Usgs Volcanic Air Pollution Report: When Was It Written?

The USGS Fact Sheet Volcanic Air Pollution Hazards in Hawaiʻi was written by HVO scientists and won the 2018 Shoemaker Award for Communications Product Excellence for the Small Print category. The fact sheet addresses the need for Hawaiʻi residents and visitors to understand vog (volcanic smog), a type of air pollution caused by noxious sulfur dioxide gas and other air pollutants emitted from the Kīlauea Volcano. Vog can negatively affect human health and agriculture, and it has been a frequent problem on the Island of Hawaiʻi since the mid-1980s. The fact sheet provides valuable information on the science of volcanic air pollution, its impacts, and how to live with vog, helping to enhance public awareness and understanding of this ongoing hazard.

Kīlauea Volcano emits noxious sulfur dioxide gas and other air pollutants that react with oxygen, moisture, and sunlight to produce vog

The Kīlauea Volcano on the Island of Hawaiʻi emits about 2,000 tons of noxious sulfur dioxide gas (SO2) each day during periods of sustained eruption. This gas is a major component of vog, a form of air pollution that has become a part of everyday life for Hawaiʻi residents since the mid-1980s. Vog is an abbreviation for volcanic smog, a visible haze that is created when SO2 and other volcanic gases chemically interact with sunlight and atmospheric oxygen, moisture, and dust.

The Kīlauea Volcano has been erupting since 1983, with lava flows burying 48 square miles (125 square kilometres) of land and adding about 500 acres (200 hectares) of new land to the Island of Hawaiʻi. Since the mid-1980s, the flow of magma to the surface has been more steady, producing a nearly constant but quiet outflow of lava and gas. People in areas downwind of the volcano began reporting a wide range of problems, including reduced visibility, health complaints, and damage to crops.

Vog is primarily composed of sulfuric acid and other sulfate compounds, with small amounts of several toxic metals, including selenium, mercury, arsenic, and iridium. It has the corrosive properties of dilute battery acid and can cause severe chemical burns on plants, damaging or even killing them. Vog can also negatively affect human health, with SO2 irritating skin and the tissues and mucous membranes of the eyes, nose, and throat. During moderate physical activity, SO2 penetrates deeply into the airway and can cause respiratory distress in some individuals.

The U.S. Geological Survey's Hawaiian Volcano Observatory (HVO) closely monitors the amount and composition of gas emissions from the Kīlauea Volcano to better understand and evaluate the hazards posed by vog. HVO scientists use both remote and direct sampling techniques to measure compositions and emission rates and advise scientific and healthcare organisations studying its effects.

Vog, or volcanic smog, negatively affects human health and agriculture and can cause respiratory distress

Volcanic smog, or vog, is a visible haze of gas and an aerosol of tiny particles and acidic droplets. Vog is formed when volcanoes erupt and release gases, primarily sulfur dioxide (SO2), into the atmosphere. These gases chemically interact with sunlight, oxygen, moisture, and dust to create vog.

Vog negatively affects both human health and agriculture. It can irritate the skin, eyes, nose, and throat, and can penetrate airways, producing respiratory distress in some individuals. The aerosol particles in vog can penetrate deep into human lungs, and at elevated levels, can induce symptoms of asthma. People with pre-existing respiratory conditions are advised to stay indoors, limit physical activity outdoors, and keep windows and doors closed when vog is present.

Vog also negatively impacts agriculture. When vog mixes with moisture on the leaves of plants, it can cause severe chemical burns, damaging or killing the plants. Sulfur dioxide can also diffuse through leaves and dissolve to form acidic conditions within plant tissue. Farmers on Hawaii Island, particularly in the Ka'u District, have reported losses to agricultural crops and flowers due to high SO2 emissions from a gas vent at Kilauea's summit.

The Kilauea Volcano on the Island of Hawai'i is a significant source of vog. Since the mid-1980s, the volcano's ongoing eruption has resulted in the constant release of volcanic gases, including about 2,000 tons of sulfur dioxide gas each day during periods of sustained eruption. The air pollution caused by these emissions has negatively impacted the health and well-being of residents and visitors to the island.

Acid rain, a byproduct of vog, can contaminate household water supplies by leaching metals from building materials

The U.S. Geological Survey (USGS) fact sheet on volcanic air pollution hazards in Hawaii, written by HVO scientists, won the 2018 Shoemaker Award for Communications Product Excellence for the Small Print category. The fact sheet, titled "Volcanic Air Pollution Hazards in Hawaiʻi", addresses the need for Hawaii residents and visitors to understand vog (volcanic air pollution), which has impacted the state since the mid-1980s.

Vog is a visible haze composed of gas and an aerosol of tiny particles and acidic droplets. It is formed when sulfur dioxide (SO2) and other gases emitted from a volcano chemically interact with sunlight, atmospheric oxygen, moisture, and dust. The sulfuric acid droplets in vog have corrosive properties similar to dilute battery acid. When vog mixes with moisture on plant leaves, it can cause severe chemical burns, damaging or killing the plants. Sulfur dioxide gas can also diffuse through leaves, forming acidic conditions within the plant tissue.

Acid rain is a byproduct of vog. It is formed when sulfur dioxide (SO2) and nitrogen oxides (NOx) emitted into the atmosphere react with water, oxygen, and other chemicals, forming sulfuric and nitric acids. These acids then mix with water and other materials before falling to the ground. While a small portion of the SO2 and NOx that cause acid rain is from natural sources such as volcanoes, most of it comes from the burning of fossil fuels.

Acid rain can contaminate household water supplies by leaching metals from building and plumbing materials in rooftop rainwater catchment systems. The presence of lead in drinking water, leached from roofing and plumbing materials such as nails, paint, solder, and metal flashings, poses a significant health hazard.

Volcanic carbon dioxide emissions can affect the global climate, but their impact is insignificant compared to human activity

Volcanic eruptions release carbon dioxide and other gases into the atmosphere, which can affect the climate. While volcanic carbon dioxide is a greenhouse gas with the potential to cause global warming, the impact of volcanic CO2 emissions on the global climate is insignificant compared to human activity.

Volcanoes emit carbon dioxide in two ways: during eruptions and through underground magma. The carbon dioxide from underground magma is released through vents, porous rocks, soils, and water that feeds volcanic lakes and hot springs. While large volcanic eruptions can inject significant amounts of carbon dioxide into the atmosphere, human activities emit far more carbon dioxide. In 2015, human activities emitted roughly 40 billion metric tons of carbon dioxide, with more than 2,000 billion metric tons added to the atmosphere since the start of the Industrial Revolution. In comparison, volcanoes produce less than 1 billion metric tons annually.

Published scientific estimates of the global CO2 emission rate for all degassing subaerial and submarine volcanoes range from 0.13 gigaton to 0.44 gigaton per year. The projected anthropogenic CO2 emission for 2010 was about 35 gigatons, which is 80 to 270 times larger than the respective maximum and minimum annual global volcanic CO2 emission estimates. While volcanic eruptions can contribute to an increase in atmospheric CO2, human activities release an amount of CO2 equivalent to a Mount St. Helens-sized eruption every 2.5 hours and a Mount Pinatubo-sized eruption twice daily.

The impact of volcanic carbon dioxide emissions on the global climate is further reduced by the conversion of sulfur dioxide to sulfuric acid during major explosive eruptions. While volcanic gases like sulfur dioxide can cause global cooling, the most significant climate impact from volcanic injections into the stratosphere comes from the formation of fine sulfate aerosols. These aerosols increase the reflection of radiation from the Sun back into space, resulting in the cooling of the Earth's lower atmosphere or troposphere.

In summary, while volcanic carbon dioxide emissions can affect the global climate, their impact is insignificant compared to human activity due to the much larger volume of carbon dioxide emitted by human sources and the mitigating effect of sulfur dioxide conversions during volcanic eruptions.

Volcanic gases like hydrogen sulfide and hydrogen halides are harmful to human health and the environment

The U.S. Geological Survey's (USGS) Hawaiian Volcano Observatory (HVO) closely monitors the amount and composition of gas emissions from the Kilauea volcano's ongoing eruption. The Kilauea volcano emits about 2,000 tons of irritating sulfur dioxide gas (SO2) each day during periods of sustained eruption. Sulfur dioxide is a colourless gas with a pungent odour that irritates the skin, eyes, nose, and throat. It is also the main component of vog (volcanic smog).

Hydrogen halides (HF, HCl, and HBr) are released by volcanoes in the form of halogens fluorine, chlorine, and bromine. These gases have high solubility and rapidly dissolve in water droplets within volcanic plumes or the atmosphere, potentially causing acid rain. Acid rain can contaminate household water supplies by leaching metals from building and plumbing materials in rooftop rainwater catchments. It can also damage crops.

Volcanic gases can also affect the global climate. While sulfur dioxide released by volcanoes has occasionally caused detectable global cooling, carbon dioxide released by volcanoes has never caused detectable global warming. However, carbon dioxide can collect in low-lying volcanic areas, posing a lethal risk to humans and animals. Scientific studies indicate that the average global volcanic carbon dioxide output is insignificant when compared to emissions from human activity.

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