Associate Professor Asa-Awuku strives to understand the molecular components of the atmosphere that exist at the ultrasmall nanoscale, where one nanometer is one-billionth of a meter. In nature, atmospheric nanoparticles have a range of effects, from interacting with cloud droplets to form or inhibit rain to modulating greenhouse gas behavior. In humans, they can be inhaled and impact the respiratory system or be used as biological or chemical threats in conflicts.