where Ew$Ig is the effective dose for ingestion, CRnw is the radon
concentration in water (kBq m3), Cw is the weighted estimated
of water consumption (60 l y1) and (EDC) is the Effective
Dose Coefficient for ingestion 3.5 nSv Bq1.
From Table 1 it is clearly seen that the annual mean
effective dose due to ingestion varies from 0.11 to
4.62 mSv y1with the mean value of 0.93 mSv y1.
The annual mean effective doses of drinking water samples
due to inhalation was calculated by using the parameters
established in UNSCEAR (2000):