Uses of Radioactive Isotopes

Radioactive isotopes have applications far beyond atomic bombs. They are widely used in fields such as scientific research, agriculture, industry, and medicine. These substances are utilised in two main ways:

• Using the radiation they emit.
• Using the radioactive element itself.

1. Natural Radioactivity

Elements with atomic numbers from 82 to 92, such as uranium and thorium, naturally emit radiation. These are called natural radioactive elements.

2. Artificial Radioactive Elements

Fredric and Irene Joliot-Curie discovered artificial radioactivity in 1934 by inducing radioactivity in elements through nuclear fission in the laboratory. These artificial radioactive elements are created by bombarding particles and have numerous scientific and industrial applications. The couple received the Nobel Prize in 1935 for their groundbreaking work.

Industrial Uses:

• Gamma rays from isotopes like cobalt-60 and iridium-192 detect cracks and flaws in metal articles through radiography.
• Radioactive substances measure thickness, density, and material levels in manufacturing processes.
• Radium, promethium, and tritium with phosphor create luminescent paints for objects visible in the dark, such as clock hands.
• Krypton-85 is used in HID lamps, and promethium-147 serves as a beta-ray source in portable X-ray units.
• Luminous paints containing uranium oxide were historically used to decorate ceramics like tiles and utensils.

Agricultural Uses:

• Radiation modifies genes in seeds for faster growth and higher productivity.
• Cobalt-60 preserves food and prevents sprouting in onions and potatoes through gamma ray exposure.
• Strontium-90 acts as a tracer in crop research.

Medical Uses:

• Phosphorus-32 treats polycythaemia, a condition with excessive red blood cells.
• Strontium-89, strontium-90, samarium-153, and radium-223 are used for bone cancer treatment.
• Iodine-123 treats hyperthyroidism by reducing overactive thyroid function.
• Boron-10, iodine-131, and cobalt-60 treat brain tumours, while arsenic-74 detects small tumours in the body.