Severe volcanic SO2 exposure and respiratory morbidities in the Icelandic population - a register study
The Holuhraun volcanic eruption September 2014 to February 2015 emitted large amounts of sulfur dioxide (SO2). Objectives The aim of this study was to determine the association between volcanic SO2 gases on general population respiratory health in the Icelandic capital area some 250 km from the eruption site. Methods Respiratory health outcomes were: asthma medication dispensing (AMD) from the Icelandic Medicines Register, medical doctor consultations in primary care (PCMD) and hospital
... nd hospital emergency department visits (HED) in Reykjavik (population: 215 000) 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-hour mean SO2 >125νg/m3) were analyzed 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). Increases in SO2 concentration were associated with an estimated increase in AMD by 1.05% (95% CI 0.48 - 1.62%) per 10 νg/m3 at lag 0-2, 1.51% (95% CI 0.63 - 2.40%) increase in individuals under 18 years of age. PCMD for respiratory causes increased by 1.52% (95% CI 1.04 - 2.00%) per 10 νg/m3 SO2 at lag 0-2. For HED, only effect estimated for individuals aged 64 years and older were significantly increased, by 1.541% (95% CI 0.02 - 3.07%) per 10 νg/m3 SO2 at lag 0-2. Following days with SO2 levels above 125 νg/m3, AMD and PCMD were increased in all age groups, in AMD mostly so in individuals under 18 by 20.4%(95%CI 4.8 - 23.4%), and adult PCMD visits by 24.1%(95%CI 16.8 - 31.3%). HED was significantly increased in elderly by 26.3% (95%CI 5.56-47.0). Discussion 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.