In recent decades it has become increasingly urgent to protect human health and wellbeing from the possible negative consequences of man's economic activities, both at the actual production sites and in areas where the im­ pact is felt. These negative effects have gradually become more and more widespread, presenting a major hazard to the natural environment, taking on an international character, and assuming global proportions. For the countries of Europe and North America, transport of pollutants and acid rain across boundaries is a serious problem. After the Chernobyl reactor accident, regular measurements of radioactive isotopes became im­ perative. It is obvious that drastic measures, including steps taken on an internationallevel, are required to limit the negative anthropogenic impact on the environment. Under the conditions of this growing man-caused impact on nature, the existing ecological reserves of the biosphere should be husbanded especially carefully. We must determine the regimes of rational utilization of these reserves and of judicious management of the natural environment, thereby maintaining a high quality of the biosphere and preserving nature's regener­ ative capacity. Reliable methods should be developed to keep the environment from being overloaded and to safeguard the elements of the biosphere from injury. Given such a situation, it is of particular importance to have objective information about the critical factors of the human impact and the actual state of the biosphere, as well as to obtain forecasts of its future state.