Increased respiratory morbidity associated with exposure to a mature volcanic plume from a large Icelandic fissure eruption.

The 2014-15 Holuhraun eruption in Iceland was the largest fissure eruption in over 200 years, emitting prodigious amounts of gas and particulate matter into the troposphere. Reykjavík, the capital area of Iceland (250 km from eruption site) was exposed to air pollution events from advection of (i) a relatively young and chemically primitive volcanic plume with a high sulphur dioxide gas (SO2) to sulphate PM (SO42-) ratio, and (ii) an older and chemically mature volcanic plume with a low SO2/SO42- ratio. Whereas the advection and air pollution caused by the primitive plume were successfully forecast and forewarned in public advisories, the mature plume was not. Here, we show that exposure to the mature plume is associated with an increase in register-measured health care utilisation for respiratory disease by 23% (95% CI 19.7-27.4%) and for asthma medication dispensing by 19.3% (95% CI 9.6-29.1%). Absence of public advisories is associated with increases in visits to primary care medical doctors and to the hospital emergency department. We recommend that operational response to volcanic air pollution considers both primitive and mature types of plumes.

Severe volcanic SO2 exposure and respiratory morbidity in the Icelandic population - a register study.

BACKGROUND: The Holuhraun volcanic eruption September 2014 to February 2015 emitted large amounts of sulfur dioxide (SO2). The aim of this study was to determine the association between volcanic SO2 gases on general population respiratory health some 250 km from the eruption site, in the Icelandic capital area. METHODS: Respiratory health outcomes were: asthma medication dispensing (AMD) from the Icelandic Medicines Register, medical doctor consultations in primary care (PCMD) and hospital emergency department visits (HED) in Reykjavík (population: 215000) for respiratory disease from 1 January 2010 to 31 December 2014. The associations between daily counts of health events and daily mean SO2 concentration and high SO2 levels (24-h mean SO2 > 125 µg/m3) were analysed using generalized additive models. RESULTS: After the eruption began, AMD was higher than before (129.4 vs. 158.4 individuals per day, p < 0.05). For PCMD and HED, there were no significant differences between the number of daily events before and after the eruption (142.2 vs 144.8 and 18.3 vs 17.5, respectively). In regression analysis adjusted for other pollutants, SO2 was associated with estimated increases in AMD by 0.99% (95% CI 0.39-1.58%) per 10 µg/m3 at lag 0-2, in PCMD for respiratory causes 1.26% (95% CI 0.72-1.80%) per 10 µg/m3 SO2 at lag 0-2, and in HED by 1.02% (95% CI 0.02-2.03%) per 10 µg/m3 SO2 at lag 0-2. For days over the health limit, the estimated increases were 10.9% (95% CI 2.1-19.6%), 17.2% (95% CI 10.0-24.4%) for AMD and PCMD. Dispensing of short-acting medication increased significantly by 1.09% (95% CI 0.49-1.70%), and PCMD for respiratory infections and asthma and COPD diagnoses and increased significantly by 1.12% (95% CI 0.54-1.71%) and 2.08% (1.13-3.04%). CONCLUSION: High levels of volcanic SO2 are associated with increases in dispensing of AMD, and health care utilization in primary and tertiary care. Individuals with prevalent respiratory disease may be particularly susceptible.

[Air pollution in Iceland and the effects on human health. Review].

This review is on air pollution in Iceland and how it affects human health. Air pollution can be described as a condition, where levels of compounds in the atmosphere are so high that it has undesirable or harmful effects on the general public or undesirable effects on the nature, flora and fauna, or man-built structures. Air pollution can have anthropogenic sources such as burning of fossil fuels, or natural sources such as volcanic eruptions, geothermal areas, and resuspension of soil (sandstorms). Air pollution decreases quality of health and shortens the lifespan. The health effects of air pollution can be divided into direct effects on health where, air pollution causes diseases and indirect effects, where air pollution increases symptoms of underlying diseases. Health protection limits are defined for certain ambient air pollutants. They are to act as reference levels for safe for individuals and are put forth to protect long-term human health. Outdoor air quality has been measured on a regular basis in Reykjavik since 1986. For the first years, only PM10 was measured on a single station, but over the years the number of pollutants measured has increased and more measuring stations have been added. In Iceland air quality is considered very good in general and the ambient pollutant concentrations are usually within defined limits. This is explained by multiple factors such as size of the country and other geographical features as well as weather conditions. Natural disasters can cause increased air pollutant concentrations, as recent volcano eruptions have shown. Several studies have been conducted on the association of air pollution and health of the Icelandic population, but it is essential that this association be examined further to increase the knowledge of adverse health effects of air pollution in Iceland.

Respiratory health among professionals exposed to extreme SO2 levels from a volcanic eruption.

Objective The Holuhraun eruption of fall and winter 2014-15 produced large amounts of sulfur dioxide (SO 2). The aim of this study was to determine if exposure to extreme SO 2levels affected the health of individuals working at the eruption site. Methods During January‒March 2015, earth scientists, technicians, and law enforcement personnel who were about to work at the eruption site were invited to a respiratory health examination. Symptom reports and lung function measures, forced expiratory volume in one second (FEV 1) and forced vital capacity (FVC) were collected before and after an eruption site visit. Those with previous exposure (N=27) reported symptoms retrospectively. Results Altogether, 41 individuals were invited to participate, 32 underwent a clinical examination at a hospital respiratory health clinic (baseline); 27 reported symptoms during earlier visits to the eruption site (retrospective symptom reports), 17 were re-examined 1-6 days after visiting the eruption site (follow-up). All participants' lung function was within normal range both before and after exposure. At baseline, average FEV 1was 107.4% of predicted versus 106.6 at follow-up (P =0.82); average FVC was 107.0% of predicted at baseline versus 107.4% at follow-up (P=0.35). Eye and nasal irritation were more frequently reported during eruption site exposure by 24% versus 6% (P =0.37) for both. Conclusion Although "healthy-worker" effects cannot be excluded, our data indicate that SO 2exposure was associated with relatively mild and transient respiratory symptoms with no clinical signs of airway inflammation or airway obstruction.

Emergency hospital visits in association with volcanic ash, dust storms and other sources of ambient particles: a time-series study in Reykjavík, Iceland.

Volcanic ash contributed significantly to particulate matter (PM) in Iceland following the eruptions in Eyjafjallajökull 2010 and Grímsvötn 2011. This study aimed to investigate the association between different PM sources and emergency hospital visits for cardiorespiratory causes from 2007 to 2012. Indicators of PM10 sources; "volcanic ash", "dust storms", or "other sources" (traffic, fireworks, and re-suspension) on days when PM10 exceeded the daily air quality guideline value of 50 µg/m3 were entered into generalized additive models, adjusted for weather, time trend and co-pollutants. The average number of daily emergency hospital visits was 10.5. PM10 exceeded the air quality guideline value 115 out of 2191 days; 20 days due to volcanic ash, 14 due to dust storms (two days had both dust storm and ash contribution) and 83 due to other sources. High PM10 levels from volcanic ash tended to be significantly associated with the emergency hospital visits; estimates ranged from 4.8% (95% Confidence Interval (CI): 0.6, 9.2%) per day of exposure in unadjusted models to 7.3% (95% CI: -0.4, 15.5%) in adjusted models. Dust storms were not consistently associated with daily emergency hospital visits and other sources tended to show a negative association. We found some evidence indicating that volcanic ash particles were more harmful than particles from other sources, but the results were inconclusive and should be interpreted with caution.