Contents of presentation:

Non-ionizing and ionizing radiationDisposal of radioactive wastes

RADIATION SAFETY

Non-ionizing and ionizing radiation

RADIATION

There are many kinds of “radiation” in our world such as:

i) sound radiationii) heat radiation (electromagnetic radiation in the

infrared iii) part of the spectrum)iv) ultraviolet radiationv) micro waves and radio

RADIATION

Radiation is a process in which energetic particles or energetic waves travel through a medium or space.

Two types of radiation are commonly differentiated in the way they interact with normal chemical matter:- ionizing- non-ionizing radiation

IONIZING RADIATION Ionizing radiation has enough energy to remove electrons from atoms or

molecules (group of atoms) when it passes through or collides with some material.

The loss of electron with its negative charge causes the atom (or molecules) to become positive charged.

The loss (or gain) of an electron is called ionization and a charged atom or ion is called an ion.

Form of ionizing radiation include:- Gamma rays- X-rays- Alpha particles- Beta particles- Neutrons

Ionizing radiation can be divided into two main categories:

i) Directly ionizing radiation- this consists of charged particles such as alpha or

beta particles, which interact with the target electrons via the Coulomb electric force.

ii) Indirectly ionizing radiation- this include neutral particles such as neutrons and

high energy photons such as X and Gamma rays.

NON-IONIZING RADIATION

Non-ionizing radiation is described as a series of energy waves composed of oscillating electric and magnetic fields traveling at the speed of light.

Non-ionizing radiation includes the:- spectrum of ultraviolet (UV)- visible light, infrared (IR)- microwave (MW)- radio frequency (RF)- low frequency (ELF).

Non-ionizing radiation is found in a wide range of occupational settings and can pose a health risk to exposed workers if not properly controlled.

SOURCES OF RADIATION EXPOSURE

Radiation is a natural part of life. It has existed since the beginning of time and is an integral part of the universe in which we live.

Life as we know it on earth has evolved in the presence of radiation. Radiation comes to us from many sources both natural and man-made.

The following table gives a summary of the contribution from these various sources of radiation.

BIOLOGICAL EFFECTS OF RADIATION

Biological effects radiation is greater than that associated with any other environmental hazard.

Two types of effects are:

i) Non-stochastic effects of radiation (Deterministic effects)- involve the malfunctioning or loss of function of tissues in organs due mainly to cell loss.- these effects result from high dose exposures.

ii) Stochastic effects- express themselves long after the exposure and include increased risk of cancer.- appear to have no threshold and may occur after low radiation doses.

GENETICS EFFECTS OF RADIATION

Three general classes of diseases which have a strong genetic component:

i) Monogenic- include dominant, recessive and cross-linked mutations of a

single gene.

ii) Chromosomal- due to changes in the structure of a number of chromosomes

in the germ cell.

iii) Multigenic (multifactorial)- the disease is associated with the interaction of a considerable number of genes and of the environment.

Example of genetic effects:

i) Radiation effects on the embryo and fetusii) Congenital abnormalitiesiii) Prenatal and neonatal deathiv) Severe mental retardationv) Reduced intelligencevi) Cancer induction

Disposal of radioactive wastes