Pilot study of indoor radon in Greek workplaces.

Radon and gamma dose rate measurements have been performed in 561 workplaces in 19 prefectures of Greece. The distribution of radon concentration can be well described by a log-normal distribution. Most of the radon concentrations are between 50 and 200 Bq m(-3) with an arithmetic mean of 123 Bq m(-3). The maximum measured value of radon gas concentration is 695 Bq m(-3). About 10% of the workplaces exceed 200 Bq m(-3). Only a small fraction ( approximately 1%) of workplaces exceed the European Commission action level (400 Bq m(-3)). Despite the relative small fraction of workplaces which exceed the value of 400 Bq m(-3), it is clear from the results of the present work that for certain prefectures, further and more extensive research is needed.