Ions and Isotopes

1. Ions and Isotopes • Ions have charge • Cations + • Anions - • Isotopes vary in mass • Neutrons • Radioisotopes • Unstable nuclei • Emit energy -radiation • Medical uses as tracers and treating disease

2. Four Primary Types of Ionizing Radiation:Alpha Particles Alpha Particles: 2 neutrons and 2 protons They travel short distances, have large mass Only a hazard when inhaled

3. Four Primary Types of Ionizing Radiation:Beta Particles Beta Particles: Electrons or positrons having small mass and variable energy. Electrons form when a neutron transforms into a proton and an electron or when a proton transforms into a positron and a neutron:

4. Four Primary Types of Ionizing Radiation:Gamma Rays Gamma Rays (or photons): Result when the nucleus releases Energy, usually after an alpha, beta or positron transition

5. Four Primary Types of Ionizing Radiation:X-Rays X-Rays: Occur whenever an inner shell orbital electron is removed and rearrangement of the atomic electrons results with the release of the elements characteristic X-Ray energy

6. Four Primary Types of Ionizing Radiation:Neutrons Neutrons: Have the same mass as protons but are uncharged They behave like bowling balls

7. Four Primary Types of Ionizing Radiation • Alpha particles • Beta particles • Gamma rays (or photons) • X-Rays (or photons) • Neutrons

8. Ionization • Ionizing radiation is produced by unstable atoms. Unstable atoms differ from stable atoms because they have an excess of energy or mass or both. • Unstable atoms are said to be radioactive. In order to reach stability, these atoms give off, or emit, the excess energy or mass. These emissions are called radiation.

9. Types or Products of Ionizing Radiation   or X-ray neutron

10. DNA and Radiation

11. Ionizing Radiation at the Cellular Level • Causes breaks in one or both DNA strands or; • Causes Free Radical formation

13. Commonly Transported Radioisotopes • Americium-241= Diagnose thyroid disorders, smoke detectors. • Cesium-137= Cancer treatment. • Iodine-125,131= Diagnosis & treatment liver, kidney,heart, lung and brain. • Technetium-99m=Bone and brain imaging; thyroid and liver studies; localization of brain tumors.

14. rad • 1 rad = 1 Roentgen

15. rem • Roentgen Equivalent Man • The unit of dose equivalent for any type of ionizing radiation absorbed by body tissue in terms of estimated biological effect - Unit of dose equivalent • Dose in health record is in units of rem • 1 rem = 1 Roentgen

16. Quality Factor (Q) The specific value that accounts for the ability of different types of ionizing radiation to cause varying degrees of biological damage • X-rays, gamma rays, & beta particles 1 • Neutrons & High energy protons 10 • Alpha Particles 20

17. Units of Radioactivity • Curie (Ci) = 2.22 E12 dpm or 3.7E10 dps • Becquerel (Bq) = 1 dps • Maximum Dose/year = 5 REM or 50 mSv • Maximum Dose/year for Declared Pregnant Woman & Minors= 0.5 REM or 5 mSv

18. Half Life Calculation

19. Adult ($18 yrs) Minor (< 18 yrs) Whole body* 5000 mrem/yr 500 mrem/yr Lens of eye 15000 mrem/yr 1500 mrem/yr Extremities 50000 mrem/yr 5000 mrem/yr Skin 50000 mrem/yr 5000 mrem/yr Organ 50000 mrem/yr 5000 mrem/yr Annual Dose Limits External/Internal Exposure Limits for Occupationally Exposed Individuals • *Effective dose equivalent

20. Dose Response Relationships • 0-150 rem—No or minimal symptoms • 150-400 rem—Moderate to severe illness • 400-800 rem—Severe illness deaths start above 500 rem • Above 800 rem—Fatal ***Acute whole body doses

21. Activity Typical Dose Smoking 280 millirem/year Radioactive materials use in a UM lab <10 millirem/year Dental x-ray 10 millirem per x-ray Chest x-ray  8 millirem per x-ray Drinking water  5 millirem/year Cross country round trip by air  5 millirem per trip  Coal Burning power plant 0.165 millirem/year  Your Annual Exposure

23. Effective doses of ionizing radiation from medical procedures Fazel R et al. N Engl J Med 2009; 361: 849-57.

24. Medical imaging procedures with largest contribution to cumulative effective dose Fazel R et al. N Engl J Med 2009; 361: 849-57.

27. Estimated Exposure To The National Population • Between 320 – 360 mr/yr