24.4. Applications of Radioactivity http://www.ck12.org
24.4 Applications of Radioactivity
Lesson Objectives
- Describe sources of radiation in our environment.
- Describe the effects of nuclear radiation on living systems.
- Describe the use of radioisotopes in the diagnosis and treatment of various diseases.
Lesson Vocabulary
- cancer cell: A cell in which the control processes that regulate cell growth and division are not working
properly. - PET scan: A medical technique known as positron emission tomography which is used to study processes in
the brain.
Check Your Understanding
- What is the relative penetrating power for each type of radioactive decay?
- What happens to a positron when it collides with an electron?
Introduction
Previously, you learned about certain devices such as a Geiger counter which are used to measure exposure to
radiation. In this lesson you will learn about the negative effects of different radiation sources in our lives, as well
as some positive ways in which radiation can be used in the medical field.
Environmental Sources of Radiation
We are all exposed to a small amount of radiation in our daily lives. Much of this exposure is due to naturally
occurring radioactive substances and cosmic radiation (literally high energy particles flying in from space). For
example, radon is a colorless, odorless gas formed from the decay of various uranium and thorium isotopes, which
are found in the soil throughout much of the U.S. As a noble gas, radon is chemically inert, but it is also radioactive
and can easily be inhaled into the lungs. Radon exposure is highest in homes that lack good air circulation, which
would allow the gas to be cycled out of the residence. Fortunately, there are a number of inexpensive approaches to
decreasing your exposure to radon.