1
|
Claes H, Cappuyns V, Swennen R, Meyer R, Seemann T, Stanjek H, Sindern S, Tock P. Importance of arsenic bioaccessibility in health risk assessment based on iron "Minette" rocks and related soils. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 266:115567. [PMID: 37864967 DOI: 10.1016/j.ecoenv.2023.115567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 10/02/2023] [Accepted: 10/08/2023] [Indexed: 10/23/2023]
Abstract
Total element concentrations by themselves are not always good predictors of toxicity and are therefore not suitable for eco- and/or human toxicological risk determination. In addition, despite the growing call for harmonization, countries show significant variation in risk assessment tools, screening/background values, protocols and legal management of soils. By incorporating mobility and bioaccessibility/availability into soil risk assessments, location-specific physico-chemical and geological conditions can be considered in routinely applied general risk assessment methodologies. Minette soils and rocks are a great case in point since they often are associated with high geogenic As concentrations and consequently potential risks. Minette iron ores form the world largest Fe ore deposits since the "great oxidation". For the first time, oral bioaccessibility during direct ingestion was assessed on Minettes from Luxembourg by applying the in vitro Solubility/Bioavailability Research Consortium (SBRC) method. Out of > 180 samples, 25 representative samples were selected providing a unique dataset which showed an average gastric bioaccessibility of ∼10% (7.8 ± 4.0 mg/kg) of the total As-concentration, with a maximum of 45% (17.9 mg/kg). Of importance is that bioaccessibility of As in Minette rocks and soils are controlled by, and can be estimated from, lithology, mineralogy and total Ca content. Soils and ooid grainstones with an iron oxide or clayey matrix, are characterized by average gastric bioaccessible As concentrations < 6 mg/kg. Gastric As bioaccessibility is highest in Fe-bearing calcite-cemented bioclastic grainstones (∼12 mg/kg). Importantly, for all samples the maximal bioaccessible As concentrations remain below the threshold from which significant adverse non-carcinogenic and/or carcinogenic health effects are expected. These new results are in strong contrast with what total As concentrations might suggest. Considering bioaccessibilities, consequently, can help to avoid disproportionate, costly and environmentally impacting risk management strategies. Furthermore, this study illustrates the importance of cross-disciplinary collaboration between geo- and health scientists.
Collapse
Affiliation(s)
- Hannes Claes
- Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200E, 3001 Heverlee, Belgium; Clay and Interface Mineralogy, RWTH Aachen University, Bunsenstrasse 8, 52072 Aachen, Germany.
| | - Valérie Cappuyns
- Centre for Economics and Corporate Sustainability (CEDON), KU Leuven, Warmoesberg 26, 1000 Brussels, Belgium
| | - Rudy Swennen
- Department of Earth and Environmental Sciences, KU Leuven, Celestijnenlaan 200E, 3001 Heverlee, Belgium
| | - Romain Meyer
- Service géologique du Luxembourg, Rue chemin de Fer 23, 8257 Bertrange, Luxembourg
| | - Timo Seemann
- Clay and Interface Mineralogy, RWTH Aachen University, Bunsenstrasse 8, 52072 Aachen, Germany
| | - Helge Stanjek
- Clay and Interface Mineralogy, RWTH Aachen University, Bunsenstrasse 8, 52072 Aachen, Germany
| | - Sven Sindern
- Institute of Applied Mineralogy and Economic Geology, RWTH Aachen University, Wüllnerstrasse 2, 52056 Aachen, Germany
| | - Pol Tock
- Environment Agency Luxembourg, 1, avenue du Rock'n'Roll, L-4361Esch-sur-Alzette, Luxembourg
| |
Collapse
|
2
|
Demaret L, Hutchinson IB, Ingley R, Edwards HGM, Fagel N, Compere P, Javaux EJ, Eppe G, Malherbe C. Fe-Rich Fossil Vents as Mars Analog Samples: Identification of Extinct Chimneys in Miocene Marine Sediments Using Raman Spectroscopy, X-Ray Diffraction, and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy. ASTROBIOLOGY 2022; 22:1081-1098. [PMID: 35704291 DOI: 10.1089/ast.2021.0128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
On Earth, the circulation of Fe-rich fluids in hydrothermal environments leads to characteristic iron mineral deposits, reflecting the pH and redox chemical conditions of the hydrothermal system, and is often associated with chemotroph microorganisms capable of deriving energy from chemical gradients. On Mars, iron-rich hydrothermal sites are considered to be potentially important astrobiological targets for searching evidence of life during exploration missions, such as the Mars 2020 and the ExoMars 2022 missions. In this study, an extinct hydrothermal chimney from the Jaroso hydrothermal system (SE Spain), considered an interesting geodynamic and mineralogical terrestrial analog for Mars, was analyzed using Raman spectroscopy, X-ray diffraction, and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The sample consists of a fossil vent in a Miocene shallow-marine sedimentary deposit composed of a marl substrate, an iron-rich chimney pipe, and a central space filled with backfilling deposits and vent condensates. The iron crust is particularly striking due to the combined presence of molecular and morphological indications of a microbial colonization, including mineral microstructures (e.g., stalks, filaments), iron oxyhydroxide phases (altered goethite, ferrihydrite), and organic signatures (carotenoids, organopolymers). The clear identification of pigments by resonance Raman spectroscopy and the preservation of organics in association with iron oxyhydroxides by Raman microimaging demonstrate that the iron crust was indeed colonized by microbial communities. These analyses confirm that Raman spectroscopy is a powerful tool for documenting the habitability of such historical hydrothermal environments. Finally, based on the results obtained, we propose that the ancient iron-rich hydrothermal pipes should be recognized as singular terrestrial Mars analog specimens to support the preparatory work for robotic in situ exploration missions to Mars, as well as during the subsequent interpretation of data returned by those missions.
Collapse
Affiliation(s)
- Lucas Demaret
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, Liege, Belgium
- Early Life Traces & Evolution-Astrobiology, UR Astrobiology, University of Liege, Liege, Belgium
| | - Ian B Hutchinson
- Department of Physics and Astronomy, University of Leicester, Leicester, United Kingdom
| | - Richard Ingley
- Department of Physics and Astronomy, University of Leicester, Leicester, United Kingdom
| | - Howell G M Edwards
- Department of Physics and Astronomy, University of Leicester, Leicester, United Kingdom
| | - Nathalie Fagel
- Laboratory Argiles, Géochimie et Environnements Sédimentaires, University of Liege, Liege, Belgium
| | - Philippe Compere
- Laboratory of Functional and Evolutionary Morphology, UR FOCUS, and Centre for Applied Research and Education in Microscopy (CAREM), University of Liege, Liege, Belgium
| | - Emmanuelle J Javaux
- Early Life Traces & Evolution-Astrobiology, UR Astrobiology, University of Liege, Liege, Belgium
| | - Gauthier Eppe
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, Liege, Belgium
| | - Cédric Malherbe
- Mass Spectrometry Laboratory, MolSys Research Unit, University of Liege, Liege, Belgium
- Early Life Traces & Evolution-Astrobiology, UR Astrobiology, University of Liege, Liege, Belgium
- Department of Physics and Astronomy, University of Leicester, Leicester, United Kingdom
| |
Collapse
|
3
|
Rolling Ironstones from Earth and Mars: Terrestrial Hydrothermal Ooids as a Potential Analogue of Martian Spherules. MINERALS 2021. [DOI: 10.3390/min11050460] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High-resolution images of Mars from National Aeronautics and Space Administration (NASA) rovers revealed mm-size loose haematite spherulitic deposits (nicknamed “blueberries”) similar to terrestrial iron-ooids, for which both abiotic and biotic genetic hypotheses have been proposed. Understanding the formation mechanism of these haematite spherules can thus improve our knowledge on the possible geologic evolution and links to life development on Mars. Here, we show that shape, size, fabric and mineralogical composition of the Martian spherules share similarities with corresponding iron spherules currently forming on the Earth over an active submarine hydrothermal system located off Panarea Island (Aeolian Islands, Mediterranean Sea). Hydrothermal fluids associated with volcanic activity enable these terrestrial spheroidal grains to form and grow. The recent exceptional discovery of a still working iron-ooid source on the Earth provides indications that past hydrothermal activity on the Red Planet is a possible scenario to be considered as the cause of formation of these enigmatic iron grains.
Collapse
|
4
|
Minerals of Rare Earth Elements in High-Phosphorus Ooidal Ironstones of the Western Siberia and Turgai Depression. MINERALS 2019. [DOI: 10.3390/min10010011] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The aim of this research was to study the rare earth (REE) minerals in ooidal ironstone deposits of the West Siberian basin and the Turgai depression. Authigenic minerals (monazite and cerite) were described, and their main mineral form was identified as light rare earth element phosphate (LREE-phosphate) in this study. LREE-phosphate is included in ferruginous ooids, peloids, and oncoids and forms a consistent mineral association with Fe-hydroxides (goethite and its hydrated amorphous derivatives) and Fe-rich layered silicates (Fe-illite-smectite, chamosite, berthierine). The constancy of the mineral association in two deposits of different ages indicates a general mechanism behind the formation of these minerals. LREE-phosphates (authigenic monazite) are characterized by microscopic sizes (up to 24 μm), diverse morphology (mainly spherical or xenomorphic), and occupy spaces between the micro-cortex in ferruginous spheroids. This mineral can be found in other deposits of ooidal ironstone. According to its mineralogical and chemical characteristics, LREE-phosphate mainly belongs to the authigenic (nodular or “gray”) monazite. However, the incomplete (not 100%) correspondence of Kikuchi bands with the reference monazite does not allow its reliable identification. Based on its small size, chemical leaching or bacterial interaction is recommended to extract REE from ooidal ironstone while predicting the associated removal of phosphorus from iron ore due to its dominant phosphate mineral form. Ooidal ironstone should be considered a complex deposit and an unconventional natural type of REE ores as an example of the largest Bakchar and Lisakovsk deposits.
Collapse
|