Nowadays, an inhalation of naturally generated aerosols has again become a widely practiced method of balneological treatment of various respiratory diseases. The aim of this study was to characterize the microbial aerosol of subterraneotherapy chambers at the Bochnia Salt Mine Health Resort in southern Poland. The measurements were carried out using a 6-stage Andersen impactor over a period of 1 year in both indoor (i.e., two subterranean chambers, where curative treatments took place) and outdoor air. The maximum bacterial aerosol concentrations in the chambers reached 11,688 cfu/m³. In such interiors, a high-performance method of microbial contaminant reduction need be introduced, especially when large groups of young patients are medically cured. Respecting fungal aerosol, its average indoor concentration (88 cfu/m³) was significantly lower than outdoor level (538 cfu/m³). It confirms that ventilation system provides efficient barrier against this type of biologically active propagules. Among identified micro-organisms, the most prevalent indoors were Gram-positive cocci, which constituted up to 80 % of airborne microflora. As highly adapted to the diverse environments of its human host (skin, respiratory tract), they can be easily released in high quantities into the air. The number of people introduced into such subterranean chambers should be in some way limited. The analysis of microclimate parameters revealed that temperature and relative humidity influenced significantly the level of bacterial aerosol only. Hence, a constant control of these parameters should be scrupulously superintended at this type of subterranean premises.

A field experiment was carried out to evaluate the effectiveness of synthetic and natural preparations in protecting potato against Leptinotarsa decemlineata (Colorado Potato Beetle). Seven substances and microorganisms with proved or potential toxic effect on the pest were used: Neem extract (Azadirachta indica), suspensions of Beauveria bassiana Balsamo (Vuillemin) (Hypocreales: Cordycipitaceae) and Isaria fumosorosea Wize (Hypocreales: Cordycipitaceae) entomopathogenic fungal spores, natural pyrethrin and three chemical insecticides (lambda-cyhalothrin, thiamethoxam and imidacloprid). Plots where no protection measures were applied served as control. Chemical insecticides were more effective in controlling L. decemlineata larvae than natural preparations. It was found that chemical insecticides protected potato yield more effectively than the preparations containing natural pyrethrin or spores of entomopathogenic fungi. Tuber yield from the plots protected with entomopathogenic fungi and Neem extract was significantly higher than that on unprotected plots but still lower than the yield obtained from the plots protected with a chemical preparation.

Purpose: to perform comparative analyzes of the size distributions of bacteria and fungi in the air of overground therapy chambers in Szczawnica sanatorium and subterranean inhalation chambers in Bochnia Salt Mine health resort taking into account influence of the season and presence of pathogenic species. Methods: bioaerosol samples were collected using 6-stage Andersen impactor. Bacterial and fungal aerosol concentrations and size distributions were calculated and isolated microorganisms were taxonomically identified based on their morphological, biochemical, and molecular features. Results: in both treatment rooms and atmospheric (outdoor) air, the acceptable microbial pollution levels were periodically exceeded. The size distribution analyzes revealed that in the case of bacteria – emission from the patients and in the case of fungi – transport with atmospheric (outdoor) air were the major processes responsible for microbiological contamination of indoor premises. The majority of microbial particulates were present in the air of studied premises as single bacterial vegetative cells, spores and fungal conidia or (most commonly) formed small microbial or microbial-dust aggregates. This phenomenon may have a significant effect on patients’ actual exposure (especially on those treated for respiratory diseases) in terms of the dose of inhaled particles. Conclusions: the microbiological quality of the air in sanatoriums and health resorts is a key factor for their therapeutic and prophylactic functions. When microbial pollution crossed the acceptable level, the measures that enable reducing undesirable contamination should be introduced, especially if large groups of patients undergo such therapy.

Sustainable horticulture is crucially based on the greenhouse production of vegetables under controlled conditions. In this study, we wanted to learn how cultivated plants may impact indoor air quality and whether the workers can be exposed to bioaerosols in a similar way in these settings. The study objective was to test the hypothesis that the microbial concentrations, distribution of bioaerosol particle sizes, and composition of the airborne microbiome are specific to greenhouses, polytunnels, and open-air sites. The air samples were collected to assess the concentration of total culturable bacteria (TCB), fungi, actinomycetes, and β-haemolytic bacteria and for the identification of bacterial and fungal strains. Higher concentrations of TCB and fungi were found in the greenhouse (log 3.71 and 3.49 cfu m⁻³, respectively) than in polytunnels (log 2.60–2.48 and 2.51–2.31 cfu m⁻³, respectively) during the vegetation of cucumbers. These airborne microbes were represented by a significant contribution of the respirable fraction with a distinct contribution of fine particles in size below 4.7 µm. Cultivation of cucumbers resulted in the higher emission of airborne microorganisms in contrast with growing herbs such as oregano and basil. In total, 35 different bacteria and 12 fungal species, including pathogenic or allergenic agents, were identified within the studied sites. The workers can be exposed to increased concentrations of TCB and fungi in the greenhouse during the plant vegetation. It might be recommended to properly manage greenhouses and polytunnels, dispose of dust sources, and maintain appropriate ventilation to sustain relevant air quality.

Air microbial quality of the municipal landfill site and in its surroundings was evaluated. Adverse impact of the municipal landfill site in Tarnow on the atmospheric environment was noted, despite the use of correct waste disposal technology. The sampling site and season of the year significantly affected the numbers of various groups of air microorganisms at the municipal landfill site and in its vicinity. For most cases, the effects of the sampling site on the microbial numbers were stronger than that of the season of the year. In this study, higher microbial numbers were observed at the sampling sites located in the area of the active landfill site compared to those located in its vicinity. The obtained results indicate, that despite the lack of current limits for bioaerosol levels the landfill site, even after its closing and reclamation, may still not be a suitable place for any public usage. Therefore, any regular microbiological studies of air should be carried out for a long time both at the area of landfill site and in its vicinity. These results could allow to define the time, when the landfill site become stable, regarding the numbers of microorganisms released to air.