An atmospheric—terrestrial heavy metal transport model. I. model theory

A general model TOHM was developed to predict the terrestrial fate of zinc, cadmium, chromium, lead and mercury emitted by the operation of a coal-fired electric generating facility. The general model consisted of interfacing submodels describing atmospheric dispersion, precipitation, soil chemistry, and soil erosion. The models were developed from input data from a semi-arid region of the southwest United States, and except for the climatic and topographic constraints, are not site specific. TOHM was found to predict no substantial increase in indigenous levels of zinc, chromium and lead in the impact (deposition) area. However, both mercury and cadmium were predicted to be emitted and eroded to the environmental sink (receiving lake) in concentrations exceeding that naturally present in the system. TOHM is currently unvalidated, though comparison of soil erosion predictions with erosion quantities measured in the impact area gives good agreement.     

An atmospheric—terrestrial heavy metal transport model. II. Process equations

The process equations used by Wagenet et al. (1978) to describe the atmospheric— terrestrial transport of heavy metals are presented in detail. The accounting procedures allowing calculation of sediment eroded, heavy metal distribution, soil chemical reactions and precipitation are explained. The process equations for the atmospheric dispersion model of Wagenet et al. (1978) are not included.