General Motors Sulfate Dispersion Experiment: Summary of EPA Measurements

Continuous Observation of Particulates During the General Motors Sulfate Dispersion Experiment

“…Both the dichotomous and "streaker" samplers collect aerosol particles on their filters and use x-ray analysis methods. The results for the fine particle fraction 3 (less orifice inertial impactors and are representative of the typical upwinddownwind size similarity observed during the experiment.…”

“…The experiment, designed to assess the dispersion of sulfate generated by catalyst equipped automobiles, has been previously described by Cadle, Chock, Monson and Heuss. 1 An interpretation of their results was given by Chock 2 and some of the EPA sponsored measurements were presented by William E. Wilson, et al 3 We present in this article the results and interpretation of our continuous time sequence measurements using "streaker" type filter Sun. Atmospheric sulfur concentrations in micrograms per cubic meter of air vs. time for the first sixteen days of October for two sampling sites using "streaker" samplers.…”

Fine Particles and Coarse Particles: Concentration Relationships Relevant to Epidemiologic Studies

“…The size distribution measurement in Figure 2, made in automobile traffic at the General Motors Proving Grounds, shows such a separation. 21 Measurements of particles in the background air, made before and after measurements in simulated freeway traffic, showed that all of the nuclei mode and a small fraction of the coarse mode were generated by the traffic, but that the accumulation mode and most of the coarse mode were present in the background air.…”

Diesel Aerosol Sampling in the Atmosphere

“…Although this concern about nanoparticle emissions is new, nanoparticle emissions are not. High concentrations of nanoparticles have been observed on and near roadways for many years [20][21][22][23][24]. Data from a 1979 roadway study [22] are also shown in Figure 2.…”