Background

According to the experts' estimations the environment contains 7-8,6 million chemical substances, and their quantity is replenished with 250, 000 new compounds annually. Most chemical substances possess cancerogenic and mutagenic properties. Due to the list compiled by UNESCO experts 200 of them constitute a serious threat, f. e. benzol, asbestos, benzapilene, pesticides, heavy metals, various dyes and food additives.

Main environmental polluters are enterprises of chemical, oil-refining, metallurgy, fuel and other industries; different types of transport, power stations; agriculture, atomic power stations and atomic energy-consuming entities.

Ecotoxicants are taken up by living organisms, and then, moving along food chains and increasing many-fold their concentrations, they affect natural ecosystems, living organisms and man.

Most pollutants are responsible for some global environmental problems: the green house effect (carbon dioxide, nitric oxide, freons), acid rains (sulfur dioxide), radioactive contamination.

Over 1500 types of pesticides are registered in the world, whose application in agriculture were leading to mass loss of wild birds and animals. Of heavy metals cadmium and mercury are especially detrimental to living organisms. Annual release of cadmium to the atmosphere comes to 8000 tons all over the world. Mercury release has already made up 40-50 thousand tons worldwide.

Radioactive contamination can derives from development of autunites, nuclear explosions for peaceful purposes, nuclear weapon testing and accidents at APSs and other enterprises.

At present a number of active reactors amount to about 430 and produce 17% of the world energy, For this reason isolation of radioactive waste from human habitats for the period enough for radionuclides decomposition is one of the urgent challenges.