Radon progeny--the decay products of radon gas--are a well-recognized cause of lung cancer in miners working underground. When radon was found to be a ubiquitous indoor air pollutant, however, it raised a more widespread alarm for public health.

To develop appropriate public policy for indoor radon, decisionmakers need a characterization of the risk of radon exposure across the range of exposures people actually receive. In response, the BEIR VI committee has developed a mathematical model for the lung cancer risk associated with radon, incorporating the latest information from epidemiology and scientific studies.

In this book the committee provides a fresh assessment of exposure-dose relationships. The volume discusses key issues--such as the weight of biological evidence and extrapolation from radon-exposed miners to the larger population--in estimating the risk posed by indoor radon. It also addresses such uncertainties as the combined effects of smoking and radon and the impact of the rate of exposure.

The committee considered the entire body of evidence on radon and lung cancer, integrating findings from epidemiological studies with evidence from animal experiments and other lines of laboratory investigation. The conclusions will be important to policymakers and environmental advocates, while the technical findings will be of interest to environmental scientists and engineers.

Contents

• COMMITTEE ON HEALTH RISKS OF EXPOSURE TO RADON (BEIR VI)
• BOARD ON RADIATION EFFECTS RESEARCH
• NATIONAL RESEARCH COUNCIL
• COMMISSION ON LIFE SCIENCES
• [The National Academies]
• Preface
• Public Summary: The Health Effects of Exposure to Indoor Radon
• Executive Summary
  • Introduction
  • The Mechanistic Basis of Radon-Induced Lung-Cancer
  • The BEIR VI Risk Models
  • Risk Assessment
  • Conclusions
• 1. Introduction
  • Radon and Lung Cancer: an Overview
  • Prior Reports on the Risk Associated with Radon
  • Population Exposure to Radon
  • The Committee's Approach
  • Critical Issues
  • Overview of Committee Risk Assessment
• 2. The Mechanistic Basis of Radon-Induced Lung Cancer
  • Introduction
  • Radiation and Oncogenes
  • Tumor-Suppressor Genes
  • Genomic Instability
  • Individual and Genetic Susceptibility
  • Cell-Cycle Effects
  • Apoptosis
  • Radiation-Induced Perturbations of Cellular Proliferation
  • Cells at Risk
  • Target Size
  • The Special Nature of Biologic Damage Induced by Alpha Particles
  • Biologic Effects of Low Exposure Levels to Alpha Particles
  • Biologic Effects of Alpha Particles at Low Exposure Rates
  • Interactions Between Lung Carcinogens
  • The Dosimetric Approach to Radon Risk Estimation
  • Mechanistic Considerations in Assessing Risks Associated with Radon
• 3. Models and Risk Projections
  • Introduction
  • Risk-Estimation Approaches
  • Rationale for the Committee's Chosen Method for Radon Risk Estimation
  • Previous Models
  • BEIR VI Risk Model for Lung Cancer in Miners
  • Coherence of Evidence from Miners and from the General Population
  • BEIR VI Risk Assessment for Lung Cancer in General Population
  • Sources of Uncertainty
  • Uncertainty Analysis
  • Comparisons with BEIR IV
  • BEIR IV and BEIR VI Risk Models
  • Summary and Conclusions
• 4. Health Effects of Radon Progeny on Non-Lung-Cancer Outcomes
  • Doses to Organs Other than Lung
  • Nonmalignant Respiratory Diseases
  • Malignancies Other than Lung-Cancer
  • Reproductive Outcomes
  • Conclusions
• Appendix A Risk Modeling and Uncertainty Analysis
• Appendix B Comparative Dosimetry
• Appendix C Tobacco-Smoking and Its Interaction with Radon
• Appendix D Miner Studies
• Appendix E Exposures of Miners to Radon Progeny
• Appendix F Exposures Other Than Radon in Underground Mines
• Appendix G Epidemiologic Studies in the Indoor Environment
• References
• Glossary
• Committee Biographies

This report was prepared under Grant No. X820576-01-0 between the National Academy of Sciences and the Environmental Protection Agency.

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard to appropriate balance.