Caution urged with elevated volcanic gas emissions

The Hawaiʻi Department of Health urges residents and visitors to take precautions as elevated volcanic gas emissions from the recently paused Kīlauea eruption continue to produce vog (volcanic smog – hazy air pollution caused by the volcanic emissions) that can result in poor air quality across the islands.

According to the US Geological Survey, the Kīlauea summit ended its 38th episodic eruption on Dec. 9. Although the eruption has paused, high levels of volcanic gas create vog conditions that can have far-reaching effects downwind of the summit and can be hazardous to human health, particularly for sensitive populations.

Additional eruption hazards may include windblown volcanic glass (known as Pele’s hair) and volcanic rock fragments and ash, which can impact surrounding communities. Air quality can change quickly depending on the amount of emissions from the volcano, wind direction and other meteorological conditions.

Since the eruption first began on Dec. 23, 2024, air quality levels at several air monitoring stations on Hawaiʻi Island, Maui and Oʻahu have varied, with periodic increases in both sulfur dioxide (SO2) and fine particulate matter (PM2.5). While most station readings have indicated good or moderate air quality levels, air monitoring stations located in the southern part of Hawaiʻi Island have at times shown unhealthy air quality levels.

Short term exposure to elevated levels of SO2 and PM2.5 may cause temporary eye, nose, or throat discomfort, coughing, or increased mucus production for some individuals. At higher concentrations or during prolonged exposure, particularly among sensitive populations, more noticeable respiratory symptoms, including difficulty breathing or worsening of existing lung conditions, may occur. To learn more about the potential health effects of vog, please visit: Health effects of vog | IVHHN

Recommendations during vog conditions:

• Contact a medical provider if symptoms develop.
• Have medications readily on hand.
• Reduce outdoor activities; stay indoors and close windows and doors.
• Set air conditioners to recirculate air.
• The DOH does not recommend the use of respirators by the general public to protect against volcanic gases.

Especially vulnerable people include:

• Individuals with preexisting respiratory conditions such as asthma, bronchitis, emphysema and chronic lung or heart disease
• Children and infants
• Elderly individuals
• People who work or exercise outdoors
• Pregnant women

Guidance for short-term cleanup activities 

If you reside in an area that has received ash, Pele’s hair, or tears from an eruptive event, the DOH recommends using a well-fitting N95 (or equivalent) mask to help protect against volcanic ash during cleanup, as well as the use of heavy-duty gloves, long clothing (e.g., long sleeves and pants), shoes and eye protection. Masks are designed to filter particles and do not provide protection against toxic gases such as SO2. Avoid sweeping, blowers, or other mechanical devices that may stir ash back into the air.

More resources

• Guidance on reducing exposure and protecting health:
  • Guide for Particle Pollution | AirNow.gov
  • Volcano Watch — Hawaii State Department of Health updates Ambient Air Quality Data website | U.S. Geological Survey
  • www.ivhhn.org/ash-protection
• Latest air quality reports:
  • Clean Air Branch | Hawaii Ambient Air Quality Data
  • Vog Information Dashboard | IVHHN
• Volcano activity updates:
  • www.usgs.gov/volcanoes/kilauea/volcano-updates
• DOH Clean Air Branch:
  • health.hawaii.gov/cab/