Browsing by Author "Horwell CJ"

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    Physicochemical hazard assessment of ash and dome rock from the 2021 eruption of La Soufriere St Vincent for the assessment of respiratory impacts and water contamination
    (Geological Society of London, 2024-01-05) Horwell CJ; Damby DE; Stewart C; Joseph EP; Barclay J; Davies BV; Mangler MF; Marvin LG; Najorka J; Peek S; Tunstall N
    La Soufrière, St Vincent, began an extrusive eruption on 27 December 2020. The lava dome was destroyed, along with much of the pre-existing 1979 dome, in explosive eruptions from 9 to 22 April 2021. Lava domes generate crystalline silica – inhalation of which can cause silicosis in occupational settings – which can become hazardous when dome material is incorporated into volcanic ash. La Soufrière ash (17 samples) was analysed, according to IVHHN protocols, to rapidly quantify crystalline silica and test for other health-relevant properties. The basaltic andesitic ash contained <5 wt% crystalline silica, which agrees with previous analyses of ash of similar compositions and mirrors the low quantities measured in dome samples (2 area %). It contained substantial inhalable material (7–21 vol% <10 µm). Few fibre-like particles were observed, reducing concern about particle shape. Leaching assays found low concentrations of potentially toxic elements, which indicates low potential to impact health, contaminate drinking-water sources or harm grazing animals through ingestion. Collectively, these data indicate that the primary health concern from this eruption was the potential for fine-grained ash to increase ambient particulate matter, an environmental risk factor for respiratory and cardiovascular morbidity and mortality. Precautionary measures were advised to minimize exposure.
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    The International Volcanic Health Hazard Network (IVHHN): reflections on 20 years of progress
    (Frontiers Media S.A., 2023-08-17) Horwell CJ; Baxter PJ; Damby DE; Elias T; Ilyinskaya E; Sparks RSJ; Stewart C; Tomašek I; Viccaro M
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    Volcanic air pollution and human health: recent advances and future directions
    (Springer Nature Switzerland AG on behalf of the International Association of Volcanology & Chemistry of the Earth's Interior, 2022-01) Stewart C; Damby DE; Horwell CJ; Elias T; Ilyinskaya E; Tomašek I; Longo BM; Schmidt A; Carlsen HK; Mason E; Baxter PJ; Cronin S; Witham C
    Volcanic air pollution from both explosive and effusive activity can affect large populations as far as thousands of kilometers away from the source, for days to decades or even centuries. Here, we summarize key advances and prospects in the assessment of health hazards, effects, risk, and management. Recent advances include standardized ash assessment methods to characterize the multiple physicochemical characteristics that might influence toxicity; the rise of community-based air quality monitoring networks using low-cost gas and particulate sensors; the development of forecasting methods for ground-level concentrations and associated public advisories; the development of risk and impact assessment methods to explore health consequences of future eruptions; and the development of evidence-based, locally specific measures for health protection. However, it remains problematic that the health effects of many major and sometimes long-duration eruptions near large populations have gone completely unmonitored. Similarly, effects of prolonged degassing on exposed populations have received very little attention relative to explosive eruptions. Furthermore, very few studies have longitudinally followed populations chronically exposed to volcanic emissions; thus, knowledge gaps remain about whether chronic exposures can trigger development of potentially fatal diseases. Instigating such studies will be facilitated by continued co-development of standardized protocols, supporting local study teams and procuring equipment, funding, and ethical permissions. Relationship building between visiting researchers and host country academic, observatory, and agency partners is vital and can, in turn, support the effective communication of health impacts of volcanic air pollution to populations, health practitioners, and emergency managers.