Assessment of Radioactive Contamination of Birds within The Exclusion Zone

Period: since 2004Customer: Civilian Research and Development Foundation (CRDF), USA

Project objective: assess radiation contamination levels for various bird species living within the Exclusion Zone, estimate carry-over of radionuclides out of the zone performed by birds.

Research results:

• values of 137Cs and 90Sr specific activity in the birds varies over a very wide range;
• logarithmically normal distribution of the total data population and gradual increase of their values are observed as territorial contamination levels increase;
• сontamination of the birds depends on their territorial behavior, the birds-migrants have lower contamination if compared to the resident birds, as a result the birds are ‘cleaner’ during migration than during their nesting period;
• nestlings accumulate much more 90Sr and less 137Cs than adult birds;
• the birds feeding in tree crowns accumulate more 137Cs, and the birds, who find their food on the ground, accumulate more 90Sr.

The obtained results (value of radionuclides specific activity in a bird’s body) were analyzed with due regard to possible impact of the following factors: peculiarities of radioecology situation within each research site; seasonal changes in radionuclides intake; sex, age, and species differences of the birds.