Social research

• Meach, R., de Terte, I., Horwell, C. J., (2025), ‘All Four Engines Have Failed’: A qualitative study of the health impacts, reactions and behaviours of passengers and crew onboard flight BA009 which flew through a volcanic ash cloud in 1982, International Journal of Disaster Risk Reduction, 124, 105558, 10.1016/j.ijdrr.2025.105558
• Horwell, C. J., 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, 103853, 10.1016/j.ijdrr.2023.103853
• McDonald, F., Horwell, C. J., (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, 10.1017/dmp.2020.37
• Covey, J., Dominelli, L., Horwell, C. J., Rachmawati, L., Martin-Del Pozzo, A. L., Armienta, M. A., 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, 102194, 10.1016/j.ijdrr.2021.102194
• Schwartz-Marin, E., Merli, C., Rachmawati, L., Horwell, C. J., Nugroho, F., (2020), Merapi multiple: Protection around Yogyakarta’s celebrity volcano through masks, dreams, and seismographs, History and Anthropology, 1-23, 10.1080/02757206.2020.1799788
• Covey, J., Horwell, C. J., 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, 101525, 10.1016/j.ijdrr.2020.101525
• Covey, J., Horwell, C. J., Rachmawati, L., Ogawa, R., Martin-Del Pozzo, A. L., Armienta, M. A., 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, 101066, 10.1016/j.ijdrr.2019.101066
• McDonald, F., Horwell, C. J., Wecker, R., Dominelli, L., Loh, M., Kamanyire, R., Ugarte, C., (2019), 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, 101376, 10.1016/j.ijdrr.2019.101376

Physicochemical or geochemical

• Horwell, C. J., Emerson, H. M., Ashwell, P., Damby, D. E., Self, S., Nattrass, C., Carey, R., Houghton, B., (2025), The crystalline silica respiratory hazard from rhyolitic lava dome eruptions in New Zealand's Taupo Volcanic Zone: A case study from the 1315 CE Kaharoa eruption, Journal of Volcanology and Geothermal Research, 461, 108309, 10.1016/j.jvolgeores.2025.108309
• Horwell, C. J., Sargent, P., Andronico, D., Lo Castro, M. D., Tomatis, M., Hillman, S. E., Michnowicz, S. A. K., 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): 12, 10.1186/s13617-017-0063-8
• Damby, D. E., Llewellin, E. W., Horwell, C. J., Williamson, B. J., Najorka, J., Cressey, G., Carpenter, M. A., (2014), The α-β phase transition in volcanic cristobalite, Journal of Applied Crystallography, 47, 1205-1215, 10.1107/S160057671401070X
• Horwell, C. J., Hillman, S. E., Cole, P. D., Loughlin, S. C., Llewellin, E. W., Damby, D. E., Christopher, T., (2014), Controls on variations in cristobalite abundance in ash generated by the Soufrière Hills volcano, Montserrat in the period 1997-2010, The Eruption of Soufriere Hills Volcano, Montserrat from 2000 to 2010, Memoir of the Geological Society of London , Geological Society of London, Chapter 21. 39: 399-406, 10.1144/M39.21, Wadge, G. , Robertson, R., Voight, B.
• Horwell, C. J., Stannett, G. W., Andronico, D., Bertagnini, A., Fenoglio, I., Fubini, B., Le Blond, J. S., Williamson, B. J., (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, 10.1016/j.jvolgeores.2010.01.014
• Martin, R. S., Mather, T. A., Pyle, D. M., Power, M., Allen, A. G., Aiuppa, A., Horwell, C. J., Ward, E. P. W., (2008), Chemical and morphological characterisation of volcanic aerosols and nanoparticles from Mt Etna, Journal of Geophysical Research – Atmospheres, 113, D17, Art. No. D17211, 10.1029/2007JD009648
• 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, 10.1016/j.epsl.2007.07.032
• 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, Montserrat, with implications for health hazards, Environmental Research, 93(2), 202-215, 10.1016/S0013-9351(03)00044-6
• 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 the Soufrière Hills volcano, Montserrat, Journal of Volcanology and Geothermal Research, 109(4), 247-262, 10.1016/S0377-0273(00)00319-X

Reviews/ Overviews

• Horwell, C. J., Ravenhall, S., Clarkson, R., Edmonds, M., Rubin, G. J., Witham, C., Howell, R., (2025), Physical, psychological and behavioural responses of aircraft occupants to volcanic emissions, Journal of Applied Volcanology, 14, 5, 10.1186/s13617-025-00153-4
• 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 Sciences, 11, 1213363, 10.3389/feart.2023.1213363
• Stewart, C., Damby, D. E., Horwell, C. J., Elias, T., Ilyinskaya, E., Tomašek, I., Longo, B. M., Schmidt, A., Carlsen, H. K., Mason, E., Baxter, P. J., Cronin, S. J., Witham, C. S., (2022), Volcanic air pollution and human health: recent advances and future directions, Bulletin of Volcanology, 84, 11, 10.1007/s00445-021-01513-9
• Samarasundera, E., Hansell, A., Leibovici, D., Horwell, C. J., Anand, S., Oppenheimer, C., (2014), Geological hazards: from early warning systems to public health toolkits, Health and Place, 30, 116-119, 10.1016/j.healthplace.2014.09.001
• Weinstein, P., Horwell, C. J., Cook, A., (2013), Volcanic emissions and health, Essentials of Medical Geology, Springer Netherlands, 217-238, 10.1007/978-94-007-4375-5_10
• Hansell, A., Horwell, C. J., Oppenheimer, C., (2006), The health hazards of volcanoes and geothermal areas, Occupational Environmental Medicine, 63(2), 149-156, 10.1136/oem.2005.022459
• 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, 10.1007/s00445-006-0052-y

Physicochemical or geochemical

• 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, The 2020–21 Eruption of La Soufrière Volcano, St Vincent, Geological Society, London, Special Publications, Geological Society of London, 539, 311-329, 10.1144/SP539-2023-46, R.E.A. Robertson, E.P. Joseph, J. Barclay, R.S.J. Sparks
• Horwell, C. J., Le Blond, J. S., Michnowicz, S. A. K., Cressey, G., (2010), Cristobalite in a rhyolitic lava dome: Evolution of ash hazard, Bulletin of Volcanology, 72, 249–253, 10.1007/s00445-009-0327-1
• Le Blond, J. S., Cressey, G., Horwell, C. J., Williamson, B. J., (2009), A rapid method for quantifying single mineral phases in heterogeneous natural dust using X-ray diffraction, Powder Diffraction, 24(1), 17- 23, 10.1154/1.3077941
• Horwell, C. J., (2007), Grain size analysis of volcanic ash for the rapid assessment of respiratory health hazard, Journal of Environmental Monitoring, 9(10), 1107 - 1115, 10.1039/B710583P
• Horwell, C. J., Sparks, R. S. J., Brewer, T. S., Llewellin, E. W., Williamson, B. J., (2003), The characterisation of respirable volcanic ash from the Soufriere Hills Volcano, Montserrat, with implications for health hazard, Bulletin of Volcanology, 65, 346-362, 10.1007/s00445-002-0266-6

Leaching

• Tomašek, I., Damby, D. E., Stewart, C., Horwell, C. J., Plumlee, G. S., Ottley, C. J., Delmelle, P., Morman, S., Yazidia, S. E., 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, 130303, 10.1016/j.chemosphere.2021.130303
• Stewart, C., Damby, D. E., Tomašek, I., Horwell, C. J., (2021), Experimental design and data relevance in a volcanic ash-leachate health study: Letter to the Editor re. Barone et al. (2021) ‘Surface reactivity of Etna volcanic ash and evaluation of health risks’ (STOTEN-143248), Science of the Total Environment, 804, 150076, 10.1016/j.scitotenv.2021.150076

Physicochemical or geochemical, Toxicological

• Tomašek, I., Damby, D. E., Andronico, D., Baxter, P. J., Boonen, I., Claeys, P., Denison, M. S., Horwell, C. J., Kervyn, M., Kueppers, U., Romanias, M. N., Elskens, M., (2021), Assessing the biological reactivity of organic compounds on volcanic ash: implications for human health hazard, Bulletin of Volcanology, 83(5), 1-11, 10.1007/s00445-021-01453-4
• Tomašek, I., Horwell, C. J., Damby, D. E., Barošová, H., Geers, C., Petri-Fink, A., Rothen-Rutishauser, B., Clift, M. J. D., (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, 67, 10.1186/s12989-016-0178-9
• Le Blond, J. S., Horwell, C. J., Baxter, P. J., Michnowicz, S. A. K., 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, 1077-1092, 10.1007/s00445-010-0382-7

Epidemiological, clinical & surveillance

• Mueller, W., Cowie, H. A., Horwell, C. J., Baxter, P. J., McElvenny, D., Booth, M., Cullinan, P., Jarvis, D., Ugarte, C., Inoue, H., (2020), Standardised epidemiological protocols for populations affected by volcanic eruptions, Bulletin of the World Health Organisation, 98(5), 362–364, 10.2471/BLT.19.244509

Epidemiological, clinical & surveillance, Modelling

• Mueller, W., Cowie, H. A., Horwell, C. J., Hurley, F., Baxter, P. J., (2020), Health Impact Assessment of volcanic ash inhalation: A comparison with outdoor air pollution methods, GeoHealth, 4(7), e2020GH000256, 10.1029/2020GH000256

Leaching

• Stewart, C., Damby, D. E., Tomašek, I., Horwell, C. J., Plumlee, G. S., Armienta, M. A., Hinojosa, M. G. R., Appleby, M., Delmelle, P., Cronin, S., Ottley, C. J., 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, 106756, 10.1016/j.jvolgeores.2019.106756

Leaching, Physicochemical or geochemical, Toxicological

• Tomašek, I., Damby, D. E., Horwell, C. J., Ayris, P. M., Delmelle, P., Ottley, C. J., Cubillas, P., Casas, A. S., Bisig, C., Petri-Fink, A., (2019), Assessment of the potential for in-plume sulphur dioxide gas-ash interactions to influence the respiratory toxicity of volcanic ash, Environmental Research, 179, 108873, 10.1016/j.envres.2019.108798
• Damby, D. E., Horwell, C. J., Baxter, P. J., Delmelle, P., Donaldson, K., Dunster, C., Fubini, B., Murphy, F. A., Nattrass, C., Sweeney, S., Tetley, T. D., 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, 10.1016/j.jvolgeores.2012.09.001
• Horwell, C. J., Baxter, P. J., Hillman, S. E., Calkins, J. A., Damby, D. E., Delmelle, P., Donaldson, K., Dunster, C., Kelly, F. J., Le Blond, J. S., Livi, K. J., Murphy, F. A., Nattrass, C., Sweeney, S., Tetley, T. D., 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, 10.1016/j.envewa.2013.08.011
• Le Blond, J. S., Horwell, C. J., Baxter, P. J., Michnowicz, S. A. K., 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, 1077-1092, 10.1007/s00445-010-0382-7

Social research

• Horwell, C. J., 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, 10.1016/j.jvolgeores.2017.06.004

PPE testing

• Mueller, W., Horwell, C. J., Apsley, A., Steinle, S., McPherson, S., Cherrie, J. W., Galea, K. S., (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, 10.1016/j.ijheh.2018.03.012
• Steinle, S., Sleeuwenhoek, A., Mueller, W., Horwell, C. J., Apsley, A., Davis, A., Cherrie, J. W., Galea, K. S., (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, 10.1016/j.ijheh.2018.03.011

Toxicological

• Damby, D. E., Horwell, C. J., Baxter, P. J., Kueppers, U., Schnurr, M., Dingwell, D. B., Duewell, P., (2018), Volcanic Ash Activates the NLRP3 Inflammasome in Murine and Human Macrophages, Frontiers in Immunology, 8: 2000, 10.3389/fimmu.2017.02000
• Tomašek, I., Horwell, C. J., Bisig, C., Damby, D. E., Comte, P., Czerwinskid, J., Petri-Fink, A., Clift, M. J. D., 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, 10.1016/j.envpol.2018.01.115
• Damby, D. E., Horwell, C. J., 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: 98, 10.1186/s12940-017-0302-9, Also Physicochemical sub-category - can we have two?
• Nattrass, C., Horwell, C. J., Damby, D. E., Brown, D., Stone, V., (2017), The effect of aluminium and sodium impurities on the cytotoxicity and pro-inflammatory potential of cristobalite, Environmental Research, 159: 164-175, 10.1016/j.envres.2017.07.054
• Horwell, C. J., Damby, D. E., 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 volcani, Journal of Hazardous Materials, 285: 366-367, 10.1016/j.jhazmat.2014.10.059

PPE testing, Social research

• Galea, K. S., Covey, J., Mutia Timur, S., Horwell, C. J., 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), 2359, 10.3390/ijerph15112359

Toxicological

• Damby, D. E., Murphy, F. A., Horwell, C. J., Raftis, J., Donaldson, K., (2016), The in vitro respiratory toxicity of cristobalite-bearing volcanic ash, Environmental Research, 145: 74-84, 10.1016/j.envres.2015.11.020

Epidemiological, clinical & surveillance, Physicochemical or geochemical

• 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, The Eruption of Soufriere Hills Volcano, Montserrat from 2000 to 2010, Memoir of the Geological Society of London , Geological Society of London, Chapter 22; 39: 407-425, 10.1144/M39.22, Wadge, G. , Robertson, R., Voight, B.

Physicochemical or geochemical, Toxicological

• Hillman, S. E., Horwell, C. J., Densmore, A., 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, 10.1007/s00445-012-0575-3

Personal, ambient & remote monitoring/sensing, Physicochemical or geochemical

• 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), 1-13, 10.1029/2008JD011211

Modelling, Reviews/ Overviews

• Stewart, C., Johnston, D. M., Leonard, G. S., Horwell, C. J., Thordarson, T., Cronin, S. J., (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, 10.1016/j.jvolgeores.2006.07.002

Leaching, Physicochemical or geochemical, Reviews/ Overviews

• Witham, C. S., Oppenheimer, C., Horwell, C. J., (2005), Volcanic ash leachates: a review and recommendations for sampling methods, Journal of Volcanology and Geothermal Research, 141, 299- 326, 10.1016/j.jvolgeores.2004.11.010

Personal, ambient & remote monitoring/sensing

• 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(3-4), 259-269, 10.1016/j.jvolgeores.2004.08.010
• Horwell, C. J., Allen, A. G., Mather, T. A., Patterson, J. E., (2004), Evaluation of a simple passive sampling technique for monitoring volcanogenic hydrogen sulphide, Journal of Environmental Monitoring, 6, 630-635, 10.1039/b400746h