2018-05-11 Kīlauea Lower East Rift Zone FAQs. and Kilauea Summit Ash Hazard page

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Kīlauea Lower East Rift Zone (LERZ) Eruption FAQs This information addresses common questions about the emissions from eruption fissures on Kīlauea Volcano's Lower East Rift Zone (LERZ), like those in Leilani Estates. At this time, the eruption and response is ongoing and this information was last updated on 11 May 2018. What are the air pollution hazards from the current eruption in Lower Puna? The LERZ eruption is different from the 2014 Pāhoa lava flows. The vent for the 2014 lava ʻ ʻu ʻ flows was located close to the Puō vent, many miles upslope from the current LERZ Ō eruption. Gas from the lava escaped as the lava flowed downhill. The active lava flows had already lost much of their gas by the time they entered the Pāhoa community. In the current situation, the eruptive vents are located within or near residential areas. The lava being erupted contains very high amounts of gas, so the gas concentrations near the lava can be much higher than during the Pāhoa event. These concentrations may be similar to the amount released from the Halema'uma'u lava lake at the Kīlauea summit. The air pollutants of most concern during the current volcanic activity are:  SO: sulfur dioxide is a colorless, irritating gas that has an acrid odor like fireworks or 2 a burning match.  Sulfate particles: as SOis released, it reacts in the atmosphere and, within hours to 2 days, converts to fine particles called sulfate aerosol. This aerosol includes sulfuric acid droplets.  HS: hydrogen sulfide is a colorless, irritating gas that smells like rotten eggs. 2  HCl: There is a small amount of hydrogen chloride gas being released and it is at much lower concentrations than the SO. This is in contrast to what happens when 2 lava flows directly into the ocean where HCl acid is created as part of the ocean entry plume, and is the main hazard.  Burning vegetation, roads and structures produce smoke (particles and gas) which may contain irritating or harmful components. Are the concentrations from this eruption hazardous?  Very high concentrations of SO (spikes above 100 parts per million) have been 2 measured close to the erupting fissures. This is a serious hazard according to the NIOSH Immediately Dangerous to Life & Health threshold (IDLH) of 100 ppm of SO 2 (https://www.cdc.gov/niosh/idlh/default.html).  The gas is diluted with distance from the erupting vents to lower, but variable concentrations, depending on the wind conditions. In downwind areas in Lower Puna, concentrations as high as 5 ppm have been measured. Hawaii Department of