Chapter 2.4: Volcanic gas impacts

Volcanic gases can pose a long-term hazard as they may be released during eruptive and non-eruptive periods. Acidic plumes, diffuse degassing, limnic eruptions and release of gases into the troposphere and stratosphere can affect natural and human environments, scaled to eruption size. The components of volcanic emissions that cause the most impact are CO2, SO2, H2S, 222Rn, HCl, HF, and PM. The consequences of volcanic gases for populations include deaths and impacts on physical and mental health. These depend on the duration of exposure and the concentration of the emissions. Socioeconomic impacts of gas emissions include evacuation of communities and abandonment of properties, damage to the built environment and disruption of tourism and agriculture even far from the degassing areas. Developing comprehensive risk management plans, including early warning systems, public education initiatives, and financial support mechanisms, may enhance community resilience and reduce the economic toll of volcanic gas emissions.