Radiation Protection

Tools for Calculating Radiation Dose and Risk

EPA bases its radiation protection activities on scientific assessment of health risks posed by radioactive substances. EPA's science-based tools help radiation-protection professionals calculate radiation dose and riskHelpriskThe probability of injury, disease or death from exposure to a hazard. Radiation risk may refer to all excess cancers caused by radiation exposure (incidence risk ) or only excess fatal cancers (mortality risk). Risk may be expressed as a percent, a fraction, or a decimal value. For example, a 1% excess risk of cancer incidence is the same as a 1 in a hundred (1/100) risk or a risk of 0.01..

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Blue Book: "EPA Radiogenic Cancer Risk Models and Projections for the U.S. Population"

The "EPA Radiogenic Cancer Risk Models and Projections for the U.S. Population," also known as the Blue Book, is an update of EPA's methodology for estimating cancer risks from radiation exposure. These updates are based on the National Research Council's 2006 report "Biological Effects of Ionizing Radiation (BEIR VII)," as well as on other updated science.

The Blue Book presents new EPA cancer incidence and mortality risk coefficients for the U.S. population from exposure to low doses of ionizing radiationHelpionizing radiationRadiation with so much energy it can knock electrons out of atoms. Ionizing radiation can affect the atoms in living things, so it poses a health risk by damaging tissue and DNA in genes.. The document also presents the scientific basis for the estimates. The Blue Book calculates cancer risk estimates separately by age at exposure, sex and potentially affected organ. Its risk estimate methodology reflects the scientific consensus of the BEIR VII committee.

Read more about EPA's Blue Book: EPA Radiogenic Cancer Risk Models and Projections for the U.S.

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HEAST Radionuclide Table

EPA, other federal agencies, states and contractors are responsible for the identification, characterization and remediation of sites contaminated with radioactive materials. These groups use radionuclideHelpradionuclideRadioactive forms of elements are called radionuclides. Radium-226, Cesium-137, and Strontium-90 are examples of radionuclides. slope factors in risk assessmentsHelprisk assessmentAn evaluation of the risk to human health or the environment from a hazard. Risk assessments may look at either existing hazards or potential hazards. to calculate potential risks to the general public. EPA calculates radionuclide slope factors to assist risk assessors with evaluations and decision-making at various stages of the remediation process. The HEAST Radionuclide Table lists ingestion, inhalation and external exposure cancer slope factors for radionuclides per unit of intake/exposure. EPA classifies all radionuclides as Group A carcinogens - known human cancer causing agents.

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).

View and download Radionuclide Table: Radionuclide Carcinogenicity Slope Factors.

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Dose and Risk Calculation Software (DCAL)

Under the sponsorship of the U.S. Environmental Protection Agency (EPA), Oak Ridge National Laboratory (ORNL) developed a comprehensive software system for the calculation of tissue dose and subsequent health risk from radionuclides in environmental media. EPA uses this system in radiation dosimetry and risk analysis.

DCAL, the Dose and Risk Calculation software, has been used in the development of two federal guidance reports (Federal Guidance Reports 12 and 13) and by the International Commission on Radiological Protection (ICRP) in the computation of age-specific dose coefficients for members of the public (ICRP publications 1989, 1993, 1995a, 1995b, 1996).


DCAL uses metabolic models from ICRP Publications 68 and 72 with data from ICRP Publications 23 and 89 to calculate dose per unit intake from over 800 radionuclides. DCAL then develops average lifetime risk estimates for a unit intake of radionuclide by a member of the U.S. population either by ingestion, inhalation or injection. DCAL applies the risk models from EPA's "Estimating Radiogenic Cancer Risks."  A detailed discussion can be found in EPA's "Federal Guidance Report No. 13, Cancer Risk Coefficients for Environmental Exposure to Radionuclides."

Download DCAL Software and Resources.

Note: This release of the DCAL system includes the nuclear decay data from ICRP Publication 107.  As a result, risk coefficients generated by this version of DCAL may not be identical with those listed in FGR 13, though differences should be negligible in most cases.  This version has also been modified to run on computers using Windows 7 or Windows 10 operating systems.

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Supplemental Software

These supplemental programs were designed to be used with Federal Guidance Report No. 13, Cancer Risk Coefficients for Environmental Exposure to Radionuclides: Updates and Supplements. For more information or additional materials, please see Federal Guidance Report No. 13: Supporting Materials.


Keith F. Eckerman and Richard W. Leggett
Oak Ridge National Laboratory

The software and data package DC_PAK (Dose Coefficient File Package) allows electronic access to nuclear decay data and dose and risk coefficients for exposure to radionuclides. DC_PAK has been built in a series of versions designed to allow access to expanded capabilities as they are completed. Eight versions of DC_PAK were built from 1996 through 2008. The present version, called DC_PAK 3.02, improves on the previous version by expanding the set of radionuclides addressed in the inhalation and ingestion scenarios. Version 3.02 also corrects an error in the module calculating the remainder dose, corrects the nuclear data file, uses of the ICRP lung deposition values as a f(amad) to improve the agreement with ICRP 72 values, and overcomes a Windows 7 and 8 issue in a commercial dll.

 DC_PAK 3.02 (EXE)(25 MB)  
Program can be installed and run from a flash drive (USD).

 DC_PAK 3.02 Abstract (WORD) (1 pg, 15 K)

AcuteDose Code Version 1.2

K. F. Eckerman
Oak Ridge National Laboratory
Nov 7, 2012

The AcuteDose code computes age-specific absorbed dose coefficients for user specified commitment periods (integration times post an acute intake) and radionuclides for inhalation and ingestion intakes of radionuclides. The upper limits for the integrals are read from \DATA\AcutDose.INI.

The absorbed dose rate files were archived on the FGR-13 CD.

The user selects

  1. either the ingestion or inhalation data set,
  2. the age(s) of interest and
  3. the organ(s) to be processed.

To select multiple ages or organs mark the desired items by holding down and clicking the left mouse button. When prompted, the user should enter the radioisotope of interest.

AcuteDose Calculator (EXE)(95 MB)
Program can be installed and run from a flash drive (USD).

RiskTab 2.2.1 Software Package

K.F. Eckerman
Oak Ridge National Laboratory 
Nov 14, 2012

RiskTab_Full_setup.exe installs the application RiskTab, its associated data files, and places the RiskTab icon on the desktop. The default folder for the installation is \RiskTab however you can select or define a different folder. Accept the defaults on any remaining questions during the installation. The installation will end with the option of displaying this file. RiskTab can be invoked by clicking its icon on the desktop. To remove RiskTab from the computer click the executable UNINS000.EXE in the in the folder to which RiskTab was installed.

RiskTab tabulates the lifetime risk per unit intake by inhalation or ingestion for a user specific radionuclide and period of chronic intake. The tabulations are derived from risk as a function of age files archived on the FGR 13 CD. The CD files have been converted to direct access files to facilitate RiskTab access to the data for the user specified radionuclide. Age and gender specific intakes for the intake period are calculated assuming a uniform concentration of the radionuclide in air and water (and in the diet). The risk coefficients for the intake are per Bq inhaled or ingested over the exposure period.

 RiskTab (EXE)(35 MB)  
Program can be installed and run from a flash drive (USD).

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