A primary objective in environmental chemistry is to forcast the concentrations of pollutants in the
environments with respect to space and time variables. Our knowledge of the behavior of
pollutants can be used to model the space and time domains of pollants once emissions are known
or estimated. Fugacity models are distribution based models incoporating all environmenal
compartments, and are based on steady-state fluxes of pollutans across compartment interfaces.