Respiratory Health Effects of Volcanic Ash with Special Reference To

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 volcanoes 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).

Recent volcano activity in Iceland During the 11 centuries of settlement in Iceland, volcanic 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. 3). Many farms are located in that area and several hundred people were exposed to the ash (10–13) (Fig. 4). The volcano eruption halted by the end of May, 2010. Since then, on windy days, this ash is resubmitted into the air; as a result, particulate matter concentration levels have been unusually high in southern and south-western part of Iceland, including Reykjavik (12). This has occurred on several occasions, Figure. 4. Satellite view of Iceland on 17 April 2010 showing the volcanic ash plume heading towards Europe. Photo by NASA Goddard Photo and Video.

causing alert to be given to people with respiratory illnesses. The volcano ash from Eyjafjallajökull when fresh was found to have up to 25% respirable particles (i.e. less than 10 microns; Fig. 5). The main constitu- ents were 60% SiO2 (silicon dioxide), 16% AlO3 (alu- minium oxide) and 10% FeO (iron oxide). Crystalline silica content was negligible (12).

Aviation hazards and effects of Eyjafjallajökull eruption on global aviation Ash clouds can pose a risk to aviation through abra- Figure. 2. The volcanic eruption in Eyjafjallajökull in April sion, e.g. of cockpit windows and damage to jet engines 2010. Photo by Arni Tryggvason. (3, 14). An International Airways Volcano Watch

Figure. 5. An image from scanning electron microscope of the volcanic ash from Eyjafjallajökull in Iceland showing respirable particles. Provided kindly by Birgir Johannesson, Innovation Center Iceland.

(http://www.icao.int/icao/en/anb/met/IAVW.htm; last of sick patients was disturbed, causing longer transport accessed 5 September 2010) responsible for monitor- times and inconvenience for many patients. The rules ing ash clouds and provision of warnings to the avia- for no-fly zones were thought to be too strict and based tion community was established by the International on limited research and measurements and too much Civil Aviation Organisation. To date, there have been on the use of atmospheric models. This will most likely no reported air crashes arising from encounters with be changed in the near future because of new informa- volcanic clouds, but there have been several near tion that was obtained during the eruption and after- misses (3, 14). Ash from the Eyjafjallajökull eruption wards. Such major disruption of flights is therefore was carried towards Europe by prevailing winds in unlikely to happen again. April and May, 2010 (15). The height of the plume was used as the main indicator of mass transfer, a crucial input parameter in atmospheric models to Previous effects of volcano eruption In define no-fly zones (10). A no-fly zone was reinforced Iceland on global health over large parts of Europe for several days in April and May of 2010 (9, 12). As a consequence of the eruption Laki or Lakagígar (Craters of Laki) is a volcanic fissure both in Europe and more distant destinations, many situated in the south of Iceland. On 8 June 1783, a thousands of travellers were stranded and the eco- fissure with 130 craters opened with explosions (8, 16). nomic impact was profound (9, 11, 12). Air transport The eruption continued until February 1784. It has

The Clinical Respiratory Journal (2011) • ISSN 1752-6981 5 © 2010 Blackwell Publishing Ltd Respiratory health effects of volcanic ash Gudmundsson been estimated that it produced 14 km3 of lava, and the increased cough, breathlessness, chest tightness and total volume of tephra emitted was 0.91 km3. The out- wheezing. Inhalation of fine ash can also exacerbate pouring of gases, including an estimated 8 million tons other previously present disease such as chronic of hydrogen fluoride and estimated 120 million tons obstructive pulmonary disease or chronic heart prob- of sulphur dioxide, gave rise to what has since become lems such as ischemic heart disease (1, 3). A recently known as the ‘Laki haze’ across Europe. The gases were published study from New Zealand showed that in carried to altitudes of about 15 km (8, 16). Sulphurous 1996 diffuse volcanic ashfall from Mt Ruapehu may air pollution was widely reported in Europe through- have contributed to increased mortality observed in out the summer of 1783. Poor air quality and acid the time period after the ashfall in the city of Hamilton deposition caused widespread damage to vegetation i.e. 166 km from the volcano (22). and crop failures. Impacts upon human health were For long-term respiratory problems, there are con- just as severe, with extensive asthma-like symptoms cerns for silicosis, a nodular type of pulmonary fibrosis and eye irritation reported (17). In England, mortality to occur. For this, three conditions have to be in place: was more than 10% in excess of the 50-year mean first, a high proportion of fine particles in the ash; and there were 10 000 more deaths than would be second, a high concentration of crystalline silica; and expected for an average year (18). In parts of France, third, is that there has to be exposure to ash over a the summer death rate in 1783 was 38% above average period of years to decades in significant amounts. (19). Over 50% of Iceland’s livestock population was However, there are no reported cases of silicosis in the killed, leading to famine which killed approximately literature (1). A recent paper describing ash from 25% of the population of Iceland. However as pointed Chaitén volcano in Chile showed that it contained high out, if Laki emissions caused all the estimated national levels of the silica polymorph cristobalite and levels mortality increase in England, then three times as increased through the time course of the eruption (23). many people died in England as a result of the eruption This site will need close monitoring over the next than in Iceland itself (20). decades. The current knowledge on the respiratory effects of volcanic ash can be compared to the available infor- Respiratory effects of volcanic ash mation on the respiratory effects of the attack on the WorldTradeCenterinNewYorkCityon11September Interest in the health effects of the inhalation of volca- 2001. It produced a massive dust cloud with acute nic ash has grown ever since the eruption of Mt St exposure and then several month exposure to burning Helens in the north-western United States that set ruble and dust during the cleaning process. The acute ashfall over populated areas in 1980. Since then, several effects were cough, dyspnea and nasal stuffiness (24). studies have been performed on the health of popula- Firefighters had significant 1-year decline in spirom- tions affected by eruptions and on ash in laboratory etry values. It was common to have spirometry values settings. Very detailed reviews are available on this in low normal range and a low forced vital capacity was subject and interested readers are referred to these most common (24). It therefore seems that the World reviews (1, 3–6). Trade Center incident has had more permanent effects Several factors are important when evaluating on lung function than volcanic ash has ever been the health effects of volcano ash. The first issue is the shown to have. One must keep in mind that this popu- concentration and size of the ash particles inhaled, lation has been studied more than any population that particularly the percentage of finer particles able to has been exposed to volcanic ash. penetrate deeply into the lung, and coarser particles that mostly affect the upper airways. The second thing is the mineralogic composition, particularly the free Epidemiological studies silica content and the third is surface properties, espe- Mt St Helens cially Fe2+ content – higher iron resulting in more free radical generation in toxicological studies, with fresh As well described in previous reviews, the eruption of ash generating more radicals than weathered samples Mt St Helens in 1980 lead to the first detailed system- (1, 3, 21). atic epidemiological and toxicological research into The acute respiratory manifestations seen after health hazards of airborne volcanic ash (1, 3–5). The heavy ashfalls include irritation of the chest and nose eruption occurred on 18 May 1980, and areas of and throat discomfort. Acute exacerbations of asthma central Washington State in the north-western United and bronchitis are seen. These patients present with States experienced around 10 cm of ashfall. Studies

6 The Clinical Respiratory Journal (2011) • ISSN 1752-6981 © 2010 Blackwell Publishing Ltd Gudmundsson Respiratory health effects of volcanic ash showed that areas with high levels of airborne ash Other sites experienced a two- to threefold increase in hospital admissions and three- to fivefold increase in emer- Emergency room visits for respiratory conditions in gency room visits for respiratory conditions, most children in Quito, Ecuador increased significantly after commonly asthma and bronchitis (25). It was also Guagua Pichinca volcanic eruption in the year 2000. found in these studies that a third of patients with These were both respiratory infections and asthma- chronic lung disease had exacerbation of their disease related conditions (32). A cross-sectional study after without seeking medical attention (26). Studies on the Mt Asama eruption in Japan on 1 September 2004 lung function in children found no effects but studies to assess the acute impact of volcanic ash on asthma on hospitalisation for asthma found an increase symptoms and treatment changes was done by using in admission rates (1, 27). Follow-up of those with a questionnaire completed by 236 adult asthmatic chronic lung conditions (25) and loggers exposed patients. In the areas where ashfall was over 100 g/m2 to the ash because of occupation found short-term area, 43% of asthma patients suffered exacerbations, increases in respiratory symptoms that persisted in peak expiratory flow decreased and drug use for some individuals for months (28). This was thought asthma increased. These authors suggested that ashfall to be because of resuspension of loose ash deposits on over 100 g/m2 is harmful, access to such areas by the ground. A small, short-term, reversible decline asthma patients needs to be restricted, and these areas in lung function was seen in loggers working in the need to improve asthma treatment (33). Sakurajima, immediate vicinity of the volcano (28). No long-term Japan is a volcano that has been erupting since 1955, effects on lung function were found. Toxicological with frequent ash falls that have affected a large studies found that Mt St Helens ash acted as an local population. The ash particles are mostly non- irritant on the airways, presenting as an increase in respirable in size and has therefore not had much mucous and inflammation (3). impact on respiratory morbidity or mortality as shown in several publications (34–37).

Soufrie’re Hills volcano, Montserrat Studies on respiratory effects of volcanic ash A volcano eruption has been ongoing since 1995 in Iceland until this date. Health studies conducted there have used a multidisciplinary approach to evaluate health Because of concerns about the health effects of volca- risks. Soufrie’re Hills ash typically contains 13%–20% nic ash, the Directory of Health in Iceland in May, inhalable particles, but crystalline silica content of 2010 initiated a study on the effects of the Eyjafjalla- these particles has varied between 10–27 wt% and jökull volcanic activity. The population studied were 4–6 wt% (29). Toxicological studies have found the individuals living closest to the volcano and that had Montserrat ash to be mildly toxic, but less harmful suffered the most exposure to the ashfall (38). From to the lungs than the cristobalite concentration might 31 May to 1 June 2010 a total of 207 individuals were indicate (1, 30). The risk of developing early radio- evaluated: of those, there were 107 males. Most were logical changes of silicosis of has been estimated to be farmers and immediate family members. The mean 0.1% for the population given 20 years of exposure. age was 44 years with the range from 7 years up to Outdoor workers such as gardeners were found to 85 years of age. A total of 60% of the study group have higher ash exposures, resulting in increased reported good health and no symptoms related to vol- risks of 2%–3% and up to 10% (30). No lung abnor- canic ash at the time of study. About 13% of the malities have been identiﬁed by chest radiographs group gave a history of previous lung condition, most following the ﬁrst 9 years of eruption. Two studies of commonly asthma. Abnormal spirometric values health effects in adults have suggested increased res- were found in 18% of the total group. Of those that piratory symptoms, particularly in those with higher reported a previous lung condition, 38% had normal exposure to ash (1). An epidemiological study with spirometry. No serious immediate consequences of detailed information on 350 children aged under volcanic ash exposure were found. About 40% of the 12 years and still living on the island in 1998 sug- individuals in the study felt acute effects of the ash fall gested fourfold increases in prevalence of wheeze as discomfort in eyes, nose and throat and felt irrita- in the preceding 12 months, and exercise-induced tion of the chest. Most reported that the use of pro- bronchospasm in children exposed to higher levels of tective eye wear and respiratory masks had decreased ash (31). symptoms (38).

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