2 DECADES OF ENVIRONMENTAL ISOTOPE RECORDS IN CROATIA - RECONSTRUCTION OF THE PAST AND PREDICTION OF FUTURE LEVELS

A two-decade-long record of environmental isotopes (H-2, H-3, C-14, O- 18) in Croatia is presented and the data are statistically analyzed. T he atmospheric C-14 activity for the period before the actual measurem ents started is reconstructed by measuring tree rings from the clean-a ir sites, and the past tritium activity in precipitation is estimated by the correlation of our data with the Vienna station record. The lon g-term H-3 record helped to determine a locally contaminated sampling site, and new clean sites are put into operation. The C-14 data were f itted by an analytical function and the prediction of future levels is given assuming that the rate of the C-14 releases remains constant. F rom the long-term stable isotope data record, the local meteoric water line and the temperature gradient of delta(18)O in precipitation are determined.