How Do Different Locations, Floors and Aspects Influence Indoor Radon Concentrations? An Empirical Study Using Neural Networks for a University Campus in Northwestern Turkey

Abstract

Indoor radon ( 222 Rn) concentrations were measured at a 10-min interval during October 2011 and January 2012. The monitoring followed a randomised and repeated pattern of experimental design, and was carried out at six faculty buildings of the Abant Izzet Baysal University, on five floor levels and two aspect directions (south vs. north) using an AlphaGUARD P30 Radon Monitor. The University campus area located in northwestern Turkey is near the North Anatolian Fault, a major active right lateral-moving strike-slip fault which runs along the transform boundary between the Eurasian Plate and the Anatolian Plate. Best artificial neural networks (ANNs) emulating indoor 222 Rn levels were selected as a function of air temperature (T a ), air pressure (P a ), relative humidity (RH), T a by RH interaction, local time, location, floor and aspect. Elevated levels of indoor 222 Rn concentrations were measured at the south-facing offices and on the first floor levels of the building. Lower concentrations were found on the upper floor levels. Out of 27 ANNs, GFF-1-B-L and MLP-2-B-L performed best and could be contributing to the 35.6% and 87.2% of variations in spatio-temporal dynamics of indoor 222 Rn levels as a function of location or floor level and aspect, respectively, in addition to T a , P a , RH, T a by RH interaction and time.

Radon Spatial Variations in University’s Buildings Located in an Italian Karst Region

“…It is well known that the soil and bedrock are the main source of radon and, as a consequence, radon levels are higher at ground or below ground floors (rooms closer to the soil) than at first floor or above [8][9][10]. Moreover, it has been observed that the contact with soil affects radon spatial variability among rooms at the same floor, which is higher at ground and underground floors than at upper floors [11].…”