This book is intended to serve as a comprehensive source for the advancements and contributions made in environmental transformation and transport modeling in general and the associated health risk assessment topics in particular. The selection of the title, Environmental Modeling and Health Risk Analysis stems from an ambitious objective of providing a review of air, surface water and groundwater quality modeling topics and linking these models with exposure and health risk analysis. Thus, the purpose is to provide the reader with an integrated perspective on these two seemingly distant fields. The ACTS and RISK software that is an integral part of this book include computational platforms for all models discussed in the book. Using these two software tools, available from http://extras.springer.com/ , the models described in the book can be readily accessed and used in classroom or professional applications as demonstrated in the book.