Volcanic Eruptions: Impacting Air Pollution And Climate Change

Volcanic eruptions can have a significant impact on air pollution, releasing toxic gases and fine particles that can travel long distances and affect air quality across broad areas. These emissions can reach up to 10 kilometres (6.2 miles) into the air and then blow hundreds or even thousands of kilometres away from the volcano, posing risks to human health, vegetation, infrastructure, and the global climate. The release of sulphur dioxide, carbon dioxide, hydrogen halides, and other harmful substances during volcanic eruptions contributes to air pollution and has both local and global effects.

Volcanic gases, including sulphur dioxide, carbon dioxide, and hydrogen fluoride, can cause air pollution

Volcanic eruptions release large quantities of greenhouse gases and other aerosols into the atmosphere. These gases form massive clouds that accumulate in the atmosphere, a process known as outgassing or off-gassing. This outgassed mixture includes volcanic particulates, known as ash or pyroclastic flow, water vapour, carbon dioxide, sulphur dioxide, hydrogen sulfide, carbon monoxide, hydrogen chloride, and hydrogen fluoride.

Carbon dioxide (CO2) is another major gas released during volcanic eruptions and is the second-largest contributor to atmospheric greenhouse gases after water vapour. While anthropogenic CO2 emissions, such as those from burning fossil fuels, are a significant concern, volcanic activity also contributes to global CO2 levels. Volcanoes release up to 130 million tons of CO2 into the atmosphere annually. High concentrations of CO2 can have detrimental effects on the Earth's biosphere. Inhaling air with CO2 concentrations above 30% can quickly lead to unconsciousness and death in both humans and animals.

Hydrogen fluoride (HF) is also released during volcanic eruptions and has severe impacts. When HF comes into contact with water droplets, it becomes acidic vapour, which is rapidly absorbed into the nose and upper respiratory tract, causing severe irritation to the eyes, nose, throat, and lungs. When volcanic ash clouds move over water bodies, HF can contaminate the water, posing risks to human populations that rely on those water sources.

The release of these volcanic gases, including sulphur dioxide, carbon dioxide, and hydrogen fluoride, contributes to air pollution and has far-reaching consequences for the environment, human health, and ecosystems.

Volcanic ash can travel thousands of miles and cause eye and respiratory irritation

Volcanic ash can travel hundreds to thousands of miles from a volcano, affecting areas far beyond its immediate surroundings. While it is not highly toxic, volcanic ash can be gritty, abrasive, corrosive, and unpleasant, and can cause eye and respiratory irritation.

Volcanic ash is composed of fine particles of fragmented volcanic rock, usually less than 2 mm in diameter. These particles are often hot close to the volcano but cool as they move away and fall to the ground. The ash can be carried by the wind, spreading out over a wide area. When it gets into the eyes, it can cause scratches to the cornea and conjunctivitis, resulting in redness, burning, and photosensitivity. It can also lead to a feeling of having foreign particles in the eyes, along with itching, bloodshot eyes, and sticky discharge or tearing.

Inhalation of volcanic ash can irritate the respiratory system, especially for individuals with pre-existing respiratory diseases such as asthma, emphysema, or chronic lung diseases. Even healthy individuals may experience chest discomfort, increased coughing, throat irritation, and sore throat. Prolonged exposure to fine volcanic ash may, in rare cases, lead to serious lung diseases such as silicosis. The ash particles can penetrate deeply into the lungs, causing acute respiratory symptoms and discomfort. Increased mucus production can further clog the airways, making breathing more difficult.

To protect against the effects of volcanic ash, it is recommended to stay indoors, keep doors and windows closed, and wear effective dust masks or goggles when outside. Reducing exposure and taking precautions can help minimise the potential health risks associated with volcanic ash.

Volcanic eruptions release water vapour, which combines with sulphur dioxide to form acid rain

Volcanic eruptions can have a significant impact on air pollution. They emit toxic gases and fine particles that can cause air pollution and have detrimental effects on the environment and human health. One of the most abundant gases released during a volcanic eruption is water vapour. While water vapour itself is harmless, it can combine with other volcanic emissions, such as sulphur dioxide, to form acid rain.

Volcanic eruptions release large quantities of water vapour (H₂O) into the atmosphere. Water vapour accounts for about 80% of the gases emitted during an eruption and is released as steam. It is one of the lightest volatiles, allowing it to be easily expelled and dispersed to high altitudes, including the troposphere and stratosphere.

Sulphur dioxide (SO₂) is another common gas released during volcanic eruptions. It is formed when magma, which contains dissolved sulphur, comes into contact with oxygen in the atmosphere and becomes oxidised. Volcanic eruptions can release about 10 parts per million (ppm) of sulphur dioxide, and in some cases, this number can exceed 20 ppm. Sulphur dioxide has a pungent odour and is irritating to the eyes, skin, and respiratory system.

When water vapour and sulphur dioxide combine in the atmosphere, they form sulphuric acid (H₂SO₄). This reaction results in acid rain, which has harmful effects on the environment. Acid rain can damage property, such as cars and buildings, and pollute water bodies, harming marine life and ecosystems. Additionally, acid rain can have detrimental effects on agriculture, reducing crop yields and impacting food security.

The combination of water vapour and sulphur dioxide can also lead to the formation of volcanic smog, often referred to as "vog". Vog is a toxic mixture of water and acid that poses significant health risks to individuals who breathe it. It can cause irritation to the eyes, skin, and lungs, as well as respiratory problems and other persistent health issues for downwind populations.

The release of water vapour and sulphur dioxide during volcanic eruptions, and their subsequent reaction to form acid rain, highlights the complex and far-reaching impacts of volcanic activity on air pollution and the environment. The effects of acid rain on ecosystems, agriculture, and human health underscore the importance of understanding and mitigating the consequences of volcanic eruptions.

Volcanic smog, or 'vog', is a mixture of water and acid that is harmful to human health

Volcanic smog, or vog, is a mixture of water and acid that is harmful to human health. Vog is a form of air pollution that results when sulfur dioxide and other gases and particles emitted by an erupting volcano react with oxygen and moisture in the presence of sunlight. The sulfur dioxide (SO2) gas can irritate skin and the tissues and mucous membranes of the eyes, nose, and throat, and can penetrate airways, producing respiratory distress in some individuals. Aerosol particles in vog can also penetrate deep into human lungs and, at elevated levels, can induce symptoms of asthma. The physical complaints associated with vog exposure include headaches, breathing difficulties, watery eyes, sore throat, flu-like symptoms, and a general lack of energy.

Vog is primarily associated with the Kīlauea volcano in Hawaii, which erupted continuously between 1983 and 2018. The gas plumes of Kīlauea rise from three locations: Halemaʻumaʻu, Puʻu ʻŌʻō, and along the coastline where lava flows from the East Rift zone enter the ocean. The plumes create a blanket of vog that can envelop the island, primarily affecting the Kona coast on the west side of the Island of Hawaii. However, prolonged periods of southerly Kona winds can cause vog to reach the eastern side of the island and even other islands across the state.

Vog is composed of a mixture of gases and aerosols, including sulfuric acid and other sulfates, which make it challenging to study and potentially more dangerous than its individual components. The aerosol particles in vog scatter light, making it visible, and they are small enough to remain in the lungs, damaging the lung tissue and impairing respiratory function. While the long-term health effects of vog are unknown, it has been linked to a range of adverse health effects, particularly in children and individuals with respiratory conditions.

In addition to its impacts on human health, vog can also negatively affect agriculture and the environment. The sulfuric acid droplets in vog have corrosive properties similar to battery acid. When vog comes into direct contact with moisture on plant leaves, it can cause severe chemical burns, damaging or killing the plants. Vog also contributes to acid rain, which can leach lead and other metals from roofing and plumbing materials, contaminating drinking water supplies.

Volcanic ash is made of rock, sand, and silt, and can cause long-term health issues such as silicosis

Volcanic ash is composed of fine particles of fragmented volcanic rock, mineral crystals, and volcanic glass. These particles are often hot close to the volcano but cool down as they travel further away. They are formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere. The force of the gases shatters the magma, propelling it into the atmosphere where it solidifies into fragments of volcanic rock and glass.

Volcanic ash is made up of a multitude of dangerous particles and gases, including aerosols. These include sulfates (sulfur dioxide), which can have serious effects on human health. Volcanic ash can also reduce visibility, posing a risk to drivers.

Volcanic ash can cause a range of respiratory issues, including nasal and throat irritation, and increased coughing. It can also lead to eye and skin irritation. In rare cases, long-term exposure to fine volcanic ash may result in serious lung diseases such as silicosis. Silicosis is a disease that impairs and scars the lungs, caused by exposure to particles of free crystalline silica. Minerals associated with silicosis, such as quartz, cristobalite, and tridymite, may all be present in volcanic ash.

Volcanic ash can have far-reaching impacts on society, including disruption to critical infrastructure and primary industries such as agriculture. It can also contaminate water supplies, posing risks to both human and animal health. The effects of volcanic ash on health are influenced by various factors, including the concentration of particles in the air, the frequency and duration of exposure, and meteorological conditions.

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