2. OUTLINE
Definition
Why do elements radiate?
How is radiation classified?
Non-ionizing radiation
Ionizing radiation
Alpha radiation
Beta radiation
Gamma radiation
Neutron decay
Radiation exposure
Radiation in medicine
Summary
3. DEFINITION
What’s Radiation?
Radiation is energy or particles from a source that travels
through space or other mediums, radiation includes
particles and electromagnetic waves that are emitted by
some materials & carry energy
4. Why do elements radiate?
The nucleus is too heavy.
There is an imbalance the atomic & mass number, Its an
isotope.
Its a neutron decay.
All of this destabilize the nucleus of atom and the nucleus
radiates particles to reach a more stable state.
There are 3 different reasons:
5. How is radiation classified?
Based on whether it has enough energy to knock off
atoms that interacts with.
Based on being able to do lower energy damage such as
breaking chemical bonds in molecules.
6. Radiation splits into:
Ionizing radiation
• Short wavelength
• High frequency
• Higher energy
• Has sufficient energy to
produce ions in molecule
level, upsetting the+/-
balance
non-ionizing radiation
• Longer wavelength
• Lower frequency
• Lower energy
• Can cause damage in the
form of thermal burns
7. Non-ionizing radiation :
Frequency Spectrum
1. ELF
2. Radio Frequencies
3. Microwave Frequencies
4. Lasers
5. Infra red
6. Visible Spectrum
7. Ultra Violet
Low frequency
High frequency
8. Types of Ionizing Radiation:
Alpha Particles
Beta Particles
Gamma ray
X-ray
Neutron Radiation
9. Alpha Radiation:
Heavy, short range particle it can also be called an ejected helium.
Nucleus, as its heavy it cannot penetrate skin its only harmful when
swallowed or absorbed in through pores or open wounds. its
detected by a thin window Geiger Mueller (GM) probe. alpha
radiation cant be detected through layers of water or dust, paper and
other materials as it doesn’t penetrate.
Examples: Radium Radon Uranium Thorium
10. Beta radiation:
Light, short ranged particles, its similar to an ejected electron there
are positive and negative unlike alpha it can penetrate skin to the
“germinal layer” where new skin cells are produced. if beta emitting
contaminants are allowed to remain on skin for a long period of time
it can cause damage that can be harmful if deposited internally, but
not as harmful as alpha particles as they are smaller. beta particles can
also be detected through “GM” probe
Examples: Hydrogen-3 Carbon-14 Sulfur-35
11. Gamma Radiation:
highly penetrating electromagnetic radiation with no mass or charge
they have the highest ability to penetrate and they penetrate most
materials and are sometimes called penetrating radiation they are
dangerous in high doses they are detected by survey meters with
sodium iodide detector probe.
Examples: iodide-131 cesium-137 cobalt-60 radium-226
12. Neutron decay:
Neutron is a natural particle it has a mass of a proton unlike the
previous radiation this one isn’t emitting from the radionuclie that
goes under the traditional decay its ejected into the radionuclie which
decays by spontaneous fission
Examples: Uranium is bombarded with a neutron through fission,
uranium splits into 2 lighter elements such as barium-141 and
krypton-42 and energy
13. How do we get exposed to radiation?
We are exposed to radiation from both manmade and natural
source from your microwaves and cellular telephones and FM and
AM radio and baby monitors we get ionizing energy
We are exposed to ionizing radiation in these following ways:
1. Cosmic radiation
2. Exposure from terrestrial radiation 4. Through inhalation
3. Exposure through ingestion
14. Chernobyl
The accident was responsible for nearly 20,000 documented cases of
thyroid cancer among individuals who were under 18 years of age at the
time of the accident in the three affected countries including Belarus,
Ukraine and the Russian federation. This was due to do the high levels of
radioactive in iodine releases from the Chernobyl reactor in the early days
after the accident.
Radioactive iodine was deposited in pastures eaten by cows who then
concentrated it in their milk which was subsequently ingested by children.
15. Acute radiation syndrome
Patients with acute
radiation syndrome
(ARS) classically go
through for clinical
phases:
Prodrome, latency,
manifest illness, and
either recovery or
death
16. Radiation in medicine:
Despite its limitations, radiation is used in many ways in medicine or
radiology as we have talked about before its used as x-rays,
mammography, computerized tomography, PET-scans ultrasound or
MRI.
Another important aspect is nuclear medicine, this is usually used to
treat disease or cancer & are called therapy. here, radioactive material
is directed at the nucleus of the damaged cells.
Radiation destroys the DNA of the damaged cells with its high energy
and prevents cells from reproducing and destroys them.
17. Radiation therapy (definition)
Side effects:
Brain:
Fatigue
Hair loss
nausea and vomiting
Skin changes
Headache
Blurry vision
Breast:
Fatigue
Hair loss
Skin changes
Swelling
tenderness