Radon concentration in basements of old town buildings in the Lublin region, Poland

Radon concentration in basements of old buildings in the oldest towns of Lu blin region (Zamosc, Chelm and Sandomierz) was determined. Two techniques w ere applied: passive Pico-rad) and alpha-spectrometry for radon progeny con centration measurement (SILENA. It was found that only 7% of results exceed ed a dose limit of 400 Bq.m(-3), established for old buildings. Radon conce ntration levels ranged from 0.2 to 5150 Bq.m(-3) Distribution of the result s satisfied a log-normal relationship. Applying these two methods at the sa me time, the radioactive equilibrium factor of radon and its progeny was de termined. In the underground ways, open for visitors, no higher radon conce ntration was observed.