This footage shows the 2021 eruption of Cumbre Vieja volcano on La Palma, which spewed lava onto 12 square kilometres of populated land🌋 Our Prof. Marie Edmonds and colleagues flew drones into these volcanic plumes to investigate emissions of volcanic pollutants. Video credit: Emma Nicholson.

Selenium is a volcanic pollutant of interest to Edmonds because it plays a dual role, both as a vital nutrient in trace amounts but as a potential toxin when present in excess. “Surprisingly little is known about volcanic sources of selenium and its persistence in the environment,” said Edmonds.