On the 26th of April 1986 a catastrophe broke out 12 kilometres off the Belarusian border. It was the major break-down of the power unit at the Chernobyl nuclear power station. It is the most severe catastrophe throughout the entire world history of the atomic energy use by its scale, complexity and long-term consequences.
As the result of the explosion of the failed reactor a huge amount of radioactive substances was released into the atmosphere. Later on they left the large fall-out «spots» on the ground surface. 23% of the territory of Belarus, 4,8% of the territory of the Ukraine and 0,5% of the territory of Russia were contaminated.
The radiation situation was determined by radionuclides with the period of half-decay from 8 days till 24390 years.
After the Chernobyl accident Belarus has become the zone of the ecological disaster. The situation got worse because radioactive contamination coincided with the formerly existing zones of high chemical pollution. 260,000 hectares of agricultural lands are forbidden to use for farming purposes. Thousands of hectares of forests are contaminated with radioactive elements. The Chernobyl catastrophe has affected the destinies of millions of people. The radioactive contamination of the ecosystems has created the conditions for making it impossible to conduct the agricultural production and manage forestry in the normal way for many decades.
In order to decrease the influence of radiation on the people considerable work was done during the post-accident period/Measures were taken to evacuate the people from the most dangerous districts, to provide for their medical check-up and treatment. Various measures were carried out — radioactive decontamination, agricultural treatment of soil, provision of clean food. However, these measures are not enough yet. And international co-operation in this field serves the interests of the entire mankind.