Overview

• Researchers at ETH Zurich identified biological processes as a major factor in the atmospheric distribution of arsenic, previously thought to be dominated by human activities.
• Using advanced measurement techniques, the team analyzed arsenic in clouds, rainwater, and particulate matter at the Pic du Midi observatory in the Pyrenees, located 2,877 meters above sea level.
• The study found that methylated arsenic compounds, produced by organisms like bacteria, algae, and fungi, accounted for a significant portion of arsenic in some cloud samples.
• The findings indicate that arsenic undergoes transformations both on land and in the sea, with natural sources like plants and pollen contributing alongside industrial pollution.
• These results highlight the need to incorporate biological processes into global models of arsenic cycling to better understand its environmental and health impacts.