What is Vog?
Very simply, vog is volcanic air pollution. While it is not quite as ugly as the urban brown clouds found in many cities, it can have a big impact on people who are sensitive to it. Visitors may not even notice vog, but if you plan to visit the Hawaii Volcanoes National Park, you will experience it while driving through the park. The articles on this page range from very simple and practical steps to reduce these effects to scientific reports on vog.
Recognize that YOU are your own best vog indicator. Pay attention to
symptoms your body exhibits and
take steps to minimize vog if you are
The Vog Measurement and Prediction Project (VMAP)
Hawaiian Lava Daily - Real Time Molten Lava Reports
Other Vog Related Pages of Interest
Madam Pele is a mysterious goddess. She can sleep for years, but when she wakes up, one of the ways she lets everyone know it is by sending a plume of sulfur dioxide into the atmosphere. Sulfur dioxide reacts with other gases, moisture, dust and sunlight to form vog. Molten lava flowing down the flanks of Kilauea often pours into the sea, where it interacts with sea water to produce hydrogen sulfide, sulfur dioxide, and other chemicals.
An Example of Extreme Vog on February 21, 2008
On this day, Shirley and I were driving along highway 11 near Keauhou, and we could barely make out the structures of Kailua-Kona and the cruise ship in the bay. The horizon is not visible at all.
An Example of No Vog on Oct. 31, 2012
There is a crusie ship on both of these photos. In this photo, there is no vog. The reported weather indicated 'Winds from the South at 5 to 10 mph'
How to Estimate the Current Vog Levels
A simple way to judge the vog level is to see how sharp the horizon line is where the ocean and sky meet. (Since the horizon always looks sharp when you're at sea level, this is helpful when you're up mauka a bit.)
- 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
A Useful Brochure about Emissions from Kilauea Volcano
Ten Things YOU Can Do to Lessen Adverse Health Effects of Vog
First, it is important to note that individuals may have a wide range of sensitivity to vog.
- Drink lots of fluids to loosen mucus and clear lungs. Hot tea may be especially good. (Caffeinated teas also contain theophyliine - a bronchial dilator, further, both of these materials also help the clearance of the lungs).
- Don't overexert yourself when vog levels are high. Even better, take it easy.
- If practical, avoid high vog areas during times of thick vog.
- Avoid exposure to other air pollutants on the job and at home. Consult your doctor, or if possible, a toxicologist or an industrial hygienist.
- Don't smoke, and avoid people smoking or burning trash, especially during vog episodes.
- When vog is strong, avoid contact with colds, flu, molds, mildew, pollen, and dust. (Some of the lung clearance and immune functions could be compromised by high vog.)
- For very high vog, stay indoors, close the windows, and run an air purifier or air conditioner. Indoor plants (especially spider plants) may help clean the air. You also can try hanging up sheets that have been soaked In a mixture of one teaspoon of baking soda to one liter of water (which can help trap acid aerosols and gases.)
- Keep any respiratory and heart medications you use handy. Consult your doctor.
- Respirators or wet handkerchiefs may help if vog levels are very high, but may hurt individuals with pre-existing respiratory or heart ailments, due to increased breathing resistance and, therefore, increased stress. Consult your doctor about your state of health, and consult an industrial hygienist about respirators.
- Get some baseline lung function tests (after breathing "clean" air one week or more), then get retested if/when breathing becomes more difficult during high vog episodes. Have your doctor keep records of both your lung function and approximate vog levels.
If planning to move to the Big Island, be aware of the vog conditions which exist on the island, and be aware that the area from Kailua-Kona to Oceanview are "generally" the most heavily affected. Areas from Volcano Village to Hilo can also experience high levels of vog.
Vog exposure generally increases with altitude. Sea level experiences the least vog. 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.