Volcano

1
Volcano

• by
• Paul Rega, M.D., F.A.C.E.P.

2
Introduction
3
Since 1700

• Over 270,000 volcano-related deaths have been
  recorded.
• There have been 2-4 fatal eruptions annually

4
The Ring of Fire

• 80 of the worlds active volcanoes are located
  around the Pacific Basin.

5
Where to find active volcanoes in the U.S.

• Hawaii
• Alaska
• Pacific Northwest

6
Why be concerned about volcanoes?

• In 1990, about 10 of the worlds population
  lived within 100 kilometers of an active volcano.

7
Definitions
8
Volcano

• Def. A vent through which molten rock has or may
  escape from the earths surface.

9
Volcanic Eruption

• Def. The ejection of gases and solid material
  from a defect in the surface of the Earth.

10
Magma

• Def. Molten rock within the Earth.
• It is under pressure within the Earth.
• When it rises to the Earths surface, the
  pressure decreases, allowing volatiles and gases
  to escape.

11
Outgassing

• Def. The release of volatiles dissolved in magma.

12
Lava

• Def. Molten rock that erupts at the Earths
  surface.
• When magma exits the Earth, it become lava.
• Its slow and easily avoidable.
• Its responsible for very few fatalities.

13
Pyroclastic Flows

• Def. A mass of hot volcanic ash, lava fragments,
  and gases that erupts from a volcano.
• It moves rapidly, up to a few hundred mph.
• Its responsible for most volcanic deaths.
• Temperatures may reach to 900 C.
• Rocks and other debris within the flow may be
  ejected from the flow causing a secondary blast
  injury.
• May extend for miles.
• The flow from the Mount St. Helens eruption
  reached 17 miles.

14
Tephra

• Def. Solid fragments of magma and volcanic rock
  that are ejected during an eruption.
• May cause significant blunt trauma and burns.
• Tephra accumulations may reach several meters in
  depth.

15
Ash

• Def. Tephra fragments that are smaller than 2
  mm.
• Ash clouds are a potential health hazard.

16
Lampilli

• Def. Tephra fragments that are between 2-64 mm
  in size.

17
Lava Bombs or Blocks

• Def. Tephra fragments that are greater than 64
  mm in size.
• May land several kilometers away from a volcanic
  eruption.

18
Lahar

• Def. Volcanic debris flows.

19
Specific Medical Consequences of
Volcanic Eruptions
20
Ashfalls

• Increase in bronchial reactivity
• During the Mount St. Helens eruption, there was
  a doubling of asthma- and bronchitis-related ER
  visits compared to the previous year.
• During ashfalls, total suspended particles (TSP)
  in the air is a useful predictor or ER visits for
  respiratory conditions.
• The number of ER visits for respiratory
  complaints, especially asthmatics, during the
  Mount St. Helens eruption was the highest when
  the TSP concentration was greater than 30,000
  µg/m?.

21
Volcanic Gases

• Water vapor
• Carbon dioxide Threat
• Sulfur dioxide Threat
• Hydrogen sulfide Threat
• Hydrogen
• Carbon monoxide
• Hydrogen fluoride Threat
• Helium

22
Sulfur dioxide

• Airways, eyes, and skin irritant
• Produces acid rain
• Reacts with zinc on sheet metal roofs.
• Releases heavy metals into drinking water.

23
Hydrogen fluoride

• Airways irritant
• If ingested by animals may produce fluorosis and
  death
• Drinking water should be checked for elevated
  fluoride levels.
• Food should be cleaned of any ash to avoid
  fluorosis.

24
Carbon dioxide

• Especially in low-lying areas, CO2 may
  accumulate.
• If the CO2 content of the air is greater than
  20-30, asphyxiation may result.
• Volcanoes can release gases even without an
  eruption.
• 1984 In the volcanic Lake Monoun in Cameroon, 73
  people died from CO2 release due to lake water
  turnover.
• 1986 A similar occurrence at Lake Nyos in
  Cameroon. About 1700 people in a low-lying area
  were killed by a massive release of CO2.

25
Hydrogen sulfide

• Because of its density, it may concentrate in
  low-lying areas.
• Rotten egg odor
• Airway and eye irritant
• High concentrations may cause pulmonary edema and
  death through cellular asphyxiation.

26
Accompanying Catastrophes

• Earthquakes
• Mudflows
• Flash floods
• Rock falls
• Landslides
• Acid rain
• Fire
• Tsunamis
• Lightning strikes

27
Living Near A Volcano
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Protective Measures

• If you live near an active volcano, add to your
  disaster supply kit
• Goggles
• Disposable breathing mask
• Best protection
• Stay away from an active volcano site

29
If you are near a volcanic eruption

• Evacuate immediately
• Avoid river valleys and low-lying areas
• Caution with mudflows
• Look upstream before crossing a bridge
• Dont cross if a mudflow is approaching
• Mudflows are faster than you can run

30
Protection from falling ash

• Wear log-sleeved shirts and long pants
• Wear goggles and eyeglasses
• Avoid contact lens
• Use a dust mask or place a damp cloth over your
  face
• Avoid being downwind and
• Stay indoors unless there is concern the roof may
  collapse from the accumulation of ash on it
• Close doors, windows, and all vents
• Clear ash from roofs and rain gutters
• Avoid running car engines to minimize clogging
  engines

31
Reference

• Are You Ready?- Volcanoes. www.fema.gov/areyourea
  dy/volcanoes.shtm. Accessed 5/19/06.
• Jay G. Volcanic Eruption. In Disaster Medicine,
  eds. Ciottone, Darling, Anderson, et al. Mosby,
  Philadelphia, PA. 2006.