Environmental study of radioactive caesium in Greek lake fish after the chernobyl accident

The radiological status of radiocaesium in the Greek environment until 1986 has been characterized by the impact of world-wide fallout. During 1986, the Chernobyl nuclear accident resulted in an average deposition of total caesium (134Cs + 137Cs) of ≈ 9 kBq m−2 in Greece, while regional averages ranged within 3–45 kBq m−2 . The radioactive contamination of the lake ecosystems is potentially a radiologically important consequence of the accident. The effects of 137Cs and 134Cs introduced into a number of major Greek lake ecosystems has been evaluated in the present work by determination of their concentrations in various lake fish species during the years 1986, 1988 and 1989. Although the representative and predominant species typically differ from lake to lake, while the local deposition of caesium varies significantly, the bioaccumulation of caesium by the examined species seems to depend rather on the fish species than on the local environmental parameters. The time-dependence of the fish contamination has been used to evaluate the contribution of lake fish consumption to the total ingestion dose of the population.