Electromagnetic Properties of Radiation

natural radiation

~ Radiation sources have always been a part of the environment, and a source of exposure to humans

~ Emits radiation spontaneously

~ Also called background radiation divided into two categories: cosmic and terrestrial

cosmic

~ The atmosphere of the earth protects against most of the _____ ionizing radiation, but “galactic” and “solar” particles still make it through the earth’s atmosphere

~ The further into the atmosphere you go, the more radiation you receive

terrestrial

~ All humans are exposed to _________ radiation coming from radionuclides in the earth or from cosmic bombardment that lands on the earth

~ Inhaled radioactivity, with major contributions from the decay of radon and thoron

~ Internally deposited natural radionuclides largely based on dietary intake of potassium-40

296 mrem

average natural radiation exposure

360 mrem

average man-made radiation exposure

360 mrem

average radiation exposure before 2009

640 mrem

average radiation exposure after 2009

0.005 mR/Hr

background radiation measures about ______ using a Geiger Counter

GM Meter

The most common Radiation survey meter in a nuclear medicine department

mili Roentgen per Hour

mR/hr

Roentgen

the measure of exposure in air

man made radiation

~ simply radioactivity made by man

~ dissipates immediately; patients do not leave radioactive and it cannot be transmitted from mother to child through breastfeeding

~ example: x-ray tube

particulate radiation

~ particles such as electrons, protons, neutrons with energy in motion

electromagnetic radiation

~ oscillating electrical and magnetic fields that carry energy in space at the speed of light

increases

As wavelength decreases, frequency _______