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Lung problems and volcanic smog

Volcanic smog is also called vog. It forms when a volcano erupts and releases gases into the atmosphere.

Volcanic smog can irritate the lungs and make existing lung problems worse.


Volcanoes release plumes of ash, dust, sulfur dioxide, carbon monoxide, and other harmful gases into the air. Sulfur dioxide is the most harmful of these gases. When the gases react with oxygen, moisture, and sunlight in the atmosphere, volcanic smog forms. This smog is a type of air pollution, which can be quite toxic.

Volcanic smog also contains highly acidic aerosols (tiny particles and droplets), mainly sulfuric acid and other sulfur-related compounds. These aerosols are small enough to be breathed deep into the lungs.

Breathing in volcanic smog irritates the lungs and mucous membranes. It can affect how well your lungs work. Volcanic smog may also affect your immune system.

The acidic particles in volcanic smog can worsen these lung conditions:

Symptoms of volcanic smog exposure include:

  • Breathing problems, shortness of breath
  • Coughing
  • Flu-like symptoms
  • Headaches
  • Lack of energy
  • More mucus production
  • Sore throat
  • Watery, irritated eyes


If you already have breathing problems, taking these steps can prevent your breathing from getting worse when you are exposed to volcanic smog:

  • Stay indoors as much as possible. People who have lung conditions should limit physical activity outdoors. Keep windows and doors closed and the air conditioning on. Using an air cleaner/purifier can also help.
  • When you do have to go outside, wear a paper or gauze surgical mask that covers your nose and mouth. Wet the mask with a solution of baking soda and water to further protect your lungs.
  • Wear goggles to protect your eyes from ash.
  • Take your COPD or asthma medicines as prescribed.
  • Do not smoke. Smoking can irritate your lungs even more.
  • Drink a lot of fluids, especially warm fluids (such as tea).
  • Bend forward at the waist slightly to make it easier to breathe.
  • Practice breathing exercises indoors to keep your lungs as healthy as possible. With your lips almost closed, breathe in through your nose and out through your mouth. This is called pursed-lip breathing. Or, breathe deeply through your nose into your belly without moving your chest. This is called diaphragmatic breathing.
  • If possible, do not travel to or leave the area where the volcanic smog is.


If you have asthma or COPD and your symptoms suddenly get worse, try using your rescue inhaler. If your symptoms don't improve:

  • Call 911 or the local emergency number right away.
  • Have someone take you to the emergency room.

Contact your health care provider if you:

  • Are coughing up more mucus than usual, or the mucus has changed color
  • Are coughing up blood
  • Have a high fever (over 100°F or 37.8°C)
  • Have flu-like symptoms
  • Have severe chest pain or tightness
  • Have shortness of breath or wheezing that is getting worse
  • Have swelling in your legs or abdomen

Alternative Names



Balmes JR, Holm SM. Indoor and outdoor air pollution. In: Broaddus VC, Ernst JD, King TE, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 6th ed. Philadelphia, PA: Elsevier; 2022:chap 102.

Centers for Disease Control and Prevention website. Key facts about volcanic eruptions. Updated January 25, 2022. Accessed May 26, 2022.

Feldman J, Tilling RI. Volcanic eruptions, hazards, and mitigations. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 17.

Jay G, King K, Cattamanchi S. Volcanic eruption. In: Ciottone GR, ed. Ciottone's Disaster Medicine. 2nd ed. Philadelphia, PA: Elsevier; 2016:chap 101.

Shiloh AL, Savel RH, Kvetan V. Mass critical care. In: Vincent J-L, Abraham E, Moore FA, Kochanek PM, Fink MP, eds. Textbook of Critical Care. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 184.

United States Geological Survey website. Volcanic gases can be harmful to health, vegetation and infrastructure. Accessed May 26, 2022.

Review Date 1/20/2022

Updated by: Denis Hadjiliadis, MD, MHS, Paul F. Harron, Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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