Excess mortality in Europe following a future Laki-style Icelandic eruption

Abstract

Historical records show that the A.D. 1783-1784 Laki eruption in Iceland caused severe environmental stress and posed a health hazard far beyond the borders of Iceland. Given the reasonable likelihood of such an event recurring, it is important to assess the scale on which a future eruption could impact society. We quantify the potential health effects caused by an increase in air pollution during a future Laki-style eruption using a global aerosol model together with concentration-response functions derived from current epidemiological studies. The concentration of particulate matter with diameters smaller than 2.5 µm is predicted to double across central, western, and northern Europe during the first 3 mo of the eruption. Over land areas of Europe, the current World Health Organization 24-h air quality guideline for particulate matter with diameters smaller than 2.5 µm is exceeded an additional 36 d on average over the course of the eruption. Based on the changes in particulate air pollution, we estimate that approximately 142,000 additional cardiopulmonary fatalities (with a 95% confidence interval of 52,000-228,000) could occur in Europe. In terms of air pollution, such a volcanic eruption would therefore be a severe health hazard, increasing excess mortality in Europe on a scale that likely exceeds excess mortality due to seasonal influenza.

Fig. 1.

Percentage positive (i.e., northwesterly air flow) Iceland to UK flow index shown as annual values at 500 hPa for the years 1958–2010 using European Center for Medium-Range Weather Forecasts reanalyses (20, 21). The years 2003 and 2005 used for the simulations are highlighted in black.

Fig. 2.

Modeled PM2.5 mass concentrations at the surface (shown as a mean of the 2003 and 2005 simulations). Twelve-month mean PM2.5 mass concentrations (microgram per cubic meter) for (A) control run without Laki emissions and (B) perturbed run including the Laki emissions, with (C) showing the absolute change (perturbed minus control run) in 12-mo mean PM2.5 concentrations, and (D) showing the absolute change in 3-mo mean PM2.5 concentrations calculated for first 3 mo following the onset of a Laki-style eruption on June 8.

Fig. 3.

Time series of surface PM2.5 mass concentrations averaged over the European domain starting on June 8 and ending on February 28 for the control runs (black) and the perturbed runs (dark blue), including the 95th percentiles for the control runs (gray) and perturbed runs (light blue). The time and magnitude of the SO₂ emissions during the 10 Laki eruption episodes are depicted by red diamonds and the y axis on the right-hand side.

Fig. 4.

Total number of days out of the 266 d considered exceeding the current WHO 24-h PM2.5 guideline of 25 μg/m³ (shown as a mean of the 2003 and 2005 simulations). Colored boxes depict the perturbed situation (including Laki emissions). Numbers in grid boxes denote the absolute change (i.e., perturbed minus control run).

Fig. 5.

Number of excess fatalities in Europe resulting from short- and long-term exposure to PM2.5. A) Time-series of daily all-cause excess mortality due to short-term exposure to PM2.5 starting with the onset of the Laki-style eruption on June 8 and ending on February 28 (shown as range for the 2003 and 2005 simulations). The mean of the 2003 and 2005 simulations is shown as the black line and the 95% confidence interval is shown in orange. B) Number of excess cardiopulmonary fatalities in the year following the onset of a Laki-style due to long-term exposure to PM2.5 (shown as a mean of the 2003 and 2005 simulations).