Vog is a term that refers to volcanic smog. It is the haze you may see in the air that is caused by a combination of weather, wind conditions and volcanic activity. Vog becomes thicker or lighter depending upon the amount of emissions from Kilauea volcano, the direction and amount of wind, and other weather conditions. More information can be found here.

Vog is primarily a mixture of sulfur dioxide (SO₂) gas and sulfate (SO₄) aerosol. SO₂ (invisible) reacts with oxygen and moisture in the air to produce SO₄ aerosol (visible). Sulfate aerosols are very small particles consisting of particulate matter less than 2.5 micrometers in diameter and are referred to as PM_2.5. Other sources of PM_2.5 include vehicle exhaust and smoke from fires. Vog contains mostly SO₂ and PM_2.5, in contrast to urban, industrial, and other pollution sources, which also contain additional toxic contaminants, such as ozone and hydrocarbons. More information can be found here.

Health effects from vog will vary depending on the amount of vog present and an individual’s susceptibility. People most likely to experience negative health effects from vog include:

• people with asthma or other respiratory conditions
• people with cardiovascular disease
• older adults
• infants and children
• new or expectant mothers

Short-term exposure to elevated levels of SO₂ can cause symptoms such as irritation of the eyes, nose, throat and skin, coughing, wheezing, chest tightness, and difficulty breathing. Some people also report fatigue and/or dizziness.
Both long- and short-term particle (PM_2.5) exposures have been linked to various health problems. In the short-term, exposure to high levels of PM_2.5 may cause eye, nose and throat irritation, as well as coughing, phlegm production, chest tightness and shortness of breath. Long term exposure to elevated levels of PM_2.5 from industrial pollution has been associated with worsening of chronic respiratory and cardiovascular diseases and may cause reproductive and developmental harm.

For more information please visit IVHHN Vog Dashboard, EPA, and American Lung Association

Vog conditions can change rapidly due to changes in winds, weather and volcanic activity. Because conditions can change quickly, it is important for people living in and visiting areas impacted by vog take steps to keep themselves safe. It is recommended that people in vog-impacted areas keep aware of conditions and get familiar with key air monitoring websites and the SO₂ and PM_2.5 advisory codes/levels.This information can be found here. If you are feeling symptoms that may be related to vog or are aware of high levels of vog in your area, the following recommendations may help protect you from vog:

• Reduce outdoor activities that cause heavy breathing. Avoiding outdoor activity and exercise during vog conditions can reduce exposure and minimize health risks. This is especially important for sensitive groups such as children, the elderly, and individuals with pre-existing respiratory conditions including asthma, bronchitis, emphysema, and chronic lung and heart disease.
• Stay indoors and close windows and doors. If an air conditioner is used, set it to recirculate.
• If you need to move out of an impacted area, turn on the car’s air conditioner and set it to recirculate.
• Take daily prescribed medication for respiratory illnesses and always keep medications on hand and readily available.
• Remember that face coverings and masks used to prevent the spread of COVID-19 do not provide protection from SO₂ or vog.
• Contact a doctor as soon as possible if any health problems develop and seek medical care right away if you have severe symptoms or difficulty breathing.
• Do not smoke and avoid second-hand smoke.
• Drink plenty of fluids to avoid dehydration.
• Have family emergency plans prepared and ready.
• Heed all warnings by county and state emergency management officials.

More information can be found here.