Impact of temporal variability of radon concentration in workplaces on the actual radon exposure during working hours

Abstract

For workplaces where significant diurnal variations in radon concentrations are likely, measurements to evaluate average radon concentration during working hours could be useful for planning an optimized protection of workers according to the 2013/59/Euratom Directive. However, very few studies on this subject, generally limited to periods of few weeks, have been published. Therefore, a study has been conducted to evaluate the actual long-term radon exposure during working hours for a sample of 33 workplaces of four different types (postal offices, shops, restaurants, municipal offices), mainly located at the ground floor, and with expected considerable air exchange rate occurring during working hours due to frequent entrance/exit of persons or mechanical ventilation. The results show that the difference between the average radon level during working hours and that one during the whole day is about 20% on average and ranges from 0 to 50%. These observed differences, generally smaller compared with those found in other similar studies, are nearly the same if the analysis is restricted to workplaces with annual radon level higher than 300 Bq m–3, and therefore natural or mechanical ventilation normally present during working hours of the monitored workplaces cannot be considered an effective mitigation measure. However, the costs and time-response characteristics of the active monitors, as those used for the present study, will probably allow using more frequently a similar measurement strategy in workplaces.

Impacts of Indoor Radon on Health: A Comprehensive Review on Causes, Assessment and Remediation Strategies

“…Thus, there are several studies that present mitigation measures that contribute to the reduction of risk, on the one hand, but also effectively to the reduction of cases of radon-induced cancers, namely, lung cancer [ 51 ]. Within the mitigation measures proposed in the various works, these can include different types of measures, which can be divided into different groups [ 52 ]. For example, constructive measures include the application of insulation materials, such as special paints and screens, which prevent the passage of radon from the ground to indoor spaces and that can be used in the renovation of pre-existing buildings and in new buildings during the construction phase, or even the construction of airboxes between the ground and the floors/walls when possible [ 53 , 54 ].…”

Thoron Interference on Performance of Continuous Radon Monitors: An Experimental Study on Four Devices and a Proposal of an Indirect Method to Estimate Thoron Concentration

“…Continuous radon monitors (CRMs) are being increasingly used in many application fields including the evaluation of short- and long-term effectiveness of remedial actions and the estimation of the actual exposure of workers [ 1 ]. Similar studies need active measurements in some to many premises, working places, or dwellings, and only the recent appearance on the market of inexpensive CRMs has made this kind of survey affordable.…”

“…Similarly, detectors capable of performing alpha spectrometry have been reported to evidence thoron interference due to energy resolution and algorithm used to calculate the radon concentration [ 4 ]. Specific correction algorithms have been conceived to avoid overestimation of radon concentration due to thoron in measurements performed by CRMs operating energy discrimination [ 1 ] or not [ 7 ].…”

Novel Algorithm for Radon Real-Time Measurements with a Pixelated Detector

“…The main techniques used to monitor radon activity concentration in air are two: (i) integration techniques, generally used by passive detectors like dosimeters or electrets [7][8][9][10], which return the integral value of radon concentration measured over the time period of the detector exposure and (ii) real-time techniques, performed by active detectors, that perform radon concentration measurements on small pre-set time intervals, that can be repeated over the total time of exposure. The large use of passive detectors, due to their low cost and simple usage, affected until now both the risk evaluation and the radiological protection limits (both referred to mean concentration values on long periods, generally one year), but according to the present knowledge of the indoor radon diffusion [11][12][13][14], the gas concentration shows a large variability between day/night time with evident seasonal variations. Hence, real-time measurements of radon concentration in air assume a fundamental importance to monitor the exposure variation over the proper timescale, allowing also to promptly undertake the appropriate countermeasures to mitigate the risk.…”