Radon variations during treatment in thermal spas of Lesvos Island (Greece)

Abstract

The aim of this paper was to study the variations of radon and daughter nuclei during treatment in the thermal spas of Lesvos Island (Greece). For this purpose, in the thermal spas of Lesvos we have measured the radon concentrations of thermal waters, as well as indoor radon, daughter and coarse particle (>500 nm) concentrations. Various instruments and procedures were employed for measurements. Radon concentrations of thermal waters were found to lie in the range 10 Bq l(-1) and 304 Bq l(-1). Concentration peaks both for radon, radon daughter and coarse particle, were found to appear during filling of baths in the treatment process. The doses delivered to the bathers during treatment were in the range of 0.00670-0.1279 mSv per year, while the doses delivered to personnel were below 20 mSv per year.

Natural radioactivity in Brazilian groundwater

“…Table 2 shows the descriptive statistics of 222 Rn, 210 Pb, 226 Ra, 228 Ra and U nat concentrations in groundwater including all geographical regions together. High radon content in groundwater is reported in the literature (Banks et al, 1998a,b;Camargo, 1974;Cho et al, 2004;Moura˜o, 1992;Przylibski and Zebrowski, 1999;Przylibski et al, 2002;Soto et al, 1995;Vogiannis et al, 2004;Zhuo et al, 2001). In particular, some spas in the GermaneCzech border are well known due to the presence of radon rich springs as the Curie source in Joachimstal with a radon content of 12 kBq L ÿ1 (http://www.wellness-kuren-online.de/tschechien/st.joachimstal/ index.htm).…”

Health risk related to radon in a thermal spa utilizing waters from Guarani aquifer

“…The mechanisms which can cause 222 Rn release from the solid phase and consequently account for the observed Rn content of groundwater and air were discussed elsewhere [30,31] and consists basically of the following processes: 222 Rn recoil following alpha-decay of 226 Ra atoms close to the surface of the solid particles (within the 222 Rn recoil range of 0.036µm); 222 Rn diffusion through the crystalline lattice from production sites below the rock surface; 222 Rn diffusion along crystal defects, grain boundaries or microfractures from greater depths below the rock surface; existence of a network of 100 -200 Å wide nanopores in rocks and minerals, many of which intersect the grain surface, and give rise to a large internal surface area of the solids (in the range of about 10 m per cm 3 ), orders of magnitude higher than the external surface calculated from grain size. Thus, the models developed for explaining the generation of radon in rocks and transfer to air and water have followed a more macroscopic approach [32] or have included many parameters that are difficult/impossible to measure practically, for instance, microscopic properties such as the surface roughness or inhomogeneous 226 Ra distribution in the solid [31,33].…”

“…On the other hand, 222 Rn also generates several daughters (heavy metals) through a sequence decay that finishes with lead, i.e. 222 Rn (3.84 222 Rn concentrations occur in groundwater in many areas where wells are used for domestic water supply and thermal spas, including small rural water supplies [2,3]. Exposure to radon and its progeny is believed to be associated with increased risks of several kinds of cancer [4].…”

Preliminary results of radon survey in thermal spas in V4 countries

“…Radon measurements in thermal waters of Lądek Zdrój in Poland showed values from 122 Bq/l to 1284 Bq/l [4]. Radon concentrations of thermal waters in the spas of Lesvos Island in Greece were found in the range 10 and 304 Bq/l [5]. Radon measurements in the air and thermal water of nine Croatian spas were performed and radon concentrations in the air and water of the swimming pools were obtained in the range of 10.9-109 Bq·m -3 and 0.73-18.6 Bq/l, respectively [6].…”