Fungal Aerosols Research Articles

Effect of ambient air temperature and solar radiation on changes in bacterial and fungal aerosols concentration in the urban environment.

Bioaerosols are particularly sensitive to sterilization processes due to their biological characteristics. Phenomena occurring in the atmosphere have major influence on airborne bacteria and fungi concentration levels. The presented study evaluates the sterilization properties of ambient air temperature and solar radiation on viable bioaerosols concentration levels in outdoor air in Gliwice, Poland. Assigned were the breakpoints indicating limited stimulation properties of the air temperature, which amounted 7.5°C for bacterial aerosol and 16.5 °C for fungal aerosol. Also revealed was the influence of solar radiation properties on decreasing the bioaerosols concentration levels. Both bacterial and fungal viable aerosol were sensitive to this radiation, although the phenomenon was more effective for airborne bacteria.

Biomarkers as indicators of fungal biomass in the atmosphere of São Paulo, Brazil

The biogenic aerosol contribution to atmospheric particulate matter (PM) mass concentration is usually neglected due to the difficulty in identifying its components, although it can be significant. In the Metropolitan Area of São Paulo (MASP)-Brazil, several studies have been performed to identify sources for PM, revealing vehicular emissions and soil re-suspension as the main identified sources. The organic fraction has been related primarily to biomass burning (BB) and fuel combustion, although there is significant presence of green areas in the city which render biogenic emissions as an additional source of organic carbon (OC). The objectives of this work are to (i) characterise the composition of the PM10 (ii) estimate the relative mass contribution of fungal spores to PM concentrations with sizes smaller than 10μm (PM10) in MASP and (iii) assess the main sources of PM10. To achieve these objectives, we measured markers of biogenic sources and BB, during the fall-winter transition, which along with other constituents, such as ions, organic/elemental carbon, elemental composition and fungal spore concentrations, help assess the PM10 sources. We used receptor models to identify distinct source-related PM10 fractions and conversion factors to convert biomarker concentrations to fungal mass. Our results show the mean contributions of fungal aerosol to PM10 and OC mass were 2% and 8%, respectively, indicating the importance of fungal spores to the aerosol burden in the urban atmosphere. Using specific rotation factor analysis, we identified the following factors contributing to PM: soil re-suspension, biogenic aerosol, secondary inorganic aerosol, vehicular emissions and BB/isoprene-related secondary organic aerosol (I-SOA). BB/I-SOA was the main source representing 28% of the PM10 mass, while biogenic aerosol explained a significant (11%) fraction of the PM10 mass as well. Our findings suggest that primary biogenic aerosol is an important fraction of PM10 mass, yet not considered in most studies.

A novel aerated surface flow constructed wetland using exhaust gas from biological wastewater treatment: Performance and mechanisms

In this study, a novel aerated surface flow constructed wetland (SFCW) using exhaust gas from biological wastewater treatment was investigated. Compared with un-aerated SFCW, the introduction of exhaust gas into SFCW significantly improved NH4+-N, TN and COD removal efficiencies by 68.30 ± 2.06%, 24.92 ± 1.13% and 73.92 ± 2.36%, respectively. The pollutants removal mechanism was related to the microbial abundance and the highest microbial abundance was observed in the SFCW with exhaust gas because of the introduction of exhaust gas from sequencing batch reactor (SBR), and thereby optimizing nitrogen transformation processes. Moreover, SFCW would significantly mitigate the risk of exhaust gas pollution. SFCW removed 20.00 ± 1.23%, 34.78 ± 1.39%, and 59.50 ± 2.33% of H2S, NH3 and N2O in the exhaust gas, respectively. And 31.32 ± 2.23% and 32.02 ± 2.86% of bacterial and fungal aerosols in exhaust gas were also removed through passing SFCW, respectively.

Inflammatory potential of low doses of airborne fungi from fungal infested damp and dry gypsum boards

This study has investigated the total inflammatory potential (TIP) of low concentration fungal samples from moisture-damaged and fungal infested gypsum boards. The fungal aerosols were generated from damp and dried surfaces, and sampled using filter sampling and liquid impingement. The TIP of the samples was analysed using a granulocyte assay based on differentiated HL60 cells. The study found a tendency to a J-shaped dose-response curve for fungal samples. Low concentrations of fungi were aerosolised from the gypsum boards, and the aerosols were dominated by Aspergillus versicolor and Penicillium chrysogenum. Bacillus infantis and Paenibacillus sp. were found on the gypsum boards, but not recovered in the aerosols. A significant correlation was found between the TIP of diluted and undiluted samples of fungal aerosols. However, diluted samples had a higher TIP than undiluted samples, and no significant association was found between concentration of fungi and the TIP of the samples. This is likely due to the J-shaped dose response curve. The aerosol samples from the dried gypsum boards had a significantly higher TIP compared to aerosols from the damp surfaces. However, the J-shaped dose-response curve weakens the conclusion on the influence of surfaces dampness, sampling time, fungal species or sampling methods. It could, however, be concluded that samples from both damp and dry surfaces induce inflammation in the HL60 cells, despite the low concentration of fungi. Thus, a dried fungal infestation in a building seem still to present a concern for the occupant.

Seasonal variation of the dominant allergenic fungal aerosols \u2013 One year study from southern Indian region

Quantitative estimations of fungal aerosols are important to understand their role in causing respiratory diseases to humans especially in the developing and highly populated countries. In this study we sampled and quantified the three most dominantly found allergenic airborne fungi, Aspergillus fumigatus, Cladosporium cladosporioides, and Alternaria alternata from ambient PM10 samples using the quantitative PCR (qPCR) technique in a southern tropical Indian region, for one full year. Highest concentrations of A. fumigatus and C. cladosporioides were observed during monsoon whereas A. alternata displayed an elevated concentration in winter. The meteorological parameters such as temperature, relative humidity, wind speed, and precipitation exhibited a substantial influence on the atmospheric concentrations of allergenic fungal aerosols. The morphological features of various allergenic fungal spores present in the PM10 were investigated and the spores were found to possess distinct structural features. In a maiden attempt over this region we correlate the ambient fungal concentrations with the epidemiological allergy occurrence to obtain firsthand and preliminary information about the causative fungal allergen to the inhabitants exposed to bioaerosols. Our findings may serve as an important reference to atmospheric scientists, aero-biologists, doctors, and general public.

Microbiological Evaluation of Indoor Air Quality of State University Library

The present study was aimed at evaluating the number of bacteria and mould fungi in the indoor and outdoor environment of Imo University Library. The sampling sites were located in the rooms serving the functions typical of libraries (i.e. in the Main Reading Room, Current Periodicals Reading Room, Collections Conservation Laboratory, Old Prints Storeroom, in rooms serving other (non-library) functions (i.e. main hall, cafeteria, and toilet) as well as outside the library building. The analyses reveal that the concentrations of bacterial as well as fungal aerosols estimated with the use of the impaction method ranged between 10 1 -10 3 CFU·m -3 , which corresponds to the concentrations normally observed in areas of this kind. Evaluation of the hygienic condition of the studied areas was based on the criteria for microbiological cleanliness in interiors submitted by the European Commission in 1993. According to this classification, the air was considered to be heavily or moderately contaminated with bacteria, while the air contamination with mould fungi was described as low or moderate. The air in the Old Prints Storeroom was considered the least contaminated with microbial aerosol

Fungal air contamination in distinct sites within a municipal landfill area

Municipal wastes collected in landfills are a significant source of air contamination and frequently characterize by elevated concentrations of different fungi. Posing a serious health threat to landfill workers and local residents, the fungal aerosol has to be monitored with respect to its quantity and quality. In this study, concentrations of airborne fungi, their particle size distribution, species composition and the presence of cytotoxic strains of Aspergillus fumigatus were assessed in different sites within the landfill area. The quantitative and qualitative changes in the fungal aerosol were determined with respect to a season and landfill activity level (i.e. exploitation or standstill periods). Within the landfill area, particular sites were grouped with regard to airborne fungi concentrations and similarities in species composition. The qualitative analysis indicated that 43 species were shared during both sampling times, and only nine species were characteristic for the standstill period. Among fungal isolates, 21 strains of A. fumigatus revealed cytotoxic activity expressed at different levels, depending on the fungal extract concentrations used in the MTT assay. The results suggested that exposure (especially in summer) to small airborne particles, containing distinct species, may occur not only in the active sector but also in close vicinity to the landfill. Hence, microbial monitoring of the landfill and surrounding area should be carried out taking into account both quantitative aspect supplemented by size distribution analysis and qualitative features, especially of those strains possessing cytotoxic activity.

Bioaerosol exposure and circulating biomarkers in a panel of elderly subjects and healthy young adults

Numerous studies have found that risk of cardiovascular diseases is associated with increased blood levels of circulating markers of systemic inflammation. We investigated associations of acute exposure to bioaerosols (bacteria and fungi) with blood markers of inflammation and coagulation using panels of elderly subjects and healthy young adults. We conducted a panel study of 44 nonsmoker elderly subjects in a retirement communities and a panel study of 40 healthy young adults living in a school dormitory within Tehran city, Iran. Blood sample biomarkers were measured weekly over 6weeks and including high sensitive C-reactive protein (hsCRP), tumor necrosis factor-soluble receptor-II (sTNF-RII), von Willebrand factor (vWF), white blood cells (WBC) count and interleukin-6 (IL-6). We found significant positive associations for IL-6 and WBC with exposure to Aspergillus spp. (As), Cladosporium spp. (Cl), Penicillium spp. (Pe), total fungi (TF) and Micrococcus spp. (MI); vWF with Cl and MI; sTNF-RII with Staphylococcus spp. (ST) in healthy young adults from the current-day and multiday averages. For elderly subjects, we observed significant positive associations for hsCRP, sTNF-RII and WBC with exposure to MI, but not with ST and total bacteria (TB). Our results showed the strongest significant positive associations for IL-6 with MI, ST and TB in elderly people. In addition, IL-6 was also positively associated with As, Cl and Pe in elderly. Also, the results showed that increase of vWF was significantly associated with bacterial and fungal aerosols, except Bacillus spp. (BA) at some lags in elderly subjects. Pooled results support the pivotal role of bioaerosols in increasing the level of some of inflammatory biomarkers, especially IL-6 and WBC in healthy young adults but possibly also in elderly people.

Characteristics of airborne bacteria and fungi in some Polish wastewater treatment plants

The aim of this study was to characterize both the viable airborne bacteria and fungi collected in different types of wastewater treatment plants in Poland. Bacterial and fungal aerosols in five different wastewater treatment plants in Poland were studied, including the pioneering antibiotic resistance testing of airborne bacteria. Concentration level was measured using the six-stage Andersen impactor. After incubation, bioaerosol particles captured on nutrient media on Petri dishes were quantitatively evaluated and qualitatively identified. It was found that the concentration levels of both airborne bacteria and fungi ranged from 10² to 10³ colony-forming units/m³, in all stages of the wastewater treatment plants. The patterns of size distributions of airborne bacteria and fungi were very similar, showing dominant peaks typically in the size range between 3.3 and 4.7 μm. The majority fraction of small bacterial and fungal particles (less than 4.7 μm) in the studied areas indicates that the bioaerosol is relatively fresh, and mostly of local origin. The Gram-positive cocci and nonsporing Gram-positive rods were the dominating forms in the studied wastewater treatment plants environment. The existing differences in the concentration levels between sampling sites enabled identification of the main bioaerosol sources. The highest concentration of bacterial aerosol appeared in sections, where activated sludge post-processing and mechanical purifying are conducted. The most frequently occurring species in the sampled bacterial aerosol were Gram-positive cocci and nonsporing Gram-positive rods. Multi-antibiotic resistance testing showed that among the isolated airborne bacteria, the most antibiotic-resistant features were present among Bacillus species (especially Bacillus mycoides).

Liquid impinger BioSampler's performance for size-resolved viable bioaerosol particles

This study aimed at studying the collection efficiencies of the widely used SKC BioSampler when sampling size-resolved biological viable aerosol particles using an Ultraviolet Aerodynamic Particle Sizer (UV-APS) unit. The test bioaerosols include aerosolized bacterial species and those from indoor air. For optimal performance, different flow rates (Qsampl) (5, 12.5 and 20L/min) and different volumes of collection liquids (Vcl) (5, 10 and 20mL) were tested for bioaerosol particles from 0.5 to 10µm. In addition, the DNA stain method-the LIVE/DEAD BacLight dye and culturing were also utilized to confirm the viable bioaerosol collection efficiencies of the BioSampler.Experimental data showed that when sampling aerosolized Bacillus subtilis at the flow rate of 12.5L/min, the collection efficiency of the BioSampler decreased from 82.7% (at Vcl=20mL) to 24.8% (at Vcl=5mL). The results from the BacLight dye and culturing performed for the samples collected by the BioSampler achieved similar conclusions. When sampling indoor air particles, the overall collection efficiencies of all viable biological particles were 95.3%, 87.7% and 65.5%, respectively, for Vcl=20mL, 10mL and 5mL at the flow rate of 12.5L/min. When Qsampl was 20L/min, the BioSampler performed better with Vcl= 5mL than other volumes. The results from this work suggest that the sampling flow rate plays a dominant role in the overall physical collection efficiency while the collection volume is crucial in preserving the viability of bioaerosol particles. Different from general practice, the operating parameters for the BioSampler should thus be adjusted respectively for target viral, bacterial and fungal aerosol particles.

Terrestrial Macrofungal Diversity from the Tropical Dry Evergreen Biome of Southern India and Its Potential Role in Aerobiology.

Macrofungi have long been investigated for various scientific purposes including their food and medicinal characteristics. Their role in aerobiology as a fraction of the primary biological aerosol particles (PBAPs), however, has been poorly studied. In this study, we present a source of macrofungi with two different but interdependent objectives: (i) to characterize the macrofungi from a tropical dry evergreen biome in southern India using advanced molecular techniques to enrich the database from this region, and (ii) to assess whether identified species of macrofungi are a potential source of atmospheric PBAPs. From the DNA analysis, we report the diversity of the terrestrial macrofungi from a tropical dry evergreen biome robustly supported by the statistical analyses for diversity conclusions. A total of 113 macrofungal species belonging to 54 genera and 23 families were recorded, with Basidiomycota and Ascomycota constituting 96% and 4% of the species, respectively. The highest species richness was found in the family Agaricaceae (25.3%) followed by Polyporaceae (15.3%) and Marasmiaceae (10.8%). The difference in the distribution of commonly observed macrofungal families over this location was compared with other locations in India (Karnataka, Kerala, Maharashtra, and West Bengal) using two statistical tests. The distributions of the terrestrial macrofungi were distinctly different in each ecosystem. We further attempted to demonstrate the potential role of terrestrial macrofungi as a source of PBAPs in ambient air. In our opinion, the findings from this ecosystem of India will enhance our understanding of the distribution, diversity, ecology, and biological prospects of terrestrial macrofungi as well as their potential to contribute to airborne fungal aerosols.

Microbial aerosol in Beijing-Tianjin-Hebei region of Eastern China

With dense population, the Beijing-Tianjin-Hebei region of China is one of the regions most severely stricken by atmospheric pollution in the world. Research shows that the annual average concentration of airborne bacteria in this region is 1,380-3,020 CFU/m3. The concentration of gram-positive (G+) bacteria (80%-85%) is significantly higher than that of G− bacteria (15%-20%) and a total of 47 genera of bacteria are found. The number of airborne fungi in Beijing is 89-2,270 CFU/m3 and a total of nine genera of fungi are detected. Bacterial aerosols in the air are mostly distributed in particles bigger than 2 µm (82.2%). Fungal aerosols are mainly found in 1-6 µm particles, accounting for 71.6%, and are the most densely distributed in 2-3.5 µm particles. The regular changes in distribution region, time, and particle size of microbial aerosol in the air may provide an important research basis for the further study on the correlation between the quantity and genera of microorganisms in haze and human infectious disease.

Time-Dependent Size-Resolved Bacterial and Fungal Aerosols in Beijing Subway

ABSTRACTDespite of an important concern, human bioaerosol emission into subway is not well and directly characterized. Here, we used bioaerosol detector and next generation sequencing methods to investigate time-dependent bioaerosol size distributions in Beijing subway system between March and April, 2015. In contrast to weekends, weekday microbial aerosol results exhibited strong time dependence with higher bacterial and fungal aerosol levels up to 2083 CFU m–3 and 483 CFU m–3 observed, respectively, for the peak hours. During the peak hour (17:30–18:30), bioaerosol emissions at 0.8–3 µm was detected, while about three times higher concentration levels were observed compared to those during the off-peak hour (22:00–23:00). Similar bioaerosol size distributions were observed between ventilation outlets and subway platform air. During off-peak hours, subway bioaerosols had similar size distributions with the outside air. Sequence results revealed a vast array of airborne microbial species which varied from one station to another, but with Aspergillus spp. as dominant fungal species, and Staphylococcus, Pseudomonas as primary bacterial genera including human opportunistic ones. Our results provide direct online observations of human contributions to subway size-resolved bioaerosols, and enhancing ventilation system might help for controlling the exposure especially during the peak-hours.

Microbial aerosol in Beijing-Tianjin-Hebei region of Eastern China

With dense population, the Beijing-Tianjin-Hebei region of China is one of the regions most severely stricken by atmospheric pollution in the world. Research shows that the annual average concentration of airborne bacteria in this region is 1,380-3,020 CFU/m3. The concentration of gram-positive (G+) bacteria (80%-85%) is significantly higher than that of G− bacteria (15%-20%) and a total of 47 genera of bacteria are found. The number of airborne fungi in Beijing is 89-2,270 CFU/m3 and a total of nine genera of fungi are detected. Bacterial aerosols in the air are mostly distributed in particles bigger than 2 µm (82.2%). Fungal aerosols are mainly found in 1-6 µm particles, accounting for 71.6%, and are the most densely distributed in 2-3.5 µm particles. The regular changes in distribution region, time, and particle size of microbial aerosol in the air may provide an important research basis for the further study on the correlation between the quantity and genera of microorganisms in haze and human infectious disease.

Culturable bioaerosols along an urban waterfront are primarily associated with coarse particles.

The source, characteristics and transport of viable microbial aerosols in urban centers are topics of significant environmental and public health concern. Recent studies have identified adjacent waterways, and especially polluted waterways, as an important source of microbial aerosols to urban air. The size of these aerosols influences how far they travel, their resistance to environmental stress, and their inhalation potential. In this study, we utilize a cascade impactor and aerosol particle monitor to characterize the size distribution of particles and culturable bacterial and fungal aerosols along the waterfront of a New York City embayment. We seek to address the potential contribution of bacterial aerosols from local sources and to determine how their number, size distribution, and taxonomic identity are affected by wind speed and wind direction (onshore vs. offshore). Total culturable microbial counts were higher under offshore winds (average of 778 CFU/m3 ± 67), with bacteria comprising the majority of colonies (58.5%), as compared to onshore winds (580 CFU/m3 ± 110) where fungi were dominant (87.7%). The majority of cultured bacteria and fungi sampled during both offshore winds (88%) and onshore winds (72%) were associated with coarse aerosols (>2.1 µm), indicative of production from local sources. There was a significant correlation (p < 0.05) of wind speed with both total and coarse culturable microbial aerosol concentrations. Taxonomic analysis, based on DNA sequencing, showed that Actinobacteria was the dominant phylum among aerosol isolates. In particular, Streptomyces and Bacillus, both spore forming genera that are often soil-associated, were abundant under both offshore and onshore wind conditions. Comparisons of bacterial communities present in the bioaerosol sequence libraries revealed that particle size played an important role in microbial aerosol taxonomy. Onshore and offshore coarse libraries were found to be most similar. This study demonstrates that the majority of culturable bacterial aerosols along a New York City waterfront were associated with coarse aerosol particles, highlighting the importance of local sources, and that the taxonomy of culturable aerosol bacteria differed by size fraction and wind direction.

Microbiological air quality at municipal waste sorting plant

Abstract Municipal waste plants can be a source of biological contamination of the environment, depending on the method of operation and the type of collected waste. The aim of this study was the quantitative characteristics of airborne microorganisms at the Barycz municipal waste sorting plant in Cracow. Bioaerosol measurements of indoor and outdoor air of the municipal waste sorting plant were performed during the summer season using a six-stage Andersen cascade impactor. The highest concentration of bacterial and fungal aerosol was observed in the medium fraction sorting room (129.02×103 cfu·m-3 and 116.21×103 cfu·m-3, respectively). There were statistically significant differences in the concentrations of bacterial and fungal aerosol between indoor and outdoor air. The calculations showed a significant correlation between the concentration of bioaerosol and particulate matter. Based on the analysis of bioaerosol particle size distribution, it was found that the concentration of bacteria and fungi has a maximum value in the diameter range 3.3-7.0 μm. The study confirmed that the municipal waste sorting plants can be causing exposure to microbiological agents.

The Antifungal Properties of Peppermint and Thyme Essential Oils Misted in Broiler Houses

ABSTRACT This study aimed at evaluating if essential oils misted in broiler houses reduce environmental fungi counts. The investigation was conducted in three experimental rooms, where broiler chickens were reared between 1 to 42 d of age. Every three days, the rooms were fogged with pure water (control) or with aqueous solutions of peppermint or thyme oils. On the next day, fogging samples from the air, flat surfaces, and litter were collected and quantitatively and qualitatively analysed for fungal contamination. The treatment with essential oils showed promising results. In the room fogged with thyme oil, aerial fungi growth was not as evident as in the control room, and presented the lowest average fungi count. Thyme oil was also the most effective in reducing fungi colonization on drinker surfaces and litter. The use of peppermint oil also reduced the population of air, wall, surface and litter fungi, although some exceptions were noted. Aspergillus, Penicillium, Fusarium and Saccharomyces genera were identified most frequently. The effect of essential oils was noticeable in the last two weeks, when the counts of Aspergillus sp. were 75% (thyme oil) and 46% (peppermint oil) lower in comparison with the control group. The results show that fogging broiler houses with essential oils may be an effective prevention method against fungal aerosol in broiler houses. However, further investigations to determine the synergistic effect of different oils and their compounds, and the best possible doses and methods of application in the field are needed.

Bacterial and Fungal Aerosols in Rural Nursery Schools in Southern Poland

This study aimed to characterize airborne bacteria and fungi populations present in rural nursery schools in the Upper Silesia region of Poland during winter and spring seasons through quantification and identification procedures. Bacterial and fungal concentration levels and size distributions were obtained by the use of a six-stage Andersen cascade impactor. Results showed a wide range of indoor bioaerosols levels. The maximum level of viable bacterial aerosols indoors was about 2600 CFU·m−3, two to three times higher than the outdoor level. Fungi levels were lower, from 82 to 1549 CFU·m−3, with indoor concentrations comparable to or lower than outdoor concentrations. The most prevalent bacteria found indoors were Gram-positive cocci (&gt;65%). Using the obtained data, the nursery school exposure dose (NSED) of bioaerosols was estimated for both the children and personnel of nursery schools. The highest dose for younger children was estimated to range: 327–706 CFU·kg−1 for bacterial aerosols and 31–225 CFU·kg−1 for fungal aerosols. These results suggest an elevated risk of adverse health effects on younger children. These findings may contribute to the promotion and implementation of preventative public health programs and the formulation of recommendations aimed at providing healthier school environments.

Aeromycological analysis of allergenic airborne fungi in Qazvin, Iran.

Background and Purpose:Airborne fungi are one of the most important agents responsible for triggering allergicreactions such as rhinitis and severe asthma. This study was conducted to analyze and monitor the prevalence and distribution patterns of atmospheric fungal aerosols in the air of Qazvin during winter of 2012.Materials and Methods:In the current descriptive study, the incidence and diversity of potentially allergenic airborne fungi were determined using two times sampling interval in 25 different locations of Qazvin city by Petri dish trappingtechnique and exposure of 10- cm diameter plates of Sabouraud’s dextrose agar medium plus chloramphenicol to the air.Results:A total of 2867 fungal colonies were counted on 156 Petri dishes. Of the identified 18 microfungi genera,Cladosporium spp. was the most frequently isolated genera representing 30.9% of isolates, followed by 30.9% Penicillium spp. (27.3%), Aspergillus spp %) . (24.5 , Alternaria spp. (3.3%), Rhizopus spp. (3.1%), and other fungal genera.Conclusion:The high prevalence, high quantity and variety of allergenic airborne fungi in the air of Qazvin showed that people residing in this area are exposed to health hazards. Furthermore, reduction of exposure to bio-aerosols containing these outdoor fungi is necessary to improve the health of individuals, especially those sensitive to fungal-induced diseases like asthma.

Subchronic exposures to fungal bioaerosols promotes allergic pulmonary inflammation in naïve mice.

Epidemiological surveys indicate that occupants of mold contaminated environments are at increased risk of respiratory symptoms. The immunological mechanisms associated with these responses require further characterization. The aim of this study was to characterize the immunotoxicological outcomes following repeated inhalation of dry Aspergillus fumigatus spores aerosolized at concentrations potentially encountered in contaminated indoor environments. Aspergillus fumigatus spores were delivered to the lungs of naïve BALB/cJ mice housed in a multi-animal nose-only chamber twice a week for a period of 13weeks. Mice were evaluated at 24 and 48h post-exposure for histopathological changes in lung architecture, recruitment of specific immune cells to the airways, and serum antibody responses. Germinating A.fumigatus spores were observed in lungs along with persistent fungal debris in the perivascular regions of the lungs. Repeated exposures promoted pleocellular infiltration with concomitant epithelial mucus hypersecretion, goblet cell metaplasia, subepithelial fibrosis and enhanced airway hyperreactivity. Cellular infiltration in airways was predominated by CD4(+) T cells expressing the pro-allergic cytokine IL-13. Furthermore, our studies show that antifungal T cell responses (IFN-γ(+) or IL-17A(+) ) co-expressed IL-13, revealing a novel mechanism for the dysregulated immune response to inhaled fungi. Total IgE production was augmented in animals repeatedly exposed to A.fumigatus. Repeated inhalation of fungal aerosols resulted in significant pulmonary pathology mediated by dynamic shifts in specific immune populations and their cytokines. These studies provide novel insights into the immunological mechanisms and targets that govern the health outcomes that result from repeated inhalation of fungal bioaerosols in contaminated environments.