1. Introduction 2. Radioactive Nuclides in Nature 3. Technologically Modified Exposure to Natural Radiation 4. Man Made Radioactivity 5. Measurements of Radioactivity 6. Radiation Safety 7. The Nuclear Fuel Cycle 8. The Bomb 9. Monitoring Accidentally Released Radionuclides in the Environment 10. Bomb Test Sites 11. International Safeguards 12. Environmental Monitoring for Safeguards 13. Comprehensive Test Ban Treaty