1. Nuclear Radiation Today Chapter 10.3 Notes

2. Where is radiation? Radiation is everywhere—the form of nuclear radiation that occurs naturally is called background radiation We are continually exposed to radiation from sources like the sun, soil, rocks, and plants More than 80% of the radiation we are exposed to comes from natural sources The other 20% of our radiation exposure comes from human-made sources, such as computer monitors, smoke detectors, and X rays

3. Rems Levels of radiation absorbed by the human body are measured in rems Occupations that involve exposure to radiation include nuclear engineering, health physics, radiology, radiochemistry, and X ray technology—the safe limit of radiation for these workers is set at 5,000 millirems per year When you get an X ray at the dentist, you are typically exposed to about 1 millirem

4. Radiation Exposure by Location The amount of radiation an individual is exposed to varies by location Individuals who live in an area of higher elevation receive more radiation from space than those in an area of lower elevation People in areas with many rocks receive more nuclear radiation than those with fewer rocks

5. Radiation Exposure by Activities Participation in different activities can also lead to an increase in nuclear radiation exposure

6. Beneficial Uses of Nuclear Radiation Nuclear radiation can be used beneficially—such as medical diagnosis and treatment, smoke detectors, manufacturing, and agriculture Doctors can view images of parts of the organs and detect dysfunction or disease through the use of ultrasound scanning, CT scanning, PET scanning, and magnetic resonance imaging (MRI) Radioactive tracers are short-lived isotopes that concentrate in the area of affected cells and can be used to locate tumors Radiotherapy uses controlled doses of nuclear radiation to treat cancer Tracers can also be used on farms to show how fast water moves through the soil or through stems and leaves of crops

7. Risks from Nuclear Radiation The risk of damage from nuclear radiation depends on both the type and amount of radiation exposure Leukemia, lung, breast, and stomach cancers are associated with exposure to high levels of radiation Remember that alpha and beta particles cannot travel very far into matter, but many feet of material might be needed to protect us from gamma rays People can get radiation sickness from repeated exposure or a single dose of a large amount of radiation—people working close to radiation need to protect themselves Radon gas is often found in basements by seeping through cracks in the foundation—too much exposure can lead to lung cancer

8. Nuclear Power: Fission Energy that is produced from nuclear fission can be used to provide electrical energy to millions of homes and businesses Advantages: no gaseous pollutants are produced, there is more energy in the known uranium reserves than in the known reserves of coal and oil Disadvantages: fission produces energy but it also produces radioactive isotopes that need to be handled carefully so they do not escape into the environment and create nuclear radiation

9. Nuclear Power: Fusion Solar energy resulting from fusion in the sun can be captured by solar panels and used to provide energy for homes and businesses Advantages: fusion releases very little waste or pollution, the fuel for fusion is abundant because hydrogen is the most common element in the universe Disadvantages: fusion can produce fast neutrons that are a highly energetic and potentially dangerous form of nuclear energy, it is expensive to operate a fusion power plant