ocarbons and
oxides of nitrogen in the atmosphere. PAN has been
studied for its phytotoxic and mutagenic properties
and for its importance in the long-range transport of
oxides of nitrogen in the troposphere (Grosjean and
Harrison, 1985a). ]En the stratosphere, model calculations indicate that NO and the compounds NO2,
HNO3, N205, HO:~NO2, and C1ONO2 are the principal reactive nitrogen species.