This page offers risk assessment publications, developed by the Radiation Protection Program. You can downloaded them to your computer or view them on-line.
On this page:
- Federal Guidance Reports
- Heast Radionuclides Table -- Radionuclides Slope Factors
- EPA Assessment of Risks from Radon in Homes
- Comparative Dosimetry of BEIR VI Revisited
- Blue Book - EPA Risk Models Based on BEIR VII
- Relative Biological Effectiveness of Low-Energy Electrons and Photons
- Perspective on LNT
- Ground-Water Modeling
- Radiation Risk Assessment, Workshop Proceedings
Federal Guidance Reports and Related Documents
- Federal Guidance Report 13: Cancer Risk Coefficients for Environmental Exposure to Radionuclides [EPA 402-R-99-001]
Includes radionuclide-specific lifetime radiogenic cancer risk coefficients for the U.S. population, based on age-dependent intake, dosimetry, and risk models.
- Uncertainties in Cancer Risk Coefficients for Environmental Exposure to Radionuclides (PDF)(148 pp, 1.4 MB About PDF) [ORNL/TM-2006/583 January 2007]
This report is from a joint study by EPA and Oak Ridge National Laboratory on uncertainties of the federal guidance report risk coefficients for both ingestion and inhalation of radionuclides.
- Estimating Radiogenic Cancer Risks [EPA 402-R-93-076] June 1994
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: We have included minor updates to this methodology in Federal Guidance Report 13.
- Addendum: Uncertainty Analysis [EPA 402-R-99-003]
The analysis describes a method for estimating the uncertainties in EPA's risk projections for cancer risk from low-LET radiation exposures.
- Addendum: Uncertainty Analysis [EPA 402-R-99-003]
- 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: Limiting Values 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.
(HEAST) Radionuclides Table -- Radionuclide Slope Factors
Health Effects Assessment Summary Tables (HEAST) Radionuclides Table
These tables contain radionuclide slope factors for estimating cancer risks at sites managed under the Comprehensive Environmental Response, Compensation, and Liability Act. EPA has developed these cancer slope factors for ingestion, inhalation and external exposure to 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/year 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.
EPA Assessment of Risks from Radon in Homes
EPA updates its assessment of health risks from indoor radon, which the National Academy of Sciences (NAS) has determined to be the second leading cause of lung cancer after cigarette smoking.
EPA Assessment of Risks from Radon in Homes [EPA 402-R-03-003] June 2003
This risk assessment is based primarily on results from a recent study of radon health effects (BEIR VI) by the NAS, with some technical adjustments and extensions.
Comparative Dosimetry of BEIR VI Revisited
In support of EPA’s Assessment of Risks from Radon in Homes, the Agency sponsored a study designed to aid in the extrapolation of risk estimates based on data from underground miner cohorts to the case of residential exposures.
Comparative Dosimetry of BEIR VI Revisited , Radiation Protection Dosimetry 108:3-26; 2004) [A.C. James, A. Birchall and G. Akabani]
estimates the radiation doses delivered to target cells in the lung from radon progeny under indoor and mine exposure conditions.
Blue Book - EPA Risk Models Based on BEIR VIIBlue Book – EPA Radiogenic Cancer Risk Models and Projections for the US Population [EPA 402-R-11-001] April 2011
The EPA Radiogenic Cancer Risk Models and Projections for the U.S. Population, also known as the Blue Book, is a revision to EPA's methodology for estimating cancer risks from radiation exposure. These updates are based on the National Research Council's latest report on the Biological Effects of Ionizing Radiation (BEIR VII) as well as other updated science.
The Blue Book uses the best science available to calculate separate cancer risk estimates by age at exposure, what age a person might get cancer, sex, and potentially affected organ. More specifically, the Blue Book presents new EPA cancer incidence and mortality risk coefficients for the U.S. population from exposure to low doses of ionizing radiation. The document also presents the scientific basis for the estimates.
The Blue Book is an important intermediate step towards updating Federal Guidance Report No. 13 - Cancer Risk Coefficients for Environmental Exposure to Radionuclides (FGR-13), which allows for straightforward calculations of risks from ingestion and inhalation of radioactive substances.
- Draft Blue Book - EPA Radiogenic Cancer Risk Models and Projections for the U.S. Population(116 pp, 513 K About PDF)The National Research Council of the National Academy of Sciences released a report on the health risks from exposure to low levels of ionizing radiation in 2006. Cosponsored by the EPA and several other federal agencies, Health Risks from Exposure to Low Levels of Ionizing Radiation BEIR VII Phase 2 (BEIR VII) primarily addresses cancer and genetic risks from low doses of low-LET radiation (high energy photons and electrons).
The draft Blue Book is a proposed revision of EPA's methodology for estimating radiogenic cancers, based on the contents of the National Research Council's BEIR VII report and some ancillary information. It takes into account the Science Advisory Board's advisory review comments on the white paper below.
- Draft White Paper: Modifying EPA Radiation Risk Models Based on BEIR VII (PDF) (36 pp, 381 K About PDF)
In this paper, we outline proposed changes in EPA’s methodology for estimating radiogenic cancers, based on the contents of BEIR VII and some ancillary information.
Relative Biological Effectiveness of Low-Energy Electrons and Photons
Relative Biological Effectiveness of Low-Energy Electrons and Photons (PDF) (25 pp, 689 K About PDF)
Different types of radiation deposit energy in biological tissues in different ways, which affects the amount of cellular damage. RBE (relative biological effectiveness) is a relative measure of the damage done by a given type of radiation per unit of energy deposited in biological tissues. Compared with higher energy photons such as cobalt-60 gamma rays, lower energy electrons and photons produce more dense clusters of ionizations, leading to more complex damage to the cell's DNA, and thus a higher RBE.
In this work, relative biological effectiveness values were derived for electrons and photons as a function of energy. There is growing evidence to support a relative biological effectiveness greater than one for low-energy electrons and photons. For example, a number of experimental studies suggest RBE values between two and three for tritium, meaning that the low-energy electrons emitted by tritium do two to three times the damage to cells per unit of energy deposited when compared to higher energy radiation. Other radiation sources with similar energy emissions may also exhibit an elevated RBE. Consideration of the potentially greater effectiveness of these radiations is important to improve the quality of risk assessments.
Perspective on LNT
Perspective on the use of the LNT for Radiation Protection and Risk Assessment by the U. S. Environmental Protection Agency (8 pp, 78 K About PDF)
This paper discusses EPA’s views on the controversy surrounding the use of the linear, no-threshold (LNT) model in radiation risk assessment, guidelines, and regulations.
- Documenting Ground-Water Modeling at Sites Contaminated with Radioactive Substances [EPA 540-R-96-003]
This report demonstrates a thorough approach to documenting model applications in a consistent manner and is intended to assist technical staff responsible for identifying and implementing flow and transport models in support of cleanup decisions at radioactive and hazardous waste sites.
- A Technical Guide to Ground-Water Model Selection at Sites Contaminated
with Radioactive Substances [EPA 402-R-94-012] June 1994
This report specifically addresses the selection of ground-water flow and contaminant transport models and is intended to be used by hydrogeologists and geoscientists responsible for identifying and selecting ground-water flow and contaminant transport models for use at sites containing radioactive materials.