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This study characterises high-fluoride groundwater in the aquifer system on the flanks of Mount Meru, focusing on parts of the flanks that were only partially or not at all covered by previous research. Additionally, we analyse the impact of rainwater recharge on groundwater chemistry by monitoring spring discharges during water sampling. The results show that the main groundwater type in the study area is NaHCO3 alkaline groundwater (average pH = 7.8). High F− values were recorded: in 175 groundwater samples, the concentrations range from 0.15 to 301 mg/L (mean: 21.89 mg/L, median: 9.67 mg/L), with 91% of the samples containing F− values above the WHO health-based guideline for drinking water (1.5 mg/L), whereas 39% of the samples have Na+ concentrations above the WHO taste-based guideline of 200 mg/L. The temporal variability in F− concentrations between different seasons is due to the impact of the local groundwater recharge. We recommend that a detailed ecohydrological study should be carried out for the low-fluoride springs from the high-altitude recharge areas on the eastern and northwestern flanks of Mount Meru inside Arusha National Park. These springs are extracted for drinking purposes. An ecohydrological study is required for the management of these springs and their potential enhanced exploitation to ensure the sustainability of this water extraction practice. Another strategy for obtaining safe drinking water could be to use a large-scale filtering system to remove F− from the groundwater.
George Bennett; Jill Van Reybrouck; Ceven Shemsanga; Mary Kisaka; Ines Tomašek; Karen Fontijn; Matthieu Kervyn; Kristine Walraevens. Hydrochemical Characterisation of High-Fluoride Groundwater and Development of a Conceptual Groundwater Flow Model Using a Combined Hydrogeological and Hydrochemical Approach on an Active Volcano: Mount Meru, Northern Tanzania. Water 2021, 13, 2159 .
AMA StyleGeorge Bennett, Jill Van Reybrouck, Ceven Shemsanga, Mary Kisaka, Ines Tomašek, Karen Fontijn, Matthieu Kervyn, Kristine Walraevens. Hydrochemical Characterisation of High-Fluoride Groundwater and Development of a Conceptual Groundwater Flow Model Using a Combined Hydrogeological and Hydrochemical Approach on an Active Volcano: Mount Meru, Northern Tanzania. Water. 2021; 13 (16):2159.
Chicago/Turabian StyleGeorge Bennett; Jill Van Reybrouck; Ceven Shemsanga; Mary Kisaka; Ines Tomašek; Karen Fontijn; Matthieu Kervyn; Kristine Walraevens. 2021. "Hydrochemical Characterisation of High-Fluoride Groundwater and Development of a Conceptual Groundwater Flow Model Using a Combined Hydrogeological and Hydrochemical Approach on an Active Volcano: Mount Meru, Northern Tanzania." Water 13, no. 16: 2159.
Exposure to volcanic ash is a long-standing health concern for people living near active volcanoes and in distal urban areas. During transport and deposition, ash is subjected to various physicochemical processes that may change its surface composition and, consequently, bioreactivity. One such process is the interaction with anthropogenic pollutants; however, the potential for adsorbed, deleterious organic compounds to directly impact human health is unknown. We use an in vitro bioanalytical approach to screen for the presence of organic compounds of toxicological concern on ash surfaces and assess their biological potency. These compounds include polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dlPCBs). Analysis of ash collected in or near urbanised areas at five active volcanoes across the world (Etna, Italy; Fuego, Guatemala; Kelud, Indonesia; Sakurajima, Japan; Tungurahua, Ecuador) using the bioassay inferred the presence of such compounds on all samples. A relatively low response to PCDD/Fs and the absence of a dlPCBs response in the bioassay suggest that the measured activity is dominated by PAHs and PAH-like compounds. This study is the first to demonstrate a biological potency of organic pollutants associated with volcanic ash particles. According to our estimations, they are present in quantities below recommended exposure limits and likely pose a low direct concern for human health.
Ines Tomašek; David E. Damby; Daniele Andronico; Peter J. Baxter; Imke Boonen; Philippe Claeys; Michael S. Denison; Claire J. Horwell; Matthieu Kervyn; Ulrich Kueppers; Manolis N. Romanias; Marc Elskens. Assessing the biological reactivity of organic compounds on volcanic ash: implications for human health hazard. Bulletin of Volcanology 2021, 83, 1 -11.
AMA StyleInes Tomašek, David E. Damby, Daniele Andronico, Peter J. Baxter, Imke Boonen, Philippe Claeys, Michael S. Denison, Claire J. Horwell, Matthieu Kervyn, Ulrich Kueppers, Manolis N. Romanias, Marc Elskens. Assessing the biological reactivity of organic compounds on volcanic ash: implications for human health hazard. Bulletin of Volcanology. 2021; 83 (5):1-11.
Chicago/Turabian StyleInes Tomašek; David E. Damby; Daniele Andronico; Peter J. Baxter; Imke Boonen; Philippe Claeys; Michael S. Denison; Claire J. Horwell; Matthieu Kervyn; Ulrich Kueppers; Manolis N. Romanias; Marc Elskens. 2021. "Assessing the biological reactivity of organic compounds on volcanic ash: implications for human health hazard." Bulletin of Volcanology 83, no. 5: 1-11.
Freshly erupted volcanic ash contains a range of soluble elements, some of which can generate harmful effects in living cells and are considered potentially toxic elements (PTEs). This work investigates the leaching dynamics of ash-associated PTEs in order to optimize a method for volcanic ash respiratory hazard assessment. Using three pristine (unaffected by precipitation) ash samples, we quantify the release of PTEs (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, Zn) and major cations typical of ash leachates (Mg, Na, Ca, K) in multiple simulated lung fluid (SLF) preparations and under varying experimental parameters (contact time and solid to liquid ratio). Data are compared to a standard water leach (WL) to ascertain whether the WL can be used as a simple proxy for SLF leaching. The main findings are: PTE concentrations reach steady-state dissolution by 24 h, and a relatively short contact time (10 min) approximates maximum dissolution; PTE dissolution is comparatively stable at low solid to liquid ratios (1:100 to 1:1000); inclusion of commonly used macromolecules has element-specific effects, and addition of a lung surfactant has little impact on extraction efficiency. These observations indicate that a WL can be used to approximate lung bioaccessible PTEs in an eruption response situation. This is a useful step towards standardizing in vitro methods to determine the soluble-element hazard from inhaled ash.
Ines Tomašek; David E. Damby; Carol Stewart; Claire J. Horwell; Geoff Plumlee; Christopher J. Ottley; Pierre Delmelle; Suzette Morman; Sofian El. Yazidi; Philippe Claeys; Matthieu Kervyn; Marc Elskens; Martine Leermakers. Development of a simulated lung fluid leaching method to assess the release of potentially toxic elements from volcanic ash. Chemosphere 2021, 278, 130303 .
AMA StyleInes Tomašek, David E. Damby, Carol Stewart, Claire J. Horwell, Geoff Plumlee, Christopher J. Ottley, Pierre Delmelle, Suzette Morman, Sofian El. Yazidi, Philippe Claeys, Matthieu Kervyn, Marc Elskens, Martine Leermakers. Development of a simulated lung fluid leaching method to assess the release of potentially toxic elements from volcanic ash. Chemosphere. 2021; 278 ():130303.
Chicago/Turabian StyleInes Tomašek; David E. Damby; Carol Stewart; Claire J. Horwell; Geoff Plumlee; Christopher J. Ottley; Pierre Delmelle; Suzette Morman; Sofian El. Yazidi; Philippe Claeys; Matthieu Kervyn; Marc Elskens; Martine Leermakers. 2021. "Development of a simulated lung fluid leaching method to assess the release of potentially toxic elements from volcanic ash." Chemosphere 278, no. : 130303.
Julian Ijumulana; KTH Royal Institute of Technology; Fanuel J. Ligate; Prosun Bhattacharya; Arslan Ahmad; Chaosheng Zhang; Ines Tomašek; Regina Filemon Irunde; Tahmidul Islam; Felix Mtalo; Joseph O. Mtamba. SPATIAL MODELLING OF FLUORIDE CONTAMINATION IN GROUNDWATER SYSTEMS IN THE EAST AFRICAN RIFT VALLEY REGIONS OF NORTHERN TANZANIA. 2020, 1 .
AMA StyleJulian Ijumulana, KTH Royal Institute of Technology, Fanuel J. Ligate, Prosun Bhattacharya, Arslan Ahmad, Chaosheng Zhang, Ines Tomašek, Regina Filemon Irunde, Tahmidul Islam, Felix Mtalo, Joseph O. Mtamba. SPATIAL MODELLING OF FLUORIDE CONTAMINATION IN GROUNDWATER SYSTEMS IN THE EAST AFRICAN RIFT VALLEY REGIONS OF NORTHERN TANZANIA. . 2020; ():1.
Chicago/Turabian StyleJulian Ijumulana; KTH Royal Institute of Technology; Fanuel J. Ligate; Prosun Bhattacharya; Arslan Ahmad; Chaosheng Zhang; Ines Tomašek; Regina Filemon Irunde; Tahmidul Islam; Felix Mtalo; Joseph O. Mtamba. 2020. "SPATIAL MODELLING OF FLUORIDE CONTAMINATION IN GROUNDWATER SYSTEMS IN THE EAST AFRICAN RIFT VALLEY REGIONS OF NORTHERN TANZANIA." , no. : 1.
George Bennett; Ghent University; Jill Van Reybrouck; Ceven Shemsanga; Mary Kisaka; Ines Tomašek; Karen Fontijn; Matthieu Kervyn; Kristine Walraevens. GEOCHEMICAL PROCESSES CONTROLLING THE GROUNDWATER CHEMISTRY AND FLUORIDE CONTAMINATION IN THE AQUIFER SYSTEMS ON THE EASTERN, WESTERN AND NORTHERN FLANKS OF MOUNT MERU, TANZANIA. 2020, 1 .
AMA StyleGeorge Bennett, Ghent University, Jill Van Reybrouck, Ceven Shemsanga, Mary Kisaka, Ines Tomašek, Karen Fontijn, Matthieu Kervyn, Kristine Walraevens. GEOCHEMICAL PROCESSES CONTROLLING THE GROUNDWATER CHEMISTRY AND FLUORIDE CONTAMINATION IN THE AQUIFER SYSTEMS ON THE EASTERN, WESTERN AND NORTHERN FLANKS OF MOUNT MERU, TANZANIA. . 2020; ():1.
Chicago/Turabian StyleGeorge Bennett; Ghent University; Jill Van Reybrouck; Ceven Shemsanga; Mary Kisaka; Ines Tomašek; Karen Fontijn; Matthieu Kervyn; Kristine Walraevens. 2020. "GEOCHEMICAL PROCESSES CONTROLLING THE GROUNDWATER CHEMISTRY AND FLUORIDE CONTAMINATION IN THE AQUIFER SYSTEMS ON THE EASTERN, WESTERN AND NORTHERN FLANKS OF MOUNT MERU, TANZANIA." , no. : 1.
Volcanic ash presents a widespread and common hazard during and after eruptions. Complex interactions between solid ash surfaces and volcanic gases lead to the formation of soluble salts that may be mobilized in aqueous environments. A variety of stakeholders may be concerned about the effects of ash on human and animal health, drinking water supplies, crops, soils and surface runoff. As part of the immediate emergency response, rapid dissemination of information regarding potentially hazardous concentrations of soluble species is critical. However, substantial variability in the methods used to characterize leachable elements makes it challenging to compare datasets and eruption impacts. To address these challenges, the International Volcanic Health Hazard Network (www.ivhhn.org) organized a two-day workshop to define appropriate methods for hazard assessment. The outcome of this workshop was a ‘consensus protocol’ for analysis of volcanic ash samples for rapid assessment of hazards from leachable elements, which was subsequently ratified by leading volcanological organizations. The purpose of this protocol is to recommend clear, standard and reliable methods applicable to a range of purposes during eruption response, such as assessing impacts on drinking-water supplies and ingestion hazards to livestock, and also applicable to research purposes. Where possible, it is intended that the methods make use of commonly available equipment and require little training. To evaluate method transferability, an interlaboratory comparison exercise was organized among six laboratories worldwide. Each laboratory received a split of pristine ash, and independently analyzed it according to the protocol for a wide range of elements. Collated results indicate good repeatability and reproducibility for most elements, thus indicating that the development of this protocol is a useful step towards providing standardized and reliable methods for ash hazard characterization. In this article, we review recent ash leachate studies, report the outcomes of the comparison exercise and present a revised and updated protocol based on the experiences and recommendations of the exercise participants. The adoption of standardized methods will improve and facilitate the comparability of results among studies and enable the ongoing development of a global database of leachate information relevant for informing volcanic health hazards assessment.
Carol Stewart; David E. Damby; Ines Tomašek; Claire J. Horwell; Geoffrey S. Plumlee; Maria Aurora Armienta; Maria Gabriela Ruiz Hinojosa; Moya Appleby; Pierre Delmelle; Shane Cronin; Christopher J. Ottley; Clive Oppenheimer; Suzette Morman. Assessment of leachable elements in volcanic ashfall: a review and evaluation of a standardized protocol for ash hazard characterization. Journal of Volcanology and Geothermal Research 2019, 392, 106756 .
AMA StyleCarol Stewart, David E. Damby, Ines Tomašek, Claire J. Horwell, Geoffrey S. Plumlee, Maria Aurora Armienta, Maria Gabriela Ruiz Hinojosa, Moya Appleby, Pierre Delmelle, Shane Cronin, Christopher J. Ottley, Clive Oppenheimer, Suzette Morman. Assessment of leachable elements in volcanic ashfall: a review and evaluation of a standardized protocol for ash hazard characterization. Journal of Volcanology and Geothermal Research. 2019; 392 ():106756.
Chicago/Turabian StyleCarol Stewart; David E. Damby; Ines Tomašek; Claire J. Horwell; Geoffrey S. Plumlee; Maria Aurora Armienta; Maria Gabriela Ruiz Hinojosa; Moya Appleby; Pierre Delmelle; Shane Cronin; Christopher J. Ottley; Clive Oppenheimer; Suzette Morman. 2019. "Assessment of leachable elements in volcanic ashfall: a review and evaluation of a standardized protocol for ash hazard characterization." Journal of Volcanology and Geothermal Research 392, no. : 106756.
Volcanic plumes are complex environments composed of gases and ash particles, where chemical and physical processes occur at different temperature and compositional regimes. Commonly, soluble sulphate- and chloride-bearing salts are formed on ash as gases interact with ash surfaces. Exposure to respirable volcanic ash following an eruption is potentially a significant health concern. The impact of such gas-ash interactions on ash toxicity is wholly un-investigated. Here, we study, for the first time, whether the interaction of volcanic particles with sulphur dioxide (SO2) gas, and the resulting presence of sulphate salt deposits on particle surfaces, influences toxicity to the respiratory system, using an advanced in vitro approach. To emplace surface sulphate salts on particles, via replication of the physicochemical reactions that occur between pristine ash surfaces and volcanic gas, analogue substrates (powdered synthetic volcanic glass and natural pumice) were exposed to SO2 at 500 °C, in a novel Advanced Gas-Ash Reactor, resulting in salt-laden particles. The solubility of surface salt deposits was then assessed by leaching in water and geochemical modelling. A human multicellular lung model was exposed to aerosolised salt-laden and pristine (salt-free) particles, and incubated for 24 h. Cell cultures were subsequently assessed for biological endpoints, including cytotoxicity (lactate dehydrogenase release), oxidative stress (oxidative stress-related gene expression; heme oxygenase 1 and NAD(P)H dehydrogenase [quinone] 1) and its (pro-)inflammatory response (tumour necrosis factor α, interleukin 8 and interleukin 1β at gene and protein levels). In the lung cell model no significant effects were observed between the pristine and SO2-exposed particles, indicating that the surface salt deposits, and the underlying alterations to the substrate, do not cause acute adverse effects in vitro. Based on the leachate data, the majority of the sulphate salts from the ash surfaces are likely to dissolve in the lungs prior to cellular uptake. The findings of this study indicate that interaction of volcanic ash with SO2 during ash generation and transport does not significantly affect the respiratory toxicity of volcanic ash in vitro. Therefore, sulphate salts are unlikely a dominant factor controlling variability in in vitro toxicity assessments observed during previous eruption response efforts.
Ines Tomašek; David E. Damby; Claire J. Horwell; Paul M. Ayris; Pierre Delmelle; Christopher J. Ottley; Pablo Cubillas; Ana S. Casas; Christoph Bisig; Alke Petri-Fink; Donald B. Dingwell; Martin Clift; Barbara Drasler; Barbara Rothen-Rutishauser. Assessment of the potential for in-plume sulphur dioxide gas-ash interactions to influence the respiratory toxicity of volcanic ash. Environmental Research 2019, 179, 108798 .
AMA StyleInes Tomašek, David E. Damby, Claire J. Horwell, Paul M. Ayris, Pierre Delmelle, Christopher J. Ottley, Pablo Cubillas, Ana S. Casas, Christoph Bisig, Alke Petri-Fink, Donald B. Dingwell, Martin Clift, Barbara Drasler, Barbara Rothen-Rutishauser. Assessment of the potential for in-plume sulphur dioxide gas-ash interactions to influence the respiratory toxicity of volcanic ash. Environmental Research. 2019; 179 ():108798.
Chicago/Turabian StyleInes Tomašek; David E. Damby; Claire J. Horwell; Paul M. Ayris; Pierre Delmelle; Christopher J. Ottley; Pablo Cubillas; Ana S. Casas; Christoph Bisig; Alke Petri-Fink; Donald B. Dingwell; Martin Clift; Barbara Drasler; Barbara Rothen-Rutishauser. 2019. "Assessment of the potential for in-plume sulphur dioxide gas-ash interactions to influence the respiratory toxicity of volcanic ash." Environmental Research 179, no. : 108798.
Communities resident in urban areas located near active volcanoes can experience volcanic ash exposures during, and following, an eruption, in addition to sustained exposures to high concentrations of anthropogenic air pollutants (e.g., vehicle exhaust emissions). Inhalation of anthropogenic pollution is known to cause the onset of, or exacerbate, respiratory and cardiovascular diseases. It is further postulated similar exposure to volcanic ash can also affect such disease states. Understanding of the impact of combined exposure of volcanic ash and anthropogenic pollution to human health, however, remains limited. The aim of this study was to assess the biological impact of combined exposure to respirable volcanic ash (from Soufrière Hills volcano (SHV), Montserrat and Chaitén volcano (ChV), Chile; representing different magmatic compositions and eruption styles) and freshly-generated complete exhaust from a gasoline vehicle. A multicellular human lung model (an epithelial cell-layer composed of A549 alveolar type II-like cells complemented with human blood monocyte-derived macrophages and dendritic cells cultured at the air-liquid interface) was exposed to diluted exhaust (1:10) continuously for 6 h, followed by immediate exposure to the ash as a dry powder (0.54 ± 0.19 μg/cm2 and 0.39 ± 0.09 μg/cm2 for SHV and ChV ash, respectively). After an 18 h incubation, cells were exposed again for 6 h to diluted exhaust, and a final 18 h incubation (at 37 °C and 5% CO2). Cell cultures were then assessed for cytotoxic, oxidative stress and (pro-)inflammatory responses. Results indicate that, at all tested (sub-lethal) concentrations, co-exposures with both ash samples induced no significant expression of genes associated with oxidative stress (HMOX1, NQO1) or production of (pro-)inflammatory markers (IL-1β, IL-8, TNF-α) at the gene and protein levels. In summary, considering the employed experimental conditions, combined exposure of volcanic ash and gasoline vehicle exhaust has a limited short-term biological impact to an advanced lung cell in vitro model.
Ines Tomašek; Claire J. Horwell; Christoph Bisig; David E. Damby; Pierre Comte; Jan Czerwinski; Alke Petri-Fink; Martin J.D. Clift; Barbara Drasler; Barbara Rothen-Rutishauser. Respiratory hazard assessment of combined exposure to complete gasoline exhaust and respirable volcanic ash in a multicellular human lung model at the air-liquid interface. Environmental Pollution 2018, 238, 977 -987.
AMA StyleInes Tomašek, Claire J. Horwell, Christoph Bisig, David E. Damby, Pierre Comte, Jan Czerwinski, Alke Petri-Fink, Martin J.D. Clift, Barbara Drasler, Barbara Rothen-Rutishauser. Respiratory hazard assessment of combined exposure to complete gasoline exhaust and respirable volcanic ash in a multicellular human lung model at the air-liquid interface. Environmental Pollution. 2018; 238 ():977-987.
Chicago/Turabian StyleInes Tomašek; Claire J. Horwell; Christoph Bisig; David E. Damby; Pierre Comte; Jan Czerwinski; Alke Petri-Fink; Martin J.D. Clift; Barbara Drasler; Barbara Rothen-Rutishauser. 2018. "Respiratory hazard assessment of combined exposure to complete gasoline exhaust and respirable volcanic ash in a multicellular human lung model at the air-liquid interface." Environmental Pollution 238, no. : 977-987.
There are justifiable health concerns regarding the potential adverse effects associated with human exposure to volcanic ash (VA) particles, especially when considering communities living in urban areas already exposed to heightened air pollution. The aim of this study was, therefore, to gain an imperative, first understanding of the biological impacts of respirable VA when exposed concomitantly with diesel particles. A sophisticated in vitro 3D triple cell co-culture model of the human alveolar epithelial tissue barrier was exposed to either a single or repeated dose of dry respirable VA (deposited dose of 0.26 ± 0.09 or 0.89 ± 0.29 μg/cm2, respectively) from Soufrière Hills volcano, Montserrat for a period of 24 h at the air-liquid interface (ALI). Subsequently, co-cultures were exposed to co-exposures of single or repeated VA and diesel exhaust particles (DEP; NIST SRM 2975; 0.02 mg/mL), a model urban pollutant, at the pseudo-ALI. The biological impact of each individual particle type was also analysed under these precise scenarios. The cytotoxic (LDH release), oxidative stress (depletion of intracellular GSH) and (pro-)inflammatory (TNF-α, IL-8 and IL-1β) responses were assessed after the particulate exposures. The impact of VA exposure upon cell morphology, as well as its interaction with the multicellular model, was visualised via confocal laser scanning microscopy (LSM) and scanning electron microscopy (SEM), respectively. The combination of respirable VA and DEP, in all scenarios, incited an heightened release of TNF-α and IL-8 as well as significant increases in IL-1β, when applied at sub-lethal doses to the co-culture compared to VA exposure alone. Notably, the augmented (pro-)inflammatory responses observed were not mediated by oxidative stress. LSM supported the quantitative assessment of cytotoxicity, with no changes in cell morphology within the barrier model evident. A direct interaction of the VA with all three cell types of the multicellular system was observed by SEM. Combined exposure of respirable Soufrière Hills VA with DEP causes a (pro-)inflammatory effect in an advanced in vitro multicellular model of the epithelial airway barrier. This finding suggests that the combined exposure to volcanic and urban particulate matter should be further investigated in order to deduce the potential human health hazard, especially how it may influence the respiratory function of susceptible individuals (i.e. with pre-existing lung diseases) in the population.
Ines Tomašek; Claire J. Horwell; David E. Damby; Hana Barošová; Christoph Geers; Alke Petri-Fink; Barbara Rothen-Rutishauser; Martin J. D. Clift. Combined exposure of diesel exhaust particles and respirable Soufrière Hills volcanic ash causes a (pro-)inflammatory response in an in vitro multicellular epithelial tissue barrier model. Particle and Fibre Toxicology 2016, 13, 67 .
AMA StyleInes Tomašek, Claire J. Horwell, David E. Damby, Hana Barošová, Christoph Geers, Alke Petri-Fink, Barbara Rothen-Rutishauser, Martin J. D. Clift. Combined exposure of diesel exhaust particles and respirable Soufrière Hills volcanic ash causes a (pro-)inflammatory response in an in vitro multicellular epithelial tissue barrier model. Particle and Fibre Toxicology. 2016; 13 (1):67.
Chicago/Turabian StyleInes Tomašek; Claire J. Horwell; David E. Damby; Hana Barošová; Christoph Geers; Alke Petri-Fink; Barbara Rothen-Rutishauser; Martin J. D. Clift. 2016. "Combined exposure of diesel exhaust particles and respirable Soufrière Hills volcanic ash causes a (pro-)inflammatory response in an in vitro multicellular epithelial tissue barrier model." Particle and Fibre Toxicology 13, no. 1: 67.