Global Impact of Sulfonamide Antibiotics on Nitrous Oxide Emissions from Aquatic Ecosystems

In this study, we combined meta-analysis, controlled incubation experiments, and quantitative global assessments to systematically evaluate the effects and underlying mechanisms of sulfonamides (SAs) on aquatic N₂O emissions. Our results demonstrate that SAs strongly stimulate N₂O emissions by as much as 94% at concentrations of 1–10 µg L^-1, preferentially inhibiting the <i>nos</i>Z gene responsible for N₂O consumption and thereby shifting microbial pathways toward net N₂O production. At the global scale, SAs increase emissions by 73% in rivers, 62% in lakes/reservoirs, and 61% in estuarine/coastal waters, corresponding to an additional 266 Gg N₂O-N yr^-1. Regionally, Africa exhibits the largest increases, while recent observations indicate a rebound in coastal ecosystems.