EVALUATING THE ENVIRONMENTAL FATE OF A VARIETY OF TYPES OF CHEMICALS USING THE EQC MODEL

The multimedia equilibrium criterion model, which can be used to evalu ate the environmental fate of a variety of chemicals, is described. Th e model treats chemicals that fall into three categories. In the first the chemicals may partition into all environmental media, in the seco nd they are involatile, and in the third they are insoluble in water. The structure of the model, the process equations, and the required in put data for each chemical type are described. By undertaking a sequen ce of level I, II, and III calculations, increasing information is obt ained about the chemical's partitioning, its susceptibility to transfo rmation and transport, and the environmental process and the chemical characteristics that most influence chemical fate. Output data, consis ting of tables and charts, give a complete picture of the chemical's f ate in an evaluative or generic environment. The model is illustrated by applying it to two chemicals, pyrene, which is a chemical of the fi rst type, and lead, which is of a second type. The role of this model as a tool for assessing the fate of new and existing chemicals is disc ussed.