Continental aerosols were collected above a deciduous forest in eastern Tennessee and subjected to selective extractions to determine the water soluble and acid leachable concentrations of Cd, Mn, Pb, and Zn. The combined contribution of these metals to the total aerosol mass is 0.5%, ~70% of which is attributable to Pb alone. A substantial fraction (~50% or greater) of the acid leachable metals are soluble in distilled water. This water fraction generally increased with decreasing particle size and with increasing frequency of atmospheric water vapor saturation during a sampling period. The pattern of relative solubilities (Zn>Mn≂Cd>Pb) is similar to the general order of the thermodynamic solubilities of the most probable salts of these elements in continental aerosols with mixed fossil fuel and soil sources. |