Production of singlet delta oxygen by atmospheric pollutants.

Singlet delta oxygen (1O2) was generated at atmospheric pressure using heterogeneous gas-phase photosensitization. Polycyclic aromatic hydrocarbons (PAH), known constituents of the atmosphere, were found to be efficient sensitizers in the production of singlet delta oxygen under simulated environmental conditions. A novel mechanism involving singlet delta oxygen is proposed in which PAH on particle surfaces are self-activated to form direct-acting mutagens.