DOI: 10.20348/storedb/1193/1284
title: Report and comprehensive database containing information to radon progeny activity concentration and aerosols characteristic in selected workplaces
title: Report and comprehensive database containing information to radon progeny activity concentration and aerosols characteristic at selected workplaces

description: The main objective of this report is to provide an overview of existing exposure to radon in underground workplaces. It constitutes deliverable 2.3 or Radonorm project which received funding from the Euratom research and training programme
2019-2020 under grant agreement No 900009.
The first part of the reports contains an exhaustive description of the specific conditions present in underground workplaces that determine exposure routes. Differences between outdoor situation or workplaces located in above ground buildings and specific role of radon decay product in the contribution to the effective dose received by workers was underlined. All processes and mechanisms leading to the specific exposure to radon as well as thoron progeny were defined and described in detail. Possible methods of exposure monitoring and dose evaluation were discussed. Hazard evaluation based on radon gas measurement have been compared with the one based on measurements of radon and thoron decay products measurements. A review of available measuring devices for radon gas as well for decay products, important from pragmatic perspective, was provided and roughly verified in terms of specific conditions present in an active mine. All pros and cons of described approaches were discussed in terms of physical as well as pragmatic terms of target use. 
At the end of this part, a review of general approaches to the monitoring of radon hazard in many countries was included that were developed in frame of required Radon Action Plans. The general conclusion from this review is that radon hazard monitoring system based on radon progeny activity concentration (or potential alpha energy concentration - PAEC) is very rare. Majority of systems is established based on radon gas activity concentration monitoring and assumed country specific radon gas activity concentration reference levels. In very few cases radon progenies are considered when a reference level is exceeded. 
The second part is focused on collecting more precise data about situation in underground mines. A database was developed for this purpose based on the information collected in the first part. The database records cover or detail the needed information for the evaluation of the radiation hazard based on radon gas activity concentration as well as decay products activity concentration or PAEC. The availability of data are limited due to the lack of such monitoring system in non-uranium mines. Where such data exist, the access is limited due to its confidential nature. The industries having such data are very hesitant to disseminate such information, due to ownership (data were gathered in frame of commercial contracts) and the fact that the problems of NORM and radon in workplaces is not often precisely regulated to date. Real examples based on available data in underground coal mines, as well as in zinc and lead mines were used for the discussion. A review of situations in some other mines based on more generic data is also included. Besides active mines, some examples of tourist mines and caves were presented. The general conclusion from the analysed features of specific underground workplaces is that the systems based on monitoring of radon progeny, or equilibrium factor for the final effective dose calculation, if exists, are using theoretical values of the effective dose per exposure, locally established, or based on ICRP recommendation. Aerosols characteristics, especially radioactive ones, are rarely used for the definition of site-specific values of the effective dose per exposure, mainly due to the lack of appropriate measuring equipment (applicable in mines) as well as the lack of driving force mobilising to more accurate effective dose evaluation. 
For pragmatic purposes as well as for an educational one a specific software was developed facilitating the understanding of radon hazard features under specific conditions present in underground workplaces. The Ventgraph system, developed in WP 5.4, is also presented, as a tool for simulation of radon and radon progeny distribution in a mine with mechanical ventilation. It can be used for developing either monitoring or mitigation of radon hazard as well as for educational purposes to know importance of main parameters determining radon hazard in an active mine.
description: Deliverable 2.3 of Radonorm describing the collection of data on workplace radon and progeny levels in different workplace environments.