The different types of background radiation - both artificial and natural.

1. Background Radiation
By Kunal, Class 10

2. What is background radiation ?
• It is low level ioinising radiation that is produced
all the time.
• It comes from different sources – natural or
artificial.

3. Why does it happen all the time ?
• When the Earth was formed , it contained many
radioactive isotopes which are still existing and
decaying.
• When a radioactive element decays, it changes
into another element along with giving out
radiation.
• This newly formed element may also be
radioactive and decay to form another element.
• This continues on and on until a element that is
not radioactive is formed.

4. Sources of background radiation
Radon gas
Ground and buildings
Medical
Cosmic Rays
Food and drink
Other
Nuclear power

5. Natural background radiation
• The radioactive isotopes formed 4.6 billion years
ago are still decaying to give out radiation.
• Most of these radioactive elements and their
decay products are gases. So, they often seep out
of radioactive rocks and become a part of the
Earth’s atmosphere.

6. Radiation from radon gas
• Classified under natural background radiation.
• Radon is a decay product of uranium and is
found in the Earth’s crust in ores.
• It seeps out into the atmosphere and can be
inhaled.
• It is highly radioactive.

7. Ground and buildings
• Dense radioactive gases build up in the
basements of buildings.
• This increases people’s exposure to radiation
from radioactive gases.
• They reach buildings from the Earth’s crust.

8. Food and drink
• The food that we eat contains radioactive atoms
such as carbon-14.
• We continuously renew the amount of
radioactive carbon in our body.

9. Cosmic radiation
• Violent nuclear reactions in stars and
supernovae give out a lot of energy and cosmic
rays that bombard the Earth all the time.
• The sun also gives out cosmic rays with lower
energy.
• Most of them do not reach us.

11. Artificial radiation

12. Artificial radiation
• Humans have used radioactivity to suit their
needs for many purposes.
• Radiation is used:
• to treat certain forms of cancer (gamma
radiation)
• for scanning the internal parts of machines and
humans
• to generate electricity (nuclear power stations)
• as weapons of mass destruction.

13. Radiation in medicine
• It is used for body scans such as X-Ray and MRI.
• It needs to be controlled to protect the patient.

14. Nuclear radiation
• Radiation is used in large power plants to
generate electricity.
• It was previously used to in weapons such as the
atom bomb.
• It can cause a lot of harm if it is not stored
properly.