Radioactive substances are generally metals with high atomic mass, like plutonium , uranium , etc. The rays emitted by radioactive substances are mainly gamma rays, alpha rays, beta rays, positrons, protons, neutrons, neutrinos and other particles.
Sources of pollution1, fallout from nuclear weapons tests. In the case of nuclear tests in the atmosphere, the instant the nuclear bomb exploded, by the incandescent steam and gas to form a large ball (i.e., mushroom cloud) carrying shells, debris, ground objects and radioactive smoke cloud rising, with the mixing of air, the gradual loss of radiant heat, the temperature tends to decrease, so the gaseous material coalesced into particles or attached to other dust particles, and finally settled to the ground.
2, the nuclear fuel cycle of the three waste emissions. The center of the atomic energy industry is the generation, use and recycling of nuclear fuel, nuclear fuel cycle at all stages will produce three wastes, can bring a certain degree of pollution to the surrounding environment.
3, radioactive pollution caused by medical irradiation. Due to the widespread use of radiation in medicine, has made the medical ray source has become the main source of artificial pollution of the environment.
4, other sources of radioactive contamination. Other sources of radioactive contamination can be summarized into two categories: First, industrial, medical, military, nuclear ships, or research with radioactive sources, due to transportation accidents, loss, theft, misuse, and waste disposal and other loss of control of the residents caused by a large dose of irradiation or pollution of the environment; Second, the general public consumption goods, including products containing natural or artificial radionuclides, such as radioactive light-emitting dials, luminous meters and color television sets Produced by the irradiation, although the pollution caused by the environment is very low, but there is also a need for research.