On the night of 26th April, 1986, something went wrong with reactor four of the nuclear power plant at Chernobyl. The result was the most serious accident so far in the world with a nuclear power station.

After the accident, a sarcophagus of concrete was constructed around the reactor, to prevent further release of radioactivity. This sarcophagus is in a very bad condition, and it is feared, amongst other things, that the roof could collapse. An area with a radius of 30 km was declared a "forbidden zone" after the accident, where no-one had the right to live. In total, 135,000 people were evacuated, of whom 91,000 were inhabitants of the "forbidden zone". But these measures were not enough.

70% of mortally dangerous radioactive products of the blown-up nuclear reactor, which is situated outside of Belarus, fell out on its territory. All the residents of the republic were concerned with the Chernobyl disaster, as at the first period short-living radioactive isotopes, first of all those of iodine, spread out on its whole territory. 23 per cent of the Byelorussian territory is contaminated with caesium-137. A considerable portion of the Chernobyl-affected areas is contaminated also with strontium and plutonium. The period for its semi-decay exceeds 24 thousand years.

The Chernobyl disaster put a lot of difficult tasks for the contaminated areas, brought essential changes in the economical activity, demanded a lot of personal and material resources. It made the inhabitants suffer, it caused their anxiety for their children's future, it changed their surroundings, their way of life and even their psychology.

Nowadays every fifth inhabitant of Belarus lives in contaminated area. Human beings have no organs of perception of radiation. That is why, it seems to some people that a lot of time has passed since the accident took place, the same trees grow and the same rivers flow. Meanwhile there has been documented a dramatic increase in cancer of the thyroid gland, especially among the children from the Gomel region.