Vulkanutbrott! Konsekvenser av svaveldioxidutsläpp

Vulkanutbrott!
Konsekvenser av svaveldioxidutsläpp
Hanne Krage Carlsen, MPH, PhD
PostDoc fellow, Icelandic Directorate of Health
& Centre of public health at University of Iceland
September 2015
Iceland and volcanoes
• Average one eruption every 5
years
• Historically catastrophic events
• Types:
• Fissure => lava (tourist eruption)
• Top crater => explosive with ash
• No good studies of health effects
2
Barðarbunga/Holuhraun eruption
• Seismic unrest August 2014
• Continued volcanic unrest near
and under the main crater of
Barðarbunga
• Was there more to come?
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Screenshot from vedur.is/en/earthquakes 16. August
2014
Barðarbunga/Holuhraun eruption
• 31. august 2014-27.February 2015
• Eruption type: Basaltic lava flow
• In the Barðabunga system
• Largest since 1783-4 Laki eruption
• but still only 10% of emissions of Laki
• 12 million ton SO2
Reference
http://www.geochemicalperspectivesletters.org/article1509
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Image: University of Iceland Geoscience departmen
Gas in volcanic eruptions
• >95%
• H2O, CO2
• SO2
• <5%
• H2S, CO, HCl, HF
Image:NASA/Landsat
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SO2 gas properties
• SO2 has no smell
• Transient
• Dose-dependent
• Quite high dose needed before effects are seen
• Susceptibility different in healthy individuals
• Individuals with obstructive lung disease probably more
susceptible
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SO2 health effects
• Irritation in eyes, nose, throat
• Most gas is absorbed in nose and upper airways
• SO2 in the lungs can provoke
• Asthma attacks
• Pulmonary oedema
7
Co-ordination!
Frequent meetings arranged by
the civil protection agency with
representatives of
• Police
• Meteorological office
• Earth scientists
• Health authorities
• Data-driven authoritative efforts
based on newest data
•
•
•
•
About eruption progress
Closed areas
SO2 levels
Dispersion
• Chief epidemiologists office
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Informing the public - health behaviour
The scientific advisory board bulletins were widely cited in the media.
Official advice
• SO2 transport to the lungs is minimized by breathing slowly and calm
• Symptoms are immediate and resolve immediately after exposure
stops
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Gathering health information from
professionals
• Health directorate had frequent and persistent contact with
MDs in the affected areas
• Other:
• Meteorological office collected reports online
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Informing the public –
health risks
• Information relayed in media
• Community meetings with
directorate of health officials in
the affected areas
• Health effects table issued,
update as new information was
available and publicized widely
• Increased monitoring
www.landlaeknir.is/english/volcanic-eruption-in-holuhraun-human-health-effext/
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Pollution monitoring
• 24-hour mean SO2
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Pollution monitoring
• 24-hour mean SO2
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SO2 dispersion
• Meteorological office made
predictions
• Warnings Published in the
media
• Accessible on the website
vedur.is
Meteorological office screenshot February 6 2015 14
Barðabunga/Holuhraun SO2 pollution
• Eruption was very SO2 rich
• First alarming message
about SO2 levels from east
Iceland
• SO2 health limits (24
hour)*
• 0-350 µg/m3 no risk
• 350-600 µg/m3 probably
effects in susceptible
individuals
• 600
*WHO air quality guidelines
Unit:
µg/m3
East Iceland
Reyðarfjörður –Ljósá
Vopnafjörður
South Iceland
Grindavik
North Iceland
Akureyri
Capital
Hafnarfjordur
Nordlingaholt
Maximum 24hour mean
Days >24 hour
limit**
Days >1hour
limit**
308
6
4
470
7
10
36
0
0
2025
4
6
323
479
8
9
6
15
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The eruption in hindsight
• No serious health events in the
public attributed to SO2
• Several scientific studies
ongoing:
• Health of professionals who were
highly exposed
• Register-studies of the general
public
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Better prepared for next time?
hkc1@hi.is
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