Radioactivity monitoring in drinking water of Attika, Greece

A survey study on radioactivity in drinking water from three lakes in the region of Attika in Greece is in progress since 2004. The measurement of gross alpha and gross beta activity is used as a screening method. All the values of alpha and beta activity in the selected water samples were lower than the permissible limit for drinking water consumption, 1.0 and 0.1 Bq/L respectively. The determination of γ-emitters was performed by use of gamma spectrometry and the determination of α-emitters by use of α-spectrometry. The values of 238U and 234 U vary between 0.91 to 17.27 and 2.13 to 22.01 mBq/L respectively. The 234U/238U activity ratio varies between 1.12 and 2.40.

Taking into account the experimental data presented in Tables 1 and 2, the measurement results from the γ-spectrometry and the screening results of total α/β, with the calculated reference concentrations (Table 3), the following conclusions can be drawn: • The levels of artificial γ-emitters in the drinking water of the suppliers for the region of Attika were below the low detection activity (LDA). • The uranium concentration is well below the 20% of the reference level for radiological protection. • The committed effective dose for one year of intake is estimated to be well below the value of 0.1 mSv/year.