Staff profile

2019 - present	Professor	IHRR & Department of Earth Sciences, Durham University, UK
2014 - present	Honorary Professor	UK Health & Security Agency (formerly PHE/HPA)
2012 - 2019	Lecturer/Sr Lecturer/Reader/Assoc Prof	IHRR & Department of Earth Sciences, Durham University, UK
2012 - 2016	Co-Director	IHRR, Durham University, UK
2011 - present	Fellow	Wolfson Institute for Health & Wellbeing, Durham University, UK
2003 - present	Director	International Volcanic Health Hazard Network
2007 - 2012	RCUK & NERC Fellow	IHRR & Department of Earth Sciences, Durham University, UK
2005 - 2007	NERC Fellow	Department of Earth Science, University of Cambridge, UK
2003 - 2005	Leverhulme Trust PDRA	School of Earth Science, University of Bristol, UK
1999 - 2002	NERC CASE PhD student	School of Earth Science, University of Bristol, UK

Career Research Highlights

I am founder/director of the International Volcanic Health Hazard Network, the umbrella organisation for volcanic health research and dissemination. I have acted as advisor to the World Health Organization, Public Health England and the UK Cabinet Office regarding the respiratory health hazards of volcanic ash. I also work with government and non-governmental agencies, around the world, helping them to prepare the health response for future volcanic eruptions, and responding during volcanic crises.

My research interest is in understanding the health hazards of natural and industrial mineral dusts and in helping communities to prepare for, and protect themselves from volcanic emissions and other particulate pollution crises. My research is split into several, interdisciplinary strands, which are conducted with multiple UK and international collaborators across the natural, social and medical sciences:

Are mineral particles harmful when inhaled?

i) Physicochemical analysis of particles: use of mineralogical and geochemical techniques to assess respiratory hazard. These are combined with my students' and collaborators’ toxicological assessements to determine potential respiratory hazard of volcanic ash, combusted biomass, diatomaceous earth, desert dust and coal dust.

ii) Fundamental questions surrounding the ‘structure-toxicity’ relationship of mineral particles and interacting elements (e.g. anthropogenic pollution), and the variable toxicity of crystalline silica are also addressed through mineralogical, geochemical and toxicological analyses. Petrological techniques are also employed to understand how crystalline silica forms in volcanic systems (paricularly lava domes).

iii) Exposure assessments to airborne particles is a key part of determining potential hazard. My group conducts air quality assessments using state-of-the-art portable aerosol monitors.

How can communities prepare for, and protect themselves from, airborne particulate crises? 

iv) Working with GOs, NGOs and behavioural psychologists and social anthropologists, we conduct social research within local communities to understand their lifestyles, cultural contexts, and how their risk perceptions influence their protective behaviours. We also investigate how their current protective strategies relate to official advice. 

v) We assess the effectiveness of community use of respiratory protection (from industry-certified RPE to cloth face-coverings) through laboratory tests and field trials, in collaboration with exposure scientists and PPE experts at the Institute of Occupational Medicine. 

vi) With social learning experts, we work with communities and local authorities to co-develop evidence-based printable and audio visual informational products which inform people on the most effective protection strategies for exposure reduction to airborne pollutants. Our products are available at www.ivhhn.org.

vii) We evaluate the ethical and legal aspects of agencies distributing or recommending different forms of respiratory protection for community use. 

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Committee and Society Service

2022 - 2024 - Member of the Royal Society's Research Grants Board

2020 - 2022 - Member of the European Geosciences Union's Plinius Medal Committee

2017- 2020- President (and former President-elect and Founding Leader); GeoHealth Section, American Geophysical Union

2017 - 2020 - Council Member, American Geophysical Union

2015 - present - Member; Scientific Advisory Group for Emergencies (SAGE) for volcanic eruptions, UK Government

2014 – 2017— Chair, Nominations & Awards Committee; International Medical Geology Association

2013 – 2015— Member; Expert Advisory Group for Risk H55, UK Government Cabinet Office

2011 – present — Member; Public Health England's expert panel for future ashfall affecting the UK

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

2011 – 2014 — Chair, Education Committee; International Medical Geology Association

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

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

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Fellowships

2007 – 2012 — Research Councils UK: Fellow

2005 – 2011 — NERC Postdoctoral Fellow

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• 2020: European Geosciences Union Plinius Medal for interdisciplinary natural hazards research:

Chapter in book

• Horwell, C., Baxter, P., & Kamanyire, R. (2015). Health Impacts of Volcanic Eruptions. In S. Loughlin, C. Vye-Brown, R. Sparks, S. Brown, & S. Jenkins (Eds.), Global Volcanic Hazards and Risk. Cambridge University Press
• Baxter, P., & Horwell, C. (2015). Impacts of eruptions on human health. In H. Sigurdsson, B. Houghton, S. McNutt, H. Rymer, & J. Stix (Eds.), The Encyclopedia of Volcanoes. (2nd). Elsevier
• Weinstein, P., Horwell, C., & Cook, A. (2013). Volcanic emissions and health. In O. Selinus, B. Alloway, J. Centeno, R. Finkelman, R. Fuge, U. Lindh, & P. Smedley (Eds.), Essentials of Medical Geology. (Rev. ed.). Springer Verlag
• Derbyshire, E., Horwell, C., Tetley, T., & Jones, T. (2011). Airborne Paricles. In J. Plant, K. Ragnarsdottir, & N. Vouvoulis (Eds.), Pollutants, human health and the environment: Introduction for environmental scientists and health professionals (255-286). Wiley

Journal Article

• Samarasundera, E., Hansell, A., Leibovici, D., Horwell, C., Anand, S., & Oppenheimer, C. (online). Geological hazards: from early warning systems to public health toolkits. Health & Place, 30, 116-119. https://doi.org/10.1016/j.healthplace.2014.09.001
• Horwell, C. J., Damby, D. E., Stewart, C., Joseph, E. P., Barclay, J., Davies, B. V., Mangler, M. F., Marvin, L. G., Najorka, J., Peek, S., & Tunstall, N. (2024). Physicochemical hazard assessment of ash and dome rock from the 2021 eruption of La Soufrière, St Vincent, for the assessment of respiratory health impacts and water contamination. Geological Society Special Publications, 539(1), https://doi.org/10.1144/sp539-2023-46
• Stowell, J. D., Anenberg, S., Zaitchik, B. F., Tong, D. Q., Horwell, C. J., Stolle, D. P., Colwell, R. R., & McEntee, C. (2024). Health‐Damaging Climate Events Highlight the Need for Interdisciplinary, Engaged Research. Geohealth, 8(2), Article e2024GH001022. https://doi.org/10.1029/2024gh001022
• Horwell, C., Elias, T., Covey, J., Bhandari, R., & Truby, J. (2023). Perceptions of volcanic air pollution and exposure reduction practices on the Island of Hawai‘i: Working towards socially relevant risk communication. International Journal of Disaster Risk Reduction, 95, Article 103853. https://doi.org/10.1016/j.ijdrr.2023.103853
• Fries, A., Dominguez, L., Jarvis, P. A., Pistolesi, M., Manrique, N., Aguilar, R., Valdivia, D., Rossi, E., Pollastri, S., Horwell, C. J., & Bonadonna, C. (2023). The post-2016 long-lasting Vulcanian activity of Sabancaya volcano (Peru) and associated aeolian remobilisation of volcanic ash. Journal of Volcanology and Geothermal Research, 441, Article 107876. https://doi.org/10.1016/j.jvolgeores.2023.107876
• Horwell, C. J., Baxter, P. J., Damby, D. E., Elias, T., Ilyinskaya, E., Sparks, R. S. J., Stewart, C., & Tomašek, I. (2023). The International Volcanic Health Hazard Network (IVHHN): reflections on 20 years of progress. Frontiers in Earth Science, 11, Article 1213363. https://doi.org/10.3389/feart.2023.1213363
• Schwartz-Marin, E., Merli, C., Rachmawati, L., Horwell, C., & Nugroho, F. (2022). Merapi multiple: Protection around Yogyakarta’s celebrity volcano through masks, dreams, and seismographs. History and Anthropology, 33(5), 588-610. https://doi.org/10.1080/02757206.2020.1799788
• Stewart, C., Damby, D., Horwell, C., Elias, T., Ilyinskaya, E., Tomašek, I., Longo, B., Schmidt, A., Carlsen, H., Mason, E., Baxter, P., Cronin, S., & Witham, C. (2022). Volcanic air pollution and human health: recent advances and future directions. Bulletin of Volcanology, 84(1), Article 11. https://doi.org/10.1007/s00445-021-01513-9
• Tomašek, I., Damby, D., Stewart, C., Horwell, C., Plumlee, G., Ottley, C., Delmelle, P., Morman, S., Yazidi, S., Claeys, P., Kervyn, M., Elskens, M., & Leermakers, M. (2021). Development of a simulated lung fluid leaching method to assess the release of potentially toxic elements from volcanic ash. Chemosphere, 278, Article 130303. https://doi.org/10.1016/j.chemosphere.2021.130303
• Covey, J., Dominelli, L., Horwell, C., Rachmawati, L., Martin-del Pozzo, A., Armienta, M., Nugroho, F., & Ogawa, R. (2021). Carers' perceptions of harm and the protective measures taken to safeguard children's health against inhalation of volcanic ash: A comparative study across Indonesia, Japan and Mexico. International Journal of Disaster Risk Reduction, 59, Article 102194. https://doi.org/10.1016/j.ijdrr.2021.102194
• McDonald, F., & Horwell, C. (2021). Air Pollution Disasters: Liability Issues in Negligence Associated With the Provision of Personal Protective Interventions (Facemasks). Disaster Medicine and Public Health Preparedness, 15(3), 367-373. https://doi.org/10.1017/dmp.2020.37
• Tomašek, I., Damby, D., Andronico, D., Baxter, P., Boonen, I., Claeys, P., Denison, M., Horwell, C., Kervyn, M., Kueppers, U., Romanias, M., & Elskens, M. (2021). Assessing the biological reactivity of organic compounds on volcanic ash: implications for human health hazard. Bulletin of Volcanology, 83(5), Article 30. https://doi.org/10.1007/s00445-021-01453-4
• Mueller, W., Cowie, H., Horwell, C., Hurley, F., & Baxter, P. (2020). Health Impact Assessment of volcanic ash inhalation: A comparison with outdoor air pollution methods. Geohealth, 4(7), Article e2020GH000256. https://doi.org/10.1029/2020gh000256
• Covey, J., Horwell, C., Ogawa, R., Baba, T., Nishimura, S., Hagino, M., & Merli, C. (2020). Community perceptions of protective practices to prevent ash exposures around Sakurajima volcano, Japan. International Journal of Disaster Risk Reduction, 46, Article 101525. https://doi.org/10.1016/j.ijdrr.2020.101525
• Smart, N., Horwell, C., Smart, T., & Galea, K. (2020). Assessment of the Wearability of Facemasks against Air Pollution in Primary School-Aged Children in London. International Journal of Environmental Research and Public Health, 17(11), Article 3935. https://doi.org/10.3390/ijerph17113935
• Mueller, W., Cowie, H., Horwell, C., Baxter, P., McElvenny, D., Booth, M., Cherrie, J., Cullinan, P., Jarvis, D., Ugarte, C., & Inoue, H. (2020). Standardized epidemiological protocols for populations affected by volcanic eruptions. Bulletin of the World Health Organization, 98(5), 362-364. https://doi.org/10.2471/blt.19.244509
• Stewart, C., Damby, D., Tomašek, I., Horwell, C., Plumlee, G., Armienta, M., Hinojosa, M., Appleby, M., Delmelle, P., Cronin, S., Ottley, C., Oppenheimer, C., & Morman, S. (2020). Assessment of leachable elements in volcanic ashfall: A review and evaluation of a standardized protocol for ash hazard characterization. Journal of Volcanology and Geothermal Research, 392, Article 106756. https://doi.org/10.1016/j.jvolgeores.2019.106756
• McDonald, F., Horwell, C., Wecker, R., Dominelli, L., Loh, M., Kamanyire, R., & Ugarte, C. (2020). Facemask use for community protection from air pollution disasters: An ethical overview and framework to guide agency decision making. International Journal of Disaster Risk Reduction, 43, Article 101376. https://doi.org/10.1016/j.ijdrr.2019.101376
• Tomašek, I., Damby, D., Horwell, C., Ayris, P., Delmelle, P., Ottley, C., Cubillas, P., Casas, A., Bisig, C., Petri-Fink, A., Dingwell, D., Clift, M., Drasler, B., & Rothen-Rutishauser, B. (2019). Assessment of the potential for in-plume sulphur dioxide gas-ash interactions to influence the respiratory toxicity of volcanic ash. Environmental Research, 179(Part A), Article 108798. https://doi.org/10.1016/j.envres.2019.108798
• Horwell, C., Ferdiwijaya, D., Wahyudi, T., & Dominelli, L. (2019). Use of respiratory protection in Yogyakarta during the 2014 eruption of Kelud, Indonesia: Community and agency perspectives. Journal of Volcanology and Geothermal Research, 382, 92-102. https://doi.org/10.1016/j.jvolgeores.2017.06.004
• Covey, J., Horwell, C., Rachmawati, L., Ogawa, R., Martin-del Pozzo, A., Armienta, M., Nugroho, F., & Dominelli, L. (2019). Factors motivating the use of respiratory protection against volcanic ashfall : a comparative analysis of communities in Japan, Indonesia and Mexico. International Journal of Disaster Risk Reduction, 35, Article 101066. https://doi.org/10.1016/j.ijdrr.2019.101066
• Pavan, C., Delle Piane, M., Gullo, M., Filippi, F., Fubini, B., Hoet, P., Horwell, C., Huaux, F., Lison, D., Lo Giudice, C., Martra, G., Montfort, E., Schins, R., Sulpizi, M., Wegner, K., Wyart-Remy, M., Ziemann, C., & Turci, F. (2019). The puzzling issue of silica toxicity: are silanols bridging the gaps between surface states and pathogenicity?. Particle and Fibre Toxicology, 16(1), Article 32. https://doi.org/10.1186/s12989-019-0315-3
• Galea, K., Covey, J., Mutia Timur, S., Horwell, C., Nugroho, F., & Mueller, W. (2018). Health Interventions in Volcanic Eruptions—Community Wearability Assessment of Respiratory Protection against Volcanic Ash from Mt Sinabung, Indonesia. International Journal of Environmental Research and Public Health, 15(11), Article 2359. https://doi.org/10.3390/ijerph15112359
• Tomašek, I., Horwell, C., Bisig, C., Damby, D., Comte, P., Czerwinskid, J., Petri-Fink, A., Clift, M., Drasler, B., & Rothen-Rutishauser, B. (2018). Respiratory hazard assessment of combined exposure to complete gasoline exhaust and respirable volcanic ash in a multicellular human lung model at the air-liquid interface. Environmental Pollution, 238, 977-987. https://doi.org/10.1016/j.envpol.2018.01.115
• Steinle, S., Sleeuwenhoek, A., Mueller, W., Horwell, C., Apsley, A., Davis, A., Cherrie, J., & Galea, K. (2018). The effectiveness of respiratory protection worn by communities to protect from volcanic ash inhalation; Part II: Total inward leakage tests. International Journal of Hygiene and Environmental Health, 221(6), 977-984. https://doi.org/10.1016/j.ijheh.2018.03.011
• Mueller, W., Horwell, C., Apsley, A., Steinle, S., McPherson, S., Cherrie, J., & Galea, K. (2018). The effectiveness of respiratory protection worn by communities to protect from volcanic ash inhalation. Part I: Filtration efficiency tests. International Journal of Hygiene and Environmental Health, 221(6), 967-976. https://doi.org/10.1016/j.ijheh.2018.03.012
• Cherrie, J., Apsley, A., Cowie, H., Steinle, S., Mueller, W., Lin, C., Horwell, C., Sleeuwenhoek, A., & Loh, M. (2018). Effectiveness of face masks used to protect Beijing residents against particulate air pollution. Occupational and Environmental Medicine, 75(6), 446-452. https://doi.org/10.1136/oemed-2017-104765
• Damby, D., Horwell, C., Baxter, P., Kueppers, U., Schnurr, M., Dingwell, D., & Duewell, P. (2018). Volcanic Ash Activates the NLRP3 Inflammasome in Murine and Human Macrophages. Frontiers in Immunology, 8, Article 2000. https://doi.org/10.3389/fimmu.2017.02000
• Nattrass, C., Horwell, C., Damby, D., Brown, D., & Stone, V. (2017). The effect of aluminium and sodium impurities on the in vitro toxicity and pro-inflammatory potential of cristobalite. Environmental Research, 159, 164-175. https://doi.org/10.1016/j.envres.2017.07.054
• Damby, D., Horwell, C., Larsen, G., Thordarson, T., Tomatis, M., Fubini, B., & Donaldson, K. (2017). Assessment of the potential respiratory hazard of volcanic ash from future Icelandic eruptions: a study of archived basaltic to rhyolitic ash samples. Environmental Health, 16, Article 98. https://doi.org/10.1186/s12940-017-0302-9
• Horwell, C., Sargent, P., Andronico, D., Lo Castro, M., Tomatis, M., Hillman, S., Michnowicz, S., & Fubini, B. (2017). The iron-catalysed surface reactivity and health-pertinent physical characteristics of explosive volcanic ash from Mt. Etna, Italy. Journal of Applied Volcanology, 6(1), Article 12. https://doi.org/10.1186/s13617-017-0063-8
• Le Blond, J., Woskie, S., Horwell, C., & Williamson, B. (2017). Particulate matter produced during commercial sugarcane harvesting and processing: a respiratory health hazard?. Atmospheric Environment, 149, 34-46. https://doi.org/10.1016/j.atmosenv.2016.11.012
• Tomašek, I., Horwell, C., Damby, D., Barošová, H., Geers, C., Petri-Fink, A., Rothen-Rutishauser, B., & Clift, M. (2016). Combined exposure of diesel exhaust particles and respirable Soufrière Hills volcanic ash causes a (pro-)inflammatory response in an in vitro multicellular epithelial tissue barrier model. Particle and Fibre Toxicology, 13(1), Article 67. https://doi.org/10.1186/s12989-016-0178-9
• Damby, D., Murphy, F., Horwell, C., Raftis, J., & Donaldson, K. (2016). The in vitro respiratory toxicity of cristobalite-bearing volcanic ash. Environmental Research, 145, 74-84. https://doi.org/10.1016/j.envres.2015.11.020
• Nattrass, C., Horwell, C., Damby, D., Kermanizadeh, A., Brown, D., & Stone, V. (2015). The global variability of diatomaceous earth toxicity: a physicochemical and in vitro investigation. Journal of occupational medicine and toxicology (London. Online), 10, Article 23. https://doi.org/10.1186/s12995-015-0064-7
• Horwell, C., Damby, D., & Hillier, S. (2015). Respirable volcanic ash is distinct mineralogically, physicochemically and toxicologically from soils originating from weathered volcanic products. A comment on Cervini-Silva et al. (2014) “Lipid peroxidation and cytotoxicity induced by respirable volcanic ash”. Journal of Hazardous Materials, 285, 366-367. https://doi.org/10.1016/j.jhazmat.2014.10.059
• Damby, D., Llewellin, E., Horwell, C., Williamson, B., Najorka, J., Cressey, G., & Carpenter, M. (2014). The α-β phase transition in volcanic cristobalite. Journal of Applied Crystallography, 47(4), 1205-1215. https://doi.org/10.1107/s160057671401070x
• Horwell, C., Hillman, S., Cole, P., Loughlin, S., Llewellin, E., Damby, D., & Christopher, T. (2014). Controls on variations in cristobalite abundance in ash generated by the Soufrière Hills volcano, Montserrat in the period 1997-2010. Memoirs, 39, 399-406. https://doi.org/10.1144/m39.21
• Baxter, P., Searl, A., Cowie, H., Jarvis, D., & Horwell, C. (2014). Evaluating the respiratory health risks of volcanic ash at the eruption of the Soufrière Hills Volcano, Montserrat, 1995-2010. Memoirs, 39(22), https://doi.org/10.1144/m39.22
• Horwell, C., Baxter, P., Hillman, S., Calkins, J., Damby, D., Delmelle, P., Donaldson, K., Dunster, C., Fubini, B., Hoskuldsson, A., Kelly, F., Larsen, G., Le Blond, J., Livi, K., Mendis, B., Murphy, F., Nattrass, C., Sweeney, S., Tetley, T., Thordarson, T., & Tomatis, M. (2013). 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. Environmental Research, 127, 63-73. https://doi.org/10.1016/j.envres.2013.08.011
• Stevenson, J., Loughlin, S., Font, A., Fuller, G., MacLeod, A., Oliver, I., Jackson, B., Horwell, C., Thordarson, T., & Dawson, I. (2013). UK monitoring and deposition of tephra from the May 2011 eruption of Grímsvötn, Iceland. Journal of Applied Volcanology, 2(1), Article 3. https://doi.org/10.1186/2191-5040-2-3
• Horwell, C., Williamson, B., Llewellin, E., Damby, D., & Le Blond, J. (2013). The nature and formation of cristobalite at the Soufrière Hills volcano, Montserrat: implications for the petrology and stability of silicic lava domes. Bulletin of Volcanology, 75, Article 696. https://doi.org/10.1007/s00445-013-0696-3
• Damby, D., Horwell, C., Baxter, P., Delmelle, P., Donaldson, K., Dunster, C., Fubini, B., Murphy, F., Nattrass, C., Sweeney, S., Tetley, T., & Tomatis, M. (2013). The respiratory health hazard of tephra from the 2010 Centennial eruption of Merapi with implications for occupational mining of deposits. Journal of Volcanology and Geothermal Research, 261, 376-387. https://doi.org/10.1016/j.jvolgeores.2012.09.001
• Horwell, C., Williamson, B., Donaldson, K., Le Blond, J., Damby, D., & 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, Article 44. https://doi.org/10.1186/1743-8977-9-44
• Le Blond, J., Tomatis, M., Horwell, C., Dunster, C., Murphy, F., Corazzari, I., Grendene, F., Turci, F., Gazzano, E., Ghigo, D., Williamson, B., Oppenheimer, C., & Fubini, B. (2012). The surface reactivity and implied toxicity of ash produced from sugarcane burning. Environmental Toxicology, 29(5), 503-516. https://doi.org/10.1002/tox.21776
• Hillman, S., Horwell, C., Densmore, A., Damby, D., 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(4), 913-930. https://doi.org/10.1007/s00445-012-0575-3
• Le Blond, J., Horwell, C., Baxter, P., Michnowicz, S., 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. https://doi.org/10.1007/s00445-010-0382-7
• Durant, A., Bonadonna, C., & Horwell, C. (2010). Atmospheric and environmental impacts of volcanic particulates. Elements, 6(4), 235-240. https://doi.org/10.2113/gselements.6.4.235
• Williamson, B., Di Muro, A., Horwell, C., Spieler, O., & Llewellin, E. (2010). Injection of vesicular magma into an andesitic dome at the effusive–explosive transition. Earth and Planetary Science Letters, 295(1-2), 83-90. https://doi.org/10.1016/j.epsl.2010.03.027
• Le Blond, J., Horwell, C., Williamson, B., & Oppenheimer, C. (2010). Generation of crystalline silica from sugarcane burning. Journal of environmental monitoring, 12(7), 1459-1470. https://doi.org/10.1039/c0em00020e
• Horwell, C., Stannett, G., Andronico, D., Bertagnini, A., Fenoglio, I., Fubini, B., Le Blond, J., & Williamson, B. (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. https://doi.org/10.1016/j.jvolgeores.2010.01.014
• Horwell, C., Le Blond, J., Michnowicz, S., & Cressey, G. (2010). Cristobalite in a rhyolitic lava dome: Evolution of ash hazard. Bulletin of Volcanology, 72(2), 249-253. https://doi.org/10.1007/s00445-009-0327-1
• Martin, R., Mather, T., Pyle, D., Power, M., Tsanev, V., Oppenheimer, C., Allen, A., Horwell, C., & Ward, E. (2009). Size distributions of fine silicate and other particles in Masaya's volcanic plume. Journal of Geophysical Research, 114, https://doi.org/10.1029/2008jd011211
• Le Blond, J., Cressey, G., Horwell, C., & Williamson, B. (2009). A rapid method for quantifying single mineral phases in heterogeneous natural dusts using X-ray diffraction. Powder Diffraction, 24, 17-23. https://doi.org/10.1154/1.3120742
• Martin, R., Mather, T., Pyle, D., Power, M., Allen, A., Aiuppa, A., Horwell, C., & Ward, E. (2008). Composition-resolved size distributions of volcanic aerosols in the Mt. Etna plumes. Journal of Geophysical Research, 113, https://doi.org/10.1029/2007jd009648
• Le Blond, J., Williamson, B., Horwell, C., Monro, A., Kirk, C., & Oppenheimer, C. (2008). Production of potentially hazardous respirable silica airborne particulate from the burning of sugarcane. Atmospheric Environment, 42(22), 5558-5568. https://doi.org/10.1016/j.atmosenv.2008.03.018
• Horwell, C., Fenoglio, I., & Fubini, B. (2007). Iron-induced hydroxyl radical generation from basaltic volcanic ash. Earth and Planetary Science Letters, 261(3-4), 662-669. https://doi.org/10.1016/j.epsl.2007.07.032
• Horwell, C. (2007). Grain-size analysis of volcanic ash for the rapid assessment of respiratory health hazard. Journal of environmental monitoring, 9, 1107-1115. https://doi.org/10.1039/b710583p
• Stewart, C., Johnston, D., Leonard, G., Horwell, C., 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(3-4), 296-306. https://doi.org/10.1016/j.jvolgeores.2006.07.002
• Horwell, C., & Baxter, P. (2006). The respiratory health hazards of volcanic ash: a review for volcanic risk mitigation. Bulletin of Volcanology, 69(1), 1-24. https://doi.org/10.1007/s00445-006-0052-y
• Hansell, A., Horwell, C., & Oppenheimer, C. (2006). The health hazards of volcanoes and geothermal areas. Occupational and Environmental Medicine, 63(2), 149-156. https://doi.org/10.1136/oem.2005.022459
• Witham, C., Oppenheimer, C., & Horwell, C. (2005). Volcanic ash-leachates: a review and recommendations for sampling methods. Journal of Volcanology and Geothermal Research, 141(3-4), 299-326. https://doi.org/10.1016/j.jvolgeores.2004.11.010
• Horwell, C., Patterson, J., Gamble, J., & Allen, A. (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. https://doi.org/10.1016/j.jvolgeores.2004.08.010
• Horwell, C., Allen, A., Mather, T., & Patterson, J. (2004). Evaluation of a novel passive sampling technique for monitoring volcanogenic hydrogen sulphide. Journal of environmental monitoring, 6(7), 630-635. https://doi.org/10.1039/b400746h
• Horwell, C., Fenoglio, I., Ragnarsdottir, K., Sparks, R., & 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. https://doi.org/10.1016/s0013-9351%2803%2900044-6
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