Ageing remarkably alters the toxicity of carbon black particles towards susceptible cells: determined by differential changes of surface oxygen groups

We uncover that O 3 -induced ageing dynamically alters the surface O-functionalities of carbon black (CB) nanoparticles, a model of airborne particles. The consequent distinct bioreactivity and toxicity towards susceptible cells under low-dose exposure are largely attributed to the variant species of O-functionalities, thereby signifying the importance of the environmental ageing process in changing CB toxicity features. Ageing process remarkably alters the toxicity of carbon black particles towards susceptible cells via changing the species of their surface oxygen groups.