RADON TIME SERIES IN FOUR FLATS IN ENERGY EFFICIENT MULTI-STOREY BUILDING

Influence of living habits and meteorological parameters on indoor radon concentration in a new energy efficiency multi-storey flat building typical for Russian cities was studied using radon time series analysis. Continuous indoor radon measurements were conducted in four flats of the same multi-storey residential building in Ekaterinburg, Russia. Factors influencing indoor radon in surveyed building (by rank) are as follows: ventilation regime> indoor/outdoor temperature difference > wind direction. Intentional ventilation frequency, temperature difference and wind direction explain together up to 46% of indoor radon variability in a flat of multi-storey building.

RADON MEASUREMENTS IN BIG BUILDINGS: PILOT STUDY IN RUSSIA

Detailed analysis of indoor radon concentration distribution by floors was conducted in four children institutions, one office building and two residential houses in Russian cities to develop approaches to draw up a program of radon survey for big buildings. Higher variability of radon concentration was found in high geogenic radon potential (GRP) area when the soil is the main source of radon. No essential dependence of radon concentration on the floor in high-rise buildings was found in low GRP area. The number of required radon measurements is estimated using obtained characteristics of radon variability.

Radon variability due to floor level in two typical residential buildings in Serbia

It is well known that one of the factors that influence the indoor radon variability is the floor level of the buildings. Considering the fact that the main source of indoor radon is radon in soil gas, it is expected that the radon concentration decreases at higher floors. Thus at higher floors the dominant source of radon is originating from building materials, and in some cases there may be deviations from the generally established regularity. In such sense, we chose one freestanding single-family house with loft and other 16-floor high-rise residential building for this study. The indoor radon measurements were performed by two methods: passive and active. We used passive devices based on track-etched detectors: Radtrak2 Radonova. For the short-term indoor radon measurements, we used two active devices: SN1029 and SN1030 (manufactured by Sun Nuclear Corporation). The first device was fixed in the living room at the ground level and the second was moved through the floors of the residential building. Every measuring cycle at the specified floor lasted seven days with the sampling time of 2 h. The results show two different indoor radon behaviours regarding radon variability due to floor level. In the single-family house with loft we registered intense difference between radon concentration in the ground level and loft, while in the high-rise residential building the radon level was almost the same at all floors, and hence we may conclude that radon originated mainly from building materials.

IRON: a permanent dense nationwide radon network to approach the challenge of monitoring seismic regions

<p><span>The deployment of multi-station and multi-parameter networks is considered fundamental in view of the investigation of Earth’s internal processes from which volcanic and seismic activity originate. The different changes often observed before the occurrence of strong earthquakes or eruptions (anomalies in sub-soil gas emission, hydrothermal discharge, chemical composition of groundwaters, Earth’s electromagnetic field) highlight the key role of fluids in the generation of these natural phenomena. Since they transfer from the underground to the surface messages about how the natural systems work, geochemistry can actively interact in a multidisciplinary context for investigating natural processes. While observational seismology has witnessed tremendous advances in the last twenty years, thanks to the development of very dense networks of stations measuring ground displacement, deformation and acceleration, the system of geochemical observations did not follow the same growth. The creation, ten years ago, of the Italian Radon mOnitoring Network (IRON) was motivated by the need for a permanent and dense network of stations aimed to make radon time series analysis a complement to traditional seismological tools. In fact, its radioactive nature makes radon a powerful tracer for fluid movements in the crust. The further step was the integration of IRON into a nationwide multi-parameter monitoring network, consisting so far of 10 homogenous sites including velocimeters, accelerometers, GPS sensors, and instruments measuring the Earth’s electromagnetic field. The potential of IRON as a tool to study the relationship between radon variability and the preparation process of earthquakes is discussed by means of two practical applications: to the 2016 Amatrice-Visso-Norcia seismic sequence and to the shorter sequence following the Ml 4.4 earthquake of 7 November 2019 in the Frusinate region.</span></p>

Inter-comparison study of atmospheric ²²²Rn and ²²²Rn progeny monitors

The use of the noble gas radon (222Rn) as tracer for different research studies, for example observation-based estimation of greenhouse gas (GHG) fluxes, has led to the need of high-quality 222Rn activity concentration observations with high spatial and temporal resolution. So far a robust metrology chain for these measurements is not yet available. A 3-month inter-comparison campaign of atmospheric 222Rn and 222Rn progeny monitors based on different measurement techniques was realized during the fall and winter of 2016-2017 to evaluate: i) calibration and correction factors between monitors necessary to harmonize the atmospheric radon observations; and ii) the dependence of each monitor’s response in relation to the sampling height, meteorological and atmospheric aerosol conditions. Results of this study have shown that: i) all monitors were able to reproduce the atmospheric radon variability on daily basis; ii) linear regression fits between the monitors exhibited slopes between 0.62 and 1.17 and offsets ranging between −0.85 Bq m−3 and −0.23 Bq m−3 when sampling 2 m above ground level (a.g.l.). Corresponding results at 100 m a.g.l. exhibited slopes of 0.94 and 1.03 with offsets of −0.13 Bq m−3 and 0.01 Bq m−3, respectively; iii) no influence of atmospheric temperature and relative humidity on monitor responses was observed for unsaturated conditions; and iv) changes of the ratio between radon progeny and radon monitor responses were observed under very high atmospheric humidity and under very low atmospheric aerosol concentrations. However, a more statistically robust evaluation of these last influences based on a longer dataset should be conducted to improve the harmonization of the data.

Multiyear indoor radon variability in a family house - a case study in serbia

The indoor radon behavior has complex dynamics due to the influence of the large number of different parameters: the state of indoor atmosphere (temperature, pressure, and relative humidity), aerosol concentration, the exchange rate between indoor and outdoor air, construction materials, and living habits. As a result, indoor radon concentration shows variation, with the usual periodicity of one day and one year. It is well-known that seasonal variation of the radon concentration exists. It is particularly interesting to investigate indoor radon variation at the same measuring location and time period, each year, due to estimation of individual annual dose from radon exposure. The long-term indoor radon measurements, in a typical family house in Serbia, were performed. Measurements were taken during 2014, 2015, and 2016, in February and July, each year. The following measuring techniques were used: active and charcoal canisters methods. Analysis of the obtained results, using multivariate analysis methods, is presented.