The U.S. Environmental Protection Agency’s (EPA) Pacific Southwest Region has deployed emergency responders and air monitoring equipment as part of the Federal Emergency Management Agency’s federal response to the Kilauea volcanic eruption on Hawaii Island.
“EPA remains on the ground assisting Hawaii and our federal partners in monitoring air quality and ensuring the public is informed of all potential health risks from the Kilauea volcano eruption,” said EPA Administrator Scott Pruitt.
As part of EPA’s ongoing response efforts, the Agency is providing experts to analyze public health threats from volcanic gas emissions and for data management support. EPA is augmenting the multi-agency air monitoring efforts of acute threats to public health from the emission of volcanic gases.
The Agency is also working with the Hawaii Department of Health’s (DOH) staff to evaluate locations for additional air quality monitoring stations, and to integrate the multi-agency air quality data collection efforts by US Geological Survey/National Park Service, County of Hawaii, Hawaii Civil Defense, and Hawaii Department of Health.
EPA has deployed four staff and will mobilize additional equipment and personnel to support twelve monitoring stations for sulfur dioxide, hydrogen sulfide and particulates, and support DOH requests for assistance in collecting, managing and interpreting air monitoring data. EPA will continue to evaluate data collected from the Air Now Network operated by the DOH.
For more information please visit the Hawaii Interagency Vog Information Dashboard which has comprehensive information and data related to vog and ash hazards and impact: https://vog.ivhhn.org
What is vog?
The term ‘vog’ refers to the hazy air pollution caused by the volcanic emissions from Kīlauea volcano, which are primarily water vapor (H2O), carbon dioxide (CO2), and sulfur dioxide (SO2) gas. As SO2 is released from the summit and east rift eruptive vents, it reacts in the atmosphere with oxygen, sunlight, moisture, and other gases and particles and, within hours to days, converts to fine particles, which scatter sunlight, causing the visible haze that is observed downwind of Kīlauea. Areas far downwind (e.g., the west side of Hawaiʻi Island and other islands in the state) are mostly affected by the fine particles, however, areas closer to the eruptive vents, including the communities ranging from Ocean View to Hilo, can be exposed to both SO2 gas and fine particles during periods of vog.
SO2 is a colorless, irritating gas that has an acrid odor like fireworks or a burning match. It is also emitted from sources such as fossil fuel power plants and motor vehicles.
Fine particles consist of particulate matter less than 2.5 micrometers in diameter and are referred to as ‘PM2.5’. These particles are smaller than the width of a human hair. PM2.5 in vog is mainly composed of acid and neutral sulfate particles. Other sources of PM2.5 include vehicle exhaust and smoke from fires.
Vog contains mostly SO2 and acid particles, in contrast to urban, industrial, and other pollution sources, which also contain additional toxic contaminants, such as ozone and hydrocarbons.