Dangers and Safety with Radiation

This lesson covers the hazards of ionising radiation, the difference between irradiation and contamination, safety precautions, and background radiation — as required by the Edexcel GCSE Physics specification (1PH0), Topic 6: Radioactivity. You need to understand how radiation damages living cells, how to minimise risk, and what contributes to background radiation.

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How Does Radiation Damage Living Cells?

Ionising radiation (alpha, beta and gamma) is dangerous because it can ionise atoms in living cells. When radiation passes through biological tissue, it can:

1. Knock electrons off atoms in important molecules, particularly DNA.
2. This can damage or break the DNA molecule.
3. Damaged DNA may cause cells to divide uncontrollably → this can lead to cancer.
4. Very high doses can cause radiation sickness — where cells are killed outright, leading to nausea, organ failure and potentially death.

Effects of Radiation on Cells

Dose Level	Effect
Low dose over time	Increased risk of cancer (mutations in DNA)
High dose in a short time	Radiation sickness — cell death, organ damage, potentially fatal