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, a nd partitioning of persistent organic pollutants. The model consists of a v ariable number of latitudinal zones with specific annual temperature course s; each zone contains soil, oceanic surface water, and tropospheric air. Th e chemicals' degradation rates and Henry's law constants (H) are implemente d as functions of temperature and the concentrations in the soil, water, an d air compartments of each latitudinal zone are calculated as functions of time. The resulting temporal and spatial concentration patterns are charact erized by persistence and spatial range. Model calculations are carried out for tetra chloromethane, alpha-hexachlorocyclohexane (alpha-HCH), and mire x, and the specific distribution patterns of these three chemicals are disc ussed. 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.