Uses of Irradiation

Irradiation for Sterilisation: To preserve fruit in supermarkets, exposed to a radioactive source (cobalt-60). The gamma rays emitted destroy any bacteria on the fruit, but don't change it in any significant way. This process doesn't cause the object to become radioactive Medical Irradiation: - Sterilisation of surgical instruments - beams of gamma rays (called gamma knife), can be used to kill cancerous tumours deep inside body Beams are aimed at tissue from many directions to maximise dose on tumour and minimise dose surrounding soft tissue. Healthy tissue can be damaged, so calculations are done to get the best dose - enough to kill tumour, but not so much that healthy tissue is damaged.