Source profiles for nonmethane organic compounds in the atmosphere of Cairo, Egypt

Profiles of the sources of nonmethane organic compounds (NMOCs) were develo ped for emissions from vehicles, petroleum fuels (gasoline, liquefied petro leum gas [LPG], and natural gas), a petroleum refinery, a smelter and a cas t iron factory in Cairo, Egypt. More than 100 hydrocarbons and oxygenated h ydrocarbons were tentatively identified and quantified. Gasoline-vapor and whole-gasoline profiles could be distinguished from the other profiles by h igh concentrations of the C-5 and C-6 saturated hydrocarbons. The vehicle e mission profile was similar to the whole-gasoline profile, with the excepti on of the unsaturated and aromatic hydrocarbons, which were present at high er concentrations in the vehicle emission profile. High levels of the C-2-C -4 saturated hydrocarbons, particularly n-butane, were characteristic featu res of the petroleum refinery emissions. The smelter and cast iron factory emissions were similar to the refinery emissions; however, the levels of be nzene and toluene were greater in the former two sources. The LPG and natur al gas emissions contained high concentrations of n-butane and ethane, resp ectively. The NMOC source profiles for Cairo were distinctly different from profiles for U.S. sources, indicating that NMOC source profiles are sensit ive to the particular composition of petroleum fuels that are used in a loc ation.