Summary

Chapter 9, “Radioactive Decay,” gets more into the mechanisms of how and why radiation is dangerous, based mainly on the concept of half-lives. Muller says that there are three main factors taken into consideration when deciding whether a material is dangerous, at least in terms of radioactivity. For how long will it emit radiation, what kind of radiation will it emit, and how much radiation will it emit at any given time? Radiation is given off when the nucleus of a cell breaks down or explodes, releasing its particles. This can only happen so many times before all of the nuclei in a given sample of material will be used up. “Radioactive Decay” is divided into five subsections.

“Dangers of Short Versus Long Half-Lives,” compares the dangers posed by different sources of radiation. The half-life of an element is the time it takes...