Showing papers on "Bioaerosol published in 2011"
TL;DR: In this article, the authors quantitatively and qualitatively study culturable fungi and bacteria in the air and settled dust in the storerooms of five Polish libraries and archives as well as to estimate the effect of water intrusion on the microbial air quality indoors.
103 citations
TL;DR: Sandstorms increased the concentrations of both culturable microbes and total microbes in the bioaerosol, and meteorological parameters had different effects on different kinds of microbes.
93 citations
TL;DR: Control methods against bioaerosols are briefly reviewed, and suggestions are offered for future research on airborne biological particles.
Abstract: Air is filled with numerous tiny organisms, with sizes ranging from 50 nm to 10 μm. These organisms are called airborne biological particles or bioaerosols. In the human history of investigating the origin of life and fighting against contagious diseases, the recognition of bioaerosols and the development of control methods against them have played crucial roles. The pandemic outbreak of flu due to the influenza A H1N1 virus in 2009 and the bio-terror incidents in 2001 have alerted us to the importance of bioaerosol research. Here, control methods against bioaerosols are briefly reviewed, and suggestions are offered for future research on airborne biological particles.
78 citations
TL;DR: In this paper, the effect of variations in temperature, relative humidity, occupancy density and location (indoor/outdoor) on the concentrations of viable airborne bacterial and fungal spores at an air-conditioned and a non-airconditioned food stall in Singapore was investigated.
76 citations
TL;DR: There were statistically significant relationships between spore concentration and environmental parameters as well as pollutants, confirmed by the Spearman's correlation rank analysis and high performance of the ANN models obtained.
76 citations
TL;DR: The utility of the NIOSH bioaerosol sampler was further extended by incorporating an enhanced infectivity detection methodology developed in the laboratory, the viral replication assay, which amplified the infectious virus making it more readily detectable.
Abstract: A unique two-stage cyclone bioaerosol sampler has been developed at NIOSH that can separate aerosols into three size fractions. The ability of this sampler to collect infectious airborne viruses from a calm-air chamber loaded with influenza A virus was tested. The sampler's efficiency at collecting aerosolized viral particles from a calm-air chamber is essentially the same as that from the high performance SKC BioSampler that collects un-fractionated particles directly into a liquid media (2.4 × 10(4) total viral particles per liter of sampled air (TVP/L) versus 2.6 × 10(4) TVP/L, respectively, after 15 min) and the efficiency is relatively constant over collection times of 15, 30 and 60 min. Approximately 34% of the aerosolized infectious virus collected after 15 min with the NIOSH bioaerosol sampler remained infectious, and infectious virus was found in all three size fractions. After 60 min of sampling, the infectious virus/liter air found in the NIOSH bioaerosol sampler was 15% of that found in the SKC BioSampler. This preservation of infectivity by the NIOSH bioaerosol sampler was maintained even when the initial infectivity prior to aerosolization was as low as 0.06%. The utility of the NIOSH bioaerosol sampler was further extended by incorporating an enhanced infectivity detection methodology developed in our laboratory, the viral replication assay, which amplified the infectious virus making it more readily detectable.
68 citations
TL;DR: The data suggest that area samples are not representative of personal bacteria exposures, which may be affected by worker movement, bacteria carried on the worker and worker location.
61 citations
TL;DR: The types and concentrations of bacterial and fungal bioaerosols found in five randomly selected primary schools in Malaysia and Terribacillus spp.
Abstract: This study reports the types and concentrations of bacterial and fungal bioaerosols found in five randomly selected primary schools in Malaysia. Normal flora bacteria was the most frequently isolated bacteria including Staphylococcus spp., Pseudomonas spp. and Bacillus spp. Terribacillus spp. found in this study had never been reported before. The most frequently isolated fungal genera were Aspergillus, Penicillium, Fusarium, Rhizopus and Zygomycetes. The average concentration of bacteria in indoor and outdoor air were 1025 ± 612 CFU/m3 and 1473 ± 1261 CFU/m3, respectively, while the average concentration of fungal bioaerosol in indoor and outdoor air were 292 ± 83 CFU/m3 and 401 ± 235 CFU/m3, respectively. The percentages of bacterial and fungal samples that were within the American Conference of Industrial Hygenists (ACGIH) recommended levels were 44% and 33.8%, respectively. The ratio of indoor to outdoor fungi concentration was below 1.0, suggesting minimal indoor generative source for fungal bioaeros...
57 citations
TL;DR: A dataset derived from repeated and replicated field studies over a period of two years at two commercial composting facilities is presented, which characterises patterns in Aspergillus fumigatus, actinomycetes, Gram-negative bacteria and endotoxin emission and downwind concentrations.
50 citations
TL;DR: The collected data indicate that workers employed in Midwest greenhouses may be exposed to elevated levels of inhalable culturable microorganisms, and self-reported respiratory symptoms was generally higher among greenhouse workers compared to controls; however, the differences were not statistically significant, likely due to the relatively low statistical power of the study.
Abstract: Objectives: Greenhouse operations are an important sector of the horticulture industry, also known as the Green Industry. The objectives of this study were (i) to investigate exposure levels to airborne culturable fungi, bacteria (total culturable bacteria and actinomycetes), endotoxin, and (1/3)-b-D-glucan in three Midwest greenhouses during summer and winter using multiple exposure assessment methods; (ii) characterize the load of microorganisms on greenhouse floors and determine potential microbial source strengths of the floors for aerosolizing microbial biocontaminants, and (iii) to estimate the prevalence of rhinitis, wheezing, asthma, and other respiratory symptoms/conditions among greenhouse workers. Methods: Stationary inhalable aerosol samples were collected from each greenhouse using Button Inhalable Aerosol Samplers. Control samples were collected from offices and nearby outdoor locations. A microbial source strength tester was used to examine the aerosolization potential of microbial contaminants from greenhouse floors. Additionally, surface samples were collected by sterile cotton swabs. Temperature, relative humidity, and wind velocity were recorded. Airborne culturable fungi, bacteria, and actinomycetes were analyzed in the extracts from field samples by cultivation in nutrient agar media. Endotoxin and (1/3)-b-D -glucan in the extracts from fi eld samples were analyzed by specific kinetic chromogenic Limulus amebocyte lysate assays. The prevalence of respiratory symptoms among greenhouse workers (n 5 35) and control subjects (office workers; n 5 14) was estimated with a standardized questionnaire. Results and Conclusions: The collected data indicate that workers employed in Midwest greenhouses may be exposed to elevated levels of inhalable culturable microorganisms (fungi and bacteria collectively on the order of 10 2 ‐10 5 CFU m 23 ), endotoxin (10 1 ‐10 3 EU m 23 ), and (1/3)-b-D-glucan (10 1 ‐10 2 ng m 23 ). Seasonal variations were observed for some bioaerosol components. The prevalence of self-reported respiratory symptoms was generally higher among greenhouse workers compared to controls; however, the differences were not statistically significant, likely due to the relatively low statistical power of the study.
50 citations
Journal Article•
TL;DR: An unrestrained infiltration of ambient air through the draughtiness of the building envelope is probably the main process responsible for indoor fungal pollution, whereas bacterial contaminants have their major sources in the indoor environment.
Abstract: The aim of this study was to check the degree and identify the sources of microbial contamination of the Jasna Gora (Bright Hill) monastery library 10 years after disinfection of the incunabula collection. The registered maximum viable indoor microbial concentrations were 1,875 and 7,100 cfu/m³ for stationary and personal measurements, whereas respective total concentrations were 71,000 and 100,000 counts/m3. There was no statistically significant difference between the concentrations of viable microorganisms measured in the stationary using Andersen, GSP, and Button samplers. Moreover, GSP and Button samplers can be interchangeably applied when viable or total microbial levels are stationary or personally measured. The culturable microorganisms constituted 0.5 - 3.9% of the total microflora only. Filamentous fungi were the most prevalent outdoors, whereas Gram-positive cocci and endospore forming Gram-positive rods dominated indoors in the air and settled dust, respectively. Hence, an unrestrained infiltration of ambient air through the draughtiness of the building envelope is probably the main process responsible for indoor fungal pollution, whereas bacterial contaminants have their major sources in the indoor environment. Moreover, even a chemically cleansed library collection, having a restricted personnel access, but under the influence of ambient air, can undergo microbial contamination and becomes an important microbial emission source.
TL;DR: Identification of several clinically important bacterial species in the samples suggests that the workers at the treatment plant are exposed to opportunistic and infectious bacteria.
Abstract: Wastewater contains a variety of microorganisms, and unit operations in the plants could release these biological components into the air environment. These airborne biological particles could have adverse health effects on plant workers and the downwind population. This study provides a first report on the concentration and characterization of the airborne biological particles in six wastewater treatment plants in Mumbai, India. The study indicates that 49% and 27% of the samples exceed, respectively, the exposure limit for airborne endotoxin and bacteria in occupational settings. Endotoxin was identified as the single most important component of the particulate matter responsible for induction of proinflammatory indicator (tumor necrosis factor-α) in in vitro assay. Identification of several clinically important bacterial species in the samples suggests that the workers at the treatment plant are exposed to opportunistic and infectious bacteria. Principal component analysis was used to identify the grou...
TL;DR: In this paper, the UHRA has published a survey of the state of the art in the field of meteorological forecasting, which includes the following papers: http://onlinelibrary.wiley.com/
TL;DR: In this article, a modified LSA-type bubbling liquid generator was used to produce experimental bioaerosols with known and controlled characteristics, such as stability, stability over time and reproducibility.
TL;DR: In this paper, an electrostatic precipitator with superhydrophobic surface (EPSS) was used to collect airborne fungal spores into small water droplets (10 and 40 μl) allowing achievement of very high concentration rates when sampling airborne bacteria.
Abstract: UNLABELLED We recently developed an electrostatic precipitator with superhydrophobic surface (EPSS), which collects particles into a 10- to 40-μl water droplet allowing achievement of very high concentration rates (defined as the ratio of particle concentration in the collection liquid vs. the airborne particle concentration per time unit) when sampling airborne bacteria. Here, we analyzed the performance of this sampler when collecting three commonly found fungal spores--Cladosporium cladosporioides, Penicillium melinii, and Aspergillus versicolor--under different operating conditions. We also adapted adenosine triphosphate (ATP)-based bioluminescence for the analysis of collection efficiency and the concentration rates. The collection efficiency ranged from 10 to 36% at a sampling flow rate of 10 l/min when the airborne fungal spore concentration was approximately 10(5)-10(6) spores/m(3) resulting in concentration rates in the range of 1 × 10(5)-3 × 10(5)/min for a 10-μl droplet. The collection efficiency was inversely proportional to the airborne spore concentration and it increased to above 60% for common ambient spore concentrations, e.g., 10(4)-10(5) spores/m(3). The spore concentrations determined by the ATP-based method were not statistically different from those determined by microscopy and allowed us to analyze spore concentrations that were too low to be reliably detected by microscopy. PRACTICAL IMPLICATIONS The new electrostatic precipitator with superhydrophobic surface (EPSS) collects airborne fungal spores into small water droplets (10 and 40 μl) allowing achievement of concentration rates that are higher than those of most currently available bioaerosol samplers. Biosamplers with high concentration rates enable detection of low ambient aerial bioaerosol concentrations in various environments, including indoors air, and would be useful for improved exposure assessment. A successful adaptation of the adenosine triphosphate (ATP)-based bioluminescence assay for the quantification of fungal spores from a specific species enables fast sample analysis in laboratory investigations. This rapid assay could be especially useful when investigating the performance of biological samplers as a function of multiple operational parameters.
TL;DR: In this article, the authors investigated the effect of different bioaerosol sampling tools and culturing methods on the culturable bacterial and fungal aerosol diversities when different samplers were applied.
Abstract: In this study, biological collection efficiencies and culturable bacterial and fungal aerosol diversities were investigated when different bioaerosol sampling tools and culturing methods were applied. The samplers included Reuter centrifugal sampler (RCS) High Flow, BioSampler, electrostatic sampler, gelatin filter, BioStage impactor, mixed cellulose ester (MCE) filter as well as gravitational settling methods. For culturable bacterial aerosol diversity, the colony-forming units (CFUs) were washed off from the agar plates, and further went through polymerase chain reaction- and denaturing gradient gel electrophoresis (PCR–DGGE). For culturable fungal aerosol diversity, microscopic identification method was applied. In general, the BioStage impactor, MCE filter, and the BioSampler remained robust when sampling culturable bioaerosols. The PCR–DGGE study revealed that the use of different samplers and culturing methods resulted in different culturable bioaerosol diversity. For indoor bacterial aerosols, the ...
TL;DR: In this paper, total bacteria and Aspergillus fumigatus emissions from a small-scale composting facility in central London were measured in different spatial and temporal dimensions.
TL;DR: In this paper, the authors investigate the culturability losses in three non-sampling processes: (1) the tracer uranine induced loss; (2) the loss during aerosolization (pre-sampled process); and (3) the bacteria and uranines recovery in air sample handling procedures for the samples of the Andersen 6-stage impactor and the Airport MD8 (post-samples process).
Abstract: By sampling aerosolized microorganisms, the efficiency of a bioaerosol sampler can be calculated depending on its ability both to collect microorganisms and to preserve their culturability during a sampling process. However, those culturability losses in the non-sampling processes should not be counted toward the sampling efficiency. Prior to the efficiency assessment, this study was designed to investigate the culturability losses in three non-sampling processes: (1) the tracer uranine induced loss; (2) the loss during aerosolization (pre-sampling process); and (3) the bacteria and uranine recovery in air sample handling procedures for the samples of the Andersen 6-stage impactor and the Airport MD8 (post-sampling process). The results indicated that uranine had no significant effect on the culturability of Enterococcus faecalis, Escherichia coli, and Mycoplasma synoviae in suspensions (P > 0.05), but negatively affected the culturability of Campylobacter jejuni (P = 0.01). The culturability of E. faecalis, E. coli, and M. synoviae was not affected by stresses caused by aerosolization (P > 0.05). Only 29% of C. jejuni were still culturable during aerosolization (P = 0.02). In the air sample handling procedures, the four species of bacteria were recovered without significant losses from the samples of the Andersen impactor, but only 33-60% uranine was recovered. E. faecalis, E. coli, and M. synoviae were recovered without significant losses from the samples of the Airport MD8. More C. jejuni was recovered (172%), probably due to multiplication or counting variation. It is suggested that tracer and bacteria should be aerosolized separately when the tracer negatively affects the bacterial culturability. In both pre- and post-sampling processes, losses of bacterial culturability (or multiplication) may occur, which should be taken into account when assessing the efficiencies of bioaerosol samplers.
TL;DR: Using uranine as a physical tracer, the authors assessed the sampling efficiencies of four bioaerosol samplers (Andersen 6-stage impactor, all glass impinger “AGI-30,” OMNI-3000, and Airport MD8 with gelatin filter) for collecting Gram-positive bacteria (Enterococcus faecalis), Gram-negative bacteria (Escherichia coli and Campylobacter jejuni), and bacteria without cell wall (Mycoplasma synoviae) which were aerosolized in a HEPA
Abstract: Using uranine as a physical tracer, this study assessed the sampling efficiencies of four bioaerosol samplers (Andersen 6-stage impactor, all glass impinger “AGI-30,” OMNI-3000, and Airport MD8 with gelatin filter) for collecting Gram-positive bacteria (Enterococcus faecalis), Gram-negative bacteria (Escherichia coli and Campylobacter jejuni), and bacteria without cell wall (Mycoplasma synoviae) which were aerosolized in a HEPA isolator In addition, the half-life times of these bacteria in aerosols were estimated The uranine concentrations collected by the samplers were used for calculating the physical efficiencies, and the bacteria/uranine ratios were used for calculating the biological efficiencies The results show the Airport MD8 had the highest physical efficiency Compared with the Airport MD8, the physical efficiencies of the AGI-30 and the OMNI-3000 were 74% and 49%, respectively A low physical efficiency of the Andersen impactor (18%) was obtained, but it was mainly caused by the incomplete r
TL;DR: Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms and porous structure, large surface area, and hydrophobicity rendered GAC an effective absorber of airbornemicroorganisms.
Abstract: Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption on granule activated carbon (GAC) was an efficient method for the purification of airborne microorganisms. The GAC itself had a maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m(3)/hr. Over 85% of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of continuous operation mode. Most of them had a particle size of 0.65-4.7 mu m. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX, BET and Boehm's titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between GAG surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity rendered GAG an effective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an effective technique as it totally destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and used adsorbents.
TL;DR: These three thermophilic phylotypes can be used as indicators of airborne microorganisms emitted by industrial composting plants and may be particularly relevant in studying the dispersal of bioaerosols around composting Plants and the exposure of nearby residents.
TL;DR: Dose retention efficiency and viable aerosol retention rate were calculated from the sampler titers to determine the efficiency of microbe retention in lungs of mice based on dose presented and respirable particle size.
TL;DR: In this article, single-walled carbon nanotube (SWNT) filters were used to collect bacterial and fungal aerosols with a total volume of 200 L air sampled in indoor and outdoor environments.
TL;DR: The objective is to investigate the effectiveness of infrared (IR) radiation heating in disinfecting air filters loaded with bioaerosols and to find out if it can be used in the treatment of infectious disease.
Abstract: Aims: To investigate the effectiveness of infrared (IR) radiation heating in disinfecting air filters loaded with bioaerosols.
Methods and Results: An irradiation device was constructed considering the unique characteristics of IR and the physical dimensions and radiative properties of air filters. Filters loaded with test bioaerosols were irradiated with the device and flash heated to an ultra-high temperature (UHT). A maximum of 3·77-, 4·38- and 5·32-log inactivation of B. subtilis spores, E. coli, and MS2 virus respectively was achieved within 5 s of irradiation. Inactivation efficiency could be increased by using a higher IR power. Microscopic analysis showed no visible damage from the heat treatment that would affect filtration efficiency.
Conclusions: Because the disinfection was a dry heat process, a temperature greater than 200°C was found necessary to successfully inactivate the test micro-organisms. The results demonstrate that IR is able to quickly disinfect filters given sufficient incident power. Compared to existing filter disinfection technologies, it offers a faster and more effective solution.
Significance and Impact of the Study: It has been shown that IR heating is a feasible option for filter disinfection; possibly reducing fomite transmission of collected micro-organisms and preventing bioaerosol reaerosolization.
TL;DR: This study demonstrated a high volume, portable aerosol-to-hydrosol sampling technique, holding broad promise in monitoring airborne biological threats when coupled with qPCR technology, yet caution should be taken in relating the bioaerosol concentrations to health risks.
Abstract: In this study, the integration of a high volume, portable aerosol-to-hydrosol sampling technique and quantitative polymerase chain reaction (qPCR) was investigated for bioaerosol monitoring by adapting the RCS High Flow to sample air with mineral-oil-strips. Bacillus subtilis var niger and Pseudomonas fluorescens were aerosolized and collected by the RCS High Flow loaded with mineral-oil-strips for 1, 2 and 5 min. In addition, the adapted aerosol-to-hydrosol sampler was also tested for sampling environmental bacterial aerosols in four different environments (a back yard, a student dorm, a dining hall, and a play ground). The performances of the RCS High Flow with mineral-oil-strips were compared with the use of agar strips under similar conditions in all experiments. Air samples collected by the RCS High Flow were cultured, and in addition those collected with mineral-oil-strips were also quantified using qPCR. When sampling B. subtilis var niger aerosols, the use of mineral-oil-strips was shown to report significantly higher culturable concentrations than those obtained by agar strips regardless of the sampling time tested (p-value = 0.04). In contrast, the differences between the two methods when sampling P. fluorescens aerosols were not statistically significant (p-value = 0.5). When coupled with qPCR, the RCS High Flow loaded with mineral-oil-strips obtained significantly higher bacterial aerosol concentrations than those detected by the culturing method. The sampling time was observed to have negligible effects on the efficiency of the technology developed here. When sampling in different environments, the use of mineral-oil-strip was observed to yield significantly higher, about 4–12 times, culturable bacterial aerosol concentration levels compared to the use of agar. This study demonstrated a high volume (100 L min−1) portable aerosol-to-hydrosol sampling technique, holding broad promise in monitoring airborne biological threats when coupled with qPCR technology. Yet, caution should be taken in relating the bioaerosol concentrations to health risks as qPCR detects both culturable and non-culturable cells including inactivated ones.
TL;DR: In this paper, the effect of condensational growth on bioaerosol culturability was assessed using Anderson-type impactor, which resulted in an increase of physical collection efficiency and decrease of impaction stress, and the culturable fraction of sampled bio-aerosols increased up to 43% for S. epidermidis, 27% for P. fluorescens, and 12% for E. coli.
TL;DR: The results suggest that mutational damage is involved in the causal chain of events leading to inactivation of aerosolized endospores exposed to heat for sub-second time periods.
Abstract: Inactivation of viable bioaerosol particles, especially stress-resistant microorganisms, has important implications for biodefense and air quality control. It has earlier been shown that the loss of viability of bacterial endospores due to exposure to dry heat is associated with mutational damage. Previous studies, however, used non-aerosolized spores, long exposure times, and moderately elevated temperatures. This study was designed to investigate the mechanism of inactivation of aerosolized Bacillus endospores exposed to high temperatures for sub-second time periods. Bioaerosol was tested in a continuous air flow chamber under two flow rates, 18 L/min and 36 L/min. The chamber had a cylindrical electric heating element installed along its axis. The estimated characteristic exposure temperature (Texposure ) ranged from 164°C to 277°C (with an uncertainty of 21–26°C). To quantify mutational frequency, spores were cultivated after dry heat exposure on tryptic-soy agar and on antibiotic nalidixic acid media...
TL;DR: Although the bioaerosol concentrations did not follow a seasonal trend, they did significantly correlate with meteorological factors and increasing temperature was found to be positively correlated with increasing bacteria, fungi, and inhalable endotoxin concentrations.
Abstract: Confined animal production systems produce increased bioaerosol concentrations, which are a potential respiratory health risk to individuals on site and downwind. In this longitudinal study, airborne endotoxin and microorganisms were collected during the spring, summer, and fall at a large, open-freestall dairy in southern Idaho. Compared with the background ambient atmosphere, both endotoxin and culturable heterotrophic bacteria concentrations were up to several-hundred-fold greater 50 m downwind from the facility, then decreased to near background concentrations at 200 m. However, downwind fungi concentrations were not increased above background concentrations. At 50 m downwind, the average inhalable endotoxin concentration ranged from 5 to 4,243 endotoxin units per m⁻³, whereas bacteria concentrations ranged from 10² to 10⁴ cfu per m⁻³ of air. Although the bioaerosol concentrations did not follow a seasonal trend, they did significantly correlate with meteorological factors. Increasing temperature was found to be positively correlated with increasing bacteria (r = 0.15, P < 0.05), fungi (r = 0.14, P < 0.05), and inhalable endotoxin (r = 0.32, P < 0.001) concentrations, whereas an inverse relationship occurred between the concentration and solar radiation. The airborne concentrations at 50 m were also found to be greatest at night, which can likely be attributed to changes in animal activity and wind speed and reduced exposure of the airborne microorganisms to UV radiation.
TL;DR: It is shown that berry pickers in this organic strawberry field were potentially subjected to higher levels of fungal spores, Cladosporium sp.
Abstract: Many working environments are predisposed for larger than average amounts of fungi and other microorganisms often due to organic material being handled. From 2003 to 2007, the area used for strawberry production in Denmark increased by 62%. The purpose of this study was to determine the levels of exposure to microorganisms, endotoxin, (1→3)-β-d-glucan (β-glucan), and pollen in a field of strawberries. The study was carried out in eastern Denmark from the middle of June to the beginning of August 2008. The strawberries were grown organically, and microbiological pest control agents (MPCAs) were applied during this and former growth seasons. In order to measure exposure to inhalable bioaerosol components, we used stationary filter samplers. Bioaerosol sampling was performed during 4 working days, and a total of 57 samplings were performed. The filters were analysed for contents of fungi, MPCAs, endotoxin, β-glucan, and pollen. The mean exposure was 6,154 CFU Cladosporium sp. m−3, 1.0 × 105 fungal spores m−3, 4.1 × 104 hyphal fragments m−3, 5.8 × 103 pollen m−3, 57.3 ng β-glucan m−3, and 8.9 endotoxin units (EU) m−3. A significant and positive correlation was found between β-glucan and fungal spores and between CFU of Cladosporium sp. and CFU of fungi. We selected specifically for Metarhizium anisopliae, Beauveria bassiana, and the applied MPCAs Trichoderma harzianum, T. polysporum, and Bacillus thuringiensis but found none of these species. In conclusion, our study shows that berry pickers in this organic strawberry field were potentially subjected to higher levels of fungal spores, Cladosporium sp., hyphal fragments, pollen, and thus also β-glucan than is usually seen in outdoor air. Exposure to MPCAs was not seen. The exposure to endotoxin was only slightly higher than e.g. in a town.
01 Jan 2011
TL;DR: Cultivation and microscopic counting are traditional analytical methods, but recently several new methods are emerging that are based on chemical, biological, or immunochemical analysis of bioaerosol components.
Abstract: Bioaerosols include viruses, bacteria, fungi, pollen, and their fragments as well as animal allergens. Bioaerosol exposure is common in indoor and outdoor environments and may cause infections, allergies, irritation, and toxic effects. The size of biological particles varies widely, from nanoscale (virions and microbial fragments) to approximately 100 μm (pollen grains). The same physical principles that are applied to nonbiological particles can be applied to bioaerosol sampling in terms of sampling efficiency of a given particle size range. When sampling bioaerosols for exposure assessment purposes, one has to consider what biological property would be the most relevant measure for the health effect in question. Cultivation and microscopic counting are traditional analytical methods, but recently several new methods are emerging that are based on chemical, biological, or immunochemical analysis of bioaerosol components. Data interpretation is based on comparisons of results in target and reference areas or populations. When comparing data with previously published values, only results that are obtained using the same methodology should be directly compared.