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Volcanic Smog
 Backpackers are surrounded by volcanic smog in this image.

140426-M-RW232-037 Photo By: Sgt. Ed Galo

Volcanic Smog (VOG) is created when sulfur dioxide gas and other pollutants emitted from volcanic activity interact chemically with atmospheric moisture, oxygen, dust, and sunlight. VOG poses a health hazard by aggravating preexisting respiratory ailments and reducing driving visibility. Additionally, when atmospheric moisture is abundant, sul­furic acid dioxide gas in VOG combines with it and falls as acid rain. 

VOG exposure generally increases with altitude. VOG is most present from 300 ft. in elevation up to 6000 ft., with the area around 1000 ft. experiencing the most. Above 6000 ft., VOG begins to diminish rapidly. However, in Hawaii, with Kona (southerly) Winds, VOG can occur at sea level and can cover the entire island.


How to Prepare
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  • Extreme—Very reduced visibility, no visible horizon. Blue/grey tint to objects a mile or less in distance.
  • Heavy—Reduced visibility, horizon barely visible. Blue/grey tint to objects 3 miles away.
  • Moderate—Horizon is blurry. Blue/ grey tint to objects 5 miles away.
  • Light—Horizon is almost sharp. Blue/grey tint to objects 10 miles away.
  • No Vog—Sharp horizon and there is little haze when viewing distant objects
  • Breathing difficulties
  • Induced asthma attacks, especially in adolescents
  • Increased susceptibility to respira­tory ailments
  • Impeded ability of the respiratory tract to remove other potentially harmful particles
  • Headaches
  • Watery eyes
  • Sore throat
  • Flu-like symptoms
  • General lack of energy
  • Long-term effects are unknown
What to Do to Minimize Risk of VOG Exposure and Health Issues
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  • Check air quality levels daily.
  • As a family, make a plan so that everyone knows what to do and where to go.
  • When possible, avoid high VOG level areas and stay in­doors with windows and doors closed and sealed.
  • Avoid physical activity when VOG levels are high.
  • Run an air conditioner or dehumidifier; both will condense water out of the indoor air and, in doing so, will remove the particulate sulfur compounds and acid gases from your indoor air.
  • When using a fan, take a hand towel or a piece of cheese­cloth, and saturate it with a thin paste of baking soda to neutralize the sulfur particles and water to remove the particles from the air. Drape the cloth over the face of the fan and turn the fan on at a low or medium speed. Keep the cloth damp at all times to ensure that it’s most effec­tive, but be very careful not to get the fan motor wet.
  • Stay hydrated.
  • Refrain from smoking or tobacco use.
  • With high VOG level conditions, avoid contact with colds, flu, molds, mildew, pollen and dust, as immune system and lung function may be compromised.
  • Listen to your body—If you find yourself being fatigued quickly, reduce your level of activity; if you start to have difficulty breathing, move to an area that is free of the irritating VOG; if your symptoms don’t improve, get medical assistance ASAP.
  • Follow your doctor’s advice, keep your medication refilled, and use your daily controller medication as prescribed.
  • If it is necessary to be outside for prolonged periods, wear a vinyl or rubber gas mask that is fitted with cartridges rated for acid gases and dust particulates. Ensure the mask is properly fitted to form a seal around your nose and mouth.

Set your own course through any hazard: stay informed, make a plan, build a kit.
Live Ready Marine Corps.

Where to Find Additional Information

Hawaii State Department of Health

U.S. Geological Survey Fact Sheet 169-97http://pubs.usgs.gov/fs/fs169-97/

University of Hawaii at Hilohttp://www.uhh.hawaii.edu/~nat_haz/volcanoes/vog.php

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