EPA's Office of Research and Development’s National Center for Environmental Assessment requested Science Advisory Board advice and recommendations on the recently-developed All-Ages Lead Model (AALM). The AALM was designed to predict lead concentration in body tissues and organs for a hypothetical individual, based on a simulated lifetime of lead exposure. Statistical methods will be used to extrapolate to a population of similarly-exposed individuals. The precursor to the AALM was the Integrated Exposure Uptake Biokinetic (IEUBK) Model for Lead in Children. Version 0.99d of the IEUBK was released in March 1994, and has been widely accepted in the risk assessment community as a tool for implementing the site-specific risk assessment process when the issue is childhood lead exposure. The All-Ages Lead Model has been developed to cover older childhood and adult lead exposure.