Radiation protection involves protecting people and the environment from the harmful effects of ionizing radiation. There are two main types of radiation: ionizing radiation, which has enough energy to remove electrons from atoms and molecules; and non-ionizing radiation, which does not have enough energy. Ionizing radiation includes alpha particles, beta particles, gamma rays, x-rays, and neutrons. Non-ionizing radiation includes visible light, microwaves, and radio waves. Radiation is quantified using units like the gray (for absorbed dose), sievert (for biological effects), and becquerel (for radioactivity).

1. RADIATION
PROTECTION

2. Radiation protection
•Also known as radiological
protection.
•Is the science of protecting people
and the enviornment from the harmful
effects of ionizing radiation.

3. Radiation
• “Radiation is an energy in the form of electro-magnetic waves or
particulate matter, traveling in the air.”

4. Types of Radiation
• Radiation is classified into:
•Ionizing radiation
•Non-ionizing radiation

5. IonizingVersus Non-ionizing
Radiation
Ionizing Radiation
– Higher energy electromagnetic waves (gamma) or
heavy particles (beta and alpha).
– High enough energy to pull electron from orbit.
Non-ionizing Radiation
– Lower energy electromagnetic waves.
– Not enough energy to pull electron from orbit,
but can excite the electron

6. Ionizing radiation
•A radiation is said to be ionizing when it has
enough energy to eject one or more electrons
from the atoms or molecules in the irradiated
medium. This is the case of a and b radiations, as
well as of electromagnetic radiations such as
gamma radiations, X-rays and some ultra-violet
rays. Visible or infrared light are not, nor are
microwaves or radio waves

8. PrimaryTypes of Ionizing Radiation
Alpha particles
Beta particles
Gamma rays (or photons)
X-Rays (or photons)
Neutrons

9. Types and Characteristics of
Ionizing Radiation
• Alpha Particles: 2 neutrons and 2 protons
• They travel short distances, have large mass
• Only a hazard when inhaled
• Beta Particles: Electrons or positrons having small mass and
variable energy. Electrons form when a neutron transforms
into a proton and an electron
• Primarily an internal hazard, but high beta can be an external
hazard to skin. In addition, the high speed electrons may lose
energy in the form of X-rays when they quickly decelerate
upon striking a heavy material. This is called Bremsstralung
(or Breaking) Radiation.
• More penetrating than alpha particles.
• Less dangerous than gamma radiation

10. • Gamma Rays (or photons): Result when the nucleus
releases energy, usually after an alpha, beta or positron
transition.
• They are high energy beams,emitted in many radioactive
decays and are very penetrating
•X-Rays: identical to gamma rays,but not nuclear in
origin.
•Gamma rays typically have higher energy (Mev's)
than X-rays (KeV's), but both are unlimited.
•Neutrons: Have the same mass as protons but are
uncharged

11. Non-ionizing Radiation
• Definition:
“ They are electromagnetic waves incapable of producing ions while
passing through matter, due to their lower energy.”

12. •All earth surface system components emit radiation---
the sun and the earth are the components we are most
interested in
•The sun emits radiation composed of high energy
infrared radiation, visible light, and ultraviolet radiation
collectively known as shortwave radiation (SW)
•The earth emits radiation composed of lower energy
infrared radiation collectively known as long-wave
radiation (LW)

13. Examples of non ionizing
radiations
Visible light
Microwaves
Radios
Sound waves

14. QUANTIFICATION OF
RADIATION
• Radiation absorbed dose and effective dose in the international
system of units (SI system) for radiation measurement uses "gray"
(Gy) and "sievert" (Sv), respectively
• The basic unit of radiation dose absorbed in tissues is the
GRAY
One GRAY represents the deposition of one joule of energy per
kilogram of tissues.

15. • Another unit is
Sievert(Sv)
It is used in setting radiological protection standards.
One gray of beta or gamma radiation has one sievert of biological
effect.
One gray of alpha particles has 20 Sv effect
One gray of neutrons is equivalent to around 10 Sv.
Sivert is relatively large value,is usully measured in
millisieverts(mSv),one thousand of sievert

16. Becquerel(Bq)
• Unit or measure of actual radioactivity
• Becquerel (Bq) = 1 dps(disintegration per sec)
• One becquerel of radioactive material is that amount which has an
average of one disintegration per sec
Curie
• 1 Becquerel (Bq) = 1 dps;
• 1 Curie (Ci) = 3.7 x 1010 dps
• 1 Becquerel = 27 picocuries or 2.7 * 10-11 curies

17. Radioactivity Absorbed Dose Dose Equivalent Exposure
Common Units curie (Ci) Rad Rem roentgen (R)
SI Units becquerel (Bq) gray (Gy) sievert (Sv) coulomb/kilogram
(C/kg)

18. Conversion Equivalence
1 curie = 3.7 x 1010
disintegrations per second
1 becquerel =
1 disintegration per second
1 millicurie (mCi) = 37 megabecquerels (MBq)
1 rad = 0.01 gray (Gy)
1 rem = 0.01 sievert (Sv)
1 roentgen (R) = 0.000258 coulomb/kilogram (C/kg)
1 megabecquerel (MBq) = 0.027 millicuries (mCi)
1 gray (Gy) = 100 rad
1 sievert (Sv) = 100 rem
1 coulomb/kilogram (C/kg) = 3,880 roentgens