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The project was aimed at evaluating the potential occupational exposure of swine farm workers to dust and microorganisms present in piggery bioaerosols (especially in its respirable fraction) under various breeding conditions. Sampling was carried out in 14 buildings located at 13 pig breeding and production farms in Poland. Concentrations of inhalable and respirable dusts in the air of the piggeries were low (means, respectively, 1.76 and 0.23 mg/m 3 ). The concentration of microorganisms was generally high (mean = 3.53 9 10 5 cfu/m 3 ). More than 96% of determined microorganisms were bacteria (mean = 3.42 9 10 5 cfu/m 3 ). The fungal concentration was distinctly lower (mean = 2.71 9 10 3 cfu/m 3 ). The concentration of bacteria in the respirable fraction of bioaerosol (mean = 1.51 9 10 5 cfu/m 3 ) made up for 48.2% of their total concentration, while the level of fungi in that fraction (mean = 1.50 9 10 3 cfu/m 3 ) formed 68.8% of the total fungal concentration. The concentration of inhalable dust was significantly modified by the type of breeding system. The factors that significantly affected the total concentrations of microbes and bacteria, as well as their levels in the bioaerosols' respirable fraction were as follows: herd size, breeding system, feeding method and the type of ventilation system. In the case of fungi, these were the livestock breeding system and the feeding method. Moreover, there was a high positive correlation of inhalable dust concentrations with the fungal concentration, CO 2 and relative humidity. A negative correlation was found between concentrations of each microbe group and the airflow velocity. Swine farm workers are exposed to relatively low dust concentrations and high concentrations of microorganisms, bacteria in particular. Fungi, to a much larger extent than bacteria, are correlated with the respirable particles of a piggery bioaerosol, which may harm the respiratory system of exposed workers.

PurposeThe objective of this study was to assess exposure to anaerobic bacteria released into air from sewage and sludge at workplaces from a wastewater treatment plant (WWTP).MethodsSamples of both sewage and sludge were collected at six sampling points and bioaerosol samples were additionally collected (with the use of a 6-stage Andersen impactor) at ten workplaces covering different stages of the technological process. Qualitative identification of all isolated strains was performed using the biochemical API 20A test. Additionally, the determination of Clostridium pathogens was carried out using 16S rRNA gene sequence analysis.ResultsThe average concentration of anaerobic bacteria in the sewage samples was 5.49 × 104 CFU/mL (GSD = 85.4) and in sludge—1.42 × 106 CFU/g (GSD = 5.1). In turn, the average airborne bacterial concentration was at the level of 50 CFU/m3 (GSD = 5.83) and the highest bacterial contamination (4.06 × 103 CFU/m3) was found in winter at the bar screens. In total, 16 bacterial species were determined, from which the predominant strains belonged to Actinomyces, Bifidobacterium, Clostridium, Propionibacterium and Peptostreptococcus genera. The analysis revealed that mechanical treatment processes were responsible for a substantial emission of anaerobic bacteria into the air. In both the sewage and air samples, Clostridium perfringens pathogen was identified.ConclusionsAnaerobic bacteria were widely present both in the sewage and in the air at workplaces from the WWTP, especially when the technological process was performed in closed spaces. Anaerobic bacteria formed small aggregates with both wastewater droplets and dust particles of sewage sludge origin and as such may be responsible for adverse health outcomes in exposed workers.

The present study is a part of a larger project on assessment of exposure to biological agents and respiratory health effects among metal workers. Objectives: The aim of this study was to evaluate the level of microbial contamination of metalworking coolants as a potential source of harmful biological agents in three different metal industry plants in Poland. Material and Methods: Ten samples of coolants with a different state of wear, including four fresh fluids, were analyzed. Qualitative and quantitative analysis of bacteria and mould content was performed using standard analytical methods. Bacterial endotoxin concentration was determined by the kinetic, chromogenic version of the LAL test. results: The analysis showed the total bacterial counts ranging from 1.0×101 CFU/ml to 3.2×10 7 CFU/ml, 60% to 100% of which were Gram-negative bacteria capable of producing endotoxins. Among the highly contaminated coolants, one unused concentrate was also found. The predominant species of bacteria was Shewanella putrefaciens present in 60% of the samples. As for moulds, the predominant species was Acremonium butyri. The average concentration of bacterial endotoxins was 773 EU/ml in the old coolants, and much lower in the fresh fluids 285 EU/ml. A correlation (r = 0.66) was found between endotoxin concentration and the number of Gram-negative bacteria detected in the coolants. conclusion: Procedures should be developed for cleaning tanks during fluid replacement to minimize the risk of bacterial growth in the coolants and limit bioaerosol emission in workplace. Due to the affinity of microflora for the water phase, it is advisable to use effective biocides with appropriate partition coefficient between the water phase and oil phase.

Objectives: To date, the scientific source materials usually focus on microbial contamination of the museum or library collections themselves, while the exposure of persons who professionally deal with this type of objects in cultural heritage conservation laboratories is ignored. Material and Methods: The study was carried out in 9 naturally ventilated conservation laboratories with no history of water damage. Viable (understood as culturable) bioaerosol stationary samples were collected in both outdoor and indoor environments using 6-stage Andersen impactor. Simultaneously, stationary and personal indoor bioaerosol measurements were carried out using both Gesamtstaubprobenahme an der Person (GSP) and Button filter samplers. These measurements were complemented by evaluation of microbial content in the dust settled on conserved works of art. All impactor, filter, and settled dust samples were quantitatively examined to obtain viable and total concentrations of bacteria and fungi. All isolated microbial strains were taxonomically identified. Results: At workplaces, the concentrations of viable microorganisms in air were below 2000 cfu/m 3 and accounted for not more than 5.5% of total microbiota. The study showed that quantitative assessment of viable bioaerosol can be made with an Andersen impactor as well as by using Button and GSP filter samplers, irrespective of whether they are applied for personal or stationary measurements. Compared to the impactor, however, the use of filter samplers for microbial contamination monitoring substantially limits the scope of qualitative information which can be obtained. Size distribution analysis revealed that the largest "load" of microorganisms can penetrate into the respiratory tract between the trachea and terminal bronchi, and thereby may be responsible for allergic inflammations in exposed workers. Conclusions: The precise assessment of microbial hazards in conservation laboratories should comprise control of both viable and total particle counts. The hermetization of such workplaces and control of relative humidity should be implemented and maintained to assure proper hygienic conditions.