Artificial radiation has many useful medical and industrial applications. As it may be harmful to health, a lot of research work has been conducted to ensure maximum protection is given to the users of radiation. As a result, our exposure to artificial radiation is much lower than that to natural radiation. Among the exposure pathways, doses due to diagnostic and radiotherapy treatments contribute the largest share.
Patients have to be exposed to radiation during diagnostic imaging, e.g. the x-ray examinations. In imaging of certain organs, some radioactive materials are ingested or injected into the patients. In radiotherapy, dose given to a patient has to be high enough to destroy the tumour.
Nuclear power generation is one of the sources of artificial radiation. During the operation of nuclear power stations, traces of radioactive gases or fluid will be discharged to the environment. Transportation and processing of nuclear wastes will also release traces of radioactive materials. These are also sources of artificial radiation.
Guangdong Nuclear Power Station and Lingao Nuclear Power Station at Daya Bay are located about 50 km from the urban areas of Hong Kong. Their design and operation are strictly in accordance with international safety standards. The risk of any serious nuclear accidents is therefore extremely low. Please click here for information on the design and operation of the nuclear power stations.
A number of atmospheric nuclear tests took place from 1945 to 1980. Radioactive particulates produced in the explosions dispersed into the atmosphere by the winds and some of them deposited onto the ground. Deposition of these radioactive materials increased the level of artificial radiation in the environment.
X-ray emission from vacuum tubes of television and video display units are also sources of artificial radiation. Consumer products, such as radioluminous watches and smoke detectors, also consist of radioactive materials. For information on radiation applications in consumer products, please click here.
Radioactive materials used in industry, medical and educational institutions would become wastes one day. The HKSAR Government has taken appropriate actions to treat these radioactive wastes to protect the public from the residual radiation in them. For details, please refer to Environmental Protection Department.
X-ray film (Source: "A Century of X-Rays and Radioactivity in Medicine", published by Institute of Physics, UK. (1993))