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Showing papers on "Bioaerosol published in 2009"


Journal ArticleDOI
TL;DR: In this paper, different types of indoor environments (primary school, kindergarten, cafeteria, restaurant, dormitory, dwelling, office, sport salon, library, classroom, and laboratory) and their outdoor environments were investigated in terms of bioaerosol contamination.
Abstract: In this study, different types of indoor environments (primary school, kindergarten, cafeteria, restaurant, dormitory, dwelling, office, sport salon, library, classroom, and laboratory) and their outdoor environments were investigated in terms of bioaerosol contamination. A total of 120 environments were investigated in Ankara, Turkey. The single-stage Andersen sampler was used for viable bioaerosol sampling. During the sampling, indoor and outdoor temperature, relative humidity, and CO 2 concentration were measured. Total bacteria counts (TBC) and fungi concentrations varied on a large scale within and between the sampling site groups (10―10 3 CFU/m 3 ). The highest TBC levels were measured in kindergartens, primary schools, restaurants, high schools, and homes, while the highest mold levels were measured in kitchens, bathrooms, and offices. Micrococcus spp., Staphylococcus auricularis, and Bacillus spp. were predominant bacteria species and Penicillium spp., Aspergillus spp., and Gladosporium spp. were the most observed mold genera detected in the samples. Indoor-to-outdoor (I/O) ratios of the observed fungi counts were calculated as approximately around 1, and for bacteria counts these ratios were higher than 1. There was no statistical difference between indoor and outdoor mold levels, while a significant difference was found between indoor and outdoor bacteria levels (p < 0.001). A significant correlation between indoor CO 2 and bioaerosols indicates insufficient ventilation.

108 citations


Journal ArticleDOI
TL;DR: Activity strength was the most statistically robust measure for relating human activities to indoor bioaerosol levels, and the number of occupants appears to be a weaker indicator for homes.
Abstract: Indoor and outdoor airborne particle mass, protein, endotoxin and (1→3)-β-d-glucan in three size fractions (PM2.5, PM10, and TSP) were measured in ten single-family homes, along with quantifying household activities in the sampling room. Correlations between human activity levels and elevations in the indoor concentrations of particles and biomarkers were evaluated using four approaches for distinguishing activity levels: diurnal differences, the number of occupants, self-estimated occupancy, and activity strength. The concentrations of particles, protein, endotoxin and (1→3)-β-d-glucan in all three size fractions (PM 10 μm) were found, in most cases, to be significantly elevated during the day, and with higher activity levels in the room. The coarser fractions of particle mass and bioaerosols were more strongly correlated with human activity levels. Activity strength was the most statistically robust measure for relating human activities to indoor bioaerosol levels. While self-...

105 citations


Journal ArticleDOI
TL;DR: In conclusion, even if these plants do not represent a potential risk for nearby populations, they may pose a potential health risk for workers.

94 citations


Journal ArticleDOI
TL;DR: Geographical location, human activity, growth cycle of organisms and meteorological factors were the main criteria controlling the temporal variations of the air microorganisms in the Wadi Hof area.

88 citations


Journal ArticleDOI
TL;DR: The BioSampler recovered higher numbers of airborne coliphage viruses than has been measured with other liquid samplers in previous studies, suggesting that this sampler has improved efficiency for sampling airbornecoliphages.

87 citations


Journal ArticleDOI
TL;DR: Higher species diversity of the family Enterobacteriaceae in the air sampled inside or near the bioreactor may imply a health risk for staff exposed for longer periods of time, although no increased emission of the analysed groups of microorganisms were found outside the WWTP.

83 citations


Journal ArticleDOI
TL;DR: There would be an association between relative humidity among environmental factors and airborne microorganism's bioactivity in Korea based on the result of the study.

68 citations


Journal ArticleDOI
TL;DR: The results show that thermal heating in a continuous air flow can be used with short exposure time to control bacterial bioaerosols by rendering the bacteria and endotoxins to a large extent inactive, and could be useful for developing more effective thermal treatment strategies for use in air purification or sterilization systems to control bioaerOSols.

65 citations


Journal ArticleDOI
TL;DR: The number of cultivable fungi and β-glucan in the total dust correlated significantly with the number of DNA/RNA-containing particles with lengths of between 1.0 and 1.5 μm, which indicates that fungal particles smaller than fungal spore size are present in the air at the plants.
Abstract: Fungi grown in pure cultures produce DNA- or RNA-containing particles smaller than spore size ( 1.5 μm. The number of cultivable fungi and β-glucan in the total dust correlated significantly with the number of DNA/RNA-containing particles with lengths of between 1.0 and 1.5 μm, with DNA/RNA-containing particles >1.5 μm, and with other fungal components in PM1 dust. Airborne β-glucan and NAGase were found in PM1 samples where no cultivable fungi were present, and β-glucan and NAGase were found in higher concentrations per fungal spore in PM1 dust than in total dust. This indicates that fungal particles smaller than fungal spore size are present in the air at the plants. Furthermore, many bacteria, including actinomycetes, were present in PM1 dust. Only 0.2% of the bacteria in PM1 dust were cultivable.

61 citations


Journal ArticleDOI
TL;DR: The thermal heating effects on fungal bioaerosols in a continuous-flow environment and the effect of a continuous high-temperature, short-time (HTST) process on airborne microorganisms has not been quantitatively investigated in terms of various aerosol properties.
Abstract: Fungi are omnipresent in indoor and outdoor environments (2, 28, 39). Most fungi are dispersed through the release of spores into the air, a phenomenon known to be driven by two kinds of energy (17): the energy provided by the fungus itself and the energy provided by external sources, such as air currents, rain, gravity, or changes in temperature and nutritional sources. Of these various mechanisms of fungal particle release, dispersal by air currents is the most prevalent mechanism for indoor fungal particles (19, 31). These airborne fungal spores, termed fungal bioaerosols, are resistant to environmental stresses and are adapted to airborne transport. Fungal bioaerosols constitute the major component of ambient airborne microorganisms (23, 50, 51). Several studies have reported that the concentration of fungal bioaerosols is relevant to the occurrence of human diseases and public health problems associated with acute toxic effects, allergies (3, 18), and asthma (4, 5, 13, 48). Fungal bioaerosols are of particular concern in healthcare facilities, where they can cause major infectious complications as opportunistic pathogens in patients with an immunodeficiency (9). For instance, invasive mycoses can affect patients undergoing high-dose chemotherapy for hematological malignancies associated with a prolonged period of neutropenia; they can also affect solid-organ transplant recipients. Despite all diagnostic and therapeutic efforts, the outcome of an invasive fungal infection is often fatal (with a mortality rate of around 50% for aspergillosis) (37). The main fungal genera responsible for these infections are as follows: Aspergillus spp., Fusarium spp., Scedosporium spp., and Mucorales spp. (10, 12, 20). However, virtually any filamentous fungus can be a pathogen (22, 41). In the hospital environment, possible sources of airborne nosocomial infection include ventilation or air-conditioning systems, decaying organic material, dust, water, food, ornamental plants, and building materials in and around hospitals (1). One of the major bioaerosols of concern is (1→3)-β-d-glucans, which comprises up to 60% of the cell wall of most fungal organisms. The (1→3)-β-d-glucans are glucose polymers with a variable molecular weight and a degree of branching (49). The results of several studies about the exposure of subjects to airborne (1→3)-β-d-glucans suggest that these agents play a role in bioaerosol-induced inflammatory responses and resulting respiratory symptoms, such as a dry cough, phlegmy cough, hoarseness, and atopy (11, 44). In addition, given that many epidemiological studies have reported that (1→3)-β-d-glucan has strong immuno-modulating effects (42, 47), (1→3)-β-d-glucan is an important parameter for exposure assessment by itself and as a surrogate component for fungi (16). To prevent the adverse health effects of fungal bioaerosols, we must ensure that control methods for airborne fungal spores are studied and developed. However, despite the necessity of controlling fungal bioaerosols, few studies have focused on such control mechanisms. The most common control methods are UV irradiation and electric ion emission. Given that UV irradiation is known to have a germicidal effect, several studies have examined how UV irradiation affects the viability of bioaerosols (35, 42). However, although UV irradiation can be easily applied by simply installing and turning on a UV lamp, the 254-nm-wavelength UV light produces ozone and radicals, which cause harmful effects to surrounding humans. Electric ion emission has also been studied as a means of controlling bioaerosols (21, 27). When the efficiency of the filter is increased, the efficacy of respiratory protection devices against bioaerosols can be enhanced. Although electric ions decrease the viability of airborne bacteria (25), the generation of the ions produces ozone, a pollutant, and also causes electric charges to accumulate on surrounding surfaces. Recently, heat treatment of indoor air using thermal processes has been considered a safe, effective, and environment-friendly method; it does not produce ozone or use ion or filter media. A thermal heating process has long been considered a suitable and reliable method for controlling microorganisms. Two types of heat are generally used, moist heat and dry heat. Moist heat utilizes steam under pressure, whereas dry heat involves high-temperature exposure without additional moisture. Several types of heat treatment are currently used for killing microorganisms. The treatments include incineration, Tyndallization, pasteurization, and autoclaving (32). However, most of these technologies were originally limited to controlling microorganisms in liquid or on material surfaces. In addition, they may not be adequate for controlling bioaerosols because the continuous surrounding environment of bioaerosols is significantly different from the conditions in liquid and on solid surfaces. Therefore, it is necessary to find adequate and practical conditions for controlling bioaerosols. Thus far, several investigations regarding the use of thermal processes against bioaerosols have been reported. Some of these studies have targeted airborne bacteria spores widely used as surrogates for biological warfare agents (8, 34), while others have focused on environmental parameters for the culture and survival of various vegetative cells (14, 29, 46). However, in these studies novel techniques for aerosols, such as measuring and analyzing aerosol particle size, distributions, and concentrations, were not utilized. In addition, to the best of our knowledge, there has been no study on the use of a thermal process for controlling fungal bioaerosols in continuous airflow. Fungal bioaerosols were found to be very resistant to a thermal environment in previous studies. In this study, we investigated the thermal heating effects on the physical, chemical, and biological properties of fungal bioaerosols using a high-temperature, short-time (HTST) sterilization process. The HTST process, a type of thermal heating process, is based on high-temperature stresses for very short periods. Although this thermal process has been used for the microbial decontamination of seeds and dried, powdered products, such as pharmaceuticals and heat-sensitive drink and food, it can be also applied to the control of an airborne microorganism in a continuous-flow system, such as a heating, ventilation, and air-conditioning system (15, 33, 38). When the fungal bioaerosol was passed through a thermal electric heating system, the fungal spores were exposed to various temperatures for short periods. Then, we examined the bioaerosol and aerosol characteristics, including aerosol size distribution, culturability, (1→3)-β-d-glucan production, and surface morphology, using a novel technique for sampling and measuring aerosols.

61 citations


Journal ArticleDOI
TL;DR: This work successfully isolated 90% of the airborne bacterium Micrococcus luteus from a mixture of bacteria and dust using a microfluidic device, consisting of novel curved electrodes that attract bacteria and repel or leave dust particles.
Abstract: Airborne microbes such as fungi, bacteria, and viruses are a threat to public health. Robust and real-time detection systems are necessary to prevent and control such dangerous biological particles in public places and dwellings. For direct and real-time detection of airborne microbes, samples must be collected and typically resuspended in liquid prior to detection; however, environmental particles such as dust are also trapped in such samples. Therefore, the isolation of target bacteria or a selective collection of microbes from unwanted nonbiological particles prior to detection is of great importance. Dielectrophoresis (DEP), the translational motion of charge neutral matter in nonuniform electric fields, is an emerging technique that can rapidly separate biological particles in microfluidics because low voltages produce significant and contactless forces on particles without any modification or labeling. In this paper, we propose a new method for the separation of airborne microbes using DEP with a simple and novel curved electrode design for separating bacteria in a solution containing beads or dust that are taken from an airborne environmental sample. Using this method, we successfully isolated 90% of the airborne bacterium Micrococcus luteus from a mixture of bacteria and dust using a microfluidic device, consisting of novel curved electrodes that attract bacteria and repel or leave dust particles. As there has been little research on analyzing environmental samples using microfluidics and DEP, this work describes a novel strategy for a rapid and direct bioaerosol monitoring system.

Journal Article
TL;DR: A highly significant correlation was found between the individual components of bioaerosol determined in this study and that of Gram-positive bacteria, Gram-negative bacteria, total microorganisms, and peptidoglycan.
Abstract: The objective of present work was to determine and compare the components of bioaerosol in several sectors of plant processing industries. The study was conducted in 10 facilities engaged in herb and grain processing, flax threshing, grain storing, baking, and cereals production. The air samples were taken on glass fibre filters with an AS-50 sampler. We determined the concentrations of airborne microorganisms, dust, endotoxin and peptidoglycan. Total concentrations of viable airborne microorganisms ranged from 0.18-861.4 x 10(3) cfu/m(3). The highest levels of microbial contamination of the air were observed at flax farms, in grain elevators and in a herb processing plant. Gram-positive bacteria and fungi were detected at all sampling sites and their median concentrations were respectively 18.1 x 10(3) cfu/m(3) and 0.66 x 10(3) cfu/m(3). The concentration of Gram-negative bacteria ranged from 0.0-168.0 x 10(3) cfu/m(3). The concentration of thermophilic actinomycetes ranged from 0.0-1.45 x 10(3) cfu/m(3). Qualitatively, Gram-positive bacteria constituted 23-93% of the total microbial count. The most common species were: Staphylococcus spp., Curtobacterium pusillum, Rhodococcus fascians, Aureobacterium testaceum, Sanguibacter keddieii, Microbacterium spp., and Bacillus spp. Gram-negative bacteria formed 0-48% of the total count. The species Pantoea agglomerans dominated in all examined air samples. Fungi constituted 2.5-76.9% of the total microbial count. Among them, Penicillium spp., Mucor spp., Alternaria spp., Aspergillus niger, and Aspergillus spp. were found. The dust concentration ranged from 0.18-86.9 mg/m(3). The concentration of endotoxin was large and ranged from 0.0041-1562.6 microg/m(3). Muramic acid, the chemical marker of peptidoglycan, was detected in 9 out of 13 (69.2%) collected samples. The concentration of peptidoglycan ranged from 1.93-416 ng/m(3). A highly significant correlation was found between the individual components of bioaerosol determined in this study. The concentration of endotoxin was correlated with the concentration of Gram-negative bacteria, total microorganisms, and peptidoglycan (R>0.9, p 0.9, p<0.001).

Journal ArticleDOI
TL;DR: An adenosine triphosphate (ATP) bioluminescence-based protocol for rapid characterization of bioaerosol sampling devices when collecting bacterial aerosols and it was determined that a majority of losses occur in sampler's inlet.

Journal ArticleDOI
TL;DR: It is recommended that flour workers at the crushing site wear breathing protection and improve the local ventilation systems to minimize the biological hazards and to investigate the effects of environmental factors on concentrations of bioaerosols.

Journal ArticleDOI
TL;DR: The results suggest that biological particles could account for an average of 40% of the organic carbon mass in particles with aerodynamic diameters less than 10μm as mentioned in this paper, and further observations are needed to better constrain these estimates.

Journal ArticleDOI
TL;DR: In terms of workers' respiratory health, barns equipped with a solid/liquid separation system may offer better air quality than conventional buildings or barns with sawdust beds, while real-time PCR revealed nonstatistically different concentrations of total bacteria in all the studied swine confinement buildings.
Abstract: Hog production has been substantially intensified in Eastern Canada. Hogs are now fattened in swine confinement buildings with controlled ventilation systems and high animal densities. Newly designed buildings are equipped with conventional manure handling and management systems, shallow or deep litter systems, or source separation systems to manage the large volumes of waste. However, the impacts of those alternative production systems on bioaerosol concentrations within the barns have never been evaluated. Bioaerosols were characterized in 18 modern swine confinement buildings, and the differences in bioaerosol composition in the three different production systems were evaluated. Total dust, endotoxins, culturable actinomycetes, fungi, and bacteria were collected with various apparatuses. The total DNA of the air samples was extracted, and quantitative polymerase chain reaction (PCR) was used to assess the total number of bacterial genomes, as a total (culturable and nonculturable) bacterial assessment....

Journal ArticleDOI
TL;DR: The results clearly show the specificity and practicability of the established qPCR assay for analysis and quantification of salmonellae in bioaerosols and the survival rate of Salmonella cells was measured on filter surfaces during filtration samplings.
Abstract: A SYBR ® Green real-time quantitative polymerase chain reaction (qPCR) assay for specific detection and quantification of airborne Salmonella cells in livestock housings is presented. A set of specific primers was tested and validated for specific detection and quantification of Salmonella-specific invA genes of DNA extracted from bioaerosol samples. Application of the method to poultry house bioaerosol samples showed concentrations ranging from 2.2 × 10 1 to 3 × 10 6 Salmonella targets m -3 of air. Salmonella were also detected by a cultivation-based approach in some samples, but concentrations were two to three magnitudes lower than the concentrations detected by molecular biological results. Specificity of results was demonstrated by cloning analyses of PCR products, which were exclusively assigned to the genus Salmonella. However, by molecular methods, microorganisms are detected independently of their viability status, leading to an overestimation of concentration. Hence, the survival rate of Salmonella cells was measured on filter surfaces during filtration samplings where 82% of the cells died within 20 min of filtration. The results clearly show the specificity and practicability of the established qPCR assay for analysis and quantification of salmonellae in bioaerosols. The results demonstrate airborne Salmonella workplace concentrations in poultry production of up to 3.3% of 4',6-Diamidino-2-phenylindole-counted total cell numbers.

Journal ArticleDOI
TL;DR: The granulocyte assay reacts to multiple contaminants in the environmental samples and can be used to obtain a measurement of TIP, and potential occupational health effects related to inflammation of the airways in a working environment can be estimated using this assay.
Abstract: Occupational health symptoms related to bioaerosol exposure have been observed in a variety of working environments. Bioaerosols contain microorganisms and microbial components. The aim of this study was to estimate the total inflammatory potential (TIP) of bioaerosols using an in vitro assay based on granulocyte-like cells. A total of 129 bioaerosol samples were collected in the breathing zone of workers during their daily working routine at 22 biofuel plants. The samples were analyzed by traditional assays for dust, endotoxin, fungal spores, (1-->3)-beta-d-glucan, total number of bacteria, the enzyme N-acetyl-beta-d-glucosaminidase (NAGase; primarily originating from fungi), Aspergillus fumigatus, and mesophilic and thermophilic actinomycetes; the samples were also assayed for TIP. In a multilinear regression four factors were significant for the TIP values obtained: endotoxin (P 3)-beta-d-glucan (P = 0.0005), and mesophilic actinomycetes (P = 0.0063). Using this model to estimate TIP values on the basis of microbial composition, the correlation to the measured values was r = 0.91. When TIP values obtained in the granulocyte assay were related to the primary working area, we found that bioaerosol samples from personnel working in straw storage facilities showed high TIP values ( approximately 50 times the TIP of unstimulated controls). In contrast, bioaerosol samples from personnel with work functions in offices or laboratories showed low TIP values ( approximately 5 times the TIP of the unstimulated control). This indicates, as expected, that these areas were less contaminated. In conclusion, the granulocyte assay reacts to multiple contaminants in the environmental samples and can be used to obtain a measurement of TIP. Therefore, potential occupational health effects related to inflammation of the airways in a working environment can be estimated using this assay.

Journal ArticleDOI
TL;DR: In this article, a 24-hour air sampling was performed on five consecutive days in four Cincinnati area homes and the results indicated that if long-term sampling methods are employed to characterize the bioaerosol exposure for a population, the sampling should be repeated in a larger number of homes as an alternative to replicate sampling in a fewer number of households.
Abstract: Characterizing the variation in bioaerosol concentrations is important for the estimation of health effects associated with bioaerosols and planning exposure assessment strategies. This investigation was conducted in order to develop a better understanding of exposure to fungal spores, pollen, and (1→3)-β-d-glucan, by determining the variations of their concentrations between and within homes. In the study, 24-h air sampling was performed on five consecutive days in four Cincinnati area homes. The samples (a total of 160) were taken simultaneously in four different rooms inside each home and at four different outside locations near the home using Button Personal Inhalable Aerosol Samplers. The relative sizes of the between- and within-home variability to the total variability were calculated for each outcome. The relative sizes of the between- and within-home variability in indoor air ranged from 0.10 to 0.52 and 0.09 to 0.10, respectively. For outdoor air, the between- and within-home variability ranged from 0.27 to 0.50 and 0.09 to 0.10, respectively. Thus, the ranges of within-home variability, both indoors and outdoors, were much less than the variability between different homes. The results suggest that, if long-term sampling methods are employed to characterize the bioaerosol exposure for a population, the sampling should be repeated in a larger number of homes as an alternative to replicate sampling in a fewer number of homes. When characterizing exposure within one home, the sampling should be repeated in different rooms, rather than repeating it on different days.

Journal ArticleDOI
TL;DR: The membrane filter method was used to study the particle size distribution of Aspergillus fumigatus spores in air 50 m downwind of a green waste compost screening operation at a commercial facility and results were significantly correlated indicating that the two methods are directly comparable across all particles sizes for As pergillus spores.

Journal ArticleDOI
Dongho Park1, Yong Ho Kim1, Chul Park1, Jungho Hwang1, Yong-Jun Kim1 
TL;DR: Haglund et al. as mentioned in this paper designed and evaluated a single stage virtual impactor, which was fabricated by micro-electro-mechanical systems (MEMS) process.

Journal ArticleDOI
TL;DR: In this article, the installation of a carbon fiber ionizer in front of a fibrous medium filter to enhance the removal of submicron aerosol particles and bio-aerosols was reported.
Abstract: This paper reports the installation of a carbon fiber ionizer in front of a fibrous medium filter to enhance the removal of submicron aerosol particles and bioaerosols. Test particles (KCl) were classified with a size range of 50–600 nm using a differential mobility analyzer (DMA). The number concentration of the test particles was measured using a condensation particle counter (CPC). The average charge per particle was estimated by current measurements using an aerosol electrometer. At the face velocity of 0.5 m/s, the particle removal efficiency was 31.4% (for dp=100 nm) when the ionizers were not operating but increased to 35.7% and 46.9% at 1.6×1011ions/s and 6.4×1012ions/s with the ionizers, respectively. For the antibacterial tests, the test bioaerosols (E. coli) were aerosolized using a nebulizer and were deposited on the filter media for 5 minutes. After the deposited bioaerosols were exposed to unipolar air ions, they were incubated for 12 hours. The survival efficiency of E. coli was measured using a colony counting method. The survival fractions of E. coli exposed to positive air ions for 1, 5 and 10 minutes were 61.7%, 45.4% and 25.2%, respectively.

Journal ArticleDOI
TL;DR: For stationary bioaerosol monitoring, sampling 1000L of air in 10min with the MAS-100 impactor and ChlamyTrap 1 impaction medium was most efficient and made it possible to detect 1 and 10 C. psittaci organisms by PCR and culture, respectively.

Journal ArticleDOI
TL;DR: A pre-operational survey was initiated by determining the concentrations of 20 volatile organic compounds and bioaerosols in airborne samples around a municipal solid waste incinerator (MSWI) in Tarragona, Spain, to evaluate its potential impact and to differentiate the impacts of MSWI from those of the MBT when the latter is operative.

Journal ArticleDOI
TL;DR: In this paper, the effect of aerosol generation, relative humidity, and sampling method on the culturability of the bacteria Pantoea agglomerans (P. herbicola) was evaluated.
Abstract: This study was conducted to evaluate the effect of aerosol generation, relative humidity, and method of sampling on the culturability of the vegetative bacteria Pantoea agglomerans (P. agglomerans) formerly known as Erwinia herbicola. This research has relevance both for the use of this organism as a biowarfare simulant and for bioaerosol exposure assessment and public health. The culturability of P. agglomerans was tested using a test chamber against two generating systems (Collison and Bubble nebulizers), two sampling systems (the all-glass impinger (AGI-30), and the BioSampler), three collection media (water, TSB, and PBS) and across a range of humidities. Results indicated that the Bubble nebulizer was 15% more efficient in generating viable P. agglomerans counts (p ≤ 0.05). No difference was observed in overall efficiency between sampling methods (p > 0.05). However, as a collection media, PBS was observed to yield higher (p ≤ 0.01) viable counts compared to sterile deionized water. Relative humidity...

Journal ArticleDOI
TL;DR: In this article, the associations of residential characteristics and occupant behavior with indoor airborne levels were investigated, and the relation between these chemical biomarkers and the more traditional culturing approaches was studied.
Abstract: Size-resolved airborne particulate matter samples (PM 2.5 , PM 10 , and TSP) collected inside ten northern California homes over four days and one night (9–12 h/sample, spanning a 3.5 week period) were analyzed for protein, endotoxin, and (1 → 3)-β-D-glucan concentrations. Some simultaneous size-resolved outdoor samples were also collected. The associations of residential characteristics and occupant behavior with the indoor airborne levels were investigated. In addition, the relation between these chemical biomarkers and the more traditional culturing approaches was studied. Most of the indoor mass concentration of airborne particles and protein was in the fine fraction (PM 2.5 ), while the mass of airborne endotoxin and (1 → 3)-β-D-glucan was mainly in the coarser fractions (PM 10–2.5 and PM TSP–10 ). No strong correlations were seen between short-term (3–6 min) culturable bacteria and fungi counts and the corresponding longer-term (9–12 h) biomarker levels. Daytime indoor levels of the biomarkers tende...

Journal ArticleDOI
TL;DR: The results demonstrate that the fungal bioaerosol generator can produce mono-dispersed fungalBioaerosols under various experimental conditions and that it is possible to control the rates of production of fungal biosols by adjusting the flow rate through thefungal generator and the rotating speed of the substrate.

Journal ArticleDOI
TL;DR: In this paper, the concentration of bioaerosols emitted during application of compost, fungi and bacteria were collected using an Andersen biosampler, and the results indicated that bioaero-sols emissions as a result of applying of compost could increase levels of exposure to bacteria and pose a potential health risk for exposed individuals.
Abstract: Although application of composted municipal waste has its benefits, there are also concerns about a range of adverse effects. Bioaerosol emissions are one cause of concern because of related health problems. To assess the concentration of bioaerosols emitted during application of compost, fungi and bacteria were collected using an Andersen biosampler. Temperature and relative humidity were also recorded at each location. Total bacterial concentrations averaged 2,887 cfu/m3 for background samples and 6,727 cfu/m3 for compost-application samples, which constitutes a significant difference. The mean concentration of fungi during application of compost was three times greater than the background, but the difference was not significant. Concentrations of total bacteria in compost-application samples decreased significantly with increasing humidity. These results indicated that bioaerosol emissions as a result of application of compost could increase levels of exposure to bacteria and pose a potential health risk for exposed individuals.

Journal ArticleDOI
TL;DR: In this article, the airborne and dust-borne concentrations of endotoxin, (1,3)-β-d-glucan and five house dust allergens were measured in office, home, and outdoor environments both in New Haven, United States and Nanjing, China.
Abstract: In this study, the airborne and dust-borne concentrations of endotoxin, (1,3)-β-d-glucan and five house dust allergens were measured in office, home, and outdoor environments both in New Haven, United States and Nanjing, China. Air samples were collected using a BioSampler at a flow rate of 12.5 l/min for 30 min. Dust samples were simultaneously collected using a surface sampler. Dust samples went through extraction and dilution before analysis, while air samples were analyzed directly. Limulus Amoebocyte Lysate (LAL) Pyrochrome and Glucatell assays were used to quantify endotoxin and (1,3)-β-d-glucan concentration levels, respectively. Enzyme-linked sorbent assay was used to measure the dust mites, cat, dog, and cockroach allergens. The experimental results indicated that endotoxin, (1,3)-β-d-glucan and allergen concentrations vary greatly both with samples and environments. In all tested environments, endotoxin concentration ranged from 0.8 to 83.7 ng/m3 for air, and 7.8 to 14.3 ng/mg for dust. (1,3)-β-d-glucan concentration ranged from 0.1 to 9.8 ng/m3 for air, and 6.6 to 110 ng/mg for dust. Cockroach allergens were detected only in New Haven office and outdoor environments, and other allergens ranged from 0.1 to 90 ng/mg for dust samples, and from 1.5 to 1,282 ng/m3 for air samples. In general, similar profiles of allergens and toxins were observed in New Haven and Nanjing environments. Linear regression analysis showed that there were better endotoxin and (1,3)-β-d-glucan linear correlations (R 2 = 0.78, 0.87, respectively) between the dust and air samples compared to those of the allergens Der f 1 and Der p 1 (R 2 = 0.5, 0.7, respectively). This research contributes to the development of robust biological exposure assessment and the elaboration of airborne and dust-borne bio-mass in the living environments.

Journal ArticleDOI
TL;DR: In this paper, a batch-type wetted wall bio-aerosol sampling cyclone (BWWC) was designed to sample air at 400l/min and concentrate the particles into 12ml of water.
Abstract: The collection efficiency and sample retention of a batch-type wetted wall bioaerosol sampling cyclone (BWWC) were experimentally characterized. The BWWC is designed to sample air at 400 l/min and concentrate the particles into 12 ml of water. Aerosol is transported into a cylindrically-shaped axial flow cyclone through a tangential slot and the particles are impacted on the inner wall, which is wetted by air shear acting on a liquid pool at the base of the cyclone. The retention of collected particles and the aerosol collection efficiency of the BWWC were evaluated with polystyrene latex beads (PSL), sodium fluorescein/oleic acid droplets, and Bacillus atrophaeus (aka BG) spores. The retention of particles was determined by adding hydrosol directly into the device, running the BWWC for a pre-set period of time, and then determining the amount of particulate matter recovered relative to the initial amount. For 1-μm diameter PSL, 90% of the particles were recoverable from the cyclone body immediately after their introduction; however, only 10% were retained in the collection liquid after 8 h of operation. The aerosol sampling efficiency was determined by comparing the amount of particulate matter collected in the liquid with that collected by a reference filter. The collection efficiency was 50–60% for 1- and 3-μm polystyrene (PSL) particles, and 1.5% for 10-μm oleic acid particles. The efficiency for 3-μm oleic acid droplets was 35%. Explanations are provided for the difference between liquid and solid particle behavior, and for the low efficiency for the large liquid particles. The collection efficiency for single spore BG was slightly lower than that for 1-μm PSL.