Methodological considerations for determining cleanup limits for uranium in treated and untreated soils

Uranium‐contaminated soils are present at various locations across the U.S. where uranium was processed for nuclear fuels or atomic weapons. Important issues in dealing with such contamination include the assessment of the potential health risks associated with human exposures to the residual uranium and the determination of safe levels of U in soils that have been treated by a given technology. This paper reviews pertinent aspects of the health risks posed by uranium in soils and discusses various methodological considerations that must be dealt with in developing cleanup limits for U in treated soils. Of special concern is the development of remediation limits that are closely tied to a set of monitoring requirements for determining compliance with derived limits. Key issues addressed include characterization of the bioavailability of uranium compounds in food and water, determination of a safe level of uranium in kidney tissue, estimation of the health risks associated with the uranium daughter products radium and radon, assessment of the potential for ground‐water contamination, biogeochemical characterization of soil‐treatment processes, and specification of appropriate monitoring and statistical protocols for analyzing treated and untreated soils.