No abstract

A recent challenge in research dedicated to residential exposure to radon comes from the growing number of houses retrofitted to reduce energy consumption. Efficiently insulated buildings and modern architectural solutions can lead to the accumulation of high levels of indoor pollutants. A systematic analysis was conducted in a residential complex (consisting of six houses) in order to assess the annual radon concentration and to evaluate the intensity of the relationships with various factors, such as the indoor-outdoor temperature differences, wind speed and wind direction. Three types of occupational behaviour, influencing the ventilation rate of the dwellings and, implicitly, the indoor radon activity concentration were observed. By calculating the partial correlation coefficient between the radon concentration and the wind direction, with the wind speed as the control variable, for all six houses the correlation coefficient presents negative values.

Mapping the geogenic radon potential in Buzău County is part of a research project aiming to apply research for sustainable development and economic growth following the principles of geoconservation in order to support the 'Buzău Land' UNESCO Geopark initiative. The mapping of geogenic radon will be used as an overview for planning purposes. The main geological formations of the studied area were identified as Cretaceous and Paleogene flysch, included in a thin-skinned nappes pile and consisting of alternating sandstones, marls, clays and, subordinately, conglomerates, all tightly folded or faulted. Significant variations in the concentration of radon were therefore determined in the ground. However, no high values were determined, the maximum measured activity concentration being 101.6 kBq m-3.

Radon is a natural radioactive gas that occurs due to the radioactive decay of radium (226 Ra) present in rocks which, in turn, cames from the radioactive decay of uranium (238 U), a primordial natural element. Along with factors such as porosity, permeability and humidity of the rocks and soils, pressure and temperature, geology setting plays one of the most important roles in the release of radon into the environment. Depending on the mineralogical compositions and characteristics of the bedrock from a certain area, a higher or lower concentration of radioactive minerals can be found in the rocks, which will directly influence the level of radon in the atmosphere, implicitly the concentration of radon measured in houses. In this study, a six months concentration of radon (222 Rn) was assessed in 256houses from Cluj-Napoca area using CR-39 nuclear track detectors. Correlations between the indoor radon levels and the geological setting was further analyzed. The aim is to better understand the influence of geology on the concentration of radon levels in homes, in order to further identify other risk areas in terms of exposure to radon. Further investigation is needed on other factors influencing the accumulation of radon in high concentrations indoor, such as ventilation, occupation patterns or constructive and architectural features for typical houses. Therefore, the results of this work are considered to be important for indoor radon management in Romania.