1. 24-2: Biological Effects of Radiation

2. Units of Radiation SI unit: Becquerel (after Henry Becquerel, discovered of radioactivity) SI unit: Becquerel (after Henry Becquerel, discovered of radioactivity) Curie: equal to the number of nuclear disentigrations/second from 1 gram of radium (named after Pierre and Marie Curie – discovered radium) Curie: equal to the number of nuclear disentigrations/second from 1 gram of radium (named after Pierre and Marie Curie – discovered radium) Rem: measures exposure to radioactivity (after Wm. Roentgen – discovered X-rays) Rem: measures exposure to radioactivity (after Wm. Roentgen – discovered X-rays)

3. Measuring Radiation Dosimeter: device that measures total radiation received by a person; uses photo film Dosimeter: device that measures total radiation received by a person; uses photo film

4. Effects of Radiation Strips electrons from molecules in living tissue. Strips electrons from molecules in living tissue. Disrupts living cells. Disrupts living cells. Commonly causes leukemia. Commonly causes leukemia.

5. Types of Radiation Damage Direct damage (somatic): burns, rashes, cancers Direct damage (somatic): burns, rashes, cancers Genetic damage: affects reproductive cells, resulting in birth defects Genetic damage: affects reproductive cells, resulting in birth defects Nagasaki Photos Nagasaki Photos Nagasaki Photos Nagasaki Photos Radiation burns Radiation burns Radiation burns Radiation burns

6. Detection Geiger counter: produces an audible “click” Geiger counter: produces an audible “click”

7. Beneficial Uses of Radioisotopes 1. Radiotracers: follow substances as they move through a system 1. Iodine-131: thyroid function 2. Barium-140: follows silt in rivers 3. Phosphorus-32: follows nutrients in plants 4. cobalt-58: traces vitamin B-12 pathways

8. Beneficial Uses of Radioisotopes 2. Cancer treatment: kills fast growing cancer cells 1. Iodine-131: thyroid cancer 2. Iridium-192 3. cobalt-60 4. Also kills other fast growing cells, such as hair and stomach lining

9. Beneficial Uses of Radioisotopes 3. Food preservation: kills bacteria on food 1. Cobalt-60