Abstract
The environmental issues concerning toxic chemical species have been getting much public attention. To make countermeasures against these issues, the concepts of risk assessment and risk management are getting popular, and they have been nearly established. Throughout these steps to know the human exposure against toxic chemicals, it is so important to know the environmental concentrations of them. However, it is difficult to obtain enough informations on these concentrations only by monitoring, and it is necessary to cover these lacks by model concentrations . Other kinds of importance have been pointed out. This paper describes on the status and importance of modeling techniques concerning such problems, and aims to discuss on their future status and perspectives.
