The objective of the study was to determine the feasibility of using measurements of the angular variation of the intensity of light scattered from single particles in the problem of identifying haze or aerosol particles originating from auto exhaust emissions. Scattering measurements were to be on single smog particles during a period of haze in Los Angeles. Analysis of scattering curves for larger laboratory aerosol particles shows measurable differences in refractive index between a photochemical pine tree aerosol and a photochemical petroleum aerosol. For particles of diameter less than 500 nanometers only the measurement of absolute scattering intensity at two angeles is required. Distinctive non-spherical and absorbing particles were observed both in automotive exhaust and atmospheric samples. Field measurements of single particle light scattering were carried out in Los Angeles and Santa Barbara.