Radiation Safety and Applications

Ionising radiation can damage living cells by breaking chemical bonds in DNA and other molecules. Managing this risk while harnessing the benefits of radiation is one of the most important challenges in modern physics and medicine. This lesson covers the principles of radiation protection, dosimetry, and the key medical and industrial applications of radioactive materials.

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Biological Effects of Radiation

When ionising radiation passes through living tissue, it can:

• Ionise atoms and molecules in cells, creating highly reactive free radicals
• Break chemical bonds in DNA, potentially causing mutations
• Kill cells if the damage is severe enough
• Cause cancer if DNA damage leads to uncontrolled cell division

The severity of the damage depends on:

• The type of radiation (alpha is most damaging inside the body due to high ionising power)
• The dose received
• The duration of exposure
• Which organs or tissues are exposed (rapidly dividing cells are most vulnerable)
• Whether the source is external to or internal within the body

External vs Internal Hazards