Uses of radioactive isotopes is a document which summarises what radioactive isotopes are used for. From smoke detectors to carbon dating, from monitoring thickness to sterilising strawberries and kidney mapping. There are lots of different uses and more are being worked out all the time in industry and medicine.
Three very important precautions when handling radioactive material:
KEEP YOUR DISTANCE.
Handle with long tongs or keep as far away from ionising radiation as possible. Imagine it like this. Little bullets are being fired in all directions. The further away you are, the less chance any of them will hit you.
REDUCE EXPOSURE TIME.
Just like using a sun lamp, radiation dosage and hence damage to body tissues increases the longer we are exposed to it. Keep it short.
GET BEHIND DENSE MATERIALS.
Radiographers taking X-rays wear lead aprons to absorb harmful radiation. When we store radioactive sources we keep them inside lead containers in a locked cupboard outside the lab. In Europe and the US, there are very strict rules for storage and safe transportation of radioactive material.
Remember: alphas have a range of a single cell or less in the body. They won’t damage us if we don’t swallow the source. Low energy betas only travel a few tens of cm in air. Radioactive tracers emitting low energy betas won’t get out of the body cavity to a detector unless the organ they are taken up by is close to the surface. Higher energy betas and gamma emitters can be used to image deeper organs. The first image is of a normal bone scan. The patient has been injected with technetium 99m – a gamma emitter with a half-life of 6 hours and scanned with a gamma camera – a special detector which detects gamma rays. Notice how the radiation has found its way to the bladder ready to be excreted. The lower image is of a bone scan from a patient suffering from cancer. The radioisotope has collected in the cancerous tissue and appears as dark spots.