Rapid metal pollutant deposition from the volcanic plume of Kilauea, Hawai'i

Long-lived basaltic volcanic eruptions are a globally important source of environmentally reactive, volatile metal pollutant elements such as selenium, cadmium and lead. The 2018 eruption of Kilauea, Hawai'i produced exceptionally high discharge of metal pollutants, and was an unprecedented opportunity to track them from vent to deposition. Here we show, through geochemical sampling of the plume that volatile metal pollutants were depleted in the plume up to 100 times faster than refractory species, such as magnesium and iron. We propose that this rapid wet deposition of complexes containing reactive and potentially toxic volatile metal pollutants may disproportionately impact localised areas close to the vent. We infer that the relationship between volatility and solubility is an important control on the atmospheric behaviour of elements. We suggest that assessment of hazards from volcanic emissions should account for heterogeneous plume depletion of metal pollutants. Volatile metal pollutants in basaltic volcanic plumes can be deposited up to 100 times faster than refractory species, and may produce disproportionate impacts at proximal locations, according to extensive sampling of Kilauea's 2018 eruption plume.

Automated summary

Through extensive sampling of Kilauea's 2018 eruption plume, it was found that volatile metal pollutants in basaltic volcanic plumes can be deposited up to 100 times faster than refractory species, potentially producing disproportionate impacts at proximal locations. The relationship between volatility and solubility was identified as an important control on the atmospheric behavior of elements, suggesting that assessment of hazards from volcanic emissions should consider heterogeneous plume depletion of metal pollutants.