Actuality. Currently the level of radiation at the Semipalatinsk nuclear test site composes from 6 to 20 micro-roentgen per hour. Only at some points the radiation level high. In this regard our aim is to clarify the cause of the reduction of radiation and space distribution of nuclear residues at Semipalatinsk nuclear test site. This study is necessary to explore the impact of radiation on human health.
Methods of research and result. Firstly, the main reason is the half-life of radioactive isotopes. Many of the radioactive isotopes decompose rapidly to radionuclides. Active products of nuclear emissions reduced by 10, 100 and 1000 times after the explosion at 7, 49 and the 343 day of the half-life. Undivided uranium, plutonium pollute environment. Subsequently, if the plutonium (239Pu) is based in the soil, 137Cs, 131I particularly 90Sr radionuclides may accumulate in the human body. Thus, 90Sr accumulate in bones and 131I in the thyroid gland .
The second reason is elution of substances into the soil with the help of water. Consequently, substances are accumulated in groundwater. We have counted the number of flushing water. As a result of counting it turned out, that every year 4 million 382 thousand 944 m3 of water washes away the radioactive isotopes in the ground water. In this regard, the wash-off radionuclides contaminate groundwater.
Third, plants and animals actively participate to reduce radiation. The plant gives a lot of biological products. In each ecosystem in the region of Semipalatinsk nuclear range of different plants grow. The overall average productivity of urgent problems steppe plant cover is - 4-5 centner. Cover the plant absorbs 5% of radioactive contamination. Here, under the laws of the ecological pyramid number of insects is 10 times more. From 1 ha of Semipalatinsk nuclear test site land 45-50 different species of insects were found. The insect feeds on the plant, bird on insects forming the process of reduction of radiation in the region.
Radiation level of Semipalatinsk nuclear test site is mainly reduced for three reasons:
First, activity products of nuclear emissions reduced by 10, 100 and 1000 times after the explosion at 7.49 and 343 days during the half-life of the radiation.
Second, sufficient level of rain for elurion of substances into the water. Every year 4 million 382 thousand m3 of water washes away the radioactive isotopes into the ground water. Thirdly, activity of living organisms such as plants and animals.