations, such as unresolved isobaric inferences in the mass spectra, or cosampling of the material of interest together with the matrix material may reduce the quality of isotope measurements. Here, we describe a method for accurate isotope ratio measurements using our laser ablation ionization time-of-flight mass spectrometer (LIMS) that is designed for in situ planetary research. The method is based on chemical depth profiling that allows for identifying micrometer scale inclusions embedded in surrounding rocks with different composition inside the bulk of the sample. The data used for precise isotope measurements are improved using a spectrum cleaning procedure that ensures removal of low quality spectra. Furthermore, correlation of isotopes of an element is used to identify and reject the data points that, for example, do not belong to the species of interest. The measurements were conducted using IR femtosecond laser irradiation focused on the sample surface to a spot size of 12 μm. Material removal was conducted for a predefined number of laser shots, and time-of-flight mass spectra were recorded for each of the ablated layers. Measurements were conducted on NIST SRM 986 Ni isotope standard, trevorite mineral, and micrometer-sized inclusions embedded in aragonite. Our measurements demonstrate that element isotope ratios can be measured with accuracies and precision at the permille level, exemplified by the analysis of B, Mg, and Ni element isotopes. The method applied will be used for in situ investigation of samples on planetary surfaces, for accurate quantification of element fractionation induced by, for example, past or present life or by geochemical processes.

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Section: Micrometer Inclusions Embedded In An Aragonite Crystal Phasementioning

confidence: 97%

Isotope abundance ratio measurements using femtosecond laser ablation ionization mass spectrometry

et al. 2020

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“…The correlation with arsenic and oxyanions, F and Sr are indicative of a volcanic source (Smedley et al 2002;Bhattacharya et al 2006;Sappa et al 2014). Volcanic rocks such as tuffs have been present in numerous sites in relation to the generation of high arsenic waters (Masuda 2018). The weathering by-products of volcanic rock can include secondary silica, Fe/Mn oxides, Al hydroxides and clay minerals (Sappa et al 2014).…”

Section: The Source Of Arsenicmentioning

confidence: 99%

Occurrence, Geochemistry and Speciation of Elevated Arsenic Concentrations in a Fractured Bedrock Aquifer System

McGrory

Henry

Conroy

et al. 2021

Preprint

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The presence of elevated arsenic concentrations (≥10 µg L-1) in groundwaters has been widely reported in areas of south east Asia with recent studies showing its detection in fractured bedrock aquifers mainly in regions of north-eastern United States. Data within Europe remains limited; therefore, the objective of this work was to understand the geochemical mobilisation mechanism of arsenic in this geologic setting. Physiochemical (pH, Eh, d-O2), trace metals, major ion and arsenic speciation samples were collected and analysed using a variety of field and laboratory-based techniques and evaluated using statistical analysis including multivariate analysis. Elevated dissolved arsenic concentrations (up to 73.95 µg L-1) were observed in oxic-alkali groundwaters with the co-occurrence of other oxyanions (e.g. Mo, Se, Sb and U), low dissolved concentrations of Fe and Mn and low Na/Ca ratios indicating that arsenic was mobilised through alkali desorption of Fe oxyhydroxides. Arsenic speciation using a solid-phase extraction methodology (n=20) showed that the dominant species of arsenic present in groundwater was arsenate, with pH being a major controlling factor. The expected source of arsenic is sulfide minerals within fractures of the bedrock aquifer with transportation of arsenic and other oxyanion-forming elements facilitated by secondary Fe mineral phases. However, the presence of methylarsenical compounds detected in the groundwaters illustrates that microbially mediated mobilisation processes were also (co)-occurring. This study demonstrates how field speciation of arsenic can be utilised to overcome analytical limitations of conventional laboratory speciation and to facilitate in the interpretation of the environmental mobility of arsenic within groundwaters.

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“…Given the low Fe concentrations, this also agrees with the oxic-alkali nature of the groundwater in the present study. Furthermore, the level of arsenic contamination is generally lower in oxic-aquifers compared to anoxic aquifers (Masuda 2018).…”

Section: Arsenic Geochemistry and Speciationmentioning

confidence: 99%

Occurrence, Geochemistry and Speciation of Elevated Arsenic Concentrations in a Fractured Bedrock Aquifer System

McGrory

Henry

Conroy

et al. 2021

Arch Environ Contam Toxicol

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The presence of elevated arsenic concentrations (≥ 10 µg L−1) in groundwaters has been widely reported in areas of South-East Asia with recent studies showing its detection in fractured bedrock aquifers is occurring mainly in regions of north-eastern USA. However, data within Europe remain limited; therefore, the objective of this work was to understand the geochemical mobilisation mechanism of arsenic in this geologic setting using a study site in Ireland as a case study. Physicochemical (pH, Eh, d-O2), trace metals, major ion and arsenic speciation samples were collected and analysed using a variety of field and laboratory-based techniques and evaluated using statistical analysis. Groundwaters containing elevated dissolved arsenic concentrations (up to 73.95 µg L−1) were characterised as oxic-alkali groundwaters with the co-occurrence of other oxyanions (including Mo, Se, Sb and U), low dissolved concentrations of Fe and Mn, and low Na/Ca ratios indicated that arsenic was mobilised through alkali desorption of Fe oxyhydroxides. Arsenic speciation using a solid-phase extraction methodology (n = 20) showed that the dominant species of arsenic was arsenate, with pH being a major controlling factor. The expected source of arsenic is sulphide minerals within fractures of the bedrock aquifer with transportation of arsenic and other oxyanion forming elements facilitated by secondary Fe mineral phases. However, the presence of methylarsenical compounds detected in groundwaters illustrates that microbially mediated mobilisation processes may also be (co)-occurring. This study gives insight into the geochemistry of arsenic mobilisation that can be used to further guide research needs in this area for the protection of groundwater resources.

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Arsenic cycling in the Earth’s crust and hydrosphere: interaction between naturally occurring arsenic and human activities

Cited by 97 publications

References 87 publications

Isotope abundance ratio measurements using femtosecond laser ablation ionization mass spectrometry

Isotope abundance ratio measurements using femtosecond laser ablation ionization mass spectrometry

Occurrence, Geochemistry and Speciation of Elevated Arsenic Concentrations in a Fractured Bedrock Aquifer System

Occurrence, Geochemistry and Speciation of Elevated Arsenic Concentrations in a Fractured Bedrock Aquifer System

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