Physicochemical and toxicological profiling of ash from the 2010 and 2011 eruptions of Eyjafjallajökull and Grímsvötn volcanoes, Iceland using a rapid respiratory hazard assessment protocol

Abstract

The six week eruption of Eyjafjallajökull volcano in 2010 produced heavy ash fall in a sparsely populated area of southern and south eastern Iceland and disrupted European commercial flights for at least 6 days. We adopted a protocol for the rapid analysis of volcanic ash particles, for the purpose of informing respiratory health risk assessments. Ash collected from deposits underwent a multi-laboratory physicochemical and toxicological investigation of their mineralogical parameters associated with bio-reactivity, and selected in vitro toxicology assays related to pulmonary inflammatory responses. Ash from the eruption of Grímsvötn, Iceland, in 2011 was also studied. The results were benchmarked against ash from Soufrière Hills volcano, Montserrat, which has been extensively studied since the onset of eruptive activity in 1995. For Eyjafjallajökull, the grain size distributions were variable: 2-13 vol% of the bulk samples were <4 µm, with the most explosive phases of the eruption generating abundant respirable particulate matter. In contrast, the Grímsvötn ash was almost uniformly coarse (<3.5 vol%<4 µm material). Surface area ranged from 0.3 to 7.7 m2 g(-1) for Eyjafjallajökull but was very low for Grímsvötn (<0.6 m2 g(-1)). There were few fibre-like particles (which were unrelated to asbestos) and the crystalline silica content was negligible in both eruptions, whereas Soufrière Hills ash was cristobalite-rich with a known potential to cause silicosis. All samples displayed a low ability to deplete lung antioxidant defences, showed little haemolysis and low acute cytotoxicity in human alveolar type-1 like epithelial cells (TT1). However, cell-free tests showed substantial hydroxyl radical generation in the presence of hydrogen peroxide for Grímsvötn samples, as expected for basaltic, Fe-rich ash. Cellular mediators MCP-1, IL-6, and IL-8 showed chronic pro-inflammatory responses in Eyjafjallajökull, Grímsvötn and Soufrière Hills samples, despite substantial differences in the sample mineralogy and eruptive styles. The value of the pro-inflammatory profiles in differentiating the potential respiratory health hazard of volcanic ashes remains uncertain in a protocol designed to inform public health risk assessment, and further research on their role in volcanic crises is warranted.

The iron-catalysed surface reactivity and health-pertinent physical characteristics of explosive volcanic ash from Mt. Etna, Italy

“…Further to this, Horwell et al (2007) confirmed that all ash, across the magmatic compositional spectrum, generated hydroxyl radicals, with basaltic samples (particularly Etna) appearing to be more reactive than other ash types. The ability of ash to generate the hydroxyl radical has now been confirmed at several other volcanoes Hillman et al 2012;Horwell et al 2013;Horwell et al 2010;Le Blond et al 2010).…”

“…These methods are detailed elsewhere using the same techniques in the same laboratories Horwell 2007;Horwell et al 2013;Le Blond et al 2009) so are only briefly mentioned here. For rapid analyses (for which the IVHHN protocol was designed), the sub-1 mm fraction is used as separation of the respirable fraction is extremely time consuming.…”

“…These samples, from Soufrière Hills volcano, Montserrat (which produces andesitic to dacitic ash), Pinatubo volcano, Philippines (also dacitic) and Cerro Negro, Nicaragua (basaltic) have previously been analysed extensively in these assays and, as in this study, have previously been used as 'standard' samples to represent a range of iron release and hydroxyl radical generation potential (e.g., Damby et al 2013; Horwell et al 2007;Horwell et al 2013;Le Blond et al 2010 and unpublished analyses;Hillman et al 2012). Due to logistical and timing constrictions of the assays, no more than a total of 8 samples were analysed.…”

“…The methods follow those used in recent years for analyses of ash for respiratory health hazard assessment, according to the protocol developed by the International Volcanic Health Hazard Network (e.g., Damby et al 2013;Horwell et al 2013;Le Blond et al 2010 and downloadable from www.ivhhn.org). A full review of the respiratory health hazards of volcanic ash can be found in Horwell and Baxter (2006).…”

Impact of Volcanic Eruptions on the Occurrence of PAHs Compounds in the Aquatic Ecosystem of the Southern Part of West Spitsbergen (Hornsund Fjord, Svalbard)

“…Particular attention is given to polycyclic aromatic hydrocarbon compounds (PAHs) due to their documented harmful effect on the flora and fauna species of the Arctic [1,18,19]. PAHs tend to enter the aquatic environment mainly from the atmosphere (through dry deposition and precipitation) and in consequence of washing out polluted soil [20][21][22].…”