Applications of radio-isotopes

 Applications of radio-isotopes

The radio-isotopes have wide applications in medicine, agriculture, industry and research. A radio-isotope is added to a particular system and the course of the isotope is studied to understand the system.

(i) Medical applications

In medical field, radio-isotopes are used both in diagnosis and therapy. Radio cobalt (Co⁶⁰) emitting γ−rays is used in the treatment of cancer. Gamma rays destroy cancer cells to a greater extent.

Radio-sodium (Na²⁴) is used to detect the presence of blocks in blood vessels, to check the effective functioning of heart in pumping blood and maintaining circulation. Radio-iodine (I¹³¹) is used in the detection of the nature of thyroid gland and also for treatment. Radio-iodine is also used to locate brain tumours.

Radio-iron (Fe⁵⁹) is used to diagnose anaemia. An anaemic patient retains iron in the blood longer than normal patient.

Radio-phosphorous (P³²) is used in the treatment of skin diseases.

(ii) Agriculture

In agriculture, radio-isotopes help to increase the crop yields. Radio-phosphorous (P³²) incorporated with phosphate fertilizer is added to the soil. The plant and soil are tested from time to time. Phosphorous is taken by the plant for its growth and radio-phosphorous is found to increase the yield.

Sprouting and spoilage of onions, potatoes, grams etc. are prevented by exposure to a very small amount of radiation. Certain perishable cereals remain fresh beyond their normal life span when exposed to radiation.

(iii) Industry

In Industry, the lubricating oil containing radio-isotopes is used to study the wear and tear of the machinery.

(iv) Molecular biology

In molecular biology radio-isotopes are used in sterilising pharmaceutical and surgical instruments.

(v) Radio-carbon dating

In the upper atmosphere, C¹⁴ is continually formed from N¹⁴ due to the bombardment by neutrons produced from cosmic rays.

₇N¹⁴ + ₀n¹  -- -- >  ₆C^14* + ₁H¹.

The C¹⁴  is radioactive with half life of 5570 years.

The production and the decay of C¹⁴ are in equilibrium in atmosphere. The ratio of C¹⁴ and C¹² atoms in atmosphere is 1 : 10⁶. Hence, carbon dioxide present in the atmosphere contains a small portion of C¹⁴.

Living things take C¹⁴ from food and air. However with death, the intake of C¹⁴ stops, and the C¹⁴ that is already present begins to decay. Hence the amount of C¹⁴ in the sample will enable the calculation of time of death i.e, the age of the specimen could be estimated. This is called radio-carbon dating. This method is employed in the dating of wooden implements, leather clothes, charcoal used in oil paintings, mummies and so on.