Where does man-made radiation come from ?

Man-made radiation sources include X-ray machines, nuclear power plants, nuclear industrial incidents, nuclear weapon tests, as well as consumer products which produce radiation.

Radiation is widely used for medical diagnosis and therapy. This includes the familiar body and dental X-ray examination, as well as computer tomography. In radiotherapy, radioactive material is used to kill cancer tumours.

Since the 1950s, the number of power stations using nuclear reactors has increased. During the operation of nuclear power stations, traces of radioactive gases or fluid are discharged to the environment. Transportation and processing of nuclear wastes also release traces of radioactive material. Like other industries, incidents may happen in the nuclear industry, resulting in radiation leakage or exposure.

Many atmospheric nuclear tests had taken place in a number of countries in the past. Radioactive particulates produced in the tests dispersed into the atmosphere. Some of them became deposited onto the ground or water, increasing the level of radiation in the environment.

The vacuum tubes of television and video display units used in our daily life emit X-ray. Other consumer products, such as radioluminous watches and smoke detectors, consist of radioactive material, and are another source of man-made radiation.