2. • Radiation is all around us.
• It comes from outer space (cosmic), the ground
and even from within our own bodies.
• Some foods such as bananas and Brazil nuts
naturally contain higher levels of radiation.
• Brick and stone homes have higher radiation
levels than homes made of other materials such
as wood.
3. A lot of our exposure is due to radon, a gas from
the Earth's crust that is present in the air we
breathe.
This natural radiation that is always present is
known as “background” radiation.
Radiation is used in medicine, to generate
electricity, to make food last longer, to sterilize
equipment, for carbon dating of archeological
finds, and many other reasons.
4. After completion of this lesson we will be able to
understand :-
Basic knowledge about Cell
Basic knowledge about Radiation
Types of radiation exposure
Sign & symptom of radiation exposure
Radiation effects of human body
Stages of radiation sickness
Threshold effects & non-threshold effects
Biological effects of Acute Exposure to Radiation
5. The smallest unit of body is called a cell.
An adult person’s body has about 1014
cells.
Cells of different organs have different shapes
sizes & functions.
Cells present in all living beings and are able to
divide and reproduce themselves.
6. Made up of Nucleus, Cytoplasm and cell
membrane.
DNA molecules constitutes the genetic material of
cell & are the most important target for induction of
radiation damage in cells.
DNA contains very specialised coded language
made up of 4 molecules, A,T, G & C which are
arranged in very specific order.
7.
8. The cells of our body can be classified into two
categories
1. Somatic cells – All cells of body except
gametes
2. Germ cells- Sperms in Males & eggs /ova in
females
9. A somatic cell is any cell
forming the body of
animal/human being, eg.:-
skin cell, lung cell, nerve
cell, muscle cell
Germ cells are the cells
involved in the formation
of a baby
Only two types.
(1) Sperms: present in
males
(2) Eggs (ova): Present in
females
10. Radiation is energy. It travels in the form of energy
waves or high-speed particles. Radiation can
occur naturally or be man-made. There are two
types:
1. Ionizing radiation
2. Non-ionizing radiation
Ionizing radiation happens when the atomic
nucleus of an unstable atom decays and starts
releasing ionizing particles.
11.
12.
13.
14. Type and energy of radiation
Dose rate and dose fractionation
Sensitivity of organs getting affected
Ability to repair from damage
presence of sensitizers and protectors.
Mode of exposure (internal or external)
Type of cells
15.
16. Some people are more sensitive to
harmful effects of radiation than others.
There are a number of factors that
influence an individual's sensitivity to
radiatio.These factors include:-
Age
Gender
Other Exposures
Genetic Factors
17. Nausea, vomiting & diarrhea
loss of appetite
malaise, or feeling unwell
headache
rapid heartbeat
Symptoms depend on the dose, and
whether it is a single dose or repeated.
18. A dose of as low as 30 rads can lead to:
•Loss of white blood cells
•Nausea and vomiting
•Headaches
A dose of 300 rads dose may result in:
•Temporary hair loss
•Damage to nerve cells
•Damage to the cells that line the digestive
tract
21. Exposed to a lot of radiation over a short
period of time, such as from a Radiation
Emergency, can cause skin burns. It may
also lead to Acute Radiation Syndrome
(ARS, or "radiation sickness").
The symptoms of ARS include headache
and diarrhea.
22. They usually start within hours. Those
symptoms will go away and the person will
seem healthy for a little while. But then they
will get sick again. How soon they get sick
again, which symptoms they have, and how
sick they get depends on the amount of
radiation they received.
In some cases, ARS causes death in the
following days or weeks
28. Human tissues and organs ranked
by sensitivity to radiation induced
cancer
High Moderate Low
Bone Marrow
Breast
(premenopausal
Thyroid (child)
Lung
Stomach
Ovary
Colon
Bladder
Skin
Brain
Bone
Uterus
Kidney
Esophagus
Liver
29.
30.
31. Dose (rem) Effects
5-20 Possible late effects; possible chromosomal damage.
20-100 Temporary reduction in white blood cells.
100-200 Mild radiation sickness within a few hours: vomiting,
diarrhea, fatigue; reduction in resistance to infection.
200-300 Serious radiation sickness effects as in 100-200 rem and
hemorrhage; exposure is a Lethal Dose to 10-35% of the
population after 30 days.
300-400 Serious radiation sickness; also marrow and intestine
destruction.
400-1000 Acute illness, early death.
1000-5000 Acute illness, early death in days.
32.
33.
34. Below 30 rads: Mild symptoms will occur in the
blood
From 30 to 200 rads: The person may become ill.
From 200 to 1,000 rads: The person may
become seriously ill.
Over 1,000 rads: This will be fatal.
35. After this completion of this lesson, now you can
describe:-
Basic knowledge about Cell
Basic knowledge about Radiation
Types of radiation exposure
Sign & symptom of radiation exposure
Radiation effects of human body
Stages of radiation sickness
Threshold effects & non-threshold effects
Biological effects of Acute Exposure to Radiation
37. www.health.ny.gov
International Atomic Energy Agency (www.iaea.or.at)
International Radiation Protection Association
(http://www.irpa.net/)
https://www.snc.edu/
https://www.atomicarchive.com/index.html
http://www.nih.gov/
The primary NIH organization for research
on Radiation Exposure is the National Institute of
Environmental Health Sciences