Question

Write about Nuclear hazards.

Answer 1

Nuclear hazards

Radioactive (nuclear) pollution is a special form of physical pollution related to all major life-supporting systems – air, water and soil. It is always convenient to discuss radioactive pollution separately because its nature of contamination is different from other types of pollution. Its effects are also of special kinds. 

Radioactivity is the phenomenon of emission of energy from radioactive isotopes (i.e., unstable isotopes), such as Carbon-14, Uranium-235, Uranium-238, Uranium-239, Radium-226, etc. The emission of energy from radioactive substances in the environment is often called as 'Radioactive Pollution'.

The sources of radioactivity are both natural and man-made. The natural sources include:

1) Cosmic rays from outer space. The quantity depends on altitude and latitude; it is more at higher latitudes and high altitudes.

2) Emissions from radioactive materials from the Earth's crust.

People have been exposed to low levels of radiation from these natural sources for several millenia. But it is the man-made sources which are posing a threat to mankind. The man-made sources of radioactivity are nuclear wastes (i.e., waste material that contains radioactive nuclei) produced during the:

1) Mining and processing of radioactive ores;

2) Use of radioactive material in nuclear power plants;

3) Use of radioactive isotopes in medical, industrial and research applications; and

4) Use of radioactive materials in nuclear weapons.

The greatest exposure to human beings comes from the diagnostic use of X-rays, radioactive isotopes used as tracers and treatment of cancer and other ailments.

Effects of nuclear hazards

The effects of radioactive pollutants depend upon half-life, energy releasing capacity, rate of diffusion and rate of deposition of the contaminant. Various atmospheric conditions and climatic conditions such as wind, temperature and rainfall also determine their effects.

All organisms are affected from radiation pollution, and the effects are extremely dangerous. The effects may be somatic (individual exposed is affected) or genetic (future generations) damage. The effects are cancer, shortening of life span and genetic effects or mutations. Some of the possible effects are listed as under:
Radiations may break chemical bonds, such as DNA in cells. This affects the genetic make-up and control mechanisms. The effects can be
instantaneous, prolonged or delayed types. Even it could be carried to future generations. Exposure at low doses of radiations (100-250 rads), men do not die but begin to suffer from fatigue, nausea, vomiting and loss of hair. But recovery is possible Exposure at higher doses (400-500 rads), the bone marrow is affected, blood cells are reduced, natural resistance and fighting capacity against germs is reduced, blood fails to clot, and the irradiated person soon dies of infection and bleeding.Higher irradiation doses (10,000 rads) kill the organisms by damaging the tissues of heart, brain, etc.Workers handling radioactive wastes get slow but continuous irradiation and in course of time develop cancer of different types.Through food chain also, radioactivity effects are experienced by man.
But the most significant effect of radioactivity is that it causes long range effects, affecting the future of man and hence the future of our civilization.