Long-term investigations of radiocaesium activity concentrations in carp in North Croatia after the Chernobyl accident

Long-term investigations of radiocaesium activity concentrations in carp in the Republic of Croatia are presented. The radiocaesium levels in carp decreased exponentially and the effective ecological half-life of 137Cs was estimated to be about 1 year during 1987–2002 and 5 years during 1993–2005. The observed 134Cs:137Cs activity ratio in carp was found to be similar to the ratio observed in other environmental samples. The concentration factor for carp (wet weight) was estimated to be 128 ± 74 L kg−1, which is in reasonable agreement with model prediction based on K+ concentrations in water. Estimated annual effective dose received by adult members of the Croatian population due to consumption of carp contaminated with 134Cs and 137Cs are small: per capita dose from this source during 1987–2005 was estimated to be 0.5 ± 0.2 μSv. Due to minor freshwater fish consumption in Croatia and low radiocaesium activity concentrations in carp, it can be concluded that carp consumption was not a critical pathway for the transfer of radiocaesium from fallout to humans after the Chernobyl accident.