Radioactive Pollution:
Radioactive Pollution is defined as a type of physical pollution of the atmosphere, hydrosphere, and lithosphere by emissions from radioactive materials. Certain materials possess the ability to emit alpha, beta, and gamma rays. Those materials are called radioactive elements. The source of radiation can be natural or manmade. Radioactive wastes are those wastes containing radioactive material, usual byproducts of nuclear power plants, nuclear reactions, or processes that involve radioactive substances such as research and medicine.
- Alpha particles have low penetrating power and can be blocked by a piece of thin paper and even human skin.
- Beta particles with medium penetrability can penetrate through the skin, while they can be obstructed by glass and metal.
- Gamma rays are highly penetrable and can penetrate easily through the human skin and damage cells on their way through reaching about 100m, and can only be blocked by a very thick and massive piece of concrete.
Natural radiation, alternatively called background radiation involves cosmic rays. Natural radiation sources can be high-energy cosmic rays or land radioactivity. Natural radiation occurs from the elements like radium, actinium, uranium, thorium, polonium, radon, strontium, potassium, and carbon which are found in rock, soil, and water.
The man-made radiation sources are the mining and refining of substances like uranium, plutonium, and thorium, nuclear power plants, and spent fuels. Nuclear weapons explosions result in radioactive fallouts.
Causes of Radioactive Pollution:
1. Cosmic rays
2. Natural radiation
3. Nuclear fuel production
4. Nuclear power plants
5. Use of radionuclides in industries and domestic sources like television, tobacco, watches
6. Nuclear weapon tests carried out by defense personnel
7. Nuclear disposal
8. Uranium, thorium, and plutonium mining
9. Diagnostic purpose – iodine
Effects of Radioactive Pollution:
1. The extent of damage depends upon the half-life period of the radioactive substance and the speed of absorption and excretion. The most sensitive regions appear to be actively dividing regions such as the skin, gonads, and intestine.
2. Reacting with the structural molecules usually forms free radicals that can damage DNA and RNA, proteins, etc. Such mechanisms may cause cancer and congenital defects.
3. In spite of the body cells possessing salvage and repair mechanisms, there is always an increase in the incidence of some types of cancer.
4. Regarding the dose, scientists opine that there is no such threshold value, and radiation at any dose poses a finite risk of causing some biological injury. The damage caused by very low doses of radiation may be cumulative.
5. Gases and particles produced by radioactive materials can be carried by the wind and rain as nuclear fallout. The Chornobyl nuclear accident is a notable example. Strontium has the ability to aggregate in the bones and cause bone cancer. Iodine may affect the WBC, bone marrow, spleen, lymph, and various damages.
6. Radioactive materials contaminating the land and water adversely affect aquatic animals. They are absorbed by the plants and ultimately enter the food chain.