This document discusses background radiation and its sources. It explains that background radiation is low-level ionizing radiation that is constantly produced from natural and artificial sources. Naturally, background radiation comes from radioactive elements formed during Earth's creation that continue to decay, releasing radiation. Specifically, radon gas seeps from the Earth's crust and uranium deposits, contributing to natural radiation exposure. Additionally, cosmic rays from stars and the sun as well as small amounts of radiation in food and buildings add to background levels. Artificially, radiation is used for medical imaging, cancer treatment, nuclear power generation, and was previously used in weapons before proper storage and regulation.

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.