Bioaerosols of subterraneotherapy chambers at salt mine health resort

Properties of Particulate Matter in the Air of the Wieliczka Salt Mine and Related Health Benefits for Tourists

This study aimed to evaluate the mass concentration of size-resolved (PM1, PM2.5, PM4, PM10, PM100) particulate matter (PM) in the Wieliczka Salt Mine located in southern Poland, compare them with the concentrations of the same PM fractions in the atmospheric air, and estimate the dose of dry salt aerosol inhaled by the mine visitors. Measurements were conducted for 2 h a day, simultaneously inside (tourist route, passage to the health resort, health resort) and outside the mine (duty-room), for three days in the summer of 2017 using DustTrak DRX devices (optical method). The highest average PM concentrations were recorded on the tourist route (54-81 µg/m3), while the lowest was in the passage to the health resort (49-62 µg/m3). At the same time, the mean outdoor PM concentrations were 14-20 µg/m3. Fine particles constituting the majority of PM mass (68-80%) in the mine originated from internal sources, while the presence of coarse particles was associated with tourist traffic. High PM deposition factors in the respiratory tract of children and adults estimated for particular mine chambers (0.58-0.70), the predominance of respirable particles in PM mass, and the high content of NaCl in PM composition indicate high health benefits for mine visitors.

Origin, distribution, and perspective health benefits of particulate matter in the air of underground salt mine: a case study from Bochnia, Poland

The composition and distribution of airborne particles in different locations in a salt mine were determined in terms of their origin, the distance from the air inlet, and the adaptation of post-mining chambers and corridors for tourists and general audience. The composition of aerosols in air was also evaluated from the perspective of human health. Air samples were collected on filters by using portable air pumps, in a historical underground salt mine in Bochnia (Poland), which is currently a touristic and recreation attraction and sanatorium. The particulate matter (PM) concentration was determined using the gravimetric method by weighing quartz filters. The content of carbon, water-soluble constituents, trace elements, and minerals was also determined. A genetic classification of the suspended matter was proposed and comprised three groups: geogenic (fragments of rock salt and associated minerals from the deposit), anthropogenic (carbon-bearing particles from tourist traffic and small amounts of fly ash, soot, and rust), and biogenic particles (occasional pollen). The total PM concentration in air varied between 21 and 79 μg/m³ (with PM₄ constituting 4-24 μg/m³). The amount of atmospheric dust components coming from the surface was low and decreased with the distance from the intake shaft, thus indicating the self-cleaning process. NaCl dominated the water-soluble constituents, while Fe, Al, Ag, Mn, and Zn dominated the trace elements, with the concentration of majority of them below 30 ng/m³. These metals are released into air from both natural sources and the wear or/and corrosion of mining and tourists facilities in the underground functional space. No potentially toxic elements or constituents were detected. The presence of salt particles and salty spray in the atmosphere of salt mine, which may have anti-inflammatory and antiallergic properties, is beneficial to human health. This study will allow for a broader look at the potential of halotherapy in underground salt mines from a medical and regulatory point of view.

History, advancements, and perspective of biological research in deep-underground laboratories: A brief review

The world is entering a new era of exploring and exploiting the deep-underground space. With humans poised to reach historical depths in the use of the deep Earth, it is essential to understand the effect of the deep-underground environment on the health of humans and other living organisms. This article outlines the history and development of biological research conducted in deep-underground laboratories and provides insight into future areas of investigation. Many deep-underground laboratories have investigated the effects of reduced cosmic ray muons flux, searching for rare events such as proton decay, dark matter particles, or neutrino interactions, but few have focused on the influence of the environmental factors in the deep-underground on living organisms. Some studies revealed that prokaryote and eukaryote cells maintained in low levels of background radiation exhibited an stress response, which manifested as changes in cell growth, enzyme activity, and sensitivity to factors that cause genetic damage; however, the underlying mechanisms are unclear. There remains an urgent need to understand the detrimental and beneficial biological effects of low background radiation and other factors in the deep-underground on humans and other organisms. Consequently, a multidisciplinary approach to medical research in the deep-underground has been proposed, creating a new discipline, deep-underground medicine, and representing a historical milestone for exploring the deep Earth and in medical research.

Salt mine microorganisms used for the biotransformation of chlorolactones

The aim of the project was to find new catalysts capable of chlorolactone biotransformation. Three bicyclic chlorolactones with structures possessing one or two methyl groups in their cyclohexane ring were subjected to screening biotransformation using seven bacterial strains and one fungal strain from a salt mine. Three strains of bacteria (Micrococcus luteus Pb10, Micrococcus luteus WSP45, Gordonia alkanivorans Pd25) and one fungal strain (Aspergillus sydowii KGJ10) were able to catalyse hydrolytic dehalogenation of one substrate. The classification of the strains that were effective biocatalysts was confirmed by 16S rDNA analysis. The best result (76%) was obtained using Aspergillus sydowii KGJ10. All strains catalysed hydrolytic dehalogenation without changing the conformation. The equatorial position of the chlorine atom in the substrate turned out to be warrant of the positive result of the biotransformation process.

Comparative analysis of airborne bacteria and fungi in two salt mines in Poland

The aim of this work was to determine the genera or species composition and the number of colony forming units of airborne bacteria and fungi, respectively, in two salt mines in Poland "Wieliczka" (Lesser Poland) and "Polkowice-Sieroszowice" (Lower Silesia). Both of them are working environments characterized by extreme conditions, and additionally "Wieliczka," officially placed on the UNESCO World Heritage Sites' list, plays a role of tourist attraction. There are also some curative chambers located in this mine. Air samples were taken once in December 2015, between 6:00 a.m. and 9:00 a.m. There were nine measurement points located about 200 m underground in "Wieliczka" and six measurement points located in the working shafts about 400 m underground in "Polkowice-Sieroszowice." The total volume of each air sample was 150 L. Air samples, collected in individual measurement points of both salt mines, were inoculated on two microbiological media: potato dextrose agar and tryptic soy agar using the impact method. We identified 10 and 3 fungal genera in the "Wieliczka" Salt Mine and in "Polkowice-Sieroszowice," respectively. The most common were fungi of the Penicillium genus. In both mines, the Gram-positive bacteria of genus Micrococcus were detected most frequently. Among identified microorganisms, there were neither pathogenic fungi nor bacteria. The most prevalent microorganisms detected in indoor air were Gram-positive cocci, which constituted up to 80% of airborne microflora. Our results showed that microorganisms recorded in the air samples are not a threat to workers, tourists or patients. Neither pathogens nor potentially pathogenic microorganisms, listed as BSL-2, BSL-3 or BSL-4, were detected. The microbes identified during our analysis commonly occur in such environments as the soil, water and air. Some of the detected bacteria are component of natural microflora of human skin and mucous membranes, and they can cause only opportunistic infections in individuals depending on their health condition.

Mycobiota of Underground Habitats: Case Study of Harmanecká Cave in Slovakia

Harmanecká Cave is located in the Harmanec Valley to the northwest of Banská Bystrica city, in the southern part of the Great Fatra Mountains, Slovakia. This cave is the most important underground locality of bat occurrence in Slovakia (population of 1000 to 1500 individuals). The study aimed at mycological evaluation of the air, the water, and the rock surface of Harmanecká Cave in Slovakia. The samples were taken on 24 July 2014. To examine the air, the Air Ideal 3P sampler was used. Microbiological evaluation of the rock surface was performed using swab sampling and the water by using the serial dilution technique. The authors observed a relationship between air temperature and the concentration of fungi. The concentration of airborne fungi increased with the increase in the air temperature and decreased with distance from the entrance to the cave. The density of airborne fungi isolated from the outdoor air samples was 810.5 colony-forming units (CFU) per 1 m3 of air and from 27.4 to 128.5 CFU for the indoor air samples. From the rock surface inside the cave, 45.0 to 106.6 CFU per 1 cm2 were isolated, whereas from the water, 29.9 CFU per 1 ml were isolated. Seven species of filamentous fungi were isolated from the external air samples and 12 species of filamentous fungi and 3 species of yeast-like fungi from the internal air samples. From the surface of the rocks inside the cave, 5 species of filamentous fungi and 1 species of yeast-like fungi were cultured, whereas from the water samples, 6 species of filamentous fungi were cultured. Cladosporium spp. were the fungi most frequently isolated from the external air; from the internal air, Penicillium urticae was most frequently isolated; from the rock surface, it was Gliocladium roseum; and from the water, it was P. chrysogenum. The species found in the cave can be pathogenic for humans and animals, especially for immunocompromised persons, and they can also cause biodegradation of the rocks. However, the concentration of airborne fungi inside the cave did not exceed official limits and norms stated as dangerous for the health of tourists.