5.6 Why Radiation is Harmful Flashcards
What is irradiation?
The process by which objects are exposed to radiation
What is contamination?
When radioactive particles get onto other objects
Ionising radiation
- Ionising radiation can enter living cells and interact with molecules.
- These interactions cause ionisation.
- Lower doses of ionising radiation damage living cells by causing mutations in the DNA. This can cause the cell to divide uncontrollably - which is cancer.
- Higher doses tend to kill cells completely, which causes radiation sickness if a lot of cells all get blasted at once.
What determines how harmful radiation is? (3)
- Type of radiation
- Where you’re exposed to it
- The amount
Is irradiation temporary or permanent?
Temporary - if the source is taken away, any irradiation it’s causing stops, and it no longer poses a risk to your health
Why is contamination worse than irradiation?
Contamination lasts longer - if the original source is taken away, the contaminating atoms are left behind. So contamination by a given source poses a higher risk of harm than irradiation as cells in the body will be exposed to ionising radiation until the source leaves the body.
Outside the body, why are beta and gamma sources the most dangerous?
This is because beta particles and gamma rays can both penetrate the body and get to delicate organs. Gamma rays can penetrate further, so they are more dangerous than beta particles.
Inside the body, why are alpha particles the most dangerous?
They do all their damage in a very localised area
Inside the body, why are beta particles less damaging than alpha particles?
Beta particles are less damaging inside the body, as radiation is absorbed over a wider area, and some passes out of the body altogether.
Inside the body, why are gamma rays the least dangerous?
Gamma rays are the least dangerous inside the body, as they mostly pass straight out without doing any damage - they have the lowest ionising power.
How do we minimise radiation? (3)
- By wearing protective gear such as gloves and overalls
- Handling the radioactive material with tools such as tongs, rather than handling it with our hands directly
- Keeping the material in a lead-lined box when not in use
______________ is when radioactive particles get onto your body or other objects
Contamination
What might happen if DNA is exposed to ionising radiation?
- The DNA could mutate
- The cell could divide uncontrollably and became cancerous
- The DNA could be destroyed
What are the factors that affect the amount of radiation you receive?
- How radioactive the substance is
- How far away from the source you are
- How long you’re exposed for
