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Wolfson Research Institute for Health and Wellbeing

Wolfson Fellow

Dr Claire Horwell

Telephone: +44 (0) 191 33 42253
Telephone: 42253 or 42336
Room number: IHRR + ES Rm 322
Member of the Durham X-ray Centre

Contact Dr Claire Horwell (email at


2013 – present — Senior Lecturer, Institute of Hazard, Risk & Resilience (IHRR), Dept. of Earth Sciences, Durham University, UK

2012 – 2013 — Lecturer, IHRR, Dept. of Earth Sciences, Durham University, UK

2012 – present — Co-Director of IHRR, Durham University, UK

2011 – present — Fellow of the Wolfson Research Institute, Durham University

2003 – present — Director of the International Volcanic Health Hazard Network (IVHHN)

2007 – 2012 — RCUK Fellow, Dept. of Earth Sciences, Durham University, UK.

2007 – 2011 — NERC Post-doctoral Fellow, Dept. of Earth Sciences, Durham University, UK.

2005 – 2007 — NERC Post-doctoral Fellow, Department of Earth Sciences, University of Cambridge, UK.

2003  2005 — Leverhulme Trust Post-doctoral Researcher, Department of Earth Sciences, University of Bristol, UK

1999 – 2002  PhD – NERC-CASE Studentship, University of Bristol, UK

Career Research Highlights

My expertise is in the health hazards of natural and industrial mineral dusts. I am one of a handful of academics, worldwide, who use mineralogical and geochemical techniques to assess respiratory hazard. My multidisciplinary approach combines my physicochemical analyses with collaborators’ medical data to address the ‘structure-toxicity’ relationship of mineral particles. I am founder/director of the International Volcanic Health Hazard Network, the umbrella organisation for volcanic health research and dissemination. My recent research has addressed a fundamental problem: why is crystalline silica variably toxic? Crystalline silica is the mineral of prime health concern in many environmental and industrial settings because it may cause silicosis (a fatal, fibrotic disease) and lung cancer. My research has focused on volcanic ash, particularly that generated from volcanoes which ‘mass-produce’ crystalline silica within lava domes. Globally, 9% of the population lives near a historically active volcano, so ash exposure is an important health concern. A key achievement, and culmination of my NERC Fellowship, has been the discovery that volcanic silica particles are ‘impure’; their surfaces are coated with more-inert phases (such as aluminium-rich glass), and aluminium also substitutes for silica within the crystalline structure. Aluminium is known to dampen silica toxicity, so these findings may explain the apparent low toxicity of volcanic silica. My PhD students are engaged in toxicological research to confirm this.

My research has expanded to include the respiratory toxicity of other siliceous dusts such as coal, desert, combusted biomass and diatomaceous earth particulate, giving me a broad expertise in mineral dust toxicity.

I have acted as advisor to the World Health Organisation, Public Health England (formerly the Health Protection Agency) and the UK Cabinet Office regarding the respiratory health hazards of volcanic ash.

Committee and Society Service (recent)

2013 – present — Member; Expert Advisory Group for Risk H55, UK Government Cabinet Office

2010 – 2011 — Member; Scientific Advisory Committee for Iceland Eruptions; World Health Organization

2011 – present — Member; Health Protection Agency expert panel for future ashfall affecting the UK.

2011 – present — Chair, Education Committee; International Medical Geology Association

2011 – present — Member of Scientific Steering Committee and Project Partner; Global Volcano Model

2005 – 2007 — Representative for Health for the ICSU 5 GeoUnions Initiative; International Union of Geodesy and Geophysics

Conferences and Workshops (recent)

Conference organizer - Volcanic and Magmatic Studies Group Annual Meeting; 2012

International Program committee member and theme chair - Geochemical Society Goldschmidt Conference; 2014

Scientific organizing committee member - Cities on Volcanoes conference; 2012

Organizing committee member - 5th International Conference on Medical Geology; 2013

Session convener & chair: “Characterization and Health Impact of Natural and Anthropogenic Dust” – MEDGEO conference; 2013

Session convener & chair: “Health aspects of volcanic eruptions: learning from recent experience.” – Cities on Volcanoes conference; 2012

Session convener & chair: " Human health problems caused by volcanic activity" - Cities on Volcanoes conference; 2010

Session convener & chair: "Responding to volcanic health hazards" - International Association of Volcanology and Chemistry of the Earth's Interior General Assembly; 2008

Editorial Roles

Associate Editor, the Journal of Applied Volcanology


2007 – 2012 — Research Councils UK: Fellow

2005 – 2011 — NERC Postdoctoral Fellow

Keynotes and Plenary Talks

2011 — The respiratory health hazards of volcanic ash: a review of current knowledge from a mineralogical and toxicological perspective. Talk presented at GeoMed 2011 conference, Bari, Italy.

2003 — Volcanic emissions and health hazards: past, present and future research. Talk presented at CoV 3, Hilo, Hawaii

Membership of Organisations and Societies

Member, International Medical Geology Association

Member, International Association of Volcanology and Chemistry of the Earth's Interior

Member, European Geosciences Union

Member, American Geophysical Union

Recent and Current Grants

2013 — VERTIGO – Volcanic ash: field, experimental and numerical investigations of processes during its lifecycle. EU Initial Training Network Co-I

2010 — Rapid assessment of the potential health hazard of ash from Eyjafjallajökull volcano, Iceland. NERC Urgency Grant. P.I.

2010 Fragmentation of volcanic dome rock for the assessment of respiratory health hazard of fresh particulate matter. Part of EVOKES ERC Advanced Investigator grant (Dingwell)

2008 — Moyes Foundation PhD Studentship Bursary. Volcanic cristobalite formation: A global study for the assessment of health hazard. 3 year Studentship from Jan. 2009. P.I.

2008 — NERC Urgency Grant. Rapid assessment of the potential health hazard of ash from Kilauea Volcano, Hawai’i. Extended after award to include Chaitén, Chile eruption. P.I.

Research Groups

Department of Earth Sciences

  • Geohazards
  • The Solid Earth

Department of Geography

Selected Publications

Chapter in book

  • Horwell, C.J., Baxter, P.J. & Kamanyire, R. (2015). Health Impacts of Volcanic Eruptions. In Global Volcanic Hazards and Risk. Loughlin, S.C., Vye-Brown, C., Sparks, R.S.J., Brown S.K. & Jenkins, S.F. Cambridge University Press.
  • Baxter, P.J. & Horwell, C.J. (2015). Impacts of eruptions on human health. In The Encyclopedia of Volcanoes. Sigurdsson, H., Houghton, B., McNutt, S., Rymer, H. & Stix, J. Elsevier.
  • Baxter, P J, Searl, A, Cowie, H A, Jarvis, D & Horwell, C J (2014). Evaluating the respiratory health risks of volcanic ash at the eruption of the Soufrière Hills Volcano, Montserrat, 1995-2010. In The Eruption of Soufrière Hills Volcano, Montserrat from 2000 to 2010. Wadge, G., Robertson, R.E.A. & Voight, B. London: Geological Society of London. 39.
  • Weinstein, P., Horwell, C.J. & Cook, A. (2013). Volcanic emissions and health. In Essentials of Medical Geology. Selinus, O., Alloway, B., Centeno, J.A., Finkelman, R.B., Fuge, R., Lindh, U. & Smedley P. Springer. 805.
  • 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 Article

Show all publications

Related Links

Selected Grants

  • 2015: HIVE: A new evidence base for respiratory Health Interventions in Volcanic Eruption crises (£585963.00 from ELRHA)
  • 2015: Health Interventions in Volcanic Eruptions (HIVE) £600,000 Wellcome Trust & DfID
  • 2014: Volcanic Ash Field, Experimental and Numerical Investigations of Processes During Its Lifecycle (£207540.46 from European Commission)