Radiation strong enough to kill cancer cells is focused on the tumour.
Beta or gamma radiation is used depending on the material the tracer needs to pass through. Alpha cannot be used as it is too easily absorbed
Gamma rays kill living cells (bacteria)
Gamma radiation kills living cells (cancer)
Tracers
Alpha particles cannot travel very far in air and pose no health risk if more than a few cm away from people
Detectors which use radiation to monitor and check the thickness of material such as paper, plastic or aluminium
Bacteria are killed by the radiation through sealed plastic wrappers
Industry detectors
Cancer treatment
Contain an alpha emitter - smoke entering the detector blocks the radiation triggering the alarm.
Smoke detector
Sterilising medical equipment
Alpha radiation is stopped by the material, beta is partially absorbed and gamma passes through.
Radiation are used in medicine and industry to find out what is happening inside objects without having to open them.