Dr Claire Horwell
Claire Horwell joined the Institute of Hazard, Risk & Resilience and the Department of Earth Sciences at Durham as an RCUK Fellow in 2007. She is now Co-Director of IHRR and Geohazards Theme Leader in the Department of Earth Sciences. Previously, she was a NERC Post-doctoral Research Fellow at the University of Cambridge. Her research field is the study of natural mineral dusts and their respiratory health hazard.
Prior to Cambridge, she held her first post-doctoral fellowship at the University of Bristol where she founded the International Volcanic Health Hazard Network (www.ivhhn.org), funded by the Leverhulme Trust.
1999-2002 PhD – NERC CASE Studentship
Characterisation of Montserrat volcanic ash for the assessment of its toxicity.
Supervisor: Professor Steve Sparks. Department of Earth Sciences, University of Bristol, U.K.
1997-1998 Diploma in Applied Science – Volcanology – (MSc equivalent)
Thesis: Geothermal hydrogen sulphide mapping across Rotorua, New Zealand: Implications for the assessment of public health. Supervisor: Professor John Gamble.
Department of Earth Sciences, Victoria University of Wellington, New Zealand.
1993-1996 BSc Honours, Environmental Sciences, 1st Class.
Thesis: The modern relationship between rainfall and magnetic susceptibility in NW Spain; a hypothesis for estimating paleoprecipitation on the Chinese Loess Plateau. Supervisor: Prof. Barbara Maher. School of Environmental Sciences, University of East Anglia, Norwich, UK.
Claire Horwell’s education, research and work experience have been broad and multidisciplinary, enabling her to become an expert in the field of volcanic health hazards. Her degree in Environmental Sciences at UEA was modular, allowing her to study such diverse subjects as geology, geophysics, public health and epidemiology. This background prompted her first dissertation in the field of volcanic health hazards during her Diploma in Volcanology in New Zealand. The interdisciplinary approach continued into her PhD for which she studied the potential toxicity of the Montserrat volcanic ash from a mineralogical and geochemical perspective. The work also required an understanding of the biological processes of disease in the lung and a knowledge of physical chemistry and toxicology for the analysis of surface reactivity of particles. In her first post-doctoral position, she founded and directed the International Volcanic Health Hazard Network (www.ivhhn.org). She also leads the UK Natural Dust & Health Network (www.dur.ac.uk/claire.horwell/ukndhn).
Claire Horwell's research currently has the following foci:
1) Addressing a fundamental problem in the field of natural dust hazards: identifying what causes variations in natural dust toxicity. This includes investigation of the mechanism of formation of crystalline silica polymorphs in volcanic settings; assessment of surface occlusion of particles by more-inert minerals, and adaptation of analytical techniques for high-resolution micro-analysis of respirable crystalline silica in natural dusts (coal dust, volcanic ash, desert dusts, diatomaceous earth and surgarcane combustion).
2) Iron-induced reactivity of particle surfaces in different volcanic ash types. This is a hitherto unreported mechanism of toxicity for volcanic particles. Claire’s research, using EPR spectrometry, has shown that all volcanic ash generates hydroxyl radicals, but particularly basaltic ash, which was not previously thought of as a health hazard due to its lack of crystalline silica.
3) Grain-size analysis of volcanic ash for the rapid assessment of volcanic health hazard. Claire Horwell has built a database of volcanic ash grain-size analyses, focusing on health-pertinent fractions, to allow rapid assessment of health hazard at the onset of new eruptions. She also has developed a methodology for predicting quantities of respirable material in an ash sample where state-of-the-art analytical techniques are unavailable.
Indicators of Esteem
- 2007: Convened and chaired workshop: Convened and will chair IVHHN's 4th workshop at the Cities on Volcanoes 5 conferenece. Shimabara, Japan. November 2007.
- 2007: Founded and run UK Dust & Health Network: In 2007 I was awarded a NERC Environment & Human Health Initiative grant to set up a UK network of multidisciplinary scientists interested in the health hazards of natural mineral dusts. We held our first meeting in June 2007 and will hold two more meetings by the end of the year. Our aim is to identify gaps in our research, interdisciplinary collaboration routes and goals for future research enabling rapid response at future funding calls.
- 2007: Honorary Research Fellow: Between 2003-2006 I was a Honorary Research Fellow at Birmingham University.
- 2007: Paper reviews: I have peer reviewed three papers for international journals
- 2007: Produced guidelines for public and scientists: A core goal of IVHHN is to produce a series of guidelines informing scientists and the public on different aspects of volcanic health hazard management. Seven documents have been produced and are available online. Two of these documents are now available in pamphlet form for worldwide distribution to the public. The are currently available in English, Spanish and Japanese.
- 2007: RCUK Fellowship: In May 2007 I was appointed to an RCUK Fellowship in the Institute of Hazard and Risk Research, University of Durham.
- 2007: Symposium co-convenor: International Union of Geodesy and Geophysics conference. Perugia, Italy. July 2007. VS012: "Cities on Volcanoes: looking at the links between volcanology and communities issues around volcanoes" (merged with VS020)
- 2007: Symposium co-convenor: Cities on Volcanoes 5 conference. Shimabara, Japan. November 2007. Symposium 1.3: "Health hazards of coexisting with active volcanoes"
- 2007: Symposium Convenor: Frontiers in Mineral Sciences conference. Cambridge, UK, June 2007. Symposium on "Respirable natural dusts: Sources, characterisation and health effects"
- 2006: Convened workshop: Convened IVHHN's 3rd workshop at the Cities on Volcanoes 4 conference. Quito, Ecuador. January 2006. (did not attend due to pregnancy)
- 2006: Invited committee member: I am an invited committee member for the Promoting Medical Geology committee run by the International Medical Geology Association.
- 2006: Invited committee member: I am an invited committee member for the committee on the Health Impacts of Geological Disasters, International Medical Geology Association.
- 2006: Symposium co-convenor: 7th International Symposium on Environmental Geochemistry. Beijing, China. September 2006. 'Special Symposium' SP01 "Natural dust and human health"
- 2006: Symposium co-convenor: Cities on Volcanoes 4 conference. Quito, Ecuador. January 2006. Symposium VII: "Human health impacts of volcanism"
- 2005: IUGG Representative for Health: In 2005 I was appointed the International Union of Geodesy and Geophysics' "Representative for Health" as part of the Five GeoUnions' Health Initiative. In this role, I have attended a meeting in Uppsala, Sweden, and work with the GeoUnions colleagues to ensure collaboration between our unions in the area of health
- 2005: NERC Postdoctoral Fellowship: In December 2005 I commenced a 3-year NERC Postdoctoral Fellowship at the University of Cambridge. The Fellowship was transferred to the University of Durham in May 2007.
- 2004: Convened and chaired workshop: Convened and chaired IVHHN's 2nd workshop at the IAVCEI General Assembly. Pucon, Chile. November 2004.
- 2003: Convened and chaired workshop: Convened and chaired an IVHHN workshop of UK experts on volcanic ash hazard to discuss writing guidelines for the public and scientists on various aspects of volcanic ash management. The guidelines are now all published online and two sets are also available as pamphlets. Held at the British Geological Survey, Keyworth, UK. November 2003.
- 2003: Convened and chaired workshop: Convened and chaired IVHHN's 1st workshop at the Cities on Volcanoes 3 conference, Hilo, Hawaii. July 2003.
- 2003: Founded and run international network: In Feb. 2003 I founded the International Volcanic Health Hazard Network. IVHHN was awarded IAVCEI Commission status in 2004 and is now an internationally recognised organisation of multidisciplinary experts in the field of volcanic health hazards. Initially funded by a 3-year Leverhulme Trust Research Interchange Grant, it is now funded by a 2-year 1851 Royal Commission Special Award. I continue to run IVHHN.
- 2003: Invited keynote talk: Invited plenary lecture at the Cities on Volcanoes 3 conference in Hilo, Hawaii in July 2003.
- 2003: Leverhulme Trust Postdoctoral Assistant: In Feb. 2003 Prof. Steve Sparks and I were awarded a Research Interchange Grant by the Leverhulme Trust to set up the International Volcanic Health Hazard Network. I was employed to setup and run IVHHN but I had complete autonomy over my research. I therefore regard this post as being akin to a Research Fellowship.
- 2002: Invited talk to Government panel: In 2002 I was invited to present my research to the UK Chief Medical Officer’s Advisory Group: Montserrat Health. London, UK.
Department of Earth Sciences
- The Solid Earth
Department of Geography
- Hansell, A. Horwell, C.J. & Oppenheimer, C. (2006). The health hazards of volcanoes and geothermal areas. Occupational and Environmental Medicine 63(Continuing Professional Development Series): 149-156.
- Horwell, C.J. & Baxter, P.J. (2006). The respiratory health hazards of volcanic ash: a review for volcanic risk mitigation. Bulletin of Volcanology 69: 1-24.
- Witham, C.S., Oppenheimer, C. & Horwell, C.J. (2005). Volcanic ash leachates: a review and recommendations for analysis methods. Journal of Volcanology and Geothermal Research 141: 299-326.
- Derbyshire, E., Horwell, C.J., Tetley, T. & Jones, T.P. (2011). Airborne Paricles. In Pollutants, human health and the environment: Introduction for environmental scientists and health professionals. Plant, J.A., Ragnarsdottir, K.V. & Vouvoulis, N. Wiley. 255-286.
Journal papers: academic
- Horwell, C.J., Williamson, B.J., Llewellin, E.W., Damby, D.E. & Le Blond, J.S. (2012). Nature and formation of cristobalite at the Soufriere Hills Volcano, Monserrat: implications for the petrology and stability of silicic volcanic domes. Bulletin of Volcanology
- Hillman, S.E., Horwell, C.J., Densmore, A.L., Damby, D.E., Fubini, B., Ishimine, Y. & Tomatis, M. (2012). Sakurajima volcano: a physico-chemical study of the health consequences of long-term exposure to volcanic ash. Bulletin of Volcanology 74: 913-930.
- Horwell, CJ, Williamson, BJ, Donaldson, K, Le Blond, JS, Damby, DE & Bowen, L (2012). The structure of volcanic cristobalite in relation to its toxicity; relevance for the variable crystalline silica hazard. Particle and Fibre Toxicology 9(November 2012 ): 44.
- Le Blond, J S, Tomatis, M, Horwell, C J, Dunster, C, Murphy, F, Corazzari, I, Grendene, F, Turci, F, Gazzano, E, Ghigo, D, Williamson, B J, Oppenheimer, C & Fubini, B (2012). The surface reactivity and implied toxicity of ash produced from sugarcane burning. Environmental Toxicology n/a.
- Horwell CJ, Stannett GW, Andronico D, Bertagnini A, Fenoglio I, Fubini B, Le Blond JS & Williamson BJ (2010). A physico-chemical assessment of the health hazard of Mt. Vesuvius volcanic ash. Journal of Volcanology and Geothermal Research 191(3-4): 222-232.
- Durant AJ, Bonadonna C & Horwell CJ (2010). Atmospheric and environmental impacts of volcanic particulates. Elements 6(4): 235-240.
- Horwell CJ, Le Blond JS, Michnowicz SAK & Cressey G (2010). Cristobalite in a rhyolitic lava dome: Evolution of ash hazard. Bulletin of Volcanology 72(2): 249-253.
- Le Blond JS, Horwell CJ, Williamson BJ & Oppenheimer C (2010). Generation of crystalline silica from sugarcane burning. Journal of Environmental Monitoring 12(7): 1459-1470.
- Williamson BJ, Di Muro A, Horwell CJ, Spieler O & Llewellin EW (2010). Injection of vesicular magma into an andesitic dome at the effusive–explosive transition. Earth and Planetary Science Letters 295(1-2): 83-90.
- Le Blond JS, Horwell CJ, Baxter PJ, Michnowicz SAK, Tomatis M, Fubini B, Delmelle P, Dunster C & Patia H (2010). Mineralogical analyses and in vitro screening tests for the rapid evaluation of the health hazard of volcanic ash at Rabaul volcano, Papua New Guinea. Bulletin of Volcanology 72(9): 1077-1092.
- Le Blond, J.S., Cressey, G, Horwell, C.J. & Williamson, B.W. (2009). A rapid method for quantifying single mineral phases in heterogeneous natural dusts using X-ray diffraction. Powder Diffraction 24: 17-23.
- Martin, R.S., Mather, T.A., Pyle, D.M., Power, M., Tsanev, V.I., Oppenheimer, C., Allen, A.G., Horwell, C.J. & Ward E.P.W. (2009). Size distributions of fine silicate and other particles in Masaya's volcanic plume. Journal of Geophysical Research – Atmospheres 114: D09217.
- Martin, R S. Mather, T A., Pyle, D M., Power, M., Allen, A G., Aiuppa, A., Horwell, C J. & Ward, E P W. (2008). Composition-resolved size distributions of volcanic aerosols in the Mt. Etna plumes. Journal of Geophysical Research - Atmospheres 113: D17211.
- Le Blond, J S., Williamson, B J., Horwell, C J., Monro, A K., Kirk, C A. & Oppenheimer, C. (2008). Production of potentially hazardous respirable silica airborne particulate from the burning of sugarcane. Atmospheric Environment 42(22): 5558-5568.
- Horwell, C.J. (2007). Grain-size analysis of volcanic ash for the rapid assessment of respiratory health hazard. Journal of Environmental Monitoring 9: 1107-1115.
- Horwell, C.J., Fenoglio, I. & Fubini, B. (2007). Iron-induced hydroxyl radical generation from basaltic volcanic ash. Earth and Planetary Science Letters 261(3-4): 662-669.
- Stewart, C., Johnston, D.M., Leonard, G., Horwell, C.J., Thordarsson, T. & Cronin, S. (2006). Contamination of water supplies by volcanic ashfall: A literature review and simple impact modelling. Journal of Volcanology and Geothermal Research 158: 296-306.
- Horwell, C.J., Patterson, J.E., Gamble, J.A. & Allen, A.G. (2005). Monitoring and mapping of hydrogen sulphide emissions across an active geothermal field: Rotorua, New Zealand. Journal of Volcanology and Geothermal Research 139: 259-269.
- Horwell, C.J., Allen, A.G., Mather, T.A. & Patterson, J.E. (2004). Evaluation of a novel passive sampling technique for monitoring volcanogenic hydrogen sulphide. Journal of Environmental Monitoring 6(7): 630-635.
- Horwell, C.J., Sparks, R.S.J., Brewer, T.S., Llewellin, E.W. & Williamson, B.J. (2003). Characterization of respirable volcanic ash from the Soufrière Hills volcano, Montserrat, with implications for human health hazards. Bulletin of Volcanology 65(5): 346-362.
- Horwell, C.J., Fenoglio, I., Ragnarsdottir, K.V., Sparks, R.S.J. & Fubini, B. (2003). Surface reactivity of volcanic ash from the eruption of Soufrière Hills volcano, Monserrat, West Indies with implications for health hazards. Environmental Research 93(2): 202-215.
- Horwell, C.J., Braña, L.P., Sparks, R.S.J., Murphy, M.D. & Hards, V.L. (2001). A geochemical investigation of fragmentation and physical fractionation in pyroclastic flows from from the Soufriere Hills volcano, Montserrat. Journal of Volcanology and Geothermal Research 109(4): 247-262.
- Jones, A.P. Bentham, G. & Horwell, C. (1999). Health service accessibility and deaths from asthma. International Journal of Epidemiology 28: 101-105.