1Why is ionising radiation dangerous to human cells?
Can cause tissue damage and mutations
Can also cause skin burns
and reduce white blood cells in blood - weakening immune system
2How can tissue damage caused by ionising radiation be useful and what do you need to be careful of?
Ionising radiation can be used to destroy cancerous tumour cells
However it can damage healthy tissue if not targetted properly.
3How can ionising radiation cause mutations in DNA?
Radiation ionises atom in a DNA strand
DNA strand becomes damaged
Cell dies or DNA becomes mutated
If mutated, the cell can replicate and form a tumour (example of cancer)
4 A student plans to use a gamma source to conduct an experiment. What should the student do to minimise the risk to themselves when using the source? (Also applies for uses of radiation in hospitals) (6 marks)
Keep source in lead container until it is needed
Use tongs and gloves to move the source
Keep as far away as possible at all times
Minimise the time source is used
Wash hands after the experiment
Record date and time the radiation was used for
5What is the amount of radiation received by a person called and what is it measured in?
Dose
Measured in Sieverts (Sv)
1 Sievert is a very big dose of radiation
6Define contamination
Unwanted presence of radioactive isotope on another object
Makes the object radioactive
7What can cause contamination and how can it be prevented?
Caused by inhalation or ingestion of radioactive sources
Prevent by safe handling and airtight safety clothing
8 Define irradiation
Process of exposing an object to ionising radiation
Does not make the object radioactive
9What can cause irradiation and how can it be prevented?
Caused by presence of radioactive sources outside the body
Prevent by using shielding, like lead clothing
10Why can contamination be more dangerous than irradiation?
When something becomes contaminated, it becomes radioactive
Meaning it will be constantly exposed to radiation