Evaluation of the Current Radiation Burden of Children Living in Regions Contaminated by the Chernobyl Accident

About 18 years after the Chernobyl accident, the verification and documentation of the long-term development of radiation doses is still required, especially in environments where ingestion considerably contributes to the current and future dose commitment of the population. A population group of special concern are the children living in the contaminated regions. Out of the two million Belarusian children, approximately 80000 children live in regions contaminated after the Chernobyl accident by a Cs-137 deposition of more than 185 kBq/m2. A German-Belarusian project funded by the German Federal Office for Radiation Protection is presently investigating radiation burdens of children in those regions. Whole-body counting results have been obtained for close to 17000 children using seven transportable in-vivo monitors. The measurements were mostly done in schools or kindergartens situated in the contaminated regions. Mean internal doses were calculated for the total group of children measured in a settlement as well as for the critical group, which was defined as the ten most highly exposed children. To compare results with the international dose limit of 1 mSv/a an external dose contribution was added based on the amount of the original Cs-deposition at the corresponding settlement. Though even for the critical group total annual doses were generally below 1 mSv/a in some cases this limit was exceeded, essentially due to high ingestion doses. The authors are deeply convinced that nearly 20 years after the Chernobyl accident doses above the international dose limit of 1 mSv/a are no longer acceptable by ethic reasons, especially not for children. Therefore, honest efforts must be performed to reach this goal.