Aerosol Measurement Principles Techniques And Applications

Review of bioaerosols in indoor environment with special reference to sampling, analysis and control mechanisms

Bioaerosols such as bacterial and fungal cells and their spores are - along with non-biological particles - part of indoor airborne particulate matter and have been related since a long time to health issues of human beings as well as flora, and fauna. To identify the different risks and to establish exposure thresholds, microbiology of air samples from a series of indoor environments must be characterized, i.e. the different microorganisms (bacteria and fungi) must be identified and quantified. This review discusses the techniques of air sampling and sample analysis. In addition, a literature study has been performed regarding the levels of these microorganisms in various indoor occupational (e.g., schools, offices, hospitals, museums) and dwelling environments. These results will provide a significant scientific basis for indoor air quality control and help in elaborating risk prevention programs for workers and dwellers. This review shall contribute to the knowledge of identification and quantification of airborne microbial constituents in various indoor environments. Combining the indoor microbial load data with data from studies focusing on health effects caused by inhalation of specific airborne microorganisms will allow the evaluation of various risks to which inhabitants are exposed.

Bioaerosols in Indoor Environment - A Review with Special Reference to Residential and Occupational Locations

This review discusses the role of fungi and fungal products in indoor environments, especially as agents of human exposure. Fungi are present everywhere, and knowledge for indoor environments is extensive on their occurrence and ecology, concentrations, and determinants. Problems of dampness and mold have dominated the discussion on indoor fungi. However, the role of fungi in human health is still not well understood. In this review, we take a look back to integrate what cultivation-based research has taught us alongside more recent work with cultivation-independent techniques. We attempt to summarize what is known today and to point out where more data is needed for risk assessment associated with indoor fungal exposures. New data have demonstrated qualitative and quantitative richness of fungal material inside and outside buildings. Research on mycotoxins shows that just as microbes are everywhere in our indoor environments, so too are their metabolic products. Assessment of fungal exposures is notoriously challenging due to the numerous factors that contribute to the variation of fungal concentrations in indoor environments. We also may have to acknowledge and incorporate into our understanding the complexity of interactions between multiple biological agents in assessing their effects on human health and well-being.

Indoor fungi: companions and contaminants

Airborne and dust borne microorganisms in selected Polish libraries and archives

The microbial quality of the working environment was assessed in winter in air-conditioned office buildings in Warsaw. The average indoor concentrations of bacterial and fungal aerosols were low (<10 3 cfu·m –3 ), below Polish proposals for threshold limit values in public service buildings. Even during cold months, if the air-conditioning system works properly, people remain the main source of bacterial aerosol in offices, whereas infiltration of outdoor air remains a major mechanism responsible for their fungal contamination. An analysis of the bioaerosol size distribution showed that microbial propagules that reach both the upper and lower respiratory tract may evoke numerous adverse health effects from irritation and asthmatic reactions to allergic inflammation. A comparative analysis of viable and total airborne microbial counts showed that viable micro-organisms accounted for up to 0.3% of the total number of microbial propagules. Hence, a comprehensive hygienic assessment of office workplaces should include an efficient control of both these elements. indoor air quality office buildings bacterial and fungal aerosols size distribution

Bacterial and fungal aerosols in air-conditioned office buildings in Warsaw, Poland--the winter season.

The aim of the presented study was to assess the exposure of poultry workers to airborne microorganisms, endotoxins and β-glucans during different stages of the chicken production cycle in 3 commercially-operated poultry houses Personal and stationary sampling was carried out to assess exposure to both viable and total microbial aerosols The stationary measurements of PM10 were performed to establish the level of endotoxins and β-glucans The concentrations of bacterial and fungal aerosols ranged from 25×10(2) CFU/m(3)-29×10(6) CFU/m(3), and from 18×10(2) CFU/m(3)-18×10(5) CFU/m(3), respectively The number of culturable microorganisms was significantly lower than their total counts, constituting from 00004%-64% of the total microbial flora The level of PM10 in poultry facilities did not exceed 45 mg/m(3) After the flock entered the clean house, the level of endotoxins and β-glucans increased from below detection limit to 8,364 ng/m(3) and from 08 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

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

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). 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. 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. 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.

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Anaerobic bacteria in wastewater treatment plant

Biodeterioration of heritage collections caused by microorganisms is a worldwide problem. To avoid degradation caused by biological contaminants transported into the indoor environment by air, proper bioaerosol protection is required. The aim of this study was to assess the level of microbial contamination of the Auschwitz-Birkenau Museum collection based on qualitative and quantitative analyses of bacteria and fungi isolated from the atmosphere and settled dust of museum storerooms. The obtained results demonstrated that a correctly operated air-conditioning system and limiting the number of visitors in the studied storerooms can significantly inhibit microbial contamination of the air and decrease deposition of bacterial and fungal particulates on exhibit surfaces. The performed analyses confirm that an aerobiological assessment of museum premises is a useful tool in their hygienic evaluation and, if necessary, in decision-making regarding interventions to minimize biological decay of collections.

Microbial contamination of storerooms at the Auschwitz-Birkenau Museum

Proper hygienic conditions in office buildings are of a high importance for both health and well-being of the employees. The aim of this study was the direct comparison of different ventilation systems on microbiological environments in 15 office buildings. The results showed that both bacterial and fungal concentrations in the naturally ventilated office buildings were between 70 and 1600 cfu/m3 , while in the offices equipped with air-conditioning and mechanical ventilation systems, concentrations were lower, that is, between 10 and 530 cfu/m3 and 20 and 410 cfu/m3 , respectively. The size distribution analysis revealed that microorganisms were present in the air mainly as single cells (1.1-3.3 μm) and large aggregates (4.7->7 μm). If deposited in the human respiratory tract, they may be responsible for nose and eyes irritations, asthmatic reactions, and allergic inflammations. The most prevalent bacterial species indoors were Gram-positive cocci (mainly from Staphylococcus and Micrococcus/Kocuria genera) and endospore-forming Gram-positive rods (from Bacillus genus). Among the most common fungal species were those from genera Penicillium, Aspergillus, and Cladosporium. Effectively working and regularly maintained mechanical ventilation or air-conditioning systems ensure a better hygienic quality in the office buildings than natural/gravitational ventilation.

Małgorzata Gołofit-Szymczak

Papers

Bacterial and fungal aerosols in air-conditioned office buildings in Warsaw, Poland--the winter season.

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

Anaerobic bacteria in wastewater treatment plant

Microbial contamination of storerooms at the Auschwitz-Birkenau Museum

Microbiological air quality in office buildings equipped with dventilation systems