A contribution to the mineralogy of Monte Guisi cave (SW Sardinia, Italy).

This note presents a preliminary mineralogical study of the skarn-hosted Monte Guisi Cave in SW Sardinia (Italy). X-ray diffraction (XRD) and environmental scanning electron microscope (including energy dispersive X-ray spectroscopy microanalysis; EDS) analyses allowed us to identify some uncommon cave minerals such as: cerussite PbCO3, rosasite (Cu,Zn)2(CO3)(OH)2, dundasite PbAl2(CO3)2(OH)4·H2O), brochantite Cu4SO4(OH)6, cuprite Cu2O, hemimorphite Zn4Si2O7(OH)2·H2O, chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O, shattuckite Cu5(SiO3)4(OH)2, and plancheite Cu8(Si4O11)2(OH)4·H2O. Dundasite and plancheite are for the first time reported as cave minerals. All these species appear to represent oxidation/hydrolysis products of the primarily Pb-Zn and Cu-rich ore mineralization that impregnates the carbonate bedrock

Radon Levels in Romanian Caves: An Occupational Exposure Survey

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/m3). The radon concentration in these caves ranges between 53 and 2866 Bq/m3, 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