An official website of the United States government.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Radiation Protection

Radionuclide Table: Radionuclide Carcinogenicity Slope Factors

The Radionuclide Table and User's Guide are available for download in PDF format only. The April 2001 update of the Radionuclide Carcinogenicity Slope Factors for HEAST is based on Federal Guidance Report No. 13, which was developed by EPA's Office of Radiation and Indoor Air (ORIA).

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.
  • User's Guide (PDF)(12 pp, 87 K)
    The User's Guide describes the derivation of the slope factors in the Radionuclide Table, information about the table, and contact information.
  • Radionuclide Table (PDF)(72 pp, 714 K)
    The Radionuclide Table, formerly HEAST Table 4, lists ingestion, inhalation and external exposure cancer slope factors (risk coefficients for total cancer morbidity) for radionuclides in conventional units of picocuries (pCi).