What is Radiation? Radioactivity is a natural and spontaneous process by which the unstable atoms of an element emit or radiate excess energy. Radiation is the result of the emission of excess energy. Explain the decay process in simple terms. Use your discretion to decide the depth for the audience. Alpha decay is illustrated on this slide and Beta and Gamma on the following slide
The depth you explain can be dependent on your age group and experience. Use the attached reference sheet for sites with more in depth information.
This slide just shows the different penetration abilities of the three decay products discussed in the previous two slides. Explanations can be modified for age group or comprehension level of the class participants. The point here is that these particles or waves can cause damage, but can also be prevented from damaging if shielded.
This slide shows the energy broken up to separate ionizing and non-ionizing radiation explain that we will use the term radiation to refer to the ionizing type for this discussion.
This slide allows us to discuss radiation in terms of all energy and equate it to wavelength and energy. The next slide deals with the distinction between ionizing and non-ionizing radiation
How to Detect Radiation Geiger counter Senses extremely tiny electrical impulses caused by radiation You can measure these electrical impulses with a small instrument or a large portal monitor. Show the student a Geiger counter. Demonstrate how it works by using the Geiger counter to read the radiation level of some common material. An optimal activity is to tell students you have hidden sources in the room. Ask for one volunteer to find the first source using the Geiger counter. Continue this for multiple sources if time permits.
We protect ourselves from radiation exposure by: Time – Distance – Shielding How do we protect ourselves from radiation exposure? Shielding OPTIONAL (TIME DEPENDENT ACTIVITY) Use a piece of paper, aluminum foil, lead plate, to demonstrate shielding effects. This ties to slide 9 with the demonstration of decay and the penetration abilities of certain types of radiation. Time We reduce exposure by limiting the time we are exposed Distance We reduce exposure by increasing the distance from the source The more ways we protect ourselves the better.
Ionizing radiation procedures In x-ray procedures, x rays pass through the body to form pictures on film or on a computer or television monitor, which are viewed by a radiologist. If you have an x-ray test, it will be performed with a standard x-ray machine or with a more sophisticated x-ray machine called a CT or CAT scan machine. Typical Effective Radiation Dose from Diagnostic X Ray—Single Exposure Exam Effective Dose mSv (mrem)1 Chest (LAT) 0.04 (4)Mammogram (four views) 0.7 (70) Chest (AP) 0.02 (2)Dental (lateral) 0.02 (2) Skull (AP) 0.03 (3)Dental (panoramic) 0.09 (9) Skull (Lat) 0.01 (1)DEXA (whole body) 0.0004 (0.04) Pelvis (AP) 0.7 (70)Hip 0.8 (80) Thoracic Spine (AP) 0.4 (40)Hand or Foot 0.005 (0.5) Lumbar Spine (AP) 0.7 (70)Abdomen 1.2 (120) • In nuclear medicine procedures, a very small amount of radioactive material is inhaled, injected, or swallowed by the patient. If you have a nuclear medicine exam, a special camera will be used to detect energy given off by the radioactive material in your body and form a picture of your organs and their function on a computer monitor. A nuclear medicine physician views these pictures. The radioactive material typically disappears from your body within a few hours or days. Exam Effective Dose mSv (mrem)2 The following shows the dose a patient could receive if undergoing an entire procedure. For example, a lumbar spine series usually consists of five x-ray exams. CT stands for computed tomography and is sometimes called a CAT scan. Complete Exams Effective Dose mSv (mrem) 1 Intravenous Pyelogram (kidneys, 6 films) 2.5 (250) Barium Swallow (24 images, 106 sec. fluoroscopy) 1.5 (150) Barium Enema (10 images, 137 sec. fluoroscopy) 7.0 (700) CT Head 2.0 (200) CT Chest 8.0 (800) CT Abdomen 10.0 (1,000) CT Pelvis 10.0 (1,000) Angioplasty (heart study) 7.5 (750) - 57.0 (5,700)3 Coronary Angiogram 4.6 (460) - 15.8 (1,580)3
Museums rely on radioactive materials to verify authenticity of fossils, paintings and art objects
Smoke detectors – rely on tiny radioactive source to sound an alarm Food sterilization and preservation Let the students see the extent to which radioactivity is used in positive ways Criminology – radiation, tests can detect the toxic element arsenic in a single hair Automobiles – test the quality of steel and integrity of welds in vehicles Manufacturers – obtain the proper thickness of tin and aluminum Construction crews – gauge the density of road surfaces Sterilization – Radiation sterilizes cosmetics, hair products, contact lens solutions
Wind energy is one of the renewable sources of energy. It is considered renewable because it is ultimately derived from the sun and is capable of being replenished on a reasonable time-scale. If asked about zero emissions: Although wind is a zero emissions electrical generation option, there are emissions in the development and construction of wind projects – concrete, transportation of components, etc.
Wind is a form of renewable energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth&apos;s surface, and rotation of the earth. Wind flow patterns are modified by the earth&apos;s terrain, bodies of water, and vegetation. Humans use this wind flow, or motion energy, for many purposes: sailing, flying a kite, and even generating electricity.
1. What is Radiation?
What is Radiation?
• Radioactivity is a natural and spontaneous process by which the
unstable atoms of an element emit or radiate excess energy
• Radiation is the result
• Alpha Decay - Alpha decay occurs when the nucleus
spontaneously ejects an ά particle. An ά particle is really 2
protons and 2 neutrons, or an Helium nucleus.
Alpha Decay of a Uranium-238 Nucleus
• Beta Decay - An excess of
neutrons in an atom's nucleus
will make it unstable, and a
neutron is converted into a
proton to change this ratio.
During this process, a ß
particle is released,
• Gamma ray emission usually
occurs with ά and ß emission.
Gamma rays have no charge or
mass, so their emission doesn't
change the chemical
composition of the atom.
Instead, it results in a loss of
radiant energy. Gamma ray
emission occurs because the
nucleus is often unstable after
ά and ß decay.
Decay Product Penetration
5. Ionizing radiation
Energy in the form of waves or particles that has enough force to remove
electrons from atoms.
6. Energy Spectrum
7. Sources of Radiation
Man Made Radiation Sources – 18%
• Medical X Rays
• Nuclear Medicine
• Consumer Products
Natural Radiation Sources – 82%
Data is U.S. Based
National Council on Radiation Protection and Measurements (NCRP) Report No. 93, “Ionizing Radiation Exposure
of the Population of the United States, “ 1987
8. •Geiger counter
impulses caused by
How to Detect Radiation
We Protect Ourselves from Radiation Exposure by:
10. Beneficial Uses of Radiation
CT Scan – Computer
MRI – Magnetic Resonance
11. Museums and archeologists rely on radiation detection to verify
the authenticity or age of art objects or archeological finds.
Beneficial Uses of Radiation
12. •Smoke detectors – rely on
a tiny radioactive source
to sound an alarm when
smoke is present
•Food sterilization and
Beneficial Uses of Radiation
13. • Living cells and tissue are made of molecules composed of
atoms united by chemical bonds
• Composition of these atoms and how they bond determines the
physical structure (shape) of molecules.
• It is the shape of these large molecules (proteins, nucleic acids,
lipids, and carbohydrates) which determines how the molecules
• Ionizing energy is powerful enough to alter the structure of
atoms or molecules, the bonds involved, and greatly affect the
function of the molecules in the cell and living tissue.
• Altering the shape of molecules in a somatic cell can change the
behavior of that cell.
•Altering the shape of molecules (especially DNA) in germ cells
(egg or sperm) can greatly effect the offspring of the organism.
Structure and Function of Living Cells
14. Molecules of living cells:
Proteins: Large molecule
• Structural Component of the cell.
• Function as Enzymes to control
• Important component of the cell
• How the atoms are connected to
each causes folding of proteins into
• This folding of proteins enhances
and supports their function within
Nucleic Acids: Also a large molecule
• Double Helix shape with hydrogen
bonding of the nitrogen bases in the
• Contains the genetic material of the
cell -- the cells’ instructional sheet.
• Responsible for the production of
proteins at the ribosomes -- by being
blueprint of how to build them.
15. Effect Of Radiation on Structure of DNA
16. Direct Or Indirect Action
• Direct Action - when ionized
energy strikes a molecule,
• Indirect Action - strikes
another molecule such as water
-- a “free radical” is produced
• Free Radicals react strongly to
restore their stable
configuration which could
create other free radicals within