INTRODUCTION • What is Radiation? Radiation is energy. It can come from unstable atoms or it can be produced by machines. Radiation travels from its source in the form of energy waves or energized particles.(EPA,UNITED STATES ,APRIL 2012)SEE FIGURE 1. (FIGURE 1 , WAVES AND PARTICLES) There are actually two kinds of radiation, and one is more energetic than the other. It has so much energy it can knock electrons out of atoms, a process known as ionization. This ionizing radiation can affect the atoms in living things, so it poses a health risk by damaging tissue and DNA in genes. While there are other, less energetic, types of non-ionizing radiation (including radio waves, microwaves—and visible light), this booklet is about ionizing radiation. .(EPA,UNITED STATES ,APRIL 2012) (FIGURE 2, PARTICLES) (FIGURE 3, WAVES) In the late 1800s, Marie and Pierre Curie were among the first to study certain elements that gave off radiation. They described these elements as radio-active, the property that is now called “radioactivity.” As scientists studied radioactivity more closely, they discovered that radioactive atoms are naturally unstable. In order to become stable, radioactive atoms emit particles and/or energy waves. This process came to be known as radioactive decay. The major types of ionizing radiation emitted during radioactive decay are alpha particles, beta particles and gamma rays. Other types, such as x-rays, can occur naturally or be machine-produced. .(EPA,UNITED STATES ,APRIL 2012) • Ionizing and Non-Ionizing Radiation Radiation is classified as being either non-ionizing or ionizing. Non ionizing radiation is longer wavelength/lower frequency lower energy. While ionizing radiation is short wavelength/high frequency higher energy.(STUDY GUIDE) Ionizing Radiation has sufficient energy to produce ions in matter at the molecular level. If that matter is a human significant damage can result including damage to DNA and denaturation of proteins. This is not to say that non-ionizing radiation can’t cause injury to humans but the injury is generally limited to thermal damage i.e. burns.(STUDY GUIDE) (FIGURE 4, IONIZING RADIATION) • Types of Non-Ionizing Radiation 1. (extremely low frequency) 2. Radio Frequencies 3. Microwave Frequencies 4. Lasers 5. Infrared 6. Visible Spectrum 7. Ultraviolet This list is in order of lowest to highest frequency. • Types of Ionizing Radiation Ionizing radiation is emitted from radioactive atomic structures as high energy electromagnetic waves (gamma and x-rays) or as actual particles (alpha, beta, neutrons). (U.S.NEUCLEAR REGULATORY COMMISIONS, October 2011) 1. Gamma Rays 2. X-Rays 3. Alpha Particles 4. Beta Particles 5. Neutrons (FIGURE 6, IONIZING RADIATION) • Sources of Radiation.

1. Biological risks of different
types of radiation.

2. Introduction
What is radiation ?
Radiation is the process of
emitting energy through a
medium or space in the form
of waves or particles

3. Introduction
PARTICLESWAVES
IONISING
NON-IONISING

4. Ionizing and Non-Ionizing Radiation
• Radiation is classified as being either
or
• Non ionizing radiation is longer
wavelength/lower frequency lower energy.
• While ionizing radiation is short
wavelength/high frequency higher
energy.(STUDY GUIDE)
Introduction

5. Introduction
What is Ionizing Radiation?
Type of radiation that has sufficient energy to knock-out
electrons in atoms and molecules
electron

6. Introduction
Types of Ionizing Radiation
 Alpha particles
 Beta particles
 Gamma rays
 X-rays
 Neutrons

7. Introduction

8. Introduction

9. • Types of Non-Ionizing Radiation
1. (extremely low frequency)
2. Radio Frequencies
3. Microwave Frequencies
4. Lasers
5. Infrared
6. Visible Spectrum
7. Ultraviolet
This list is in order of lowest to highest frequency.
Introduction

10. Sources of Radiation
• 1. Natural Sources of Radiation (Radioactive
materials)
-Radioactive materials continuously emit radiation.
-Cannot be turned OFF.
- Radon gas (55%)
• is the second leading cause of lung cancer in the
United States after smoking.
Introduction

11. • Sources
2. Radiation emitting devices or equipment (e.g. X-ray
machines)
-Machines can be turned ON and OFF
• When turned OFF, no radiation is emitted.
3. Man-made sources.
-Nuclear reactors
-Medicine (Modern Health Care)
-Food & agriculture
-Industry
-Nuclear weapons
Introduction

12. • What could happen to the body when exposed to
radiation?
• -Biological effects on living cells
1. Cells experience DNA damage that are
detected & repaired.
2. DNA damage not repaired and causes cell
death.
3. Cell experiences DNA mutation and may induce
cancer.
Introduction