The monograph is dedicated to the fate of Chernobyl-born radionuclides in the central part of the East-European Plain. It is based primarily on the original materials obtained in the course of a 12-year study in the temperate forest environments contaminated due to the Chernobyl accident. The monitoring network from which the data have been obtained covers a distance of 3 to 550 km from the Chernobyl Power Plant and includes sites which received deposition of radionuclides.