4.4.3.1 - Background radiation

What is background radiation?

Background radiation refers to the low-level radiation that is around us all the time

From where does background radiation come from?

• Natural sources

• Man-made sources

What natural sources contribute to background radiation?

E.g. rocks / cosmic rays

The radioactivity of naturally occurring isotopes in rocks

Cosmic rays from space - mostly coming from the sun

What man-made sources contribute to background radiation?

E.g. fallout / nuclear accidents

Radiation that is due to human activity like fallout from nuclear weapons testing or nuclear waste or nuclear accidents

What is meant by ‘radiation dose’?

Radiation dose - tells you the risk of harm to the body tissues due to the exposure to radiation

What is radiation dose measured in?

Measured in sieverts (Sv)

How many Sieverts are there in 1000 milisieverts?

1000 mSv = 1 Sv

What can the level of background radiation ( / radiation dose) be affected by?

The level of background radiation / radiation does can be affected by occupation and / or location