Effect of Soil Properties on Metal Bioavailability: Field Scale Validation to Support Regulatory Acceptance.

摘要

The U.S. Department of Defense (DoD) faces a potentially daunting task of remediating thousands of metal-contaminated sites within the U.S. and its territories that contain unacceptable levels of the toxic metal(loid)s arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb). With the exception of Pb contaminated soils, human health and ecological risk drivers have prompted the U.S. Environmental Protection Agency (EPA) to assume that the total soil metal concentration is 100% bioavailable. Previous Strategic Environmental Research and Development Program (SERDP) funded research (ER-1166) has shown that the ubiquitous metal-sequestering properties of soil can significantly lower the bioavailability and risk of heavy metals to human and ecological receptors. This investigation brought together regulators, EPA, end-users, and scientists to demonstrate the applicability of these concepts by showing that simple, readily available soil properties can often be used to predict the bioavailability of As, Cd, Cr, and Pb with a reasonable level of confidence. We have shown that in vitro methods can often be used for risk assessment of toxic metals in soil by comparing in vitro and in vivo metal bioavailability studies.