Assessing Oral Bioavailability of Metals in Soil / by Mark E. Kelley ... [Et Al.].

Assessing Oral Bioavailability of Metals in Soil has been developed as a resource for anyone involved in remediating hazardous waste sites. The book brings together the most current information on bioavailability of metals in soils, and synthesizes this information into a practical handbook that explains concepts, identifies methods and data for assessing bioavailability, and illustrates how bioavailability adjustments can be incorporated into risk assessments to generate risk-based cleanup values that are more site specific than those based on the default assumptions of complete bioavailability. Although the guide focuses on oral bioavailability of metals to human receptors, many of the basic principles described can also be applied to assessing bioavailability of organic compounds and for assessing bioavailability to ecological receptors. Situations that are appropriate for conducting a bioavailability study are identified, In addition, the basic steps involved in concucting a bioavailability study are outlined and important factors that affect the acceptability of the results are discussed. A summary of metal-specific bioavailability data is provided for six metals that are common contaminants at hazardous waste sites-arsenic, cadmium, chromium, lead, mercury, and nickel. For each metal, the document provides a discussion of specific considerations relevant to the design of an in-vitro and an in-vivo bioavailability study. Standard operating procedures are provided for two generally accepted in-vitro test methods that measure the fraction of a metal solubilized under simulated gastrointestinal tract conditions. In addition, "example" protocols for in-vivo study design that have beenemployed to assess the oral bioavailability of arsenic and lead are provided. With input from appropriate experts, these protocols can be tailored to the specific needs of a particular site. They also provide a framework for professionals interested in designing and performing in-vivo studies for other metals discussed in this book. Laboratories and individuals experienced in conducting bioavailability studies of the type discussed in this book are also identified.