Hypothetical Health Risks from Exposure to Low Levels of Ionizing Radiation
Key LNT studies (for and against) are provided below in reverse chronological order.
Linear No Threshold (LNT) Model of Radiation Risk
- The History of the Linear No Threshold (LNT) Model. A 10-hour 22-episode video series by Dr. Edward Calabrese. This series hosted by the Health Physics Society demonstrates that research supporting LNT is based on scientific errors, profound bias, professional self-interest, scientific misconduct and lack of peer review. May 2022
- Linear No-Threshold Model and Standards for Protection Against Radiation. NRC denial of petition to remove LNT as the basis for its regulations. August 17, 2021.
- NCRP Report No. 186: Approaches for Integrating Information from Radiation Biology and Epidemiology to Enhance Low-Dose Health Risk Assessment. 2020
- American Nuclear Society Position Statement on "Risks of Exposure to Low-Level Ionizing Radiation." "Because of limitations of the LNT model, long-term research in lowlevel ionizing radiation exposure is needed to determine whether these exposures result in any relevant health impacts and how such information should be used in risk-informed decision-making." June 2020.
- Background Information. Excellent summary of existing research on low level radiation effects with 27 references.
- Health Physics Society Position Statement PS010-4: "Radiation Risk in Perspective." It states, "Due to large statistical uncertainties, epidemiological studies have not provided consistent estimates of radiation risk for effective doses less than 100 mSv." February 2019.
- Linear No Threshold Model of Radiation Risk. November 18, 2018.
- NCRP Commentary No. 27: Implications of Recent Epidemiologic Studies for the Linear-Nonthreshold Model and Radiation Protection. May 2018.
- Overview. NCRP recommends continued use of LNT as being he most "practical, prudent and pragmatic" model compared to other dose-response relationships.
- Table of Contents
- PDF or Hard Copy. $55.
- Health Physics Society SP001-01: Radiation and Risk: Expert Perspectives. 2017
- LNT 101. John Boice. September 2015
- Althogh Dr. Boice would describe himself as an LNT advocate, he acknowledges many of the anti-LNT arguments as illustrated below.
- "The LNT model is an assumption and has not been and cannot be scientifically validated in the low-dose range."
- "Other dose-response relationships for the mutagenic and carcinogenic effects of low-level radiation cannot be excluded, and there are notable exceptions to the LNT relationship seen in experimental and epidemiologic studies."
- "Exaggerated risks at low doses could result in spending limited societal resources to reduce exposures unnecessarily."
- "Exaggeration of risks also fans the flames of the growing public aversion to medical exposures and other man-made sources of radiation."
- "It is inappropriate to calculate the hypothetical number of cancers or heritable diseases that “might” be associated with very tiny radiation doses received by large numbers of people over very long periods of time, especially since such predictions are not observable."
- "Will the LNT hypothesis ever be validated? No. Epidemiology is an observational (i.e., non-experimental) science. It is not possible to provide convincing and consistent evidence of risks in the low-dose domain because of the inability to control for confounding factors and biases as well as the statistical inability to detect a tiny signal against a huge background noise (i.e., cancer is not an uncommon disease); the inherent uncertainties are just too great."
- One statement that Dr. Boice makes that does not hold water is, "Practical and prudent guidance has been provided on ways to protect workers and the public from any harmful effects of radiation without curtailing, hopefully, the beneficial uses of radiation in our society." The radiation paranoia that engulfs the public is due in no small part to LNT that encourages the mantras, "no safe level of radiation", "cleanup to background", opposition to nuclear power that is the solution to climate change, and the failure to extablish a national spent fuel reprocessing and/or disposal program.
- Health Physics Society Position Statement PS008-2: Uncertainty in Risk Assessment. February 2013
- NCRP Report No. 171: Uncertainties in the Estimation of Radiation Risks and Probability of Causation. 2012
- Radiation Risks in Everyday Life. Paper presented to the 2010 Mid-Year Conference of the Health Physics Society, Albuquerque, New Mexico. Theme - Radiation Risk Communication to the Public. Abstract. January 27, 2010.
- Linear No Threshold Model of Radiation Risk. September 10, 2007. DOE source.
- Background Radiation. A brief list of contributions to background radiation, with equivalent risk values, assuming that LNT is valid at background levels. September 10, 2007. DOE source.
- Communicating Radiation Risks - Crisis Communications for Emergency Responders. EPA-402-F-07-008. A resource for emergency responders and federal, state, and local officials communicating with the public and the media during a radiological crisis. It provides communications techniques and advice based on proven risk and crisis communications strategies as well as radiological scenarios and messages for use in radiologicaI emergencies. September 2007. EPA Source.
- Radiation Risk and Cleanup Standards. Paper presented to the 2007 Mid-year Health Physics Society Conference on Decontamiantion, Decommissioning and Environmental Cleanup. January 23, 2007.
- National Academy of Sciences, BEIR VII, "Health Risks from Exposure to Low Levels of Ionizing Radiation." BEIR VII states, "At doses of 100 mSv (10,000 mrem) or less, statistical limitations make it difficult to evaluate cancer risk in humans." Nevertheless BEIR VII confirmed the validity of the LNT model and recommends its continued use. June 2005.
- ICRP Publication 99: Low-dose Extrapolation of Radiation-related Cancer Risk. While existence of a low-dose threshold does not seem to be unlikely for radiation-related cancers of certain tissues, the evidence does not favour the existence of a universal threshold. The LNT hypothesis, combined with an uncertain DDREF for extrapolation from high doses, remains a prudent basis for radiation protection at low doses and low dose rates. October 2004
- Radiation Risk. A briefing (47 pages) on risks in everyday life, background radiation, and radiation risk. August 2002.
- How to Explain Radiation Risk. Washington State Department of Health. July 2002.
- NCRP Report No. 136: Evaluation of the Linear-Nonthreshold Dose-Response Model for Ionizing Radiation. June 2001
- General Accounting Office Report on Radiation Standards. This report concludes that there is lack of conclusive evidence of low level radiation effects below total exposures of 5,000 to 10,000 millirem, and therefore there is no public health difference between the NRC's 25 mrem/y standard and the EPA's 15 mrem/y standard. June 2000. Testimony before the U.S. Senate. July 2000.
- Low Dose Risk, Decisions, & Risk Communication. This project provides basic research in the areas of risk perception and decision making as applied to the requirements for communication on behalf of the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research, and the Low Dose Radiation Research Program. Decision Science Research Institute. June 12, 2000.
- Is a Linear Extrapolation of Cancer Risks to Very Low Doses Justified? Dan Strom. May 3, 2000.
- Radiation Risk and Ethics. Zbigniew Jaworowski. Physics Today. September 1999.
- Validity of the Linear No-Thresold Theory of Radiation Carcinogenesis at Low Doses. Bernard L Cohen. September 11, 1998.
- Linear, No-Threshold Dose-Response Model: Both Sides of the Story. Dan Strom. July 24, 1996.
- NRC SECY-96-110, Completion of Response to the Staff Requirements Memorandum, for SECY-95-249, on Risk Harmonization White Paper and Recommendations by the Interagency Steering Committee on Radiation Standards. This NRC staff paper compares theoretical radiation and chemical risks, in particular background levels of radiation and chemical risks. NRC source. May 1996.
- The Myth of 10-6 as a Definition of Acceptable Risk, Kathryn E, Kelly, June 1991
- National Academy of Sciences, BEIR V, "Health Effects of Low Levels of Ionizing Radiation." BEIR V states, "Studies of populations chronically exposed to low-level radiation, such as those residing in regions of elevated background radiation, have not shown consistent or conclusive evidence of an ssociated increase in the risk of cancer." June 1990.
EPA Radiation Risk Assessment Guidance
- Radiation at Superfund Sites. Provides EPA remedial project managers with information and guidance on the cleanup of radioactive contamination at Superfund sites.
- Cleanup Levels and ARARs Radiation Guidance
- Headquarters Consultation for Radioactively Contaminated Sites. OSWER Directive 9200.1-33P. July 2000.
- Establishment of Cleanup Levels for CERCLA Sites with Radioactive Contamination. This memorandum provides clarifying guidance for establishing protective cleanup levels for radioactive contamination at CERCLA sites. Cleanups of radionuclides are governed by the risk range (generally 10-4 to 10-6) for all carcinogens established in the National Contingency Plan when ARARs are not available or are not sufficiently protective. Dose limits in the NRC decommissioning rule (e.g., 25/100 millirems per year) should generally not be used to establish cleanup levels under CERCLA. OSWER Directive 9200.4-18, August 1997.
- Clarification of the Role of Applicable, or Relevant and Appropriate Requirements in Establishing Preliminary Remediation Goals under CERCLA. This memorandum clarifies that EPA may establish preliminary remediation goals (PRGs) at levels more protective than required by ARARs, even at sites that do not involve multiple contaminants or pathways of exposure. Although this memo does not focus on radiation issues, its general policy is part of the determination in OSWER Directive 9200.4-18 that dose limits in the NRC decommissioning rule should generally not be used to establish cleanup levels under CERCLA. OSWER Directive 9200.4-23. August 1997.
- Interim Final Evaluation of Facilities Currently or Previously Licensed NRC Sites under CERCLA. his memorandum provides interim guidance to clarify EPA's role under CERCLA at facilities previously or currently licensed by the NRC. This guidance is in response to EPA increasingly receiving requests to conduct response actions under CERCLA at previously or currently licensed facilities, or to make a determination if a past or proposed NRC decommissioning would meet CERCLA cleanup levels. OSWER Directive 9272.0-15P. February 2000.
- Superfund Risk Assessment Guidance
- EPA Risk Assessment Models
- Preliminary Remediation Goals (PRG). Soil cleanup levels based on a theoretical 1E-6 risk level.
- OSWER 9355.01-83A. Distribution of OSWER Radionuclide Preliminary Remediation Goals (PRGs) for Superfund Electronic Calculator.
- Dose Compliance Concentrations (DCC). Soil cleanup levels based on 1 mrem/y dose level.
- OSWER 9355.0-86A. Distribution of OSWER Radionuclide ARAR Dose Compliance Concentrations (DCCs) for Superfund Electronic Calculator.
- Buiding Preliminary Remediation Goals (BPRG). Interior building cleanup goals based on theoretical 1E-6 risk level.
- Building Dose Compliance Concentrations (BDCC). Interior building cleanup goals based on 1 mrem/y dose level.
- Surface Preliminary Remediation Goals (SPRG). Exterior hard surface cleanup goals based on theoretical 1E-6 risk level.
- Surface Dose Compliance Concentrations (SDCC). Exterior hard surface cleanup goals based on 1 mrem/y dose level.
- EPA Radiogenic Cancer Risk Models and Projections for the U.S. Population. This document referred to as the "BlueBook",presents new estimates of cancer incidence and mortality risks due to low doses of ionizing radiation for the U.S. population, as well as their scientific basis. It replaces the 1994 EPA report, Estimating Radiogenic Cancer Risks and the 1999 EPA report, Estimating Radiogenic Cancer Risks: Addendum: Uncertainty Analysis. In 1999, the Agency applied the 1994 Blue Book contents, metabolic models, and usage patterns to publish Federal Guidance Report 13 (FGR-13), Cancer Risk Coefficients for Environmental Exposure to Radionuclides. FGR-13 includes coefficients for calculating estimates of cancer risk for over 800 radionuclides.
It is anticipated that results presented here will be applied to update the radionuclide risk coefficients in the next revision of FGR-13. For the most part, estimates of radiogenic risk in this document are calculated using models recommended in the National Academy of Sciences report: Health Risks from Exposure to Low Levels of Ionizing Radiation, BEIR VII Phase 2 (NAS 2006). The NAS report, often referred to as BEIR VII, was sponsored by EPA and several other federal agencies. As in BEIR VII, models are provided here for estimating risk as a function of age at exposure, age at risk, gender, and cancer site, but a number of extensions and modifications to the BEIR VII approach have been implemented. April 2011. EPA source.
- EPA Superfund Radiation Risk Assessment Calculator Training. July 15, 2016. EPA source.
Interstate Technology & Regulatory Council (ITRC)
- Guidelines for use of ITRC materials and disclaimer.
- RISK-1. Examination of Risk-Based Screening Values and Approaches of Selected Sites. Provides information on the different methods used by regulatory agencies to develop and apply screening values for evaluating contaminated media. December 2005. ITRC source.
- Training Course. Risk Assessment and Risk Management: Determination and Application of Risk Based Values.
- RISK-2. Use of Risk Assessment in Management of Contaminated Sites. Through actual and hypothetical case studies, examines state regulatory agencies’ use of risk assessment and risk-related practices in managing contaminated sites. August 2008. ITRC source.
- Training Course. Use of Risk Assessment in Management of Contaminated Sites.
- RISK-3. Decision Making at Contaminated Sites: Issues and Options in Human Health Risk Assessment. Assists effective decision-making among state, local, and federal project managers and decision makers tasked with developing or reviewing risk assessments for contaminated sites using site-specific approaches, scenarios, and parameters. The document discusses commonly encountered issues organized around seven risk-assessment subjects (planning, data evaluation, toxicity, exposure assessment, risk characterization, risk management, and risk communication) when site-specific alternatives are proposed, and provides options for addressing these issues. Links to resources and tools that provide more detailed information on the specific issues and potential options are also provided. Community members and other stakeholders may find this document helpful for understanding and using risk assessment information to make better environmental decisions. January 2015. ITRC source.
- Training Course. Use of Risk Assessment in Management of Contaminated Sites.
- RRM-1. Project Risk Management for Site Remediation. Presents tools and processes to help remediation practitioners anticipate, plan for, and mitigate project risks. March 2011. ITRC source.
- Training Course: Project Risk Management for Site Remediation.
- RRM-2. Using Remediation Risk Management to Addres Groundwater Cleanup Challenges at Complex Sites. Applies the framework of project risk management for site remediation to identify and manage such challenges. January 2012. ITRC source.
- Electronic Risk Resource Sheet. August 20, 2008. ITRC source.