Correcting Some Misconceptions about EPA's Superfund Approach for Radiation Risk Assessment (Jan 31, 2024)

Contaminated Site Clean-Up Information (CLU-IN): Internet Seminar Video Archives

The U.S. Environmental Protection Agency (EPA) Office of Superfund Remediation and Technology Innovation (OSRTI) has primary responsibility for implementing the remedial long-term (non-emergency) portion of a key U.S. law regulating cleanup: the Comprehensive Environmental Response, Compensation and Liability Act, CERCLA, nicknamed "Superfund." The Superfund program generally addresses radioactive contamination in a consistent manner as it addresses chemical contamination, except where there are technical differences between radionuclides and other chemicals. For example, cleanup levels for radioactive contamination at sites are generally expressed in terms of risk levels (e.g., 10-4), rather than millirem or millisieverts, as a unit of measure. Although EPA and other US agencies have issued millirem-based regulations under other statutory authorities, under CERCLA EPA promulgated a risk range of 10-4 to 10-6 as a standard of protectiveness for all carcinogens including radionuclides. CERCLA guidance recommends the use of slope factors when estimating cancer risk from radioactive contaminants, rather than converting from millirem. Current slope factors are based on risk coefficients in Federal Guidance Report 13. The Superfund remedial program uses 10-6 as a point of departure and establishes Preliminary Remediation Goals (PRGs) at 1 x 10-6. PRGs not based on other environmental standards known as Applicable or Relevant and Appropriate Requirements (ARARs) are risk-based concentrations, derived from standardized equations combining exposure information assumptions with EPA toxicity data. The policy rationale and technical underpinnings for this risk management approach is often misunderstood by radiation professionals. This presentation will help clarify some of these misunderstandings by focusing on misstatements about the Superfund approach that the author has encountered from radiation professionals. Often, they are citing the wrong EPA documents or portions of documents incorrectly, or not reading sections of the correct Superfund guidance. To view this archive online or download the slides associated with this seminar, please visit http://www.clu-in.org/conf/tio/RadRA_013124/