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The concentration levels of airborne bacteria were measured in clinical/hospital rooms in Upper Silesia, Poland, in buildings of varying conditions. It was found that the typical level of bacterial aerosol concentration is about 10³ CFUm⁻³ in clinical outpatient rooms and ranges from 10² CFUm⁻³ to 10³ CFUm⁻³ in hospitals, depending on the number of occupants and physical quality of the building. The increased level of the airborne bacteria in patient rooms resulting from bed-making was noticed. The Staphylococcus/Micrococcus group was a dominating part of the bacteria in studied hospitals/clinic air, contributing together 58-78% of the total bacteria concentration, confirming that detected airborne bacteria mainly originated from human organisms. The size distributions of bacterial aerosol in naturally ventilated rooms have peaks in the size range between 1.1 and 3.3 μm while in the mechanically ventilated hospital rooms with HVAC the peak appears in the diameter range from 3.3 μm to 4.7 μm.
The aim of the presented study was to assess the exposure of poultry workers to airborne microorganisms, endotoxins and β-glucans during different stages of the chicken production cycle in 3 commercially-operated poultry houses. Personal and stationary sampling was carried out to assess exposure to both viable and total microbial aerosols. The stationary measurements of PM10 were performed to establish the level of endotoxins and β-glucans. The concentrations of bacterial and fungal aerosols ranged from 2.5×102 CFU/m3 – 2.9×106 CFU/m3, and from 1.8×102 CFU/m3 – 1.8×105 CFU/m3, respectively. The number of culturable microorganisms was significantly lower than their total counts, constituting from 0.0004% – 6.4% of the total microbial flora. The level of PM10 in poultry facilities did not exceed 4.5 mg/m3. After the flock entered the clean house, the level of endotoxins and β-glucans increased from below detection limit to 8,364 ng/m3 and from 0.8 ng/m3 to 6,886 ng/m3, respectively. The presented study shows that professional activities in poultry farms are associated with constant exposure to bioaerosol, which may pose a health hazard to workers. It was found that workers’ exposure to airborne microorganisms increased with consecutive stages of the chicken production cycle.
The effects of microwave radiation on viability of fungal and actinomycetal spores growing on agar (medium optimal for growth) as well as on wooden panel and drywall (common building construction/fi nishing materials) were studied. All materials were incubated at high (97-99%) and low (32-33%) relative humidity to mimic “wet” and “dry” environmental conditions. Two microwave power densities (10 and 60 mW/cm2) and three times of exposure (5, 30, and 60 min) were tested to fi nd the most effective parameters of radiation which could be applied to non-invasive reduction or cleaning of building materials from microbial contaminants. Additionally, a control of the surface temperature during the experiments allowed differentiation between thermal and microwave effect of such radiation. The results showed that the viability of studied microorganisms differed depending on their strains, growth conditions, power density of microwave radiation, time of exposure, and varied according to the applied combination of the two latter elements. The effect of radiation resulting in a decrease of spore viability on “wet” wooden panel and drywall was generally observed at 60 min exposure. Shorter exposure times decreased the viability of fungal spores only, while in actinomycetes colonizing the studied building materials, such radiation caused an opposite (supporting growth) effect.
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