Evaluation of radon gas concentration in indoor air of spas and in spring water in the central Anatolia region of Turkey.

The present study aimed to determine the concentration of radon (222Rn) levels of indoor air of spas and of spring water sites in the Turkish cities of Nigde and Aksaray, both located in Cappadocia, Anatolia, which is a well-known tourist area. In this area there are a lot of spring water and thermal water sites providing both drinking water and water for spas, which are used for therapeutic treatments of diseases and for health services. Therefore, it is necessary to quantify radon gas concentrations in the air of sites that use geothermal waters and spring water. Consequently, radon measurements were carried out using CR-39 detectors placed at different locations within each investigated thermal spa and spring water site. The results obtained indicate that, in the air of spring water at Helvadere, there is a high radon concentration. The average radon concentrations obtained for the air of Ciftehan and Ziga thermal spas were 12.5 ± 1.4 Bq/m3 and 15.5 ± 2.1 Bq/m3, respectively, while in the air of Kemerhisar, Helvadere, and Okcu village spring water sites the average radon concentrations were 32 ± 4.2 Bq/m3, 265 ± 37.9 Bq/m3, and 35 ± 5.1 Bq/m3, respectively. The corresponding average effective doses were calculated both for patients and workers for Ciftehan and Ziga thermal spas, and for workers 0.09 and 0.11 mSv/year for Ciftehan and Ziga, respectively, were obtained. Doses for patients were 0.0007 and 0.0008 mSv/year for Ciftehan and Ziga, respectively. It is concluded that based on the measured radon concentrations and corresponding effective doses no radiation protection measures must be implemented.

Eco-Geopolymers: Physico-Mechanical Features, Radiation Absorption Properties, and Mathematical Model.

Waste ashes and radiation are hazardous environmental and health factors; thus, a lot of attention is paid to their reduction. We present eco-geopolymer building materials (GPBMs) based on the class F fly ashes (FFAs) from thermal power plants (TPPs) and their implementation as a barrier against radioactive radiation. Different methods of production, ratios of FFA to alkali activator, and temperatures of curing were tested. Small spherical particles and higher content of SiO2 resulted in developed surface area and higher reactivity of Isken TPP FFA than Catalagzi TPP FFA. Lower activator concentration (10% vs. 20%) and curing temperature (70 vs. 100 °C) caused an increase in GPBM compressive strength; the highest value was measured as 93.3 MPa. The highest RA was measured for GPBMs, provided alkali activator ratio (Na2SiO3/NaOH) was >2 and its concentration was 20%. The mathematical model developed in this study proved FFA quantity, and thus GPBM mechanical properties, as key factors influencing RA. In the light of these results, the lightweight GPBMs can be excellent materials for the construction sector dedicated to immobilization, storage, and disposal for radionuclides or barriers against radiation; however, multiple steps of their production require careful optimization.