Extrapolation from Higher to Lower Exposure Rates

 

32

   

Interactions of Radon Progeny with Other Agents

 

32

   

Susceptibility

 

33

   

Links Between Biologic Evidence and Risk Models

 

33

   

Signatures of Radon Effects

 

33

   

Overview of Committee Risk Assessment

 

34

2

 

The Mechanistic Basis of Radon-Induced Lung-Cancer

 

36

   

Introduction

 

36

   

Radiation and Oncogenes

 

38

   

Tumor-Suppressor Genes

 

39

   

Genomic Instability

 

40

   

Individual and Genetic Susceptibility

 

41

   

Cell-Cycle Effects

 

44

   

Apoptosis

 

45

   

Radiation-Induced Perturbations of Cellular Proliferation

 

45

   

Cells at Risk

 

46

   

Target Size

 

48

   

The Special Nature of Biologic Damage Induced by Alpha Particles

 

49

   

Biologic Effects of Low Exposure Levels to Alpha Particles

 

56

   

Biologic Effects of Alpha Particles at Low Exposure Rates

 

58

   

Interactions Between Lung Carcinogens

 

62

   

The Dosimetric Approach to Radon Risk Estimation

 

63

   

Mechanistic Considerations in Assessing Risks Associated with Radon

 

64

   

Biologically-Based Risk Models

 

64

   

Extrapolation From High to Low Radon-Progeny Exposures

 

65

   

Effect of Changing Exposure Rate

 

67

   

Interaction of Radon Progeny with Other Agents

 

67

   

Biologic Signatures of Alpha-Particle Cancers

 

68

   

Individual Susceptibility

 

68

3

 

Models and Risk Projections

 

69

   

Introduction

 

69

   

Risk-Estimation Approaches

 

70

   

Dosimetric Approach

 

70

   

Biologically Motivated Approach

 

70

   

Empirical Approach

 

71

   

Rationale for the Committee's Chosen Method for Radon Risk Estimation

 

72

   

Previous Models

 

74

   

BEIR VI Risk Model for Lung-Cancer in Miners

 

76

   

Introduction

 

76

   

Sources of Data

 

76



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement