Radon levels in household waters in southern Poland

Determination of radon concentrations in household waters were performed in 1997 in three regions of south-western Poland which are considered to have an enhanced natural radioactivity level: in the Jelenia Gora and Walbrzych regions (both in south-western Sudety Mountains) and in the Upper Silesian Coal Basin. Water samples were collected from taps, wells and springs and were analyzed in a liquid scintillation counter. In the Upper Silesian Coal Basin all values are below 50 Bq/dm3 with a maximum of 32 Bq/dm3 and in the Sudety Mts. the radon concentration in water exceed this level in 68% of houses, reaching a maximum value of ca. 1400 Bq/dm3 in drilled well water in the Jelenia Gora region. The annual ingestion dose calculated for this value equals to ca. 0.5 mSv for infants, 0.4 mSv for children and 0.3 mSv for adults. The average annual effective whole body doses calculated for tap water samples for a representative population in the investigated regions range from about 0.02 mSv to 0.32 mSv and the maximum value reaches 1.39 mSv. The inhalation doses corresponding to the unit of water-borne radon concentration are about one order higher than the ingestion ones for tap water supplies

stawarz.p65

Abstract PicoRad system based on activated charcoal collectors and liquid scintillation counter is one of the most popular passive methods of radon measurements which may be used both indoors and in other environments such as caves, tunnels, mines etc. It is well known that charcoal is also a very good adsorber of water vapor and it can reduce adsorption efficiency for radon. In PicoRad collectors, the charcoal is mixed with a dessicant to lower this effect. A series of expositions of PicoRad detectors was performed in a Central Laboratory for Radiological Protection (CLOR) radon calibration/climatic chamber to study the effect of high relative humidity on the airborne radon concentration measurements and the dependence of the results on the duration of exposure. The results obtained from the PicoRad system were referred to the mean concentrations delivered by an AlphaGUARD monitor, Genitron (GmbH), Germany. The main conclusions are the following: 1) the PicoRad system results are not affected by high relative humidity, including extreme values of 90−96%, for the duration of exposure up to ca. 24 h; 2) in the relative humidity range of 75−96% the correction coefficient linearly depends on the duration of exposure reaching a value of ca. 16 for 96 h exposure; 3) the PicoRad system delivers results corresponding better to the mean value of radon concentration in the last 6 h interval of exposure than that in the whole exposure duration. This finding is particularly important for the calibration of PicoRad collectors in the conditions of decreasing radon concentration due to radon decay

Investigation of the influence of high humidity and exposure duration on the measurement results of radon concentration by means of PicoRad system in the CLOR calibration chamber

PicoRad system based on activated charcoal collectors and liquid scintillation counter is one of the most popular passive methods of radon measurements which may be used both indoors and in other environments such as caves, tunnels, mines etc. It is well known that charcoal is also a very good adsorber of water vapor and it can reduce adsorption efficiency for radon. In PicoRad collectors, the charcoal is mixed with a dessicant to lower this effect. A series of expositions of PicoRad detectors was performed in a Central Laboratory for Radiological Protection (CLOR) radon calibration/climatic chamber to study the effect of high relative humidity on the airborne radon concentration measurements and the dependence of the results on the duration of exposure. The results obtained from the PicoRad system were referred to the mean concentrations delivered by an AlphaGUARD monitor, Genitron (GmbH), Germany. The main conclusions are the following: 1) the PicoRad system results are not affected by high relative humidity, including extreme values of 90-96%, for the duration of exposure up to ca. 24 h; 2) in the relative humidity range of 75-96% the correction coefficient linearly depends on the duration of exposure reaching a value of ca. 16 for 96 h exposure; 3) the PicoRad system delivers results corresponding better to the mean value of radon concentration in the last 6 h interval of exposure than that in the whole exposure duration. This finding is particularly important for the calibration of PicoRad collectors in the conditions of decreasing radon concentration due to radon decay