Forests and forestry: radiation protection measures with special reference to the Chernobyl accident zone

A large proportion of the area contaminated by the Chernobyl accident in the former USSR is forested and has presented unique problems when considering appropriate post-contamination management and clean-up techniques. These problems are related to the forest's role as both a source and sink for radioactive contamination. Although it has been suggested that resuspension from forested areas may provide a secondary source of contamination to adjacent land, data collected after the Kyshtym and Chernobyl accidents suggest that forest ecosystems may also be effective in limiting the further spread of contamination away from the point of initial deposition and that this effect will increase over time. Such evidence serves to highlight the importance of these ecosystems in influencing the behaviour of radionuclides immediately after their release to the environment. Management practices for forested areas adopted since 1986 are described and a critical appraisal is presented of engineering-based countermeasures implemented over the initial post-accident period. These were intended to remove large quantities of contaminated materials from the forest environment. However, it is suggested that the natural processes of self-decontamination of trees and forest floor litter layers are sufficiently rapid and efficient to necessitate radical alterations to the technology based approaches adopted in the first 2 years after the Chernobyl accident.