This page is a collection of resources about vog (volcanic smog) in Hawaii. Vog, a kind of air pollution, is a product of emissions from Kilauea Volcano on the Big Island of Hawaii.
The volcano emits smoke, ash and gases in amounts that vary constantly. Weather factors, especially the direction and speed of the wind, determine whether the emissions from Kilauea are blown out to sea, or over the coasts and interior of the Big Island. A combination of increased emissions, coupled with winds from the south or southwest, sometimes will carry the vog plume hundreds of miles up the island chain, affecting all of the Hawaiian Islands.
We rely on a partnership among Federal, State, and County agencies to monitor levels of volcanic emissions, and to warn us of potentially hazardous conditions. The Hawaii County Civil Defense Agency has made available an online brochure in a printable ('pdf') format, updated in April 2008, which explains the hazards and summarizes measures that residents can take to protect themselves, their livestock, and their crops. The brochure is a good starting point for understanding how to cope with vog. Here is the link: Emissions from Kilauea Volcano
Sulfur Dioxide
Sulfur dioxide (SO2), one of the gases emitted by Kilauea volcano, is considered to be a potential health hazard. The agencies that monitor concentrations of SO2 in the ambient air use a color code system, illustrated at right, to inform the public of SO2 hazard status.
The new Hawaii County Civil Defense brochure mentioned above says, "It is expected that any area down wind of the vent site of Halema‘uma‘u can expect SO2 levels to be higher than in previous years." Remember: which areas are construed as 'down wind' varies, based on the wind speed and direction.
Health and Environmental Effects of SO2
Sulfur dioxide is irritating to the eyes, nose, throat and respiratory tract. Short-term exposure to elevated levels of SO2 may cause inflammation and irritation, resulting in burning of the eyes, coughing, difficulty in breathing and a feeling of chest tightness. Prolonged or repeated exposure to higher levels of SO2 may be dangerous to children and to people with any pre-existing respiratory or heart conditions.
SO2 also contributes to the formation of acid rain, which can damage trees, gardens, landscaping, and crops. Acid rain can make the soil acidic.
Hawaii County Civil Defense says that in the event that SO2 reaches the red or purple level, information will be given to the public utilizing all means available, including radio stations and field units. Here is the link to the Hawaii County Civil Defense web page, where such notices are posted: Hawaii County Civil Defense Messages.
Vog Haze
According to the U. S. Environmental Protection Agency (EPA), SO2 reacts with other chemicals in the air to form tiny sulfate particles. Haze occurs when light is scattered or absorbed by particles and gases in the air, reducing visibility. In the case of vog, it is important to note that the SO2 component usually diminishes with distance from the volcano. Even if the vog haze looks heavy, it does not necessarily mean there is a high concentration of SO2 in the haze. Conversely, SO2 levels can be high even though the vog haze is light. Heavy vog haze does mean higher levels of particulate matter and smoke.
Hawaii Civil Defense lists these symptoms that can arise from exposure to vog haze: headaches; breathing difficulties; increased susceptibility to respiratory ailments; watery eyes; sore throat. The EPA notes that when particles are breathed in, they gather in the lungs and are associated with increased respiratory symptoms and disease, difficulty in breathing, and premature death.
Ash Fall Hazards
Volcanic ash is composed of tiny rock particles emitted during eruption. The particles can range in size from grit to a very fine powder. Ash particles can be inhaled, causing chest discomfort, wheezing, and coughing. Other symptoms of ash inhalation: runny nose; sore throat; difficulty breathing; and worsening of pre-existing respiratory conditions.
More online resources:
- Kilauea Status Reports - daily info from the Hawaiian Volcano Observatory, including current emissions rates
- Hawai`i Volcanoes National Park Current Sulfur Dioxide (SO2) Conditions - National Park Service report on current conditions, with map showing the direction of the gas plumes from Kilauea vents
- Air Quality in the Hawaiian Islands - Maps showing air quality data from the Hawaii State Department of Health (Note: Java scripts - may take awhile to load)
- What Is Vog? - information page prepared by the KonaWeb online community
- How Sulfur Dioxide Affects the Way We Live - EPA information on health and environmental impact
- Air Quality Guide for Particle Pollution - Key Facts from the EPA
- Volcanic Ash - Effects on Water Supply and Mitigation Strategies - information from the USGS
- Kilauea Eruption Update - information from the County of Hawaii, including FAQs
- Halema'uma'u Web Cam - live panorama shot of Kilauea summit
- Pu'u O'o Web Cam - live panorama shot of the east rift zone of Kilauea
- New Activity on Kilauea - regularly updated satellite photos of the Hawaiian Islands and the vog plume, from NASA
- Kilauea SO2 Graphic - chart that maps the location of the SO2 plume from Kilauea volcano for the current date, and three preceding dates, from NOAA Satellite and Information Service
Note: I have been blogging about Kilauea volcano and the vog since March of 2008. To read more of what I have written on these subjects, click here.
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