EPA has released an enormously useful tool to quickly find information regarding physiologically-based pharmacokinetic modeling (PBPK). The PBPK Literature Visualization Project has recently released a "second generation computational and informatics tools can be used to automatically organize and give rapid access to the body of PBPK modeling literature." The revised tool now houses about 3,000 references that address the toxicology, mode of action, etc. of many types of chemicals. Take the revised tool for a test spin at http://pbpk.labworks.org. You can learn more about the application of PBPK in risk assessment here.