Airborne Fungal Concentrations Research Articles

Airborne fungi in arctic settlement Tiksi (Russian Arctic, coast of the Laptev Sea)

Biodiversity and number of airborne fungi isolated from indoor and outdoor air of different location in the areas of arctic settlement Tiksi (Russian Arctic) are described. Different locations (coastal areas, landscape, streets of Tiksi, abandoned empty houses, flats, public buildings) were observed. Aeromycota characterized by a significant biodiversity (50 species), but only several species were abundant. Airborne fungal spores concentration (CFU) in Tiksi locations was found low. The maximum spore concentrations were observed in air of the abandoned empty houses (inhabited in the past). Many species common for soil were observed at the samples taken at streets and abandoned buildings. Most of them are also known as inhabitants of building materials. Microfungi CFU at settlement territory was twice as high as natural territory. Phospholipase, albuminase and hemolytic activities of microfungi isolates as well as their relation to temperature were studied. Most of the tested isolates demonstrated high levels of all the tested activities. It was concluded that there is a risk of ‘‘mold’’ allergy diseases for the people especially with weakening of immunity at arctic settlement Tiksi. Main sources of the air contamination in arctic settlements and houses could be many anthropogenic substrates which were colonized by soil fungi.

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.

Air microbial contamination and factors affecting its occurrence in certain book libraries in Egypt.

Bacterial and fungal contamination in the air and settled dust were studied in old and new book libraries located in the National Research Center (NRC), Dokki, Giza, Egypt. The investigated libraries differ in age, design, size, ventilation type, and number of occupants in relation to microclimatic parameters and particulate matter (PM) load. Airborne microorganisms were collected using an Andersen two stage impactor sampler. Indoor airborne bacteria and fungi ranged from 0-1060.4 CFU/m3 and 11.8-315.6 CFU/m3, respectively. Outdoor airborne bacteria and fungi ranged within 11.7-2514.7 CFU/m3 and 0-713.7 CFU/m3, respectively. Bacteria and fungi associated surface settled dust ranged from 0.4-10x106 CFU/gm and 0-73x104 CFU/gm, respectively. Fine microbial fraction (particles ≤ 8 μm in size) constituted 2-24.94% and 68.35-94.15% of the total airborne bacterial and fungal concentrations, respectively. Indoor/outdoor (I/O) ratios of airborne microorganisms were less than 1 at both libraries, indicating no indoor microbial sources. Gram positive cocci (14.3-47%) and bacilli (52.9-85.7%) were the dominant bacterial isolates in the air state, while bacilli represented 100% of the total isolates in the surface settled dust. Bacillus pseudomycoides and B. subtilis dominated indoors while B. subtilis and Staphylococcus outdoors. Aspergillus and Penicillium, were the common fungal species in both libraries under investigation. Many of the isolated fungal taxa had enzymatic activities (lipase, protease and cellulase), with A. flavus, Curvularia pallescens, Fusarium oxysporium, P. notatum and Trichoderma viride presented all enzymatic activities. Complex correlations and no-clear patterns were found between the airborne microorganisms and the environmental factors.

Evaluation of Airborne Bacteria and Fungi in Surgical Areas at the Animal Hospital

Seongsoo Jeong, Yuntae Kang, Yawon Hwang, Seungwon Yoo, Hyejin Jang, Hyejong Oh, Jihoon Kang, Dongwoo Chang, Kijeong Na, Gonhyung Kim. J Vet Clin 2017;34:76-81. https://doi.org/10.17555/jvc.2017.04.34.2.76

Building-integrated agriculture: A first assessment of aerobiological air quality in rooftop greenhouses (i-RTGs)

Building-integrated rooftop greenhouse (i-RTG) agriculture has intensified in recent years, due to the growing interest in the development of new agricultural spaces and in the promotion of food self-sufficiency in urban areas. This paper provides a first assessment of the indoor dynamics of bioaerosols in an i-RTG, with the aim of evaluating biological air quality in a tomato greenhouse near Barcelona. It evaluates the greenhouse workers' exposure to airborne pollen and fungal spores in order to prevent allergy problems associated with occupational tasks. Moreover, it evaluates whether the quality of the hot air accumulated in the i-RTG is adequate for recirculation to heat the building.Daily airborne pollen and fungal spore concentrations were measured simultaneously in the indoor and outdoor environments during the warm season. A total of 4,924pollengrains/m3 were observed in the i-RTG, with a peak of 334pollengrains/m3day, and a total of 295,038 fungal spores were observed, reaching a maximum concentration of 26,185spores/m3day. In general, the results showed that the most important source of pollen grains and fungal spores observed indoors was the outdoor environment. However, Solanaceae pollen and several fungal spore taxa, such as the allergenic Aspergillus/Penicillium, largely originated inside the greenhouses or were able to colonize the indoor environment under favourable growing conditions. Specific meteorological conditions and agricultural management tasks are related to the highest observed indoor concentrations of pollen grains and fungal spores. Therefore, preventive measures have been suggested in order to reduce or control the levels of bioaerosols indoors (to install a system to interrupt the recirculation of air to the building during critical periods or to implement appropriate air filters in ventilation air ducts). This first evaluation could help in making decisions to prevent the development of fungal diseases, specifically those due to Oidium and Torula.

Seasonal Fluctuations of Microbial Aerosol in Live Poultry Markets and the Detection of Endotoxin.

Microbial aerosol whose species and concentrations are closely related to human health is ubiquitous. The effect of microbes on human and animal health and production performance is, in many cases, caused by the spreading of air. Samples in this experiment were from a live poultry market (LPM) in Tai’an, China, collected three times a day (8 am, 14 pm, and 20 pm) over three consecutive days each month for 11 months (Original sampling plan was a year, the government due to the environmental protection, the was LPM closed). The main indicators of the test were concentrations of cultural airborne bacteria, airborne fungi, and Gram-negative bacteria. At the same time the species of Gram-negative bacteria and the concentration of endotoxin were tested. Temperature and humidity were recorded in the process of each sampling. The results showed that the diurnal variation of the concentration of bacteria, fungi, and Gram-negative bacteria is higher in the morning and evening, but lower at noon. The concentrations of airborne bacteria and Gram-negative bacteria increased in earlier months and decreased in later months, with the peak appearing in the autumn. The concentration of fungi showed a decrease first and then tended to stabilize, with the peak occurring in the spring. The concentration peak of endotoxin occurred in the summer. Endotoxin levels were significantly correlated with humidity (r = 0.90, p < 0.01). Most bacteria were distributed at the third and fourth stages (2.1–4.7 μm) in the ANDERSEN-6 sampler. The dominant species of Gram-negative bacteria during the four seasons were Pseudomonas aeruginosa, Acinetobacter, Klebsiella pneumoniae, and Salmonella. In China, people have a habit of eating fresh poultry, LPM distribution is widespread, stream of people and traffic flow are large, easily caused the spread of bacteria and viruses, so the LPM microbial aerosol research have significant public health implications.

A study on microbiological contamination on air quality in hospitals in Egypt

This study aims to evaluate airborne environmental bacteria (environmental origin), mesophilic bacteria (human related bacteria) and fungi at governmental (GH) and private (PH) hospitals, in addition to assess sink drain biofilms and dust accumulated on air conditioning filters and floor surfaces to determine if they constitute potential sources of airborne microbial biodiversity. Samples were collected from intensive care unit (ICU), operating theatre (OT), admission department (AD) and outdoor for comparison. Airborne bacteria and fungi were collected using an Andersen two-stage impactor sampler which divides particles into fine (≤8 µm) and coarse (≥8 µm) size ranges. Airborne environmental bacteria, mesophilic bacteria and fungi concentrations, were respectively in the range of 0.0–2638; 0.0–1654.9 and 11.7–566.5 CFU/m3 indoors and 155–32436; 11.7–5554 and 35–664 CFU/m3 outdoors. Bacillus atrophaeus was commonly isolated in all locations. However, Alloiococcus otitis was only found at the GH and Bacillus licheniformis at the PH. Aspergillus and Penicillium were the common fungal types in the air state and dust. Dust was accumulated on air conditioning filters and floor surfaces and these would constitute important sources of airborne bacteria and fungi inside these hospitals.

Mold Allergens in Indoor Play School Environment

Abstract Moulds are found in nature for the breakdown of leaves, wood, and other plant and animal materials. The spores of these moulds can be easily drifted by wind and travel distant places. Presence of these moulds in air can cause allergies to susceptible individuals. These moulds can directly enter into a building or their spores being carried by air in homes, offices and play schools. They are usually found to be growing on wood, dry wall, wall paper, fabric, ceiling tiles and carpeting. Air borne fungi can cause asthma and allergic rhinitis. The present study aimed to isolate and identify airborne fungi in different play schools of Visakhapatnam area. Gravity Petri-plate method is used to isolate filamentous fungus. The study was carried out for ten months viz. June 2015-March 2016. In one of the examined schools a high prevalence of fungi was observed. Most of the dominating fungi belonged to genera: Aspergillus, Cladosporium, Penicillium, Alternaria, Rhizopus and Curvularia. Aspergillus flavus and Cladosporium Cldosporiodes were reported dominating in one of the play schools which show the possibility of allergy. One of the play schools reported more spores in indoor environment. The present study stated that the presence of air borne fungal concentration varied significantly in indoor play school. The study gives a data about allergic fungi in indoor play schools where the children are exposed to these fungal spores. A further detailed research is necessary to assess the exposure levels, influence of a climate conditions as well as the clinical aspects of the presence of allergic fungal spores.

Exposure to airborne fungi during sorting of recyclable plastics in waste treatment facilities.

In working environment of waste treatment facilities, employees are exposed to high concentrations of airborne microorganisms. Fungi constitute an essential part of them. This study aims at evaluating the diurnal variation in concentrations and species composition of the fungal contamination in 2 plastic waste sorting facilities in different seasons. Air samples from the 2 sorting facilities were collected through the membrane filters method on 4 different types of cultivation media. Isolated fungi were classified to genera or species by using a light microscopy. Overall, the highest concentrations of airborne fungi were recorded in summer (9.1×10³-9.0×10⁵ colony-forming units (CFU)/m₃), while the lowest ones in winter (2.7×10³-2.9×10⁵ CFU/m³). The concentration increased from the beginning of the work shift and reached a plateau after 6-7 h of the sorting. The most frequently isolated airborne fungi were those of the genera Penicillium and Aspergillus. The turnover of fungal species between seasons was relatively high as well as changes in the number of detected species, but potentially toxigenic and allergenic fungi were detected in both facilities during all seasons. Generally, high concentrations of airborne fungi were detected in the working environment of plastic waste sorting facilities, which raises the question of health risk taken by the employees. Based on our results, the use of protective equipment by employees is recommended and preventive measures should be introduced into the working environment of waste sorting facilities to reduce health risk for employees. Med Pr 2017;68(1):1-9.

Air Microbial Contamination and Factors Affecting Its Occurrence In Certain Book Libraries In Egypt.

Bacterial and fungal contamination in the air and settled dust were studied in old and new book libraries located in the National Research Center (NRC), Dokki, Giza, Egypt. The investigated libraries differ in age, design, size, ventilation type, and number of occupants in relation to microclimatic parameters and particulate matter (PM) load. Airborne microorganisms were collected using an Andersen two stage impactor sampler. Indoor airborne bacteria and fungi ranged from 0-1060.4 CFU/m3 and 11.8-315.6 CFU/m3, respectively. Outdoor airborne bacteria and fungi ranged within 11.7-2514.7 CFU/m3 and 0-713.7 CFU/m3, respectively. Bacteria and fungi associated surface settled dust ranged from 0.4-10x106 CFU/gm and 0-73x104 CFU/gm, respectively. Fine microbial fraction (particles ≤ 8 μm in size) constituted 2-24.94% and 68.35-94.15% of the total airborne bacterial and fungal concentrations, respectively. Indoor/outdoor (I/O) ratios of airborne microorganisms were less than 1 at both libraries, indicating no indoor microbial sources. Gram positive cocci (14.3-47%) and bacilli (52.9-85.7%) were the dominant bacterial isolates in the air state, while bacilli represented 100% of the total isolates in the surface settled dust. Bacillus pseudomycoides and B. subtilis dominated indoors while B. subtilis and Staphylococcus outdoors. Aspergillus and Penicillium, were the common fungal species in both libraries under investigation. Many of the isolated fungal taxa had enzymatic activities (lipase, protease and cellulase), with A. flavus, Curvularia pallescens, Fusarium oxysporium, P. notatum and Trichoderma viride presented all enzymatic activities. Complex correlations and no-clear patterns were found between the airborne microorganisms and the environmental factors.

Summer airborne mycoflora of Timişoara (Romania) and relationship to meteorological parameters

The present aeromycological investigation was undertaken to study atmospheric fungal spores in Timişoara (western Romania). This study was carried out using a Hirst type volumetric sampler. The study revealed the existence of a rich airborne mycoflora. The atmospheric fungal spores were classified and evaluated into three groups (‘major’, ‘minor’ and ‘sporadic’) depending upon their catch percentage in the air. Cladosporium/Fusarium/Leptosphaeria-group, Alternaria, Helminthosporium airborne fungal spores and airborne fungal fragments regularly recorded (frequency 100% of days). Cladosporium accounted for 81.09% of the outdoor fungal spores. The airborne fungal fragments have been identified as abundant in our geographic area. Spearman’s correlations were applied to meteorological parameters and airborne fungal spore concentrations. In addition, correlations were calculated between the fungal spore concentrations and the meteorological variables from the previous day. A total of eleven weather factors were selected for this investigation. Following Spearman’s correlations, I identified two patterns of behaviour: most of the airborne fungal spores prefer cloudiness, lower near-surface soil temperature, lower atmospheric pressure, higher relative humidity and precipitation (pattern A) while other spore concentrations favour increased sunshine, higher near-surface soil temperature and dry conditions (pattern B). The behaviour of some fungal spores during the warm season has proven unclear (pattern C). This study demonstrates the need for investigations throughout the year and the evaluation with complementary statistical methods, regarding the correct interpretation of airborne mycoflora relationships with meteorological parameters.

Assessment of Indoor Bioaerosols in Public Spaces by Real-Time Measured Airborne Particles

ABSTRACTHumans spend a considerable amount of time indoors, and indoor biological airborne pollutants may harm human health. Active bioaerosol samplers and conventional microbiological culture methods, which are widely applied in studies of airborne microbial contamination, are not only unable to perform continuous monitoring over long periods, but are also time-consuming and expensive. In order to rapid assess indoor airborne microbial contamination, multiple linear regression models were constructed by statistically analyzing the measured bioaerosol samples and the real-time measured mass and number concentrations of airborne particles using a direct reading instrument from 43 air-conditioned public spaces. There were significant positive correlations of indoor airborne bacterial and fungal concentrations with indoor size-segregated particle mass and number concentrations. The predictive power of the model was sufficient for predicting indoor bacterial concentrations from the indoor and outdoor size-segregated particle number concentrations as independent variables. Particle number concentration outperforms particle mass concentration as an independent variable in predicting indoor bioaerosol concentrations. The prediction model for indoor bacterial bioaerosol levels constructed in this study could facilitate a rapid assessment of potential airborne bacterial contamination via the simple and feasible measurement of particle number concentration, thus helping to improve the management and maintenance of indoor air quality.

A study of airborne fungal allergens in sandstorm dust in Al-Zulfi, Central region of Saudi Arabia

Background The impact of sandstorm dust events on local air quality and public health are becoming a greater concern in the Kingdom of Saudi Arabia. Among sandstorm dust particles, airborne fungal spores cause serious respiratory ailments to those who are exposed to the dust. Although the study of dust storm material has attracted research interest, little work has been carried out in Saudi Arabia and no major study has been conducted in the Al-Zulfi, Riyadh province region. Hence, the aim of the study was to investigate airborne fungal allergen concentrations in sandstorm dust in the Al-Zulfi city, Saudi Arabia. Methods During the study period 12 sandstorm dust samples and 3 control samples were collected from various locations (educational campus, people gathering and recreational places) by gravitational plate exposure method using Sabouraud Dextrose Agar. Following incubation, the fungal colonies were identified by microscopic and morphological identification. Results A total of 2590 fungal isolates were identified among 36 exposures of sandstorm dust samples. From the samples dematiaceous fungi and hyaline fungi were observed, divided 56.2%, 43.8 % respectively. The incidences of predominant fungal genera were Fusarium (21%), Cladosporium (15.8%), Ulocladium (11.1%), Aspergillus (10.9%), and Alternaria (8.6%). Conclusion Our observations infer that some of the most important allergenic fungal spores are predominantly observed in sandstorm dust samples and incidences of dematiaceous fungi are higher than hyaline fungi. The present study highlights the need for precautionary safety measures to protect the public against sandstorm dust exposures.

Field measurement of indoor air quality and airborne microbes in a near-zero energy house with an earth tube in the cold region of Japan

This study was conducted to evaluate the level of microbial contamination of indoor air during 3 years for two residences in one building equipped with heat recovery ventilation devices and located in Kimobetsu town of Hokkaido, Japan. This article documents a case study aimed at monitoring the microbes contaminations indoors for a safe use of energy saving ventilation devices and sanitary indoor air. This articles describes an investigative approach with three components. First, the authors evaluated the indoor air quality and microbial concentration by comparing the concentrations of particulate matter (PM10 and PM2.5), carbon dioxide, and airborne bacteria and fungi of indoor air and outdoor air during spring, summer and winter. Second, the microbial concentration inside an earth tube and a fixed sensible heat exchanger was evaluated by measuring the airborne microbial concentration of the supply air. Third, the authors assessed the possibility of microbial contamination inside the earth tube using the fungal index and by measuring temperature and relative humidity at the tube's outlet airflow. The results showed that the total concentration of airborne fungi was higher in summer than in spring or winter and that the fungal genera Cladosporium sp. and Penicillium sp. were dominant in the samples. Additionally, it was found that the environment inside the earth tube allowed easy growth of fungi from May to September with the highest fungal index measured in August. It was also confirmed that the earth tube did not affect the supply air for a building constructed 4 years ago.

A study of the energy consumption and airborne microbe concentration in the Sapporo underground walkway, in a cold region of Japan

The present study sought to evaluate the energy consumption, indoor air quality and concentration of airborne bacteria and fungi in the Sapporo underground walkway, which is in a cold region of Japan. The energy consumption, temperature, relative humidity, and carbon dioxide concentrations of the underground walkway were investigated for 4 years from its opening in 2011 (until 2014). The temperature, relative humidity, and carbon dioxide concentrations were automatically detected using sensors and data from Sapporo city hall. To evaluate the microbial contamination in the ventilation system and indoors, the concentrations of airborne bacteria and fungi were measured on 2 days (a weekday and a weekend day) during opening hours in both summer and winter. The concentration of airborne microbes in the supply air, indoor air, and outside air was compared. Species of airborne bacteria were identified using 16S rDNA sequence analysis. The energy use intensities were decreased in 2013, when the walkway temperature was changed during both winter and summer. The carbon dioxide concentration in the walkway was maintained below 1000 ppm. The number of airborne bacteria and fungi in the supply air from the ceiling diffuser was lower than those in the outdoor and indoor air. These results indicate that both energy consumption and indoor air quality were maintained in the walkway throughout the 4-year period. This study could be helpful for developing the related standards for indoor air quality and for developing control strategies to properly operate air conditioning and ventilation systems in underground spaces.

Erratum to: Concentrations and identification of culturable airborne fungi in underground stations of the Seoul metro.

The purpose of this study was to measure the culturable airborne fungi (CAF) concentrations in the underground subway stations of Seoul, Korea at two time points. This study measured the CAF concentrations in enclosed environments at 16 underground stations of the Seoul Metro in 2006 and 2013 and investigated the effects of various environmental factors, including the presence of platform screen doors, temperature, relative humidity, and number of passengers. CAF concentrations at the stations in 2006 were significantly higher than that at the same stations in 2013 (p < 0.001). Furthermore, there was a significant correlation between CAF concentration and relative humidity (r = 0.311, p < 0.05). Geotrichum and Penicillium were the predominant genera. The CAF concentrations in stations with an operating supply air were significantly higher than that in stations with no supply air (p < 0.001). Therefore, it is recommended that special attention be given to stations with clean supplied air to improve the indoor air quality of these subway stations.

A Case Study on the Health Risks Related to Flood Disasters in South Africa

Floods occurred in the Ndlambe Local Municipality in South Africa in October 2012. During various stages of the post-disaster recovery, bacterial concentrations were measured in water and soil samples from the flood zone. All drinking water concentrations ofE. coliwere below 1–3 colony forming units per 100 millilitres (CFUs/100 mL). The flood waters contained between 46500 to more than 100000 CFUs/100 mL ofE. coli. {The concentrations ofSalmonellaspp. in the flood waters varied from 5000 to 250000 CFUs/100 mL. The presumptiveVibriospp. concentrations in flood waters ranged from 1000 to over 150000 CFUs/100 mL. {The soil concentrations forE. coliranged from 1 to above 330 colony-forming units per 1 g of soil dry weight (CFUs/g). The soil concentrations ofSalmonellaspp. varied from below 1 to 22 CFUs/g. The estimated airborne fungal concentrations ranged from 16820 to 28540 colony-forming units per 1 cubic meter. An outbreak of an infectious disease was recorded among the volunteers who assisted with the post-disaster recovery. The likely bacterial causative agents included strains ofAeromonasspp. andVibrio cholerae. Any human contact with either the contaminated flood waters or of flooded dwellings should only occur, if the individuals in questions are equipped with the full-body personal protective gear. Non-governmental stakeholders performed majority of the post-disaster recovery operations, as the local government could only cover 11% of the required costs. Applying sanitation funds to disaster recovery and increased use of the low-cost flood defence products in high risk areas could provide a solution for the future.

Concentrations and identification of culturable airborne fungi in underground stations of the Seoul metro.

The purpose of this study was to measure the culturable airborne fungi (CAF) concentrations in the underground subway stations of Seoul, Korea at two time points. This study measured the CAF concentrations in enclosed environments at 16 underground stations of the Seoul Metro in 2006 and 2013 and investigated the effects of various environmental factors, including the presence of platform screen doors, temperature, relative humidity, and number of passengers. CAF concentrations at the stations in 2006 were significantly higher than that at the same stations in 2013 (p<0.001). Furthermore, there was a significant correlation between CAF concentration and relative humidity (r=0.311, p<0.05). Geotrichum and Penicillium were the predominant genera. The CAF concentrations in stations with an operating supply air were significantly higher than that in stations with no supply air (p<0.001). Therefore, it is recommended that special attention be given to stations with clean supplied air to improve the indoor air quality of these subway stations.

Bats Increase the Number of Cultivable Airborne Fungi in the "Nietoperek" Bat Reserve in Western Poland.

The “Nietoperek” bat reserve located in Western Poland is one of the largest bat hibernation sites in the European Union with nearly 38,000 bats from 12 species. Nietoperek is part of a built underground fortification system from WWII. The aims of the study were (1) to determine the fungal species composition and changes during hibernation season in relation to bat number and microclimatic conditions and (2) evaluate the potential threat of fungi for bat assemblages and humans visiting the complex. Airborne fungi were collected in the beginning, middle and end of hibernation period (9 November 2013 and 17 January and 15 March 2014) in 12 study sites, one outside and 11 inside the complex. Ambient temperature (Ta) and relative humidity (RH) were measured by the use of data loggers, and species composition of bats was recorded from the study sites. The collision method (Air Ideal 3P) sampler was used to detect 34 species of airborne fungi including Pseudogymnoascus destructans (Pd). The density of airborne fungi isolated from the outdoor air samples varied from 102 to 242 CFU/1 m3 of air and from 12 to 1198 CFU in the underground air samples. There was a positive relationship between number of bats and the concentration of fungi. The concentration of airborne fungi increased with the increase of bats number. Analysis of other possible ways of spore transport to the underground indicated that the number of bats was the primary factor determining the number of fungal spores in that hibernation site. Microclimatic conditions where Pd was found (median 8.7 °C, min-max 6.1–9.9 °C and 100 %, min-max 77.5–100.0 %) were preferred by hibernating Myotis myotis and Myotis daubentonii; therefore, these species are most probably especially prone to infection by this fungi species. The spores of fungi found in the underground can be pathogenic for humans and animals, especially for immunocompromised persons, even though their concentrations did not exceed limits and norms established as dangerous for human health. In addition, we showed for the first time that the air in bats hibernation sites can be a reservoir of Pd. Therefore, further study in other underground environments and wintering bats is necessary to find out more about the potential threat of airborne fungi to bats and public health.

Associations of dwelling characteristics, home dampness, and lifestyle behaviors with indoor airborne culturable fungi: On-site inspection in 454 Shanghai residences

From March 2013 to December 2014, we collected air samples of airborne culturable fungi from 454 residences with young children (mean age: 6.9 years-old) in Shanghai, China. We also measured indoor air temperature and relative humidity, and compiled information regarding dwelling characteristics, lifestyle habits, and dampness-related indicators. Mean concentrations (mean ± SD) of culturable fungi in the child's bedrooms (n = 445) and in the living rooms (n = 436) were 310 ± 313 (range: 6–3184) cfu/m3 and 300 ± 288 (range: 19–3044) cfu/m3, respectively. The concentrations of airborne fungi were higher in spring and winter than in other seasons, but were only slightly correlated with indoor air temperature and relative humidity in any season. Higher levels of airborne culturable fungi in the child's bedroom were significantly associated with location in a rural area, constructed before 2000, ground/top floor of the residential building, and building area <10 m2. Among those residences inspected in winter, rooms with poor ventilation and residences with spiders and cockroaches, damp spots and moldy spots on the wall surface were associated with higher concentrations of indoor airborne culturable fungi. We found that the household level of airborne fungi was acceptable in most of Shanghai's current residences. The possibility of indoor airborne culturable fungi during cold spring and winter requires more attention than in other seasons. Preventing dampness-related damage, improving indoor ventilation, and maintaining a dwelling free of spiders and cockroaches may decrease indoor level of airborne culturable fungi.