Characterization of the aerosol in the Great Smoky Mountains

A 6-day field study was conducted in the Great Smoky Mts to measure the composition of the aerosol that pervades this region. Sampling was performed with three dichotomous samplers, a mobile laboratory containing instruments to measure gaseous pollutants, and two gas chromatographs for measuring halocarbons. Sulfate and its associated cations represented 61% of the particle mass. The average ionic composition of the SO sub(4) super(2) super(-) , H super(+) , and NH sub(4) super(+) was equivalent to ammonium bisulfate. Of the total mass measured in the fine particles, elemental carbon accounted for 5% and organic carbon accounted for 10%. Crustal elements such as aluminum, calcium, iron, and silica were minor constituents of the fine-particle mass. During the period of the study, the fine-particle aerosol in the Great Smoky Mts was dominated not by natural organic compounds but by acid sulfates.