background radiation - artificial and natural

Background RadiationBy Kunal, Class 10

What is background radiation ?

•It is low level ioinising radiation that is produced all the time.

•It comes from different sources – natural or artificial.

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.

Sources of background radiation

Radon gasGround and build-ingsMedicalCosmic RaysFood and drinkOtherNuclear power

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.

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.

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.

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.

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.

Artificial radiation

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.

Radiation in medicine

•It is used for body scans such as X-Ray and MRI.

•It needs to be controlled to protect the patient.

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.