Long-dismissed gas emerges as a hidden driver of urban air pollution

Researchers from Tampere University and the University of Helsinki have identified an unexpected chemical process that may influence the formation of air pollution particles in urban environments. The study shows that nitric oxide (NO)—a pollutant primarily emitted by vehicles, power plants and other combustion sources—can promote the formation of aerosol particles, challenging a long-standing assumption in atmospheric science. The research is published in the journal Nature Communications.