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RADON MEASUREMENT FROM TOURISTIC UNDERGROUND WATERS IN MARAMURES COUNTY

S. Morcovescu*, C. Cosma**, J. Ferenczi***
Industrial Construction High School Baia Mare, Baia Mare, Romania
University “Babes-Bolyai”, Faculty of Physics, Cluj-Napoca, Romania
Hygiene Laboratory of Baia Mare, Baia Mare, Romania
*- Industrial Construction High School, Progresului no.43,4800 Baia Mare, Maramures,
Romania; phone no.:4062415803;
**- University “Babes-Bolyai”, Faculty of Physics, M. Kogalniceanu no.1, 3400 Cluj-Napoca, Cluj,
Romania; phone no.: 4064194315;
*** - Hygiene Laboratory of Baia Mare, Victoriei 112, 4800 Baia Mare, Maramures, Romania,
phone no.: 4062275898;

Three different methods were used to measure radon concentration in groundwater near Baia Mare and
in other places of touristic interest from Maramures, the northest district of Romania. The majority of
the samples have been measured using two methods of alpha detection. The Radon Emanometer
method has a sensibility ofl 0.074 Bq/l (2 pCi/l) and it uses a device of Russian provenience. We made
seventy (70) different measurements with this device. From these 70 measurements, ten were also
made with the second method, which used a device of Czech provenience, LUK-3A, which has a
standard deviation of ± 10% and a sensibility of 0.56 Bq/l (15 pCi/l). We also measured radon
concentration in five different underground waters by absorbing radon on charcoal and using gamma
spectrometry. The methods have been compared and we have used the first two methods to evaluate
the accuracy of the third one (the sensibility was estimated to be about 2.962 Bq/l or 80 pCi/l). The
variation domain of our measurements goes from 1 Bq/l to 35 Bq/l, their graphic representation
indicating a log-normal distribution. The geometric mean of this log-normal distribution, GM=5.785
Bq/l, is lower than the same value of the domestic water supplies from Iran (10-20 Bq/l) but
comparable with that for the South -Central Texas Water supplies (5-7 Bq/l). Some of our values are
higher than EPA proposed drinking water standard of 300 pCi/l (11 Bq/l). The measurement of radium
proved that radium concentration in these underground waters is negligible. We have also put under
observation one of the springs in order to point out the temporal fluctuations of radon concentration
both in summertime and wintertime and we concluded that rainfalls are an important factor which
influences the 222 Rn content.
Keywords: 222 Rn; water; radioactivity; method; touristic