DYNAMICS AND DISTRIBUTION OF RADIOCESIUM IN BROILER CHICKEN

The distribution and biological half-life of radiocaesium (Cs-137) in broiler chickens after three oral applications (in course of 1 day at the age of 14 days) of artificially contaminated feed mixture were stu died. There was a rapid uptake of the orally administered Cs-137 (with in a few hours) and also a rapid loss of Cs-137 which varied in the di fferent organs (the initial biological half-life was: liver 0.6 day, i ntestine 0.6 day, breast meat 2 days, leg meat 1.2 days). More than on e-half of the total administered Cs-137 activity (55%) was excreted fr om the body within the 1st day after dosage, and after 14 days more th an 90% had been excreted. The highest accumulation of Cs-137 occurred in meat (50%-90%), and the proportion of total activity in breast and leg meat varied during decontamination. The transfer of radiocaesium f rom feed into the chicken body (measured as ratios of the Cs-137 activ ity concentrations in the organ to the Cs-137 activity concentration i n the applied dose) 1 day after application was: 0.0220, 0.0294, 0.021 6 and 0.0195 for breast meat, leg meat, intestine and liver, respectiv ely. Significant differences between the values were demonstrated (P<0 .05) except between those of breast meat and intestine. For the first 3 days there was a higher proportion of Cs-137 activity in leg meat, w hereas from the 4th day a greater part of total activity was found in breast meat. The latter results were confirmed in a subsequent study. Data from this study suggest that if broiler chickens are contaminated by radiocaesium to a level of 5 kBq/chicken in the course of 1 day at the age of 14 days, then immediate feeding with uncontaminated feed m ixture for 18 days should be effective in decontaminating the chicken' s meat below the intervention levels for radiocaesiumin animal product s, i.e. below 1000 Bq . kg(-1).