Radon levels in Romanian caves: an occupational exposure survey

Abstract

A comprehensive radon survey has been carried out in seven caves located in the western half of Romania's most significant karst regions. Touristic and non-touristic caves were investigated with the aim to provide a reliable distribution of their radon levels and evaluate the occupational exposure and associated effective doses. Radon gas concentrations were measured with long-term diffusion-type detectors during two consecutive seasons (warm and cold). All investigated caves exceed the European Union reference level of radon gas at workplaces (300 Bq/m). The radon concentration in these caves ranges between 53 and 2866 Bq/m, reflecting particular cave topography, season-related cave ventilation, and complex tectonic and geological settings surrounding each location. Relatively homogeneous high radon levels occur in all investigated touristic caves and in Tăuşoare and Vântului along their main galleries. Except for Muierii, in all the other caves radon levels are higher during the warm season, compared to the cold one. This suggests that natural cave ventilation largely controls the underground accumulation of radon. The results reported here reveal that the occupational exposure in Urşilor, Vadu Crişului, Tăuşoare, Vântului, and Muierii caves needs to be carefully monitored. The effective doses to workers vary between an average of 0.25 and 4.39 mSv/year depending on the measuring season. The highest values were recorded in show caves, ranging from 1.15 to 6.15 mSv/year, well above the European recommended limit, thus posing a potential health hazard upon cave guides, cavers, and scientists.

Assessment of occupational exposure from radon in the newly formed underground tourist route under Książ castle, Poland

“…In Poland, like in other countries, the increased ionising radiation in underground spaces is related to the accumulation of radon—a radioactive gas (Chibowski and Komosa 2001 ; Skowronek et al 2004 ; Fijałkowska-Lichwa and Przylibski 2016 ; Przylibski et al 2017 ; Alvarez-Gallego et al 2015 ; Bekteshi et al 2017 ; Chao et al 1997 ; Da Silva et al 2011 ; Cucoş Dinu et al 2017 ; Dueñas et al 2011 ; Dumitru et al 2015a , b , 2016 ; Espinosa et al 2013 ; Font et al 2008 ; Gillmore et al 2002 , 2005 ; Korhonen et al 2000 ; Lario et al 2006 ; Liu et al 2018 ; Özen et al 2019 ; Perrier et al 2007 ; Richon et al 2005 ; Shahrokhi et al 2017 ; Trevisi et al 2012 ; Wang et al 2019 ; Vaupotič et al 2001 ; Zhou et al 2019 ). Existing and newly opened underground facilities of various types and functions are becoming workplaces for a growing number of people.…”

Passive-Type Radon Monitor Constructed Using a Small Container for Personal Dosimetry

“…However, radon concentrations in mines and caves are higher than indoor concentrations because radon generated from surrounding rocks and soil can be easily accumulated due to the low ventilation. Recently, it has been reported that mean radon concentrations at several mines and caves were over~1000 Bq m −3 [9][10][11][12].…”

Radon Levels Inside the Caves of Bohol Island, Philippines

“…These observations are connected to the temperature difference between the inside and outside of the cave environment. Furthermore, spatial variation of radon in caves was observed to be at a maximum in areas further from the cave entrance and generally affected by ventilation (Dinu et al 2017;Paz et al 2019;Weng et al 2021).…”