USG S

U.S. GEOLOGICAL SURVEY—REDUCING THE RISK FROM HAZARDS Volcanic —A Hazard in Hawai‘i

oxious dioxide gas and Nother pollutants emitted from Kïlauea Volcano on the Island of Hawai‘i react with and atmos- pheric moisture to produce volcanic (vog) and acid rain. Vog poses a health hazard by aggravating preexist- ing respiratory ailments, and acid rain damages crops and can leach lead into household water supplies. The U.S. Geological Survey’s Hawaiian Volcano Observatory is closely moni- toring gas emissions from Kïlauea and working with health professionals and local officials to better understand vol- canic air pollution and to enhance public awareness of this hazard.

Kïlauea Volcano on the Island of Hawai‘i emits about 2,000 tons of sulfur On the morning of February 8, 2000, Harry dioxide (SO2 ) gas each day during periods of sustained eruption. Air pol- Kim, Director of Hawai‘i County Civil Defense, lution caused by SO2 and other volcanic gases became a frequent prob- asked radio stations on the Island of Hawai‘i to lem on the island in mid-1986, when the volcano’s ongoing eruption, broadcast a special message concerning the which began in 1983, changed from episodes of spectacular fountaining (shown here) to a nearly constant but quiet outflow of lava thick, acrid that had covered the southeast- and gas. Inset shows U.S. Geological Survey scientists sampling volcanic ern part of the island for several days. Listeners gases from Kïlauea. were told that outdoor activities in parks might be canceled in affected areas and that schools tons of irritating (SO2) gas each and damage to crops. The word “vog,” an ab- might need to keep children indoors. People day during periods of sustained eruption. Deep breviation for volcanic smog, was coined to were also warned to be aware of respiratory inside the volcano, where pressure is high, the identify this form of air pollution, which unfor- problems, as these conditions could deteriorate SO2 is dissolved in molten rock (magma). tunately has become a part of everyday life for more rapidly in areas of heavier haze. This chok- When the magma rises toward the surface, people in Hawai‘i. ing haze was not caused by a forest fire or indus- where pressure is lower, the gas bubbles out Vog is created when SO2 and other volcanic trial pollution but by light winds blowing gas and escapes. gases combine and interact chemically in the emissions from Kïlauea Volcano into the area. Air pollution caused by SO2 and other gases atmosphere with oxygen, moisture, dust, and Best known for its spectacular lava foun- emitted from Kïlauea became a frequent prob- sunlight over periods of minutes to days. Vog is tains and flows, Kïlauea also emits about 2,000 lem on the Island of Hawai‘i in 1986. Until that a visible haze consisting of gas plus a sus- time, the volcano’s ongoing eruption, which pended mixture of tiny liquid and solid par- began in 1983, consisted of short, spectacular ticles, called . The aerosol in vog is episodes of lava fountaining about once every 3 composed primarily of sulfuric acid and other weeks. Since mid-1986, the flow of magma to sulfate compounds. Small amounts of several the surface has been more steady, producing a toxic metals, including selenium, mercury, ar- nearly constant but quiet outflow of lava and senic, and iridium, have also been found in the gas. People in areas downwind of the volcano volcanic air pollution coming from Kïlauea. began reporting a wide range of problems, in- Far away from the volcano, such as along the cluding reduced visibility, health complaints, Kona coast on the Island of Hawai‘i’s west side, aerosol particles dominate vog, but near Sulfur dioxide gas and other pollutants emitted Kïlauea SO gas is a major component of vog. from Kïlauea Volcano interact chemically with 2 atmospheric moisture, oxygen, dust, and - SO2 is a poisonous gas that irritates skin and light to produce volcanic smog (vog) and acid the tissues and mucous membranes of the eyes, rain. Vog poses a health hazard by aggravating nose, and throat. During even moderate physical preexisting respiratory ailments, reduces driv- activity, SO penetrates deeply into the airway ing visibility (top), and damages crops (lower 2 left), and acid rain can leach lead from rainwa- and can produce respiratory distress in some in- ter catchment systems (lower right) into house- dividuals. In the absence of strong winds, SO2 hold water supplies. emitted by Kïlauea can accumulate in the air and

U.S. Department of the Interior USGS Fact Sheet 169–97, version 1.1 U.S. Geological Survey Revised June 2000 During prevailing trade-wind condi- KAUA‘I 100 MILES NOAA Satellite Image O‘AHU tions, the nearly constant stream of vol- NI‘IHAU MOLOKA‘I canic smog (vog) produced by Kïlauea Honolulu MAUI Volcano on the Island of Hawai‘i is LÄNA‘I P blown to the southwest and west (sat- AC KAHO‘OLAWE HAWAI‘I I F ellite image shows increasing amounts I C Hilo O Island of Hawai‘i C of vog aerosol particles in yellow, or- E A N KÏLAUEA ange, and red, respectively); traces Kohala TRADE have been detected as far away as WINDS Johnston Island, 1,000 miles to the Mauna Kea southwest. On the Island of Hawai‘i, the Hualälai trade winds (blue arrows) blow the vog Kailua-Kona from its main source on the volcano Hilo Mauna Loa (white plume) to the southwest, where South Kona wind patterns send it up the island’s Kïlauea Kona coast. Here, it becomes trapped by daytime (onshore) and nighttime N (offshore) sea breezes (double-headed arrows). In contrast, when light “kona” winds (red arrows) blow, much of the vog is concentrated on the eastern side of South Point the island, but some can even reach O‘ahu, more than 200 miles to the northwest. KONA WINDS (The names of the five volcanoes that make up the Island of Hawai‘i are shown in yellow. National Oceanic and Atmospheric Administration (NOAA) satellite image processed by John Porter and collected by Pierre Flament, University of Hawai‘i.)

reach levels that exceed Federal health standards. als, and SO2 gas in vog may account for the amount and composition of gas emissions from Since 1986, this has occurred more than 85 times wide variety of physical symptoms reported. the volcano’s ongoing eruption. In addition, within Hawai‘i Volcanoes National Park, which Like smog, the presence of vog reduces vis- HVO collects and integrates information on includes much of Kïlauea. ibility. Moisture in the air causes vog particles volcanic air pollution from other sources and Because of their small size, aerosol particles to enlarge, decreasing visibility still further. On advises scientific and health-care organizations such as those in vog penetrate deep into the hu- the Island of Hawai‘i, people often turn their studying its effects. HVO scientists are also man lung and are readily retained. Studies of headlights on during daylight hours when driv- working closely with government officials and air pollution in the United States and elsewhere ing in vog, and vog sometimes limits visibility health professionals in Hawai‘i to inform resi- indicate that elevated levels of acidic particles for air traffic. dents and visitors about this hazard. like those in vog can induce asthma attacks, es- The tiny sulfuric acid droplets in vog have the The studies of volcanic air pollution carried pecially in adolescents, and can also impede corrosive properties of dilute battery acid. When out at HVO by scientists with the USGS Volcano the ability of the upper respiratory tract to re- atmospheric moisture is abundant, these droplets Hazards Program complement the observatory’s move other potentially harmful particles. combine with it and fall as acid rain, damaging other studies of Hawai‘i’s volcanoes. The work Many residents and visitors on the Island of plants and accelerating the rusting of metal ob- of HVO is part of the ongoing USGS effort to Hawai‘i report physical complaints associated jects, such as cars, industrial and farm equip- help protect people’s lives and property from with vog exposure. These complaints include ment, and building components. However, in volcano hazards in all of the volcanic regions of headaches, breathing difficulties, increased sus- drier conditions, such as those that prevail on the United States, including Hawai‘i, Alaska, ceptibility to respiratory ailments, watery eyes, Hawai‘i’s Kona coast, the acid in vog Wyoming, California, and the Pacific Northwest. sore throat, flu-like symptoms, and a general may actually impede the formation of raindrops, lack of energy. In contrast to SO2 gas concen- resulting in decreased summer rainfall for crops Jeff Sutton, Tamar Elias, tration near Kïlauea, the amount of aerosol par- and drinking water. Vog can also mix directly James W. Hendley II, and Peter H. Stauffer ticles in Hawai‘i’s air does not routinely exceed with moisture on the leaves of plants and in less Graphic design by Susan Mayfield and Sara Boore Federal standards, but the unique combination than a day cause severe chemical burns. Farmers Banner design by Bobbie Myers of acidic particles, trace amounts of toxic met- on the Island of Hawai‘i have suffered losses even to crops in greenhouses, because vog can COOPERATING ORGANIZATIONS enter through the air vents. American Lung Association of Hawai‘i Many homes on the Island of Hawai‘i rely on Hawai‘i County Civil Defense rooftop rainwater-catchment systems to provide Hawai‘i State Department of Health National Centers for Disease Control and Prevention their drinking water. In 1988, the drinking water National Oceanic and Atmospheric Administration of nearly 40% of homes using such systems in National Park Service the Kona Districts of the island was found to be University of Hawai‘i, Center for the Study contaminated with lead leached by acid rain of Active Volcanoes from roofing and plumbing materials, such as University of Hawai‘i, School of Ocean and Earth Science and Technology nails, paint, solder, and metal flashings. Tests confirmed that the blood of some residents of these homes had elevated lead levels, leading to For more information contact: a major islandwide effort to remove lead-bearing U.S. Geological Survey materials from rainwater-catchment systems. Hawaiian Volcano Observatory P.O. Box 51, Hawai‘i National Park, HI 96718 Molten lava from Kïlauea Volcano frequently flows Much is still unknown about vog’s composi- Tel: (808) 967-7328, Fax: (808) 967-8890 through underground lava tubes to reach the Pacific tion and its effects on health. To better under- http://hvo.wr.usgs.gov/ Ocean, where it vigorously reacts with cold seawater stand and evaluate the hazards posed by vog or to create large steam plumes laden with hydrochloric and other forms of volcanic air pollution, scien- U.S. Geological Survey Volcano Hazards Program acid. These plumes, known as “laze”, are another form tists from the U.S. Geological Survey’s http://volcanoes.usgs.gov/ of volcanic air pollution and pose a local environmental See also Living On Active Volcanoes—The Island of Hawai‘i hazard along the Island of Hawai‘i’s southeast coast, (USGS) Hawaiian Volcano Observatory (HVO) (USGS Fact Sheet 074-97) and What are Volcano Hazards? especially to people who visit these ocean-entry sites. at the summit of Kïlauea closely monitor the (USGS Fact Sheet 002-97)