The higher the height of nuclear explosion, the less the settlement in the nearby area. When the ground explodes, the radioactive materials settled near the ground account for 60% ~ 80% of the total radioactive materials. More than 30 kilometers above the ground exploded, and there was almost no near-field settlement. The global pollution caused by nuclear test is much more serious than that caused by nuclear industry. Before 1970, 9 billion strontium atoms in the stratosphere caused by atmospheric nuclear tests reached 5.74 billion Bekkerel, of which 5.55 billion Bekkerel had fallen to the ground.
Ionizing radiation produced by radioactive substances has adverse effects on people's health. Since the discovery of X-ray and radium, radiation injury, dermatitis, skin cancer, leukemia, aplastic anemia and other diseases have appeared one after another. Later, it was found that female workers exposed to radium, a luminescent coating, suffered from mandibular cancer, and uranium mines were particularly likely to suffer from lung cancer. From 65438 to 0945, the United States dropped atomic bombs on Nagasaki and Hiroshima in Japan. After the atomic bomb explosion, the local residents were affected by radiation for a long time, and the incidence of tumor and leukemia increased obviously, thus attracting people's attention to the harm of radioactive substances.
After 1954, the nuclear explosion test increased sharply, and the environmental pollution caused by radioactive fallout affected the whole world.
Various radioactive substances are transferred to the human body through the food chain in the environment and are affected by many factors. These effects include the physical and chemical properties of radionuclides, environmental factors, metabolism in animals and plants, people's eating habits and so on. After the radionuclides enter the human body, the radiation will continue to irradiate the human body until the radionuclides are converted into stable radionuclides or all of them are excreted.
The pollution of some trace radionuclides to human body does not affect health. When the internal radiation dose is large, short-term effects may occur. These effects include nervous system and digestive system symptoms such as headache, dizziness, loss of appetite and sleep disorder, and then there will be symptoms such as leukopenia and thrombocytopenia. Long-term effects Excessive radioactive substances in the body will have long-term effects, such as tumors, leukemia and genetic diseases.
The impact of radioactive pollutants on the environment is long-term and permanent. This requires people to be soberly aware of the possible environmental pollution when using radioactive substances and conducting nuclear tests. In the process of scientific and technological development, people will use more and more radioactive substances. Similarly, people's preventive measures against it will become more and more strict and effective.