Radiation Risk Assessment

This page is brought to you by the Radiation Protection Program, which provides the methods and scientific basis for EPA's radiation exposure, dose, and risk assessments. These assessments, in turn support the development of EPA policy, guidance, and rulemakings concerning radiation protection and risk management. Among other functions, the Radiation Protection Program develops radionuclide fate and transport models, dose and risk models, and dose and risk coefficients. We also provide expert assistance, as requested, to other EPA program offices, EPA regional offices, other Federal Agencies, States, and occasionally, the general public. 

The Radiation Protection Program has developed useful software and publications to assist professionals who conduct radiation risk assessments. 

Includes radionuclide-specific lifetime radiogenic cancer risk coefficients for the U.S. population, based on age-dependent intake, dosimetry, and risk models. 

FEDERAL GUIDANCE REPORT 12 
 External Exposure to Radionuclides In Air, Water, and Soil
[EPA 402-R-93-081 September 1993]

Includes exposure-to-dose coefficients for general application, based on the 1987 Federal Radiation Protection Guidance.

FEDERAL GUIDANCE REPORT 11
 LimitingValues of Radionuclide Intake and Air Concentration and Dose conversion Factors for Inhalation, Submersion, and Ingestion. 
[EPA 520/1-88-020 September 1988]

Includes derived guides for control of occupational exposure and exposure-to-dose conversion factors for general application, based on the 1987 Federal Radiation Protection Guidance.

ESTIMATING RADIOGENIC CANCER RISKS
This document presents a revised methodology for EPA's estimation of cancer risks due to low-LET radiation exposures developed in light of information that has become available since the publication of BEIR III, especially new information on the Japanese atomic bomb survivors. NOTE: Minor updates to this methodology are contained in Federal Guidance Report 13.
[EPA 402-R-93-076 June 1994] 

HEAST TABLE 4 -- RADIONUCLIDE SLOPE FACTOR
EPA has developed radionuclide slope factors for estimating cancer risks at sites, managed under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), that are contaminated with radionuclides.

The Health Effects Assessment Summary Tables (HEAST) Table 4 lists ingestion, inhalation and external exposure cancer slope factors for radionuclides in units of picocuries (pCi). Ingestion and inhalation slope factors are central estimates in a linear model of the age-averaged, lifetime attributable radiation cancer incidence (fatal and nonfatal cancer) per unit of activity inhaled or ingested, expressed as risk/pCi. External exposure slope factors are central estimates of lifetime attributable radiation cancer incidence for each year of exposure to external radiation from photon-emitting radionuclides distributed uniformly in a thick layer of soil, and are expressed as risk/yr per pCi/gram soil. When combined with site-specific media concentration data and appropriate exposure assumptions, slope factors can be used to estimate lifetime cancer risks to members of the general population due to radionuclide exposures.

Documenting Ground-Water Modeling at Sites Contaminated with Radioactive Substances (WP 6/7/8, 2.09 MBytes zipped)

A Technical Guide to Ground-Water Model Selection at Sites Contaminated with Radioactive Substances (Adobe PDF, 1.45 MBytes)

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This page was updated on July 27, 2007