Health
The insidious hazard of volcanic SO2 gas to human health: an in vitro study of the respiratory effects (RESPIRATORY)
Published on April 25, 2025 – Updated on May 19, 2025
Volcanic eruptions are natural disasters representing an important source of natural air pollutants, including, but not limited to, sulphur dioxide (SO2) gas and fine particulate matter (PM10, PM2.5). Volcanic emissions increase the ambient pollutant concentrations, with SO2 levels in particular often exceeding recommended air quality thresholds, and thereby contributing to poor air quality in populated areas. While several scenario-based volcanic risk studies have noted the potential for volcanic gas emission to cause impacts on downwind populations, agriculture and infrastructure, this insidious volcanic hazard has so far received little attention. Considering that both short-lived volcanic events and persistent gas plumes from degassing volcanoes can pose a significant risk to human lives, it is critical to gain an understanding of the possible mechanisms of adverse health effects associated with exposure to such emissions. This knowledge is necessary to put in place appropriate hazard communication and risk mitigation plans that can help to build local resilience and reduce the overall socio-economic impact of volcanic eruptions, especially in the context of developing countries.
The focus of this project is SO2, as it is one of the principal toxic gases released in abundance by volcanic activity. On a biological level, the mechanisms of lung injury caused by exposure to gaseous volcanic pollutants remain poorly investigated, even though they often represent the dominant exposure. In contrast, substantial knowledge of the respiratory hazard posed by volcanic ash has been obtained over the past decade, through in vitro and in vivo toxicology assessments and extensive characterisation of its physicochemical properties. Since SO2 is rarely inhaled in isolation, and is, instead, commonly exposed to the human population concomitantly with additional substances, such as volcanic ash or urban PM. Understanding how such co-exposure may influence the biological response in the lungs and whether it could contribute to an increase in adverse respiratory effects for exposed populations, is of critical importance. This is why the overall objective of the project is to experimentally investigate the hazard of inhaling volcanic SO2 gas concomitantly with volcanic ash in human lung cells. In the experiments, we use a sophisticated cell exposure system (CelTox Sampler, MedTek Biolab Inc, USA) featuring a unique temperature and humidity regulation, which is set up at the iGReD laboratory.
The potential hazard of concomitant exposure is important to understand so that civil protection managers and health agencies can make informed decisions on whether to advise that citizens, and particularly susceptible/sensitive individuals, take action to protect themselves during periods of intense or prolonged exposure to volcanic emissions. This research is a critical next step in deducing the respiratory health effects from exposure to multiple volcanic pollutants, which will increase our ability to forecast and mitigate volcanic hazards in the events of future eruptions and at persistently degassing volcanoes.
The focus of this project is SO2, as it is one of the principal toxic gases released in abundance by volcanic activity. On a biological level, the mechanisms of lung injury caused by exposure to gaseous volcanic pollutants remain poorly investigated, even though they often represent the dominant exposure. In contrast, substantial knowledge of the respiratory hazard posed by volcanic ash has been obtained over the past decade, through in vitro and in vivo toxicology assessments and extensive characterisation of its physicochemical properties. Since SO2 is rarely inhaled in isolation, and is, instead, commonly exposed to the human population concomitantly with additional substances, such as volcanic ash or urban PM. Understanding how such co-exposure may influence the biological response in the lungs and whether it could contribute to an increase in adverse respiratory effects for exposed populations, is of critical importance. This is why the overall objective of the project is to experimentally investigate the hazard of inhaling volcanic SO2 gas concomitantly with volcanic ash in human lung cells. In the experiments, we use a sophisticated cell exposure system (CelTox Sampler, MedTek Biolab Inc, USA) featuring a unique temperature and humidity regulation, which is set up at the iGReD laboratory.
The potential hazard of concomitant exposure is important to understand so that civil protection managers and health agencies can make informed decisions on whether to advise that citizens, and particularly susceptible/sensitive individuals, take action to protect themselves during periods of intense or prolonged exposure to volcanic emissions. This research is a critical next step in deducing the respiratory health effects from exposure to multiple volcanic pollutants, which will increase our ability to forecast and mitigate volcanic hazards in the events of future eruptions and at persistently degassing volcanoes.
Ines Tomašek
Laboratoire Magmas et Volcans (LMV)
Institut de Génétique, Reproduction et Développement (iGReD)
Université Clermont Auvergne