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Introduction and Objective: Ultraviolet light in the UV-C band is known as germicidal radiation and was widely used for both sterilization of the equipment and creation of a sterile environment. The aim of the study is to assess the effectiveness of inactivation of microorganisms deposited on surfaces with various textures by UV-C radiation disinfection devices., Material and Methods: Five microorganisms (3 bacteria, virus, and fungus) deposited on metal, plastic, and glass surfaces with smooth and rough textures were irradiated with UV-C light emitted by low-pressure mercury lamp and ultraviolet emitting diodes (LEDs), from a distance of 0.5 m, 1 m, and 1.5 m to check their survivability after 20-minute exposure., Results and Conclusions: Both tested UV-C sources were effective in inactivation of microorganisms; however, LED emitter was more efficient in this respect than the mercury lamp. The survival rate of microorganisms depended on the UV-C dose, conditioned by the distance from UV-C source being the highest at 0.5 m and the lowest at 1.5 m. For the tested microorganisms, the highest survival rate after UV-C irradiation was usually visible on glass and plastic surfaces. This observation should be considered in all environments where the type of material (from which the elements of technical equipment are manufactured and may be contaminated by specific activities) is important for maintaining the proper level of hygiene and avoiding the unwanted and uncontrolled spread of microbiological pollution.

The wastewater treatment processes are associated with the emission of microbial aerosols, including enteropathogenic bacteria. Their presence in this work environment poses a real threat to the health of employees, both through the possibility of direct inhalation of the contaminated air and indirectly through the pollution of all types of surfaces with such bioaerosol particles. This study aimed to investigate the prevalence of enteropathogenic bacteria in the air, on surfaces, and in wastewater samples collected in four wastewater treatment plants (WWTPs). The effectiveness of conventional culture-biochemical, as well as spectrometric and molecular methods for the rapid detection of enteropathogenic bacteria at workstations related to particular stages of wastewater processing, was also evaluated. Bioaerosol, surface swab, and influent and effluent samples were collected from wastewater plants employing mechanical-biological treatment technologies. The air samples were collected using MAS-100 NT impactor placed at a height of 1.5 m above the floor or ground, simulating aspiration from the human breathing zone. Surface samples were collected with sterile swabs from different surfaces (valves, handles, handrails, and coveyor belts) at workplaces. The raw influent and treated effluent wastewater samples were aseptically collected using sterile bottles. The identification of bacterial entheropathogens was simultaneously conducted using a culture-based method supplemented with biochemical (API) tests, mass-spectrometry (MALDI TOF MS), and molecular (multiplex real-time PCR) methods. This study confirmed the common presence of bacterial pathogens (including enteropathogenic and enterotoxigenic Escherichia coli, Salmonella spp., Campylobacter spp., and Yersinia enterocolitica) in all air, surface, and wastewater samples at studied workplaces. Higher concentrations of enteropathogenic bacteria were observed in the air and on surfaces at workplaces where treatment processes were not hermetized. The results of this study underline that identification of enteropathogenic bacteria in WWTPs is of great importance for the correct risk assessment at workplaces. From the analytical point of view, the control of enteropathogenic bacterial air and surface pollution using rapid multiplex-PCR method should be routinely performed as a part of hygienic quality assessment in WWTPs., (© 2024. The Author(s).)

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-1β, 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)-β-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)-β-D-glucan concentrations at workplaces reached the levels of 4.12 mg/m 3 , 45.21 ng/m 3 , and 56.54 ng/m 3 , respectively. The IL-1β, 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)-β-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.

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 × 10 8 CFU/m 3 and 3.77 × 10 4 CFU/m 3 , 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.

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.

This study aimed to qualitatively and quantitatively assess the prevalence of the most common respiratory and gastrointestinal viruses in the air, surface swab, and influent/effluent samples collected in wastewater treatment plants (WWTPs). Application of qPCR/RT-qPCR (quantitative polymerase chain reaction/reverse-transcription quantitative polymerase chain reaction) assays combined with PMA (propidium monoazide) dye pretreatment allowed detecting the potentially infectious and disintegrated viral particles in collected samples. In the air at workplaces in WWTPs, the most frequent isolation with the highest concentrations (reaching up to 10 3 gc/m 3 of potentially infectious intact viral particles) were observed in case of adenoviruses (AdVs) and rotaviruses (RoVs), followed by noroviruses (NoVs). Viruses were significantly more often detected in the air samples collected with Coriolis μ impinger, than with MAS-100NT impactor. The temperature negatively (Spearman correlation: -1 < R < 0; p < 0.05), while RH (relative humidity) positively (0 < R < 1; p < 0.05) affected airborne concentrations of potentially infectious viral particles. In turn, the predominant viruses on studied surfaces were RoVs and noroviruses GII (NoV GII) with concentrations of potentially infectious virions up to 10 4 gc/100 cm 2 . In the cases of SARS-CoV-2 and presumptive SARS-CoV-2 or other coronaviruses, their concentrations reached up to 10 3 gc/100 cm 2 . The contamination level of steel surfaces in WWTPs was similar to this on plastic ones. This study revealed that the qualitative and quantitative characteristics of respiratory and gastrointestinal viruses at workplaces in WWTPs is important for proper exposure assessment and needs to be included in risk management in occupational environment with high abundance of microbial pollutants derived from wastewater., (© 2022. The Author(s).)

In many countries, the management of household waste has recently changed with an increased focus upon waste sorting resulting in lower collection frequency for some waste fractions. A consequence of this is the potential for increased growth of microorganisms in the waste before collection, which can lead to an increased exposure via inhalation for waste collection workers. Through a review of the literature, we aimed to evaluate risks caused by waste collecting workers' exposure to bioaerosols and to illuminate potential measures to reduce the exposure. Across countries and waste types, median exposure to fungi, bacteria, and endotoxin were typically around 10 4 colony forming units (cfu)/m 3 , 10 4 cfu/m 3 , and 10 EU/m 3 , respectively. However, some studies found 10-20+ times higher or lower median exposure levels. It was not clear how different types of waste influence the occupational exposure levels. Factors such as high loading, ventilation in and cleaning of drivers' cabs, increased collection frequency, waste in sealed sacks, and use of hand sanitizer reduce exposure. Incidences of gastrointestinal problems, irritation of the eye and skin and symptoms of organic dust toxic syndrome have been reported in workers engaged in waste collection. Several studies reported a correlation between bioaerosol exposure level and reduced lung function as either a short or a long term effect; exposure to fungi and endotoxin is often associated with an inflammatory response in exposed workers. However, a better understanding of the effect of specific microbial species on health outcomes is needed to proceed to more reliable risk assessments. Due to the increasing recycling effort and to the effects of global warming, exposure to biological agents in this working sector is expected to increase. Therefore, it is important to look ahead and plan future measures as well as improve methods to prevent long and short-term health effects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

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.

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.

We aimed to assess the occurrence of bovine viruses (bovine leukemia virus-BLV and bovine adenovirus-BAdV) at workplaces in traditional dairies and to evaluate the potential role of airborne and surface contamination in spreading of these viruses derived from raw milk. The total amount of 122 samples-including 37 air (bioaerosol), 40 surface, and 45 milk samples-were checked for the presence of BLV and BAdV genomes using RT-qPCR/qPCR method. The study showed that the viruses were present in 7 air (among them 71.4% were BLV-positive and 28.6% were BAdV-positive), 14 surface (among them 85.7% were BLV-positive and 14.3% were BAdV-positive), and 34 milk (all were BLV-positive only) samples. Statistical analysis revealed that both the air and surfaces in studied occupational environment were more frequently contaminated with BLV than with BAdV ( Chi-square test : p = 0.002, Fisher's Exact test: p = 0.002). Kruskal-Wallis tests showed significant differences in BLV genome concentrations in the air (p = 0.045) as well as in BLV and BAdV genome concentrations on surfaces (p = 0.005 and p = 0.040, respectively) between studied processing areas. In units of genome copies (gc) per area, the highest concentrations of BLV and BAdV genomes in the air (9.8 × 10 1 ± 1.14 × 10 2 gc/m 3 and 5.4 × 10 1 ± 9.1 × 10 1 gc/m 3 , respectively) and on surfaces (9.83 × 10 2 ± 7.41 × 10 2 gc/100cm 2 and 2.30 × 10 2 ± 3.8 × 10 2 gc/100cm 2 , respectively) were observed in milk reception area. The air and surfaces of pre-production zones were also significantly more contaminated with BAdV genomes compared to production areas (Mann-Whitney test: p = 0.039 and p = 0.029, respectively). This study showed that dairy workers may be exposed to bovine viruses through the inhalation of bioaerosols and contact with contaminated surfaces. To reduce the probability of virus transmission from the raw milk to humans, efficient surface cleaning procedures degrading viral particles should be introduced and the use of personal protection equipment, especially within pre-production zones, should be required. As the raw milk may be a source of bovine viruses, the development of strategies for both the control and eradication of BLV and BAdV among cattle seems to be also urgently needed.

Occupational exposure to wood dust and bioaerosols may lead to numerous respiratory tract diseases. We aimed to assess a degree of workplace contamination with dust, bacteria, fungi, endotoxins, and (1 → 3)-β-D-glucans released into the air during wood processing in pellet production facilities and to check against this background the usefulness of nasal lavage (NAL) as analytical tool for assessment of combined workers' exposure to airborne dust and microbiological contaminants. In 10 pellet plants, the particulate (wood dust) aerosol concentrations were determined by using Grimm aerosol spectrometer and CIS filter sampler. The collected CIS samples were subsequently used to evaluate endotoxin and (1 → 3)-β-D-glucan concentrations. Simultaneously with particulate aerosol, bioaerosol samples were collected by using 6-stage Andersen and single-stage MAS impactors. Bacterial and fungal aerosol concentrations were calculated and all isolated microorganisms were taxonomically identified. NAL fluid samples were collected from workers exposed to studied aerosols and the concentrations of proinflammatory mediators (IL-1β, IL-6, IL-8, and TNFα) and cytological image of nasal mucosa (expressed as cell counts) were established. The dynamics of production activities resulted in wide range of observed wood dust, microorganism, endotoxin and (1 → 3)-β-D-glucan concentrations reaching periodically extremely high values up to 65 mg m -3 , 19,320 CFU m -3 , 215 ng m -3 and 1525 ng m -3 , respectively. Environmental stress caused by exposure to particulate and microbial aerosols stimulated immune response among workers of pellet production facilities. Correlation analysis revealed that interleukin levels and the number of cells in NAL were significantly affected by both wood dust and bioaerosol concentrations. As nasal mucosa serves as the primary barrier against inhaled pollutants, NAL seems a reliable analytical material to assess work-related adverse respiratory health outcomes derived from such exposure., (Copyright © 2019 Elsevier B.V. All rights reserved.)

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 1β (IL-1β), 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/m 3 , END - 96.31 ng/m 3 and PGN - 571.88 ng/m 3 . 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.

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., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Solid waste storage in specially designated areas - landfills - has been the basic method of municipal solid waste disposal management for many years. However, thermal treatment is the currently preferred method of solid waste disposal. Hygienic assessment of working conditions in municipal waste incineration plants is hindered due to the variability and complexity of pollutants emitted during the combustion process. For many years studies describing this problem have focused mainly on chemical pollution inside the plants as well as emitted into the atmosphere. Available data indicates the presence of organic dust at workplaces in the range 0.1-14 mg/m 3 . It has been proven that it is a carrier of a wide spectrum of microorganisms, including bacteria, fungi and both mesophilic and thermophilic actinomycetes as well as adenoviruses and torque teno virus (TTV). In the air, at workplaces, bacterial endotoxins have also been found in concentrations reaching even 50 000 EU/m 3 , which may significantly affect the occurrence of pro-inflammatory reactions in the lungs as well as toxic pneumonitis. Biological agents should be taken into account in the occupational risk assessment for harmful agents present in this environment, and an in-depth characterization of exposure and health effects resulting from contact with these agents should be continued to an even greater extent than before. Med Pr. 2019;70(1):99-105., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

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 × 10 4 CFU/mL (GSD = 85.4) and in sludge-1.42 × 10 6 CFU/g (GSD = 5.1). In turn, the average airborne bacterial concentration was at the level of 50 CFU/m 3 (GSD = 5.83) and the highest bacterial contamination (4.06 × 10 3  CFU/m 3 ) 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.

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 środointernal 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/m 3 . 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/m 3 ). 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., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

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 × 10 6 cfu/m 3 and 3.8 × 10 4 cfu/g, respectively. The number of bacteria in the swab and mask samples also reached a high level of 1.4 × 10 4 cfu/ml and 1.9 × 10 3 cfu/cm 2 , 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.

The aim of the study was to assess the levels of inhalable dust, endotoxins and (1-3)-β-d-glucans as agents harmful to the respiratory tract of workers of municipal waste sorting plants and interaction between these agents based on the measurements taken in two plants with different processing capacities. The study was conducted in summer season in two waste sorting plants (WSPs) differing in processing capacity. Samples of bioaerosol for inhalable dust (gravimetric method), endotoxins (LAL test in kinetic, chromogenic version) and (1-3)-β-d-glucans (Glucatell test in kinetic version) were collected from 42 sorting workers using individual aspirators with glass fiber filters during the work shift. Average geometric concentrations (geometric standard deviation; min-max) of inhalable dust, endotoxins and (1-3)-β-d-glucans were: WSP1: 1.7 mg m -3 (2.2; 0.6-6.9 mg m -3 ); 15.9 ng m -3 (2.1; 5.4-78.9 ng m -3 ), 55.1 ng m -3 (1.8; 20.7-188.6 ng m -3 ) and WSP2: 0.8 mg m -3 (2.2; 0.2-3.8 mg m -3 ), 9.8 ng m -3 (2.4; 1.6-29.7 ng m -3 ), 45.0 ng m -3 (3.2, 5.7-212.9 ng m -3 ), respectively. A significantly higher concentration of inhalable dust was recorded in WSP1 with bigger processing capacity compared to WSP2 (less processing capacity). Significant ( p  < 0.05) and very high correlations (Spearman rank R  > 0.7) were found between the concentrations of all analyzed harmful agents. Processing capacity of waste sorting plants differentially affects the concentrations of inhalable dust, whereas concentrations of endotoxins and glucans are less clearly affected. This suggests that relative concentrations of endotoxin and glucan are depending on the waste sorting capacity.

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., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

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., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

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., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

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., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Objectives: The inhaled endotoxin is considered as a causative factor in the process of acute bronchial obstruction, which can be measured by a decrease in forced expiratory volume in 1 s (FEV1). The aim of this study was to assess endotoxin exposure among sewage treatment plant workers (STPW) and its effect on across-shift changes in respiratory airflow., Material and Methods: A group of 78 STPW from a large sewage treatment plant was studied. Inhalable dust for endotoxin assessment was collected using personal aerosol samplers. Endotoxin was assayed with the kinetic, chromogenic Limulus amebocyte lysate test. Across-shift spirometric measurements were performed on Mondays, after 2-days absence from work, with the use of portable spirometer. The forced vital capacity (FVC), and FEV1 parameters were analyzed. Multifactor regression modeling was performed to determine parameters significantly associated with endotoxin exposure., Results: The concentration of inhalable dust and endotoxin ranged from 0.01-1.38 mg/m3 and 0.68-214 endotoxin units per cubic meter of air (EU/m3), respectively. Endotoxins were characterized with the skewed distribution (arithmetic mean (AM) = 38.8 EU/m3, geometric mean (GM) = 15.4 EU/m3, geometric standard deviation (GSD) = 4.21). Through the use of multifactor analysis, which excluded the main confounders (inhalable dust and smoking habit) it was found that, despite low levels of endotoxin, it had significant impact on the observed across-shift decline in FEV1 (p = 0.044). For this parameter, the regression slope was additionally calculated (r = -0.017, p = 0.071)., Conclusions: Relatively low levels of endotoxin among sewage treatment plant workers may cause small, but significant across-shift declines in FEV1. The observed relationship was independent of organic dust concentrations and smoking habit. The respiratory protection should be provided for STPW., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

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.

Objectives: The main objective of the study was to determine the levels of house dust mite (Der p1), dog (Can f1), cat (Fel d1) and cockroach (Bla g2) allergens in kindergartens localized in an urban agglomeration., Material and Methods: A quantitative analysis of allergens was carried out in settled dust samples collected by vacuuming the floor surface in three kindergartens (N = 84) and children's clothing (N = 36). The samples were collected in spring-summer and autumn-winter periods as well as at the beginning and end of the week. The allergen dust concentration was determined by enzyme-linked immunoenzymatic assay (ELISA)., Results: The mean geometric concentrations (±geometric standard deviations) of allergens Der p1, Can f1, Fel d1 and Bla g2 determined in kindergartens were: 0.02 ± 3.21 μg/g of dust; 0.97 ± 4.49 μg/g of dust; 0.30 ± 4.43 μg/g of dust and 0.01 ± 3.08 μg/g of dust, respectively. Younger classrooms (children aged from 3 to 4 years) were characterized by almost twice higher mean concentration of allergen Fel d1, as compared to older classrooms (children aged from 5 to 6 years) (p < 0.05). A significant impact of seasonality on the level of dog allergen Can f1 was found (p < 0.05). No significant weekly variation was found in average concentrations of the allergens. Children who had a dog and/or cat at home were characterized by high concentrations of allergens Can f1 and Fel d1 on their clothes (59.2 ± 5.39 μg Can f1/g of dust; 3.63 ± 1.47 μg Fel d1/g of dust), significantly higher than concentrations of allergens in children who did not have any pets (p < 0.001)., Conclusions: Special attention should be paid to keeping the kindergarten rooms tidy and clean and to an appropriate choice of furnishings and fittings which would prevent the proliferation of the house dust mite and accumulation of allergens.

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.

Background: Indoor air is contaminated with microorganisms coming from both the atmospheric air and sources present in premises. The aim of this study was to analyze the concentrations of biological agents in office buildings, dependending on ventilation/air conditioning system and season., Materials and Methods: The study covered office buildings (different in the system of ventila-tion/air conditioning). Air samples for assessing the levels of inhalable dust, endotoxins and (1-->3)-beta-D-glucans, were taken at the selected stationary points of each building during summer and winter. The air was sampled for 6 h, using portable sets consisting of the GilAir 5 pump and the head filled with a filter of fiber glass. The samples for the presence of airborne bacteria and fungi were collected twice during the day using the impaction method., Results: Average concentrations of inhalable dust, bacteria, fungi, endotoxins and (1-->3)-beta-D-glucans in office premises were 0.09 mg/m3, 6.00 x 10(2) cfu/m3, 4.59 x 10(1) cfu/m3, 0.42 ng/m3 and 3.91 ng/m3, respectively. Higher concentrations of the investigated agents were found in summer. In premises with air conditioning concentrations of airborne fungi, (1-->3)-beta-D-glucans and inhalable dust were significantly lower in winter. In summer the trend was reverse except for (1-->3)-beta-D-glucans., Conclusions: Concentrations of biological agents were affected by the season and the presence of air conditioning. Concentrations of inhalable dust, bacteria, fungi, endotoxins and (1-->3)-beta-D-glucans, observed inside the office buildings, were significantly higher in summer than in winter. The presence of the air conditioning system modified in various ways the levels of biological agents. Its influence was greater on the concentration of fungi and (1-->3)-beta-D-glucans than on that of bacteria and endotoxins.

Background: In this paper the exposure assessment to airborne biohazards (organic dust, microorganisms, endotoxins and ((1 --> 3)-beta-D-glucans) as well as to ammonia and hydrogen sulfide among CAFO (swine farms) workers is presented., Materials and Methods: Occupational exposure assessment was carried out on 30 swine farms. Personal dosimetry was carried out among 90 swine farm workers to assess the exposure to organic dust, endotoxins and glucans. Concentrations of ammonia and hydrogen sulfide were measured using Draeger pipes. Endotoxins were assayed with the LAL test in a kinetic, chromogenic version and ((1 --> 3)-beta-D-glucans with the Glucatell test in a kinetic version., Results: Concentrations of inhalable dust ranged from 0.16 to 37.2 mg/m3, with AM = 3.65 mg/m3, whereas AM for respirable fraction was 0.39 mg/m3 with the range from zero to 4.28 mg/m3. Mean concentration of culturable bacteria was 4.79 x 10 (5) jtk/m3, and fungi concentration was ten times lower - 1.55 x 10(4) jtk/m3. Exposure to endotoxins with high degree of differentiation ranged from 95 to 147 885 EU/m3 in inhalable and from 5.5 to 18 708 EU/m3 in respirable fractions. Glucan concentrations ranged from 6 to > 5200 ng/m3 in unhalable and from 1 to 800 ng/m3 in respirable fraction. Ammonia concentrations in the workplace air ranged from 1.78 mg/m3 (2.50 ppm) to 30.1 mg/m3 (42.4 ppm). Hydrogen sulfide did not exceed the level of 4.1 mg/m3., Conclusion: Work conditions found in CAFOs may induce adverse effects on workers' respiratory system and should be considered as an important harmful agent. The protection of workers respiratory airways should be recommended.

Background: The quantitative assessment and qualitative identification of moulds at workplaces in wastewater treatment plants were the aim of the study., Materials and Methods: The study was carried out in four wastewater treatment plants, where 15 stationary points were selected according to mechanical, biological and sewage sludge treatment processes. In addition, background level samples from the city area were also collected. Bioaerosols were sampled with use of a Burkard Aerosol Sampler and directly put on Malt Extract Agar plates. Identification of moulds was based on morphological properties described in the professional literature., Results: The identified concentrations of moulds were low and ranged between 0.11 and 16.75 x 10(2) cfu/m3. The highest mean levels of fungal microflora were found during sewage sludge treatment processes. In total, there were 65 fungal isolates, of which 80% were found in wastewater treatment plants. In bioaerosol samples of the occupational origin, the highest (40%) amount of isolates originated from sewage sludge treatment processes and the lowest (25%) from biological treatment stages. In wastewater treatment plants, moulds of Aspergillus genus predominated and represented nearly 35% of all identified fungi. Comparing to background levels, the content of this genus was almost 4.5 times higher. Pathogenic Aspergillus fumigatus was found at all stages of wastewater treatment and Trichophyton genus at the stage of mechanical treatment. Moreover, there were numerous moulds of Mucor, Penicillium and Alternaria genera. In background samples moulds of Penicillium genus predominated and no pathogenic species were found., Conclusions: The obtained results reveal that the sewage sludge is the main source of mould emission into the air at workplaces in wastewater treatment plants. On account of the presence of moulds with the evidenced infectious and allergic activity it is suggested that personal protective equipment should be used by employees.

Mycotoxins are a quite numerous group of substances released as metabolites by molds, which badly affect human and animal health. Their impact on organisms resulting from alimentary exposure is well recognized, but the mechanisms by which they exert their health effects after inhalation exposure are still poorly investigated. The aim of this work was to review the literature concerning the outcomes of occupational exposure to mycotoxins present in the work environment. The author discusses the major mycotoxin classes, their chemical structure, some physicochemical properties and biological activity properties. This paper summarizes the results of investigations on the impact of occupational exposure to molds present in the workplace air in various branches of industry. Problems of identifying the mechanism of health effects exerted due inhalation exposure to mycotoxins are also discussed. This review shows that there is lack of good hygiene standards and legislation regulating the presence of these compounds in the workplace air. These is due to insufficient number of analyses aimed at estimating short-term inhalation exposure to mycotoxins and lack of monitoring of long-term exposure and its health effects. The authors concludes that occupational exposure to mycotoxins and their role in the development of pathological changes in the respiratory system require further investigations.

Unlabelled: 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 1.0x10(1) CFU/ml to 3.2x10(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.

Background: The aim of the study was to quantitatively and qualitatively identify moulds occurring in the air of selected office rooms., Material and Methods: The study was conducted in the wintertime inside four office rooms with moisture trace and one control room. To assess mycological contamination of the air, triple samples were directly collected on Petri dishes (Malt Extract Agar medium) using a Burkard air sampler. Qualitative evaluation of moulds was based on the microscopic view and morphological features of colonies., Results: Total number of moulds determined in the air of office rooms did not exceed the level of 4 x 10(2) cfu/m3. The highest concentration of moulds (3.44 x 10(2) cfu/m3) was found in the room that was also used as an archive. It was over tenfold higher than in the control room (0.33 x 10(2) cfu/m3). The qualitative analysis of moulds showed the presence of 15 species. Some of them, including Aspergillus fumigatus, Aspergillus versicolor, Aspergillus ochraceus, Cladosporium spp., Penicillium spp. and Alternaria spp., are recognized as potential health hazards to workers due to the production of mycotoxins and allergic reactions., Conclusions: The archive was the only room, where concentration of moulds slightly exceeded the reference value. To protect the health of workers who perform their duties in this place, the documents, which are an ideal place of mould growth, should be moved to a separate room. Respiratory complaints reported by workers could be associated with concentrations and species of moulds found in the office rooms under study.

In metalworking, the temperature of the cutting edge can reach 700 degrees C, which can adversely affect either the surface of the metal processed or the cutting edge itself. To reduce the heat and friction, the metalworking fluids and coolants are used. The most common are the oil-in-water emulsions, which are a mixture of concentrated mineral oils, different additives, and water. The presence of water and organic substrates generates conditions for microbial growth. Bacterial endotoxins can also be frequently detected in metalworking fluids. Rapid rotation of the metalworking tools makes various biological agents to be released as droplet bioaerosols that can be inhaled by the workers, thus producing adverse health effects, mainly on the respiratory system. More than 130 species of bacteria (including pathogens), moulds and yeasts have so far been found in the metalworking fluids and coolants. This paper summarizes the outcomes of projects on the impact of biological agents present in metalworking fluids. Exposure to oil mist, bacteria and endotoxins as well as the variety of health effects resulting from that exposure have been discussed. The findings indicate that the most frequent symptoms reported by the workers include cough with phlegm, wheezing breath, chest tightness and throat irritation. The most common among the diagnosed diseases are chronic allergic bronchitis, asthma, hypersensitivity pneumonitis and acute respiratory dysfunction indicated by decreased FEV1 values. The main skin diseases include oil acne, bacterial infections, dermatomycosis and allergic reactions. The review made the authors conclude that the problem of occupational exposure to biological agents released with coolants during metalworking has not been well recognized in Poland.

Background: The purpose of the study was to evaluate exposure to bioaerosols among sewer workers., Materials and Methods: The study was carried out in the summertime, based on the standard PN-EN 13098. Air samples were collected on gelatine filters at three stationary sites: inside the sewer, next to the sewer manhole during under pressure cleaning and at effluent discharge point. In collected samples the qualitative and quantitative analysis of bacteria and fungi were performed., Results: Bacteria and fungi concentrations were at low levels. The highest concentration of bacteria (about 5.0 x 10(2) cfu/m3) was found inside the sewer and of fungi (about 1.0 x 10(2) cfu/m3) at effluent discharge point. Among all determined microorganisms Gram-positive bacteria were predominated, especially Staphylococcus lentus. Others bacteria there were also found, like rod-shaped of the genus Bacillus and Enterococcus faecalis. The diversification of Gram-negative bacteria was small. Among fungi there were determined representatives of two genera Aspergillus spp. and Penicillium spp., including species Aspergillus fumigatus., Conclusions: According to the law in force among all determined microorganisms only bacteria Enterococcus faecalis (Enterococcus spp.) and mould Aspergillus fumigatus are classified as harmful biological agents (occupational risk group 2). It is suggested using by employees personal protective equipment, especially for respiratory airways and skin protection and also keeping the rules of individual hygiene.

Objectives: The aim of the study was to assess the microbiological air quality at the selected municipal waste landfills., Materials and Methods: The study was conducted during the summer at two municipal landfills. Air samples were collected on agar plates. The evaluation was based on the concentration levels of airborne bacteria and fungi and the identification of isolated strains., Results: The total number of bacteria and fungi did not exceed the level of 10(3) cfu/m3. The highest concentrations of bacteria in air were observed during unloading, disposing and compacting of municipal wastes (landfill 1 - 6,1 x 10(3) cfu/ml, landfill 2 - 5,4 x 10(2) cfu/m3). The highest concentrations of fungi in air were observed at filled up parts of the landfills (landfill 1 - 4,8 x 10(2) cfu/m3, landfill 2 - 1,2 x 10(3) cfu/m3). The qualitative analysis of the air samples indicated the presence of 21 bacterial and fungi. Among of them bacteria Enterococcus faecalis, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Proteus mirabilis and fungi Aspergillus fumigatus, Candida albicans are classified as harmful biological agents., Conclusions: The total number of bacteria and fungi in air samples collected at the selected municipal waste landfills did not exceed the reference values. The concentration levels of bioaerosols are diversified according to the size of the landfill, the total number of accumulated wastes and the level of area usage. It is suggested using by municipal waste workers personal protective equipment, especially for respiratory airways and skin and also keeping the rules of individual hygiene.

Background: The purpose of the study was to evaluate exposure to biological and chemical agents in a sewage treatment plant., Materials and Methods: Sampling was carried out in the summer and wintertime at the morning workshift. Ninety-nine sewage workers taking part in the study were divided into four occupational subgroups: mechanical treatment, biological treatment, sewage sludge treatment, and operation control workers. Exposure to: H2S, SO2, Pb, Cd, Cr3+, Cr6+, endotoxins, (1 --> 3)-beta-D glucans, and microorganisms was evaluated with special identification of Gram-negative rods., Results: The concentrations of dust containing heavy metals and concentrations of gases from all stations did not exceed MAC values. Concentrations of endotoxins ranged from 0.08 to 223 ng/m3, and glucans from 0.00 to 163 ng/m3. The highest concentrations were found among sewage sludge treatment workers, in the summertime (geometric mean value = 37 ng/m3). In the winter, concentrations were almost ten times lower. Over sixty percent of all results exceeded the proposed reference value for airborne endotoxins (10 ng/m3). Concentrations of airborne bacteria in the sewage plant were at low level (10(2)( cfu/m3), except the sludge lagoon and sludge concentration building, where the results exceeded the proposed reference value for mesophilic bacteria (10(5) cfu/m3) "Environmental" bacteria (Pseudomonas, Burkholderia, Shewanella) predominated in the samples. There were also found enterobacteria genus (Enterococcus, family Enterobacteriaceae)--good indicators of hygienic cleanliness of the air., Conclusions: The study proved that the exposure varied and depended on the stage of sewage treatment. The sewage sludge treatment process was characterized by the highest emission of bioaerosols. All microorganisms found in the sewage plant belong to the second occupational risk group, under the ordinance of the Ministry of Health.

A questionnaire study was performed in 99 workers at a large sewage treatment plant to investigate self-reported health complaints from workplace exposure to bioaerosols. The study population was divided into subgroups according to different work stations: mechanical treatment (MT), biological treatment (BT), sewage sludge treatment (SST) and operation control (OC). The questionnaire included personal data, workpost and job characteristics, exposure to chemicals, history of employment and exposure, workplace hygiene and protective measures, smoking and drinking habits. There was also a series of 25 questions on subjective health complaints grouped into the following clusters: 'flu-like symptoms', 'respiratory symptoms', 'nose, eye, throat and skin irritation', 'neurological symptoms' and 'gastrointestinal symptoms'. Each subject was asked whether the complaints had occurred 'frequently', 'rarely', or 'never' within the previous 12 months. Air concentrations of endotoxins and (1 --> 3)- beta-D-glucans in the worker's breathing zone were also determined. The measurements of concentrations were made in the summertime during a morning shift. To determine endotoxins concentration, the Chromogenic Limulus Amebocyte Lysate (LAL) Test was applied. The questionnaire data and determination results were subject to a statistical analysis. No statistically significant relationship was found between the reported health complaints and such variables as job title, exposure to endotoxins and glucans, tobacco smoking, age and period of employment as sewage worker. The findings revealed that among the complaints, muscle and joint ache was reported most frequently, while among the symptom clusters, the flu-like symptoms prevailed. These symptom clusters occurred most frequently in OC workers, and were least often found in SST workers. In the worker's breathing zone, the geometric mean concentration of endotoxins amounted to 20.3 ng/m3 and of glucans to 7.76 ng/m3, and was not related to job title or job characteristics. A high correlation was found between endotoxins and (1 --> 3)- beta -D-glucans concentrations (Pearson correlation coefficient 0.86, p < 0.0005).

Chemical and biological hazards and health effects of exposure to some selected agents on the workers of municipal wastewater treatment plants are reported. This issue has not as yet been thoroughly analyzed in Poland. The workers of wastewater treatment plants are exposed to: heavy metals (Pb, Cu, Zn, Cd, Cr, Ni), polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), volatile organic matter, hydrogen sulfide, organic agents, including bacteria, viruses and fungi, organic-produced endotoxins and glucans. The most frequent disorders reported by the wastewater--treatment workers comprise respiratory and gastrointestinal infections, ocular and dermal irritations, headache and discomfort. The assessment of hygienic conditions at individual workplaces is difficult because of lack of hygiene standards for airborne microorganisms and endotoxins. Up to now, the exposure of workers employed in municipal wastewater treatment plants has not been assessed in Poland. The number of the affected workers is estimated at 11,000-19,000 people.

The aim of the study was to assess the occupational exposure of workers employed in the municipal waste collection and management industry. Air samples were collected in the workers' breathing zone; two samples were collected parallely. The assessment concerned exposure to organic dust, endotoxins, bacteria and fungi. The questionnaire data showed that workers found themselves in good or very good health. They also regarded noise, dustiness, odor, physical effort and changeable atmospheric conditions as the most strenuous factors. The highest dust concentrations were observed on the sites of waste collection (mean, 7.7 mg/m3) and composting (mean, 4.6 mg/m3). Samples collected on the composting site contained the largest amount of endotoxins (mean concentration, 76 ng/m3). This was followed by sorting facility (61 ng/m3) and waste collection area (36 ng/n3). Gram-negative rods (primarily intestinal) were found in all samples collected at workposts, which justified the adoption of the air concentrations of endotoxins as a criterion for assessing their hygienic conditions. Taking MAC for total suspended dust (4.0 mg/m3) and the concentration of 10 ng/m3 for endotoxin as the criteria for the exposure evaluation, it must be considered that waste collectors and composting site workers are working in poor hygienic conditions. Workers employed at the most hazardous workposts did not use personal protective equipment (glasses, antirespirators), thus infringing a fundamental condition for limiting health hazards (Directive 2000/54/EC).