Uses and Hazards of Radiation in Medicine and Industry — AQA GCSE Physics
Nuclear radiation has valuable uses, especially in medicine, but it must be used carefully because it is ionising.
Medical uses
- Medical tracers — a radioactive substance (a gamma emitter with a short half-life) is put into the body. Its radiation is detected outside the body to monitor organs (e.g. the thyroid or kidneys) or blood flow. Gamma is used because it can pass out of the body, and a short half-life limits exposure.
- Radiotherapy — high doses of radiation (often gamma rays, or beams from outside, or implanted sources) are used to kill cancer cells.
- Sterilising equipment — gamma rays kill microbes on medical instruments without damaging them.
Industrial uses
- Measuring thickness — radiation passing through a sheet (e.g. paper, metal) depends on its thickness, allowing automatic control.
- Detecting leaks in pipes using tracers.
Hazards
Radiation is ionising, so it can damage cells and DNA, potentially causing cancer or cell death. Radiation dose (the risk of harm) is measured in sieverts (Sv). The benefits of medical use must be weighed against the risks, and exposure is kept as low as possible.
Exam tips
- A good tracer is a gamma emitter with a short half-life (detectable outside, limits exposure).
- Radiotherapy kills cancer cells; sterilisation kills microbes.
- Radiation is ionising → can cause cancer; dose is measured in sieverts.
- Benefits are weighed against risks; exposure is minimised.