The Clinical Respiratory Journal REVIEW ARTICLE Respiratory health effects of volcanic ash with special reference to Iceland. A reviewcrj_231 2..9 Gunnar Gudmundsson1,2 1 Landspitali University Hospital, Reykjavik, Iceland 2 Faculty of Medicine, University of Iceland, Reykjavik, Iceland Abstract Key words Background and Aims: Volcano eruptions occur around the world and can have an health – respiratory – review – volcanic ash – impact on health in many ways both locally and on a global scale as a result of volcanic gases airborne dispersion of gases and ash or as impact on climate. In this review, a recent Correspondence volcanic eruption in Eyjafjallajökull in Iceland is described and its effects on avia- Gunnar Gudmundsson, MD, PhD, Department tion around the globe and on respiratory health in those exposed to the volcanic of Respiratory Medicine, Allergy and Sleep, ash in Iceland. Also, the effects of a large volcano eruption in Iceland in 1789 are Landspitali-University Hospital, E-7 Fossvogur, described that also had effect on a global scale by causing air pollution. IS-108 Methods and Results: The available studies reviewed here suggest that the acute Reykjavik, Iceland. and chronic health effects of volcanic ash depend on particle size (how much Tel: +354-5436876 Fax: +354-5436568 respirable), mineralogical composition (crystalline silica content) and the physico- email: [email protected] chemical properties of the surfaces of ash particles. These can vary between volca- noes and even between eruptions, making comparison difficult. Acute respiratory Received: 05 October 2010 symptoms suggesting asthma and bronchitis have been well described. Exacerba- Revision requested: 17 October 2010 tions of pre-existing lung and heart disease are common after inhalation of volcanic Accepted: 20 October 2010 ash. Limited information is available on increase in mortality from recent eruptions but historical evidence is well described. No long-term effects on lung function have DOI:10.1111/j.1752-699X.2010.00231.x been found after exposure to volcanic ash.There are concerns for the long-term risks Authorship of silicosis from chronic exposure to volcanic ash but no cases have been described. Gunnar Gudmundsson wrote and revised the Conclusion: Acute respiratory symptoms after exposure to volcanic ash are well paper. described but no long-term effects have been found. Conflicts of interest Please cite this paper as: Gudmundsson G. Respiratory health effects of volcanic ash The authors have stated explicitly that there with special reference to Iceland. A review. Clin Respir J 2011; 5: 2–9. are no conflicts of interest in connection with this article. Introduction 3–5). This was shown in a recent volcano eruption in Iceland where air traffic was put to halt for several days Volcanic eruptions are different from other kinds of in large areas of Europe causing major economical natural disaster in that they can result in a wide range impact. The same was also true in 1783 when a volca- of health impacts (1). It has been estimated that over nic eruption in Iceland had major effects on climate 500 million people worldwide live within a potential in Europe and in other areas of the world (1, 3, 4). exposure range (100 km) of a volcano that has been Although eruptions are most often short-lived, ashfall active within recorded history (2). Many volcanic deposits remain in the environment for years up to regions are densely populated and several are close to decades, being redistributed by wind or by human major cities. Volcanic eruption is also unique in that it activity (1, 3, 6). can also affect areas hundreds or thousands of kilome- This review focuses on the respiratory effects of ash tres away from the volcano itself, as a result of airborne particles, so other health hazards will not be considered distribution of ash, or even on a hemispheric to global here. Special attention will be given to a recent volcano scale because of impacts on climate and aviation (1, eruption in Eyjafjallajökull in southern Iceland and 2 The Clinical Respiratory Journal (2011) • ISSN 1752-6981 © 2010 Blackwell Publishing Ltd Gudmundsson Respiratory health effects of volcanic ash previous volcano eruption in Iceland that had effects on global health. Geology of volcanoes Volcanic activity can be broadly defined as either effusive (predominantly quiet emission of lavas, e.g. eruption of Kilavez, Hawaii) or explosive (e.g. the eruption of Eyjafjallajökull, Iceland in 2010). Explosive eruptions are basically of two categories, magmatic eruptions where the explosive fragmentation is prima- rily caused by the expansion of magmatic gases and phreatomagmatic eruptions where fragmentation results from magma–water interaction (7). Volcanoes Figure. 1. The volcanic eruption at Fimmvorduhals from March are most commonly associated with tectonic plate to April, 2010. This was a popular attraction for tourists. Photo margins. Most volcano eruptions in history have by Arni Tryggvason. occurred on continental margins or island arcs where the edge of one tectonic plate drops beneath another during an eruption (1, 3, 6–8). The location of a (7). Most of these volcanoes are tall cones with summit volcano relative to inhabited areas is also important craters and tend to erupt infrequently but violently. with respect to potential hazards from tephra fallout. Examples from the so-called ‘Ring of Fire’, i.e. around It is more likely that inhabited areas that are close to the Pacific Ocean include Pinatubo (Philippines). the volcano will be more affected. This could be from Mt St Helens (United States) and Mt Fuji (Japan). social factors such as disruption of daily life activities European volcanoes include Vesuvius in Italy, whose and also from health effects because of likelihood of catastrophic eruption in AD 79 destroyed Pompeii and more exposure to volcanic ash. Freshly erupted ash Santorini in Greece (7). Volcanoes are also found differs from other natural dusts in several ways. The where tectonic plates are separating, e.g. those in particle surfaces are unweathered and are therefore not the African Rift Valley (3, 7). Some volcanoes are not oxidised and can carry condensed volatiles such as related to tectonic plates and instead to deeper seated acids, polycyclic hydrocarbons and trace metals (1). convective processes occurring within the Earth’s Those compounds adhering to the surface of tephra mantle. They can be found in both oceanic and conti- particles can cause pollution of water supplies and nental regions. Examples are the volcanoes of Hawaii grazing lands in areas remote to the erupting volcanoes Islands and Yellowstone (United States) (1, 3, 4, 7). (1, 3). Drinking water may become contaminated by Iceland is on the tectonic plate margin. There volcanic fluorine, but fluorine poisoning in humans is thought eruptions occur every 3–4 years, with more than to be rare (3). However, grazing animals can ingest half occurring beneath glaciers. (Fig. 1) In Iceland, toxic quantities of fluorine. Heavy falls of tephra by far, the greatest majority of explosive events are can damage vegetation, including agricultural crops. phreatomagmatic explosive eruptions. These often Tephra by itself can present many types of health occur in volcanic systems that are partly covered by ice hazard (1, 3). Health hazards are most commonly caps such as the Grímsvötn and Katla volcanoes (7, 8). through inhalation and abrasion of skin and mucus membranes such as conjunctiva, but also from loading on roofs causing buildings to collapse and through Tephra and ash falls impacts on environments (1, 3, 6). Tephra is a general term for any fragmentary material emitted from volcanoes, while ash refers to tephra par- Volcanic gases ticles that are less than 2 mm across. (1, 3, 4, 7). The factors influencing tephra distribution can be divided Volatiles that can be emitted during volcano eruptions into those governed by (i) the type, intensity and mag- include CO and CO2, SO2, HCl, HF,H2S and radon (3, nitude of the eruption, including height of the erup- 4, 6). Exposure to acidic gases without wearing respi- tion column; (ii) the duration of the eruption; and ratory protection, especially if repeated frequently, may (iii) those governed by external factors such as wind lead to irritant-induced asthma including reactive strength, wind direction and changes in wind direction airways dysfunction syndrome (3, 4). The Clinical Respiratory Journal (2011) • ISSN 1752-6981 3 © 2010 Blackwell Publishing Ltd Respiratory health effects of volcanic ash Gudmundsson Recent volcano activity in Iceland During the 11 centuries of settlement in Iceland, vol- canic activity has repeatedly affected the population (8). Most part of Iceland is sparsely populated with no permanent settlements in the interior highlands. Popu- lation clusters mainly occur along the coast, with about 70% of the 300 000 inhabitants living in the greater Reykjavík area and along the shore in southwest Iceland (8). The Reykjavík metropolitan area is located just outside the margins of the active volcanic zone (8). Eyjafjallajökull is a glacier on the southern shore of Iceland about 150 km from Reykjavik that rises to 1666 m above sea level. There is agricultural land on its southern slopes, with farms located as close as 7 km Figure. 3. Seljavellir, the cultivated fields that had the most volcanic ashfall during the Eyjafjallajökull eruption in 2010. from the summit. An explosive eruption started on 14 Photo by Gunnar Gudmundsson on 31 May 2010. April 2010 and was located within the ice-capped summit of the volcano (Fig. 2) (9–11). Erupting from beneath the ice cap, ash was formed by the contact of magma (at over 1000°C temperature) with water and ice. It was the interaction between the magma and water that gave rise to the explosivity generating large volumes of finely comminuted ash. The eruption plume reached heights of almost 10 km on the first day of the eruption (9).Three days of sustained tephra pro- duction followed, leading to ash dispersal towards the southeast (Fig.