Production of pro-inflammatory mediators stimulated by exposure of poultry house workers to airborne dust particulates.

INTRODUCTION AND OBJECTIVE: Poultry house employees spend a significant part of their work shift being exposed to airborne particulate pollutants. The aim of this study was to assess their exposure at different stages of chicken production cycle, based on quantification of pro-inflammatory mediators (IL-1ß, IL-6, IL-8, and TNFα) in nasal lavage (NAL) samples. MATERIAL AND METHODS: The concentrations of airborne dust at 3 different stages of the production cycle (i.e. empty poultry house, with 7- and 42-day-old chickens) were stationary measured using Grimm spectrometer, as well as CIS and Button samplers. The dust collected by the latter 2 samplers was analyzed for endotoxin and (1→3)-ß-D-glucan content. NAL samples were collected from employees after their work shift to determine the pro-inflammatory mediator levels. RESULTS: The maximum particulate aerosol, endotoxin, and (1→3)-ß-D-glucan concentrations at workplaces reached the levels of 4.12 mg/m3, 45.21 ng/m3, and 56.54 ng/m3, respectively. The IL-1ß, IL-6, and IL-8 concentrations in NAL samples ranged between 0.62-18.12 pg/mL, <0.70-25.37 pg/mL, and <3.50-259.5 pg/mL, respectively. All TNFα levels were below 4 pg/mL. There were no significant differences between these cytokine concentrations in NAL samples collected at different stages of chicken breeding in either 'winter' or 'summer' seasons. CONCLUSIONS: Inhalation stimulation with poultry dust containing endotoxins and (1→3)-ß-D-glucans resulted in the production of pro-inflammatory mediators, which proves the course of immunological processes in the exposed employees that may lead to adverse effects. The use of nasal lavage fluid in the control of such exposure confirms that NAL analysis is a reliable laboratory tool for assessing the impact of poultry dust on exposed farm workers.

Poultry house as point source of intense bioaerosol emission.

INTRODUCTION AND OBJECTIVE: Intensive poultry farming is usually associated with massive exposure to organic dust, which is largely composed of microbiological origin particulates. The aim of the study is to assess occupational and environmental exposures to airborne bacteria, fungi, and Marek's disease virus emitted by a poultry house. MATERIAL AND METHODS: The concentrations of airborne microorganisms in a poultry house and its vicinity (250-500 m) at 3 different stages of the production cycle (i.e. empty poultry house, with 7-day-old and 42-day-old chickens) were stationary measured using Andersen and MAS impactors, as well as Coriolis and BioSampler impingers. The collected microbiota was taxonomically identified using molecular and biochemical techniques to characterize occupational exposure and its spatial dissemination. RESULTS: Although Marek's disease virus was not present in the tested air samples, the appearance of reared chickens in the poultry house resulted in an increase in airborne bacterial and fungal concentrations up to levels of 1.26 × 108 CFU/m3 and 3.77 × 104 CFU/m3, respectively. These pollutants spread around through the ventilation system, but their concentrations significantly decreased at a distance of 500 m from the chicken coop. A part of the identified microbiota was pathogens that were successfully isolated from the air by all 4 tested samplers. CONCLUSIONS: The poultry house employees were exposed to high concentrations of airborne microorganisms, including pathogens that may lead to adverse health outcomes. To protect them, highly efficient hygienic and technical measures regarding the poultry house interior and its ventilation, respectively, should be introduced to prevent both unwanted pollution and subsequent emission of microbial contaminants during intensive chicken breeding.

Intensive poultry farming: A review of the impact on the environment and human health.

Poultry farming is one of the most efficient animal husbandry methods and it provides nutritional security to a significant number of the world population. Using modern intensive farming techniques, global production has reached 133.4 mil. t in 2020, with a steady growth each year. Such intensive growth methods however lead to a significant environmental footprint. Waste materials such as poultry litter and manure can pose a serious threat to environmental and human health, and need to be managed properly. Poultry production and waste by-products are linked to NH3, N2O and CH4 emissions, and have an impact on global greenhouse gas emissions, as well as animal and human health. Litter and manure can contain pesticide residues, microorganisms, pathogens, pharmaceuticals (antibiotics), hormones, metals, macronutrients (at improper ratios) and other pollutants which can lead to air, soil and water contamination as well as formation of antimicrobial/multidrug resistant strains of pathogens. Dust emitted from intensive poultry production operations contains feather and skin fragments, faeces, feed particles, microorganisms and other pollutants, which can adversely impact poultry health as well as the health of farm workers and nearby inhabitants. Fastidious odours are another problem that can have an adverse impact on health and quality of life of workers and surrounding population. This study discusses the current knowledge on the impact of intensive poultry farming on environmental and human health, as well as taking a look at solutions for a sustainable future.

Across-Shift Changes in Viable Nasal Bacteria among Waste-Incineration Plant Workers-A Pilot Study.

The aim of this pilot study was to assess the time-related changes in viable nasal bacteria concentrations among waste-incineration plant (WIP) workers compared to a group of office building (OB) workers outside the plant. In total, 20 volunteers participated in the study, including 14 WIP and 6 OB workers. WIP workers were divided into two sub-groups: supervisory staff (SVS) and maintenance and repair workers (MRW). Nasal swabs were collected before and after the morning work shift. Airborne bacteria were sampled with a six-stage impactor to assess the bioaerosol size distribution. The analysis showed that a significant, almost three-fold increase in nasal bacterial concentration was found only among WIP workers, and this referred mainly to anaerobic species. The load of anaerobic bacteria at the beginning of work was 12,988 CFU/mL, and after work shift 36,979 CFU/mL (p < 0.01). Significant increases in microbial concentrations was found only in the MRW subgroup, among non-smoking workers only. The results showed increased bacterial concentration in WIP nasal samples for as many as 12 bacterial species, including, e.g., Streptococcus constellatus, Peptostreptococcus spp., E. coli, and P. mirabilis. These preliminary data confirmed that the nasal swab method was helpful for assessment of the workers' real-time exposure to airborne bacteria.

Occupational exposure to anaerobic bacteria in a waste sorting plant.

The study focused on exposure assessment to bacterial aerosols and organic dust in waste sorting plant. Samples were collected at different workplaces of waste sorting cycle i.e.: waste press, reloading area, loading of conveyor belt, sorting cabin, sorting hall, and control room. A quantitative analysis of aerobic and anaerobic bacteria was supplemented by qualitative analysis of anaerobic biota with the use of culture-based methods and biochemical tests. In addition, inhalable dust concentrations were also evaluated. To confirm the presence of Clostridium genus, the PCR reaction with specific primers (Chis150f and ClostIr) was performed. The average concentration of total bacteria in waste sorting plant was 4347 CFU m-3 (SD = 2439), of which 66% were anaerobic strains (2852 CFU m-3; SD = 2127). It was found that about 24% of anaerobic bacteria belonged to Clostridium genus (682 CFU m-3; SD = 633). The highest contamination with anaerobic bacteria was observed near the waste reloading plant (3740 CFU m-3), and the lowest in the control room (850 CFU m-3). The average concentration of inhalable dust in the waste sorting plant was 0.81 mg m-3 (SD = 0.59). The correlation analysis showed that the presence of anaerobic bacteria, including clostridia was significantly determined by the microclimate parameters. Qualitative analysis showed the presence of 16 anaerobic species belonging to 9 genera, of which Actinomyces, Clostridium, and Gemella were present at all workplaces. The molecular analysis confirmed the presence of Clostridium genus in both bioaerosol and settled dust samples.Implications: The study showed that anaerobic bacteria should be taken into account as an important component of this microbiota when assessing the exposure of waste sorting workers to biological agents. However, future studies should investigate more precisely how the composition of sorted waste as well as the season can affect the diversity of anaerobic bacteria in this working environment. More attention should be paid to regular cleaning of equipment surfaces in the plant, as deposited organic dust is an important reservoir of anaerobic bacteria, including those of a potentially pathogenic nature.

Microbial contamination of money sorting facilities.

INTRODUCTION: Money is the most common item with which we have daily contact. Circulated banknotes and coins can become microbiologically contaminated and act as both a source and a means of spreading such pollutants. MATERIAL AND METHODS: The study was carried out in three money sorting facilities in Poland. Bioaerosol samples were collected using a 6-stage Andersen impactor, and microorganisms deposited on tabletop surfaces were sampled using the swab method. Bacterial and fungal concentrations were calculated and all isolated species were taxonomically identified. RESULTS: The study confirmed that means of payment are active sources of microbial emission in money sorting facilities. The bioaerosol concentrations did not exceed the threshold limit values proposed for this type of office premises. It confirms that ventilation systems in these facilities worked efficiently, protecting them from the migration of microbial contaminants present in both indoor and outdoor (atmospheric) background air. On the other hand, the average concentrations of bacteria and fungi on tabletop surfaces in banknote and coin sorting rooms were above the proposed purity levels for indoor surfaces and should be treated as microbiologically contaminated. Microbiota isolated from the air and surfaces were very diverse and among those strains were bacterial and fungal pathogens that can pose a health threat to exposed individuals. CONCLUSIONS: The results showed that employees in money sorting facilities were exposed to microorganisms that may contribute to the development of adverse health outcomes. To protect them, highly efficient hygienic measures should be introduced in this working environment, to prevent both unwanted pollution and subsequent secondary emission of microbial contaminants from sorted means of payment and tabletop surfaces.

Across-shift changes in upper airways after exposure to bacterial cell wall components.

INTRODUCTION: To assess the across-shift changes of cytokine concentrations in nasal lavage (NAL) samples were collected from workers exposed to bacterial cell wall components present in organic dust in three different occupational environments. MATERIAL AND METHODS: The study was conducted in 38 employees including 10 workers from a municipal waste sorting plant (WSP), 20 from a sewage treatment plant (STP) and 8 from an office building (OB), who were established as a reference group, not exposed to organic dust. Interleukins 1ß (IL-1ß), 6 (IL-6), 8 (IL-8) and tumour necrosis factor alpha (TNF-α) were examined in NAL before and after work shift on Wednesdays. Bioaerosol exposure was determined by personal measurements and analysed for organic dust, endotoxins (END) and peptidoglycans (PGN). RESULTS: The analysis included the results for IL-8 only, because for the other cytokines their concentrations in 80% of cases were below the detection level. The most polluted were the workplaces in WSP with average concentrations of organic dust - 3.47 mg/m3, END - 96.31 ng/m3 and PGN - 571.88 ng/m3. The results of IL-8 showed a significant difference between the studied groups after the work shift (p=0.007). Among WSP workers concentrations of IL-8 increased also significantly (p=0.015) during the work shift. Multivariate analysis showed that organic dust and END were the factors that in the most distinct way (p<0.001) influenced changes of IL-8 levels in NAL. CONCLUSIONS: Each alteration in the composition of bioaerosols will probably determine the changes in the mechanisms responsible for both formation and modulation of inflammatory reactions in exposed workers.

Bacterial aerosols in a municipal landfill environment.

Landfills collecting substantial amounts of municipal waste support multiplication of different bacteria mainly due to organic matter contained in the deposited materials. With time, they may become active emission sources of these microorganisms. Taking into account both occupational and public health and safety, there is an indisputable necessity to monitor the level of air contamination caused by both bacterial cells and their components (e.g., endotoxins). In this study, the concentrations of total viable bacteria (TVB), and Gram-negative bacteria (GNB), as well as their particle size distributions and concentrations of GNB endotoxins were assessed at various locations within the landfill area. The concentrations of TVB and GNB in the air samples changed depending on the season, location (i.e. active sector versus surroundings) and landfill activity level (i.e. exploitation or standstill periods). Higher abundances of endotoxins were found during the standstill period, and they were significantly correlated with organic dust concentrations. The microbial particle size distribution was associated with the landfill operational state, being predominated by fine below 4.7 µm and coarse fractions above 7.0 µm within the active sector during exploitation and standstill periods, respectively. These results supported by a spatial distribution of bacterial aerosol indicate a clear impact of operated landfill on microbiological air quality within the occupied location and nearby areas. Considering health and safety of landfill workers and neighboring residents, who can be exposed to airborne microbial pollutants, repeated bioaerosol monitoring need to be established. It should facilitate both a special planning within the landfill area and undertaking preventive actions in its near and distant surroundings.

[Assessment of fungal aerosol exposure at selected workplaces contaminated with organic dust of different origin]. / Ocena narazenia na aerozol grzybowy na wybranych stanowiskach pracy zanieczyszczonych pylem organicznym o róznym pochodzeniu.

BACKGROUND: In recent years, the number of people suffering from diseases caused by fungi has been increasing. However, knowledge of the biodiversity of fungal pathogens in the work environment is still insufficient. The aim of this work was to evaluate the exposure to fungi being disseminated in the air of workplaces contaminated with organic dust of plant and animal origin. MATERIAL AND METHODS: Bioaerosol samples were collected at 3 occupational settings (poultry farm, biomass burning power plant and wastewater treatment plant) using button samplers. Quantitative and qualitative analysis of fungal aerosol was conducted by employing macro- and microscopic methods. Selected strains were then studied by polymerase chain reaction (PCR) using srodointernal transcribed spacers (ITS): ITS1-ITS2, ITS3-ITS4 and ITS1-ITS4 primer pairs. RESULTS: Average concentrations of fungal aerosol at workplaces ranged 1.2×102-2.1×106 cfu/m3. The highest fungal concentrations were recorded in the poultry farm, while the lowest were noted at the wastewater treatment plant. Aspergillus fumigatus was a predominant component of the mycobiota in the power plant and wastewater treatment plant. Almost 100% identification agreement of this pathogen between the traditional and molecular method was noted. CONCLUSIONS: The fungal concentrations in poultry farms exceeded the Polish proposal for the threshold limit value (5×104 cfu/m3). The results of the study demonstrate a high compatibility of A. fumigatus' identification using the traditional and molecular methods. Taking into account the fact, that a long term exposure to A. fumigatus conidia at workplaces may result in numerous health complaints, the use of proper protective equipment by workers must be a standard procedure. Med Pr 2018;69(3):269-280.

Anaerobic bacteria in wastewater treatment plant.

PURPOSE: The 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). METHODS: Samples 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. RESULTS: The 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. CONCLUSIONS: Anaerobic 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.

Monitoring of bacterial pathogens at workplaces in power plant using biochemical and molecular methods.

PURPOSE: The aim of this study was to characterize the ways of spreading of the most common bacterial species isolated from workers as well as from the air and raw materials at the workplaces in power plant utilizing biomass sources. To monitor microbial transmission and identify the source of contamination in the working environment, a combination of molecular and biochemical methods was applied. METHODS: The study was carried out at workplaces in power plant utilizes biomass as a main fuel source. At each of the studied workplaces, bioaerosol particles were collected on sterile Teflon filters using personal conical inhalable samplers (CIS), and biomass samples (straw pellets and briquettes, corn briquettes, sunflower pellets and wood chips) were directly taken from their storage places. Simultaneously with that, the swab samples from the hands of ten workers and their used respiratory masks (of FFP2 class) were also collected after the work shift to evaluate individual workers' microbial contamination. In all collected samples, total bacterial concentrations were assessed and the most common microbial isolates were identified to the species level using both biochemical (API tests) and molecular polymerase chain reaction (PCR), followed by random amplification of polymorphic DNA (RAPD) typing methods. RESULTS: The mean concentrations of culturable bacteria in the air and in biomass samples at the studied workplaces were high, i.e. 1.2 × 106cfu/m3 and 3.8 × 104cfu/g, respectively. The number of bacteria in the swab and mask samples also reached a high level of 1.4 × 104 cfu/ml and 1.9 × 103 cfu/cm2, respectively. Among the most frequently isolated microorganisms from all types of samples were Gram-positive bacteria of the genus Bacillus and Staphylococcus xylosus. 37 bacterial strains belonging to the genus Bacillus (B. licheniformis 8, B. pumilus 15 and B. subtilis 4) and Staphylococcus (10) were genotyped by the RAPD-PCR method. Based on RAPD-PCR analyses, the genomic similarity among 19 Bacillus strains isolated from biomass, air, protective mask and hand samples as well as 6 S. xylosus strains isolated from air, mask and hand samples exceeded 80%. CONCLUSION: This study demonstrated that biomass is the primary source of bacteria at power plant workplaces. These results also revealed that biomass-associated bacteria can be easily transferred to workers' hands and mask during their routine activities. To improve health protection at the workplaces, adequate training courses on hand hygiene and how to use and remove respiratory masks correctly for workers should be introduced as a key element of the prevention strategy. From the occupational point of view, the PCR-based methods seem to be an efficient tool for a fast and precise typing of bacterial strains isolated from different sources in the occupational environment. Such methods may help to implement appropriate prophylactic procedures and minimize transmission of infectious agents at workplaces.

Airborne peptidoglycans as a supporting indicator of bacterial contamination in a metal processing plant.

OBJECTIVES: The aim of this study was to assess exposure to airborne endotoxins and peptidoglycans (PGs) as well as possibility of using PGs as a surrogate measure of bacterial exposure in workplaces in a metal processing plant. MATERIAL AND METHODS: Personal dosimetry (N = 11) was used to obtain data on concentrations of viable bacteria, total number of bioaerosol particles, endotoxins and peptidoglycans. To investigate the size distributions of aerosol particles responsible for transport of endotoxins and PGs, air samples (N = 5) were additionally collected using the 8-stage cascade impactor. Endotoxins and PGs were assayed with the Limulus amebocyte lysate (LAL) test and a kinetic version of the silkworm larvae plasma (SLP) test, respectively. RESULTS: Median concentrations of airborne PGs (14.6 ng/m3), endotoxins (0.2 ng/m3), viable bacteria (1.16×103 CFU/m3) and the total number of bioaerosol particles (1.81×106 cells/m3) were determined. Qualitative analysis revealed presence of 19 bacterial species belonging to 14 genera. The calculations showed strong, significant correlations (p < 0.05) between endotoxins, viable bacteria (r = 0.75) and the total number of bioaerosol particle concentrations (r = 0.76) as well as between PGs and the total number of bioaerosol particle concentrations (r = 0.72). Size distribution analysis showed that the highest concentrations of bacterial aerosols occurred in the range of 2.1-3.3 µm. In the case of endotoxins, an increase of concentrations in 2 ranges of aerodynamic diameters: 1.1-3.3 µm and 5.8-9 µm was shown. For PGs there was a visible gradual increase of their concentrations in the range 2.1-9 µm. CONCLUSIONS: Peptidoglycans can be treated as a supporting indicator of bacterial contamination in metal processing plants, particularly when an assessment of an immunotoxic potential of microbiological hazards needs to be performed. However, to be extrapolated to other occupational and non-occupational environments, the obtained results require a further verification.

Exposure to culturable and total microbiota in cultural heritage conservation laboratories.

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/m3 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.

[Bacterial and fungal aerosols in the work environment of cleaners]. / Aerozole bakteryjne i grzybowe w srodowisku pracy firm sprzatajacych.

BACKGROUND: Cleaning services are carried out in almost all sectors and branches of industry. Due to the above, cleaners are exposed to various harmful biological agents, depending on the tasks performed and the commercial sector involved. The aim of this study was to assess the exposure of cleaning workers to biological agents based on quantitative and qualitative characteristics of airborne microflora. MATERIAL AND METHODS: A six-stage Andersen sampler was used to collect bioaerosols during the cleaning activities in different workplaces, including schools, offices, car services, healthy services and shops. Standard Petri dishes filled with blood trypticase soy agar and malt extract agar were used for bacterial and fungal sampling, respectively. RESULTS: The bioaerosol concentration values obtained during testing of selected workposts of cleaners were lower than the Polish recommended threshold limit values for microorganisms concentrations in public service. The most prevalent bacterial species in studied places were Gram-positive cocci (mainly of genera Micrococcus, Staphylococcus) and endospore-forming Gram-positive rods (mainly of genera Bacillus). Among the most common fungal species were those from genera Penicillium and Aspergillus. The size distribution analysis revealed that bioaerosols present in the air of workposts at shops, schools and car services may be responsible for nose and eye mucosa irritation and allergic reactions in the form of asthma or allergic inflammation in the cleaning workers. CONCLUSIONS: The study shows that occupational activities of cleaning workers are associated with exposure to airborne biological agents classified into risk groups, 1. and 2., according to their level of infection risk, posing respiratory hazard.

[Fibers as carriers of microbial particles]. / Wlókna jako nosniki czastek mikrobiologicznych.

BACKGROUND: The aim of the study was to assess the ability of natural, synthetic and semi-synthetic fibers to transport microbial particles. MATERIAL AND METHODS: The simultaneously settled dust and aerosol sampling was carried out in 3 industrial facilities processing natural (cotton, silk, flax, hemp), synthetic (polyamide, polyester, polyacrylonitrile, polypropylene) and semi-synthetic (viscose) fibrous materials; 2 stables where horses and sheep were bred; 4 homes where dogs or cats were kept and 1 zoo lion pavilion. All samples were laboratory analyzed for their microbiological purity. The isolated strains were qualitatively identified. To identify the structure and arrangement of fibers that may support transport of microbial particles, a scanning electron microscopy analysis was performed. RESULTS: Both settled and airborne fibers transported analogous microorganisms. All synthetic, semi-synthetic and silk fibers, present as separated threads with smooth surface, were free from microbial contamination. Natural fibers with loose packing and rough surface (e.g., wool, horse hair), sheaf packing and septated surface (e.g., flax, hemp) or present as twisted ribbons with corrugated surface (cotton) were able to carry up to 9×10(5) cfu/g aerobic bacteria, 3.4×10(4) cfu/g anaerobic bacteria and 6.3×10(4) cfu/g of fungi, including pathogenic strains classified by Directive 2000/54/EC in hazard group 2. CONCLUSIONS: As plant and animal fibers are contaminated with a significant number of microorganisms, including pathogens, all of them should be mechanically eliminated from the environment. In factories, if the manufacturing process allows, they should be replaced by synthetic or semi-synthetic fibers. To avoid unwanted exposure to harmful microbial agents on fibers, the containment measures that efficiently limit their presence and dissemination in both occupational and non-occupational environments should be introduced.

Peptidoglycans in cutting fluids - a good indicator of bacterial contamination?

OBJECTIVE: The aim of this study was to estimate the content of peptidoglycans in cutting fluids (CFs) and to assess the possibility of using them as a marker of bacterial contamination in this type of occupational environment. MATERIALS AND METHODS: A total of 11 samples of CFs were collected: 8 were taken from the working machine systems and 3 were unused CF samples. The peptidoglycans were determinated with the kinetic version of the Silkworm Larvae Plasma (SLP) test. RESULTS: The average concentration of bacteria was 5.58×105 CFU/mL, and peptidoglycans - 28.2 ng/mL. The variability for peptidoglycans concentration was less pronounced than that for bacteria (GSD 6 and 13.3, respectively). Taking into consideration the National Research and Safety Institute (INRS - Institut National de Recherche et de Sécurité) limit value the concentrations of bacteria and peptidoglycans, as well as the usage of the fluids, the analysis showed that peptidoglycans reflect the differences between the studied factors much more accurately than bacteria. The correlation analysis, however, showed that the levels of peptidoglycans in the examined CFs strongly correlated with the concentrations of viable bacteria (R² = 0.50, p<0.05). CONCLUSIONS: The study confirmed that the CFs may contain immunologically active substances of bacterial origin even though they did not show any bacterial growth. Moreover, it showed that the concentrations of peptidoglycans in CFs precisely reflect the exposure to bacteria, and as a structural component of the cell wall can be treated as their marker.

Occupational exposure to airborne microorganisms, endotoxins and ß-glucans in poultry houses at different stages of the production cycle.

The aim of the presented study was to assess the exposure of poultry workers to airborne microorganisms, endotoxins and ß-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 ß-glucans. The concentrations of bacterial and fungal aerosols ranged from 2.5×10(2) CFU/m(3)-2.9×10(6) CFU/m(3), and from 1.8×10(2) CFU/m(3)-1.8×10(5) CFU/m(3), 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/m(3). After the flock entered the clean house, the level of endotoxins and ß-glucans increased from below detection limit to 8,364 ng/m(3) and from 0.8 ng/m(3) to 6,886 ng/m(3), 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.

Exposure of ventilation system cleaning workers to harmful microbiological agents.

BACKGROUND: Regular inspection of the cleanliness of the ventilation systems, as well as their periodic cleaning and disinfection, if necessary, are the main factors of the proper maintenance of each system. Performing maintenance operations on the ventilation system, workers are exposed to risk associated with the exposure to harmful biological agents. The aim of this study was to assess the employees' exposure to bioaerosols during maintenance work on ventilation systems. MATERIAL AND METHODS: Bioaerosol measurements were carried out using a button sampler. The microbial particles were collected on gelatin filters. Settled-dust samples from the inner surface of the air ducts and filter-mat samples were selected for the microbiological analysis. In the collected air, dust and filter samples the concentration of bacteria and fungi were determined. RESULTS: Bacteria and fungi concentrations ranged between 3.6 x 10(2)-2.2 x 10(4) CFU/m3 and 4.7 x 10(2)-4.5 x 10(3) CFU/m3 at workplaces where the operations connected with mechanical ventilation cleaning were performed and 2.2 x 10(4)-1.2 x 10(5) CFU/m2 and 9.8 x 10(1)-2.5 x 10(2) CFU/m3 at workplaces where filter exchange was performed, respectively. The qualitative analysis of microorganisms isolated from the air in all studied workplaces revealed that the most prevalent bacteria belonged to Bacillus genus. The average concentrations of bacteria and fungi in filter-mat samples were 3.3 x 10(3) CFU/cm2 and 1.4 x 10(4) CFU/cm2, respectively. In settled-dust samples, average concentrations were 591 CFU/100 cm2 and 52 CFU/100 cm2, for bacteria and fungi respectively. CONCLUSIONS: Workers cleaning ventilation systems are exposed to harmful biological agents classified into risk groups, 1 and 2, according to their level of the risk of infection. The research conducted in the workplace can be the basis of risk assessment related to exposure to harmful biological agents during maintenance work in ventilation.

Exposure to harmful microbiological agents during the handling of biomass for power production purposes.

BACKGROUND: Despite numerous benefits related to the utilization of biomass as an alternative source of energy, the handling of biomass creates a risk for the power industry workers of exposure to harmful microbiological agents. The purpose of this study was to evaluate the exposure of the workers to such agents at a power plant co-firing biomass with coal. This assessment was based on quantitative and qualitative characteristics of bioaerosols, supplemented with the analysis of biomass samples. MATERIAL AND METHODS: Air samples were collected with both MAS and Andersen six-stage impactors. Two different kinds of biomass samples used in the co-firing technological process were collected: sunflower seed peel pellet and wood chips. Bacterial and fungal concentrations were assessed in the air and biomass samples, and isolated microbial colonies were identified to the genus and/or species level. RESULTS: Bacterial and fungal concentrations at workplaces ranged between 5.1 x 10(2) cfu/m3 and 2.0 x 10(4) cfu/m3, and between 2.2 x 10(2) cfu/m3 and 2.3 x 10(4) cfu/m3, respectively. The highest concentrations were determined at workplaces related to reloading, screening and biomass transport via conveyor belts to silos. Fungi representing the genus Aspergillus, including A. fumigatus, A. niger, A. flavus and Gram-negative rods of the genus Citrobacter, Pseudomonas and Rahnella prevailed in the air at all investigated workplaces. Bacterial and fungal concentrations in biomass samples amounted to 1.8 x 10(6) cfu/g and 1.1 x10(6) cfu/g, respectively. The qualitative analysis revealed that the composition of species in the biomass samples was similar to that observed in the air at workplaces. CONCLUSIONS: Workers engaged in the biomass combustion technology are exposed to bioaerosol containing potentially pathogenic bacteria and fungi.

Effect of two aerosolization methods on the release of fungal propagules from a contaminated agar surface.

The effect of perpendicular and swirling aerozolization methods on the release of fungal fragments and spores from agar surface was studied. Three fungal species (Aspergillus versicolor, Cladosporium cladosporioides, Penicillium chrysogenum) were selected for the tests as they commonly occur indoors, create different hyphae structure when they grow on surfaces, and have different spore shapes, aerodynamic sizes, and formation mechanisms. As the tested surface, Petri dishes filled with malt extract agar, separately inoculated with fungal strains and cultivated to obtain an abundant and even growth were used. For the purpose of these experiments, a new aerosolization chamber was built in which HEPA-filtered air stream responsible for fungal propagule release was either perpendicularly directed towards the contaminated surface or set in swirling motion above it. The experiments were conducted at 2 air velocities, typical for outdoor environment (11.6 m/s) and ventilation ducts (29.1 m/s). Concentrations and size distributions of released fragments and spores were measured using an optical particle counter. The results showed that the propagule release depends on the direction (swirling motion was able to release up to 3.4 × 10(5) fragments and 3 × 10(5) spores from 1 cm( 2) of contaminated surface, i.e. significantly more than the perpendicularly directed air stream), velocity (the higher the swirling air velocity applied, the higher the number of released propagules) of the air stream above the contaminated surface, and varied due to the taxonomical species origin (the higher number of particulates was released by Aspergillus colonies). Hence, the efficient control of both microbial fragments and spores, not only in the air, but also in their source should be an integral part of the quality control procedure.