Search

Tungurahua volcano (Ecuador) intermittently emitted ash between 1999 and 2016, enduringly affecting the surrounding rural area and its population, but its health impact remains poorly documented. We aim to assess the respiratory health hazard posed by the 16-17 August 2006 most intense eruptive phase of Tungurahua. We mapped the spatial distribution of the health-relevant ash size fractions produced by the eruption in the area impacted by ash fallout. We quantified the mineralogy, composition, surface texture, and morphology of a respirable ash sample isolated by aerodynamic separation. We then assessed the cytotoxicity and pro-inflammatory potential of this respirable ash towards lung tissues in-vitro using A549 alveolar epithelial cells, by electron microscopy and biochemical assays. The eruption produced a high amount of inhalable and respirable ash (12.0-0.04 kg/m2 of sub-10 µm and 5.3-0.02 kg/m2 of sub-4 µm ash deposited). Their abundance and proportion vary greatly across the deposit within the first 20 km from the volcano. The respirable ash is characteristic of an andesitic magma and no crystalline silica is detected. Morphological features and surface textures are complex and highly variable, with few fibres observed. In-vitro experiments show that respirable volcanic ash is internalized by A549 cells and processed in the endosomal pathway, causing little cell damage, but resulting in changes in cell morphology and membrane texture. The ash triggers a weak pro-inflammatory response. These data provide the first understanding of the respirable ash hazard near Tungurahua and the extent to which it varies spatially in a fallout deposit. Key Points The 16-17 August 2006 Tungurahua eruption produced a high amount of inhalable (12.0-0.04 kg/m2 of sub-10 µm deposited on the ground) and respirable ash (5.3-0.02 kg/m2 of sub-4 µm ash deposited on the ground). The abundance and proportion of inhalable and respirable ash vary greatly across the deposit within the firs

Krzysztof Marycz,1,2 Agnieszka Śmieszek,1 Katarzyna Kornicka-Garbowska,1,2 Ariadna Pielok,1 Maciej Janeczek,3 Anna Lipińska,3 Anna Nikodem,4 Jarosław Filipiak,4 Paulina Sobierajska,5 Jean-Marie Nedelec,6 Rafał J Wiglusz2,5 1Department of Experimental Biology, Wroclaw University of Environmental and Life Sciences, Wroclaw, 50-375, Poland; 2International Institute of Translational Medicine, Malin, 55-124, Poland; 3Department of Biostructure and Animal Physiology, Wroclaw University of and Life Sciences, Wroclaw, 51-631, Poland; 4Department of Mechanics, Materials and Biomedical Engineering, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370 Wrocław, Poland; 5Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, 50-422 Wroclaw, Poland; 6Universite Clermont Auvergne, Clermont Auvergne INP, CNRS, ICCF, Clermont-Ferrand, FranceCorrespondence: Krzysztof MaryczThe Department of Experimental Biology, The Faculty of Biology and Animal Science, University of Environmental and Life Sciences Wroclaw, Norwida 27B St, Wroclaw, 50– 375, PolandTel +48 71 320 5201Email krzysztof.marycz@upwr.edu.plPurpose: Healing of osteoporotic defects is challenging and requires innovative approaches to elicit molecular mechanisms promoting osteoblasts-osteoclasts coupling and bone homeostasis.Methods: Cytocompatibility and biocompatibility of previously characterised nanocomposites, i.e Ca5(PO4)3OH/Fe3O4 (later called nHAp/IO) functionalised with microRNAs (nHAp/IO@miR-21/124) was tested. In vitro studies were performed using a direct co-culture system of MC3T3-E1 pre-osteoblast and 4B12 pre-osteoclasts. The analysis included determination of nanocomposite influence on cultures morphology (confocal imaging), viability and metabolic activity (Alamar Blue assay). Pro-osteogenic signals were identified at mRNA, miRNA and protein level with RT-qPCR, Western blotting and immunocyto