Background radiation and contamination Flashcards
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What is Background Radiation?
Low level radiation that’s around us all the time.
Where does background radiation come from?
Radioactivity of naturally occuring unstable isotopes which are all around us - in the air, foods, building materials and some rocks under our feet.
Cosmic rays
Radiation due to human activity.
What is the amount of radiation you’re exposed to called?
The absorbed radiation dose.
The absorbed radiation dose varies depending on…
where you live or if you have a job that involves radiation.
What is irradiation?
When an object is exposed to radiation.
What are ways of reducing effect of irradiation?
Lead lined boxes
Standing behind barriers
Using remote controlled arms.
What is Contamination?
When unwanted radioactive atoms get onto an object.
Contaminating atoms might then decay, releasing…
radiation which could cause you harm.
What happens once a person is contaminated?
They are at risk of harm until either the contamination is removed or all the radioactive atoms have decayed.
What should be used when handling sources and why?
Gloves and tongs to avoid particles getting stuck to your skin or under your nails.
How can radiation lead to tissue damage?
Radiation can enter living cells and ionise atoms and molecules within them.
How does cancer happen?
Lower doses of radiation tend to cause minor damage without killing the cells. This can give rise to mutant cells which divide uncontrollably.
Higher doses of radiation tends to…
Kill cells completely, causing radiation sickness if a lot of cells all get blatted at once.
Why is Beta and Gamma radiation the most dangerous outside the body?
They can penetrate the body and get to the delicate organs. Alpha is less dangerous because it can’t penetrate the skin.
What source is the most dangerous inside the body?
Alpha sources. Alpha particles are strongly ionsing, so they do all their damage in a very localised area.
