Since bioavailability can alter health risk estimates by a factor of 10, 100 or more, its importance in risk assessment cannot be underestimated. Presenting the basic principles that govern bioavailability and how it is measured, this very unique and timely book fills a void in the existing literature on toxicology and toxicokinetics. It contains clear and concise discussions on the behavior of environmental contaminants and how they reach the bloodstream in living organisms. It also presents an exhaustive review of measured bioavailability factors for environmental contaminants most frequently encountered at contaminated sites.