Health related environmental monitoring

Radioactive elements and penetrating radiations have been present in earth's environment since the beginning of the solar system and hence the life forms on earth have always been subjected to ionising radiations. These natural radiations comprise the cosmic rays which originate in outer space and those from the radioactive materials normally present in soil, air, water, food and the body. To this natural radiation man had added artificial sources of radiations. These man-made sources are from the nuclear fuel cycle operations that are essential for a nuclear power programme, from the industrial uses of radiation, from defence related activities and from the medical uses of radiation. Natural background radiation is the major contributors to radiation exposures received by mankind and these exposures have remained fairly constant over several thousand years. Enhanced natural radiation levels due to man's activities have been identified, like for example in some mining areas. Fly ash from thermal power plants contain natural radioactive elements and the dispersal of this fly ash can result in enhanced natural radiation exposures. There are also other such sources like phosphatic fertilizer and supersonic travel. United Nations Scientific Committee on the Effects of Atomic Radiations (UNSCEAR) has periodically reviewed the current information on this subject