Performance of a soil model in predicting consequences of smelter emissions, including abatement scenarios: Fid-Bau Portal

Performance of a soil model in predicting consequences of smelter emissions, including abatement scenarios

Sheppard, Marsha I. / Hawkins, Janice L. / Aucoin, Richard

Surface soils have been sinks for contaminants for many decades, both intentionally and inadvertently. Most of the models used in risk assessments to determine surface soil concentrations have been very simple, one‐compartment, one‐direction models that compute total soil concentration from a source term. They may also provide an estimate of soil retention or storage and an output or loss term. The soil contaminant transport model SCEMR1, Soil Chemical Exchange and Migration of Radionuclides Version 1, predicts migration upward from a buried contaminated layer, dividing the surface soil into thin layers to provide detail. The computed concentrations can be used to estimate consequences of soil resuspension, soil ingestion, soil adhesion, and plant uptake. The SCEMR1 model is particularly well‐suited to inorganic contaminant migration. This study investigates the performance of the model in predicting surface soil concentrations of Pb, As/ Cd, and Sb from shelter emissions. Simulations for two decades of emissions are generally well within the range of the observed values for three smelters. Clear definition of the source term, the speciation or solubility of the element in the dustfall, the soil retention value, and the soil hydrological characteristics are important for good predictions. The predictions also show the model is useful in assessing emission‐control strategies and remediation of surface or buried contamination. Finally, we discuss how the model is superior to other simple compartment models for risk assessments.