N-nitroso compounds: evidence for their presence in airborne particles.

Chemical, infrared, and thermal energy analyses have provided evidence for the presence of the N-nitroso functional group in extracts of airborne particles. The total molar N-nitroso concentrations in New York City air are equivalent to the total concentrations of polycyclic aromatic hydrocarbons. Since 90 percent of the N-nitroso compounds that have been tested are carcinogens, the newly discovered but untested materials may represent a significant environmental hazard.