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 world’s 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 world’s 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 earth’s 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 Earth’s 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 Earth’s surface. • When magma exits the Earth, it become lava. • It’s slow and easily avoidable. • It’s 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. • It’s 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

28. 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 • Don’t 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/areyouready/volcanoes.shtm. Accessed 5/19/06. • Jay G. Volcanic Eruption. In Disaster Medicine, eds. Ciottone, Darling, Anderson, et al. Mosby, Philadelphia, PA. 2006.