Investigation of the cold condensation of persistent organic pollutants with a global multimedia fate model

In this paper we present a new global multimedia fate model that considers the influence of temperature on the environmental transport, degradation, and partitioning of persistent organic pollutants. The model consists of a variable number of latitudinal zones with specific annual temperature courses; each zone contains soil, oceanic surface water, and tropospheric air. The chemicals' degradation rates and Henry's law constants (H) are implemented as functions of temperature and the concentrations in the soil, water, and air compartments of each latitudinal zone are calculated as functions of time. The resulting temporal and spatial concentration patterns are characterized by persistence and spatial range. Model calculations are carried out for tetra chloromethane, alpha-hexachlorocyclohexane (alpha-HCH), and mirex, and the specific distribution patterns of these three chemicals are discussed. The model results show that the soil and water concentrations of the polar zones are strongly sensitive to changes of the latitudinal gradient of H and of washout ratios, adsorption to aerosol particles, and deposition rates.