Class 10 > Unit # 20:Nuclear Structure > Applications of Radioisotopes

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Applications of Radioisotopes in Medicine, Agriculture, and Industry

Radioactive Isotopes (Radioisotopes)

"A radioisotope (radionuclide or radioactive nuclide) is a variant of an element with a different mass number that undergoes spontaneous radioactive decay, emitting radiation to dissipate excess nuclear energy."

Stable, non-radioactive elements can also be transmuted into radioactive elements by exposing them to neutrons or alpha particles. These artificially produced radioactive elements are collectively known as radioisotopes.

Applications of Radioisotopes

Radioisotopes play vital roles across medical diagnostics, treatments, agricultural research, and industrial testing.

1. Radioactive Tracers

A radioactive tracer is a chemical compound in which a short-lived radioisotope has replaced specific atoms. Tracers are utilized to monitor the metabolism and pathways of chemical reactions inside humans, animals, and plants.

• In Medicine: Patients can drink a liquid containing radioactive iodine-131 ($_53^{131}\text{I}$), a gamma emitter, to evaluate thyroid function. Over 24 hours, a radiation detector measures tracer activity to see how quickly it concentrates in the thyroid gland. Additionally, phosphorus-32 ($_15^{32}\text{P}$) is used to diagnose brain tumors, as malignant tissue absorbs higher concentrations.
• In Industry: Manufacturers use tracers to monitor fluid flow, filtration rates, and locate pipeline leaks. Small amounts of short-lived radioactive substances are introduced into liquids, powders, or gases to scan flow rates and pinpoint structural cracks or leaks.
• In Agriculture: Fertilizer uptake from plant roots to leaves is tracked by mixing tracer phosphorus-32 into soil water and tracing its movement through the plant.

2. Medical Treatment (Radiosurgery)

In nuclear medicine, radioisotopes are employed to treat various diseases and malignant conditions. For example, cobalt-60 ($_{27}^{60}\text{Co}$) is a powerful gamma emitter whose penetrating rays can target and destroy malignant tumor cells inside the body. This specialized treatment is known as radiosurgery.

3. Testing for Cracks (Industrial Radiography)

Because gamma rays possess high penetrating power, they can be used to radiograph heavy metals to inspect internal cracks and structural integrity. Cobalt-60 serves as a reliable natural gamma source that operates without needing an external electrical power supply like conventional X-ray tubes.

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