| Popis: |
Results of systematic, long-term measurements of 137Cs activities in wheat for the period 1965-2003 are summarized. Radiocaesium fallout activities affect wheat activity concentrations, the coefficient of correlation being 0.91. In the observed period, the highest activity of 137Cs deposited by fallout, 6321 Bqm-2, eas recorded in 1986, i.e., in the year of Chernobyl accident, causing peak137Cs activity concentration in wheat of 38.0 13.0 Bqkg-1. After the Chernobyl nuclear accident the 134Cs :137Cs activity ratio in wheat was 0.5, and did not differ from the value found in other environmental samples. The transfer coefficient from 137Cs fallout deposition to wheat was calculated to be 8.6 x 10-3 Bq y kg-1 per Bq m-2, indicating the low transfer of radiocaesium from fallout towheat. The upper limit for the collective effective dose for the Croatian population due to 137Cs and 134Cs ingestion by wheat and wheat products consumption for period 1965-2003 was estimated to be 665 person-Sv, the upper limit for the annual collective effective dose in 2003 being only about 0.061 person-Sv. |
