Once dead, the organic material stops taking in carbon. This is what is known as carbon dating. Here's just a sampling of radioactive materials and the many ways they improve lives. There are some small sources of radiation in the home. Television sets accelerate electrons to make the picture on the screen, and produce a few low energy X-rays.
Smoke detectors contain small sources.
These sources emit radiation that is easily stopped even by smoke, and that way detect the presence of smoke. The sources of radiation around the home, not counting natural sources like radon, tend to make up a small fraction of the background dose. Persons in many occupations encounter radiation above normal background as a natural part of their jobs. The doses received can be up to several rem of exposure over the course of a year. Medical uses of radiation Medical uses of radiation are roughly broken into therapy and diagnosis.