Comparative analysis of techniques for estimating radon exhalation from building materials.

Evaluating the radon emissions from building structures to determine optimal strategies for either preventing radon infiltration into buildings or decreasing its concentration in occupied areas is essential. This research presents a study of different methodologies for determining the radon exhalation rate in three samples of granite: two techniques based on passive detectors (Electret Ion Chamber (EIC) and Solid State Nuclear Track Detectors (SSNTD)) and one technique based on the use of a continuous radon detector. The operating principle of the three methodologies is based on the accumulation of radon inside an experimental container, hermetically sealed. Passive detectors offer the concentration measurement, integrated over time, while the continuous detector monitors the increase in concentration hour by hour. In this last case, three mathematical models have been applied to adjust the experimental results. According to a previous radiological characterization of the building material samples, those exceeding the legal limit of the radioactive activity index (I = 1) have been analyzed: Rose Porriño granite, Blue Vizag granite and Julia Cream granite. The obtained results indicate that the five methodologies used present radon exhalation rate values within a consistent range for each sample. Therefore, the protocols detailed in this work could be used interchangeably to calculate the radon gas exhalation rates in building materials, providing flexibility in selecting the most suitable method depending specific experimental requirements or constraints. • Radon exhalation rate in building materials has been determined. • Developed different methodologies to measure radon exhalation rate. • Passive and continuous detectors procedures have been validated through experimental results. • Reduction of sampling times compared to ISO 11665-9 procedure. [ABSTRACT FROM AUTHOR]