Nuclear Pollution

Nuclear or radioactive pollution is the physical pollution of living organisms and their environment as a result of the release of radioactive substances into the atmosphere during nuclear explosions, testing, production, and decommissioning. Unlike other forms of pollution, radioactive waste remains active and hazardous for thousands of years due to the long half-lives of certain isotopes.

Types of Radiation

Radiation is broadly classified based on its energy levels and ability to displace electrons (ionization).

• Non-ionizing Radiation: Low-energy radiation such as ultraviolet (UV), infrared (IR), and radio waves. They generally cause thermal effects.
• Ionizing Radiation: High-energy radiation including Alpha particles, Beta particles, and Gamma rays. These possess enough energy to break chemical bonds and damage DNA.

Sources of Nuclear Pollution

Sources are categorized into natural (background) and anthropogenic (man-made) origins.

Natural Sources

• Cosmic Rays: High-energy particles from outer space that reach the Earth’s surface.
• Terrestrial Radiation: Naturally occurring radioactive elements in the Earth’s crust, such as Radium-224, Uranium-238, and Thorium-232.
• Radon Gas: A naturally occurring radioactive gas resulting from the decay of uranium in soil and rocks; it is a leading cause of lung cancer.

Anthropogenic Sources

• Nuclear Power Plants: Accidental leakages or improper disposal of coolant and radioactive fuel.
• Nuclear Weapons: Testing and usage of nuclear warheads result in “radioactive fallout.”
• Mining and Milling: Extraction of Uranium and Thorium ores releases radioactive dust and radon gas.
• Medical and Industrial Waste: Use of isotopes like Cobalt-60 or Iodine-131 in radiotherapy, X-rays, and industrial gauges.

Biological and Environmental Impacts

The impact of radiation depends on the dose, duration of exposure, and the type of tissue affected.

Somatic Effects (Individual Level)

• Acute Radiation Syndrome (ARS): High-dose exposure leading to nausea, hair loss, and internal bleeding.
• Cancers: Increased risk of leukemia, thyroid cancer (often linked to Iodine-131), and bone cancer (linked to Strontium-90).
• Organ Damage: Damage to sensitive tissues like bone marrow and the lining of the digestive tract.

Genetic Effects (Hereditary Level)

• DNA Mutation: Radiation can alter the molecular structure of genes in reproductive cells, leading to congenital disabilities and deformities in future generations.

Management and Classification of Radioactive Waste

Radioactive waste is categorized by its activity level and the duration it remains hazardous.

Global and Domestic Regulatory Frameworks

• International Atomic Energy Agency (IAEA): An intergovernmental organization that promotes the peaceful use of nuclear energy and sets international safety standards.
• Atomic Energy Regulatory Board (AERB): The Indian authority responsible for ensuring that the use of ionizing radiation and nuclear energy does not cause undue risk to health and the environment.
• Atomic Energy Act, 1962: Provides the legal framework for the development, control, and use of atomic energy in India.

Important Facts and Trivia for UPSC

• Half-Life Concept: The time required for half of the radioactive atoms in a sample to decay. For example, Plutonium-239 has a half-life of 24,000 years.
• Strontium-90 and Calcium: Strontium-90 is chemically similar to calcium; the body often mistakes it for calcium and deposits it in bones, leading to bone cancer.
• Biological Accumulation: Radioactive isotopes like Cesium-137 can undergo biomagnification, increasing in concentration as they move up the food chain.
• Major Nuclear Accidents:
  • Chernobyl (1986, USSR): Classified as Level 7 (Major Accident) on the INES scale.
  • Fukushima Daiichi (2011, Japan): Caused by a Tsunami; led to significant marine contamination.
  • Three Mile Island (1979, USA): A partial meltdown event.