Airborne Fungal Concentrations Research Articles

The indoor air as a potential determinant of the frequency of invasive aspergillosis in the intensive care

Invasive aspergillosis (IA) seems to be an emerging condition in intensive care units (ICUs). However, little attention has been given to the role of environmental factors that could increase the risk for IA in the ICU. The objective of this study was to determine the concentration of airborne fungi in three Brazilian ICUs, in an attempt to correlate fungal burden with the frequency of Aspergillus spp isolation from clinical samples of patients hospitalised in these units. During a 1-year period we quantitatively evaluated the presence of fungi in the air of three ICUs in Porto Alegre, Brazil. The quantity of fungi was correlated with environmental factors. Only one of the ICUs studied showed equal concentrations of Aspergillus conidia in the indoor air, in comparison with the outdoor environment. All cases of Aspergillus colonisation and IA cases observed during the study occurred in that particular ICU. Environmental factors have a direct influence on fungal spore concentration in the air in ICUs, as well as air filtration systems in air conditioners. Fungal contamination of the indoor air may influence the frequency of AI in ICU patients.

Coarse and fine culturable fungal air concentrations in urban and rural homes in Egypt.

The main objective of the present study was to assess culturable airborne fungal concentrations, and types in different seasons. Two-stage viable impactor samplers were used with malt extract agar medium as the collection media. Culturable airborne fungal concentrations were collected indoors and outdoors of 43 homes in urban and rural environments from November 2008 to October 2009 in Egypt. Fungal concentrations were significantly higher in the rural environment than the urban environment. The median indoor and outdoor total fungal concentrations were 608 and 675 CFU/m3 in the urban environment and 1,932 and 1,872 CFU/m3 in the rural environment, respectively. The greatest concentrations were found in the autumn and spring season. Indoor and outdoor concentrations were significantly correlated (P < 0.001). The highest concentrations were observed in the fungal size range of <8 µm (fine fraction). The indoor/outdoor (I/O) ratios were not statistically different between seasons. Alternaria, Aspergillus, Cladosporium, Penicillium and yeasts were the predominant genera indoors and outdoors, and the abundance of genera varied by season and region. This study is of a potential interest as little reported research on the indoor fungal air quality from Egypt.

Aeromikologiczne badania występowania zarodników grzybów patogenicznych dla roślin w piętrze subalpejskim Karkonoskiego Parku Narodowego

Fungi occurring as saprophytes or parasites on a variety of substrata. Concentrations of airborne fungi depend on several factors f.ex.: weather conditions, vegetation, height above the sea level and human activities. The experiment was conducted in 2011–2012. The occurence of plant pathogenic fungi was found in the air of subalpine zone of Karkonosze National Park and in Izerskie Mountains. Air samples were taken from 3 locations on the Karkonosze Mts and one from Izerskie Mts. To examine the air Air Ideal 3P sampler and acidified PDA (Potato Dextrose Agar) medium were used. The highest numbers of CFU/m3 air (Colony Forming Unit of 1 m3 air) of fungus were isolated from the Hala Izerska in Izerskie Mts on April 2011, and Szrenica top in Karkonosze Mts on September 2011. Cladosporium cladosporioides was the most abundant species at all locations (up to 30%) followed by Alternaria alternata (16–20%), Fusarium spp. (up to 10%) and Sclerotinia sclerotiorium (up to 6%). The genus Cladosporium is one of the most abundant airborne fungi. Also A. alternata shows a similar pattern in response, like another fungi species Fusarium or S. sclerotiorium. W latach 2011–2012 przeprowadzono badania aeromikologiczne w odstępach 3–4 tygodniowych od maja do października. Badania wykonano metodą zderzeniową przy użyciu urządzenia Air Ideal 3P. Pomiar był wykonywany w trzech lokalizacjach, w piętrze subalpejskim Karkonoskiego Parku Narodowego oraz porównawczo na Hali Izerskiej w Górach Izerskich. W trakcie przeprowadzonych badań stwierdzono występowanie zarodników 34 gatunków grzybów w pierwszym roku i 25 gatunków w drugim roku prowadzenia badań. Występowały zarodniki grzybów zarówno saprotroficznych, jak i patogenicznych dla roślin. Wśród tych drugich największym udziałem charakteryzował się gatunek Cladosporium cladosporioides – 25,4% wszystkich uzyskanych zarodników w roku 2011 i 28,8% w drugim roku badań. Drugim gatunkiem patogenicznym dla roślin, którego zarodniki występują w dużym nasileniu w piętrze subalpejskim Karkonoszy był grzyb Alternaria alternata. W pierwszym roku badań stanowił on 24% wszystkich stwierdzonych zarodników, a w 2012 roku – 16,4%. W obydwu latach badań obserwowano także występowanie w powietrzu zarodników Sclerotinia sclerotiorum na wszystkich obiektach badawczych. Oprócz wspomnianych gatunków w powietrzu piętra subalpejskiego Karkonoszy oraz na Hali Izerskiej notowano także zarodniki innych patogenów, jak np. Botrytis cinerea czy też Ulocladium botrytis. W powietrzu, w piętrze subalpejskim Karkonoszy oraz na Hali Izerskiej stwierdzono także obecność zarodników grzybów rodzaju Fusarium.

Concentration and distribution characteristics of airborne fungi in indoor and outdoor air of Tehran subway stations

The concentration and distribution characteristics of airborne fungi were investigated in indoor and outdoor air of two metro stations (Imam Khomeini and Sadeghiyeh stations) in Tehran subway. Samples were taken from indoor air at each station from platform and ticket office area also from adjacent outdoor air of each station. Indoor sampling was conducted for two types of trains, old and new. The concentration of airborne fungi ranged from 21 CFU/m3 at the outdoor air of Imam Khomeini station to 1,402 CFU/m3 in the air samples collected from the platform of this station. Results showed that airborne fungi concentrations at indoor air were higher than the outdoor air (p < 0.05), and fungal levels significantly correlated with the number of passengers (p < 0.05; r = 0.68) and RH % (p < 0.05; r = 0.43). Sixteen genera of fungi were isolated in all sampled environments. The predominant genera identified in indoor and outdoor air were Penicillium spp. (34.88 % of total airborne fungi) and Alternaria spp. (29.33 % of total airborne fungi), respectively. The results of this study showed that the indoor air quality in subway is worse than the outdoor air.

Changes in concentration of Alternaria and Cladosporium spores during summer storms

Fungal spores are known to cause allergic sensitization. Recent studies reported a strong association between asthma symptoms and thunderstorms that could be explained by an increase in airborne fungal spore concentrations. Just before and during thunderstorms the values of meteorological parameters rapidly change. Therefore, the goal of this study was to create a predictive model for hourly concentrations of atmospheric Alternaria and Cladosporium spores on days with summer storms in Szczecin (Poland) based on meteorological conditions. For this study we have chosen all days of June, July and August (2004–2009) with convective thunderstorms. There were statistically significant relationships between spore concentration and meteorological parameters: positive for air temperature and ozone content while negative for relative humidity. In general, before a thunderstorm, air temperature and ozone concentration increased, which was accompanied by a considerable increase in spore concentration. During and after a storm, relative humidity increased while both air temperature ozone concentration along with spore concentrations decreased. Artificial neural networks (ANN) were used to assess forecasting possibilities. Good performance of ANN models in this study suggest that it is possible to predict spore concentrations from meteorological variables 2 h in advance and, thus, warn people with spore-related asthma symptoms about the increasing abundance of airborne fungi on days with storms.

Applicability of a modified MCE filter method with Button Inhalable Sampler for monitoring personal bioaerosol inhalation exposure

In this study, a "modified" mixed cellulose ester (MCE) filter culturing method (directly placing filter on agar plate for culturing without extraction) was investigated in enumerating airborne culturable bacterial and fungal aerosol concentration and diversity both in different environments. A Button Inhalable Sampler loaded with a MCE filter was operated at a flow rate of 5 L/min to collect indoor and outdoor air samples using different sampling times: 10, 20, and 30 min in three different time periods of the day. As a comparison, a BioStage impactor, regarded as the gold standard, was operated in parallel at a flow rate of 28.3 L/min for all tests. The air samples collected by the Button Inhalable Sampler were directly placed on agar plates for culturing, and those collected by the BioStage impactor were incubated directly at 26 °C. The colony forming units (CFUs) were manually counted and the culturable concentrations were calculated both for bacterial and fungal aerosols. The bacterial CFUs developed were further washed off and subjected to polymerase chain reaction-denaturing gradient gel electrophoresis (DGGE) for diversity analysis. For fungal CFUs, microscopy method was applied to studying the culturable fungal diversity obtained using different methods. Experimental results showed that the performance of two investigated methods varied with sampling environments and microbial types (culturable bacterial and fungal aerosols). For bacterial aerosol sampling, both methods were shown to perform equally well, and in contrast the "modified" MCE filter method was demonstrated to enumerate more culturable fungal aerosols than the BioStage impactor. In general, the microbial species richness (number of gel bands) was observed to increase with increasing collection time. For both methods, the DGGE gel patterns were observed to vary with sampling time and environment despite of similar number of gel bands. In addition, an increase in sampling time from 20 to 30 min was found not to substantially alter the species richness. Regardless of the sampling methods, more species richness was observed in the outdoor environment than the indoor environment. This study described a new personal bioaerosol exposure assessment protocol, and it was demonstrated applicable in monitoring the personal bioaerosol exposure in replace of an Andersen-type impactor.

A survey of outdoor and indoor airborne fungal spora in the Redemption City, Ogun State, south-western Nigeria

The concentration and biodiversity of airborne fungi of the Redemption City, an immense campground for Christian faithful and the temporary site of the Redeemer’s University in south-western Nigeria, was studied between February and May 2011 using the culture plate method. The study was undertaken to assess the concentrations of fungal spores and their health implication in this ever-busy environment. Fifteen different sites classified as closed or open were selected. During the experiment, a total of 228 colonies were counted, and 29 fungal species belonging to 26 genera were isolated which include the following: Aspergillus flavus, Aspergillus niger, Bipolaris spp., Chrysosporium spp., Cladosporium spp., Coniothyrium corda, Curvularia spp., Diplodia spp., Fusarium spp., Gliocladium spp., Monilia spp., Mucor spp., Mucor plumbeus, Penicillium spp., Phycomyces spp., Phytophthora spp., Pilobolus spp., Pyrenochaeta spp., Rhizopus stolonifer, Torula spp., Trichoderma spp. and Trichophyton spp. The most frequently occurring fungi were A. niger, C. corda and M. plumbeus, while the least recorded were Torula and Trichophyton species. Majority of the fungi isolated are known allergens; they could also be opportunistic causing various diseases in man. There is therefore a dire need for good sanitation practices within the studied areas of the camp.

Biosafety Assessment and Airborne Fungal Concentration as an Evaluation Index in University Laboratories and Hospital Diagnostic Korean Laboratories

ABSTRACT This study evaluated both biosafety levels (BLs) and airborne fungal concentrations in microbiological laboratories in Seoul, Korea. To evaluate biosafety facilities, we used a checklist containing 67 questions in nine categories. We also measured airborne fungal concentration according to the BLs. Airborne fungal concentrations were higher in BL-1 facilities (240 CFU/m3) than in BL-2 facilities (25 CFU/m3). The airborne fungal concentrations significantly differed among the laboratories that were graded as poor, fair, and good. Especially, a significant negative correlation was observed between the airborne fungal concentrations and the biosafety levels (p = .001). We recommend that the guidelines of biosafety be followed to improve laboratory environment.

Characterization of allergens and airborne fungi in low and middle‐income homes of primary school children in Durban, South Africa

The South Durban Health Study (SDHS) is a population-based study that examined the relationship between exposure to ambient air pollutants and respiratory disease among school children with high prevalence of asthma who resided in two purposely selected communities in north and south Durban, KwaZulu-Natal, South Africa. From the SDHS participants, a subgroup of 135 families was selected for investigation of household characteristics potentially related to respiratory health. In these households, a walkthrough investigation was conducted, and settled dust and air samples were collected for allergen and fungal measurements using standardized techniques. Asp f1 allergen was detected in all homes, and Bla g1 allergen was detected in half of the homes. House dust allergens, Der f1 and Der p1 exceeded concentrations associated with risk of sensitization and exacerbation of asthma in 3% and 13%, respectively, of the sampled homes, while Bla g1 exceeded guidance values in 13% of the homes. Although airborne fungal concentrations in sleep areas and indoors were lower than outdoor concentrations, they exceeded 1,000 CFU/m(3) in 29% of the homes. Multivariate analyses identified several home characteristics that were predictors of airborne fungal concentrations, including moisture, ventilation, floor type, and bedding type. Airborne fungal concentrations were similar indoors and outdoors, which likely reduced the significance of housing and indoor factors as determinants of indoor concentrations. Allergen concentrations were highly variable in homes, and a portion of the variability can be attributed to easily recognized conditions.

Particle counting and microbiological air sampling: Results of the simultaneous use of both procedures in different types of hospital rooms

IntroductionIn order to assess the relationship between the concentrations of airborne fungi and particles, particle counting was combined with fungal air sampling in several rooms of a hospital. MethodsConcentrations of ≥0.5μm particles (P05) and ≥1μm particles (P1) were measured using a particle counter; fungal air sampling was performed with volumetric air samplers, which impacted air on Rodac plates with Sabouraud chloramphenicol agar. Particle counts were categorised according to ISO 14644-1 standard cut-off points; their association with fungal detection was assessed with Fisher's exact test. ResultsForty-two simultaneous samplings were carried out: 24 in operating rooms, 13 in rooms for burns or haematology patients, 3 in pharmacy clean rooms, and two in other procedure rooms. Filamentous fungi were recovered in 5 samples, which also had higher particle counts. No fungi were detected in 12 samplings with both P05 and P1 concentrations below the maximum for class 6 clean rooms; 4 of 7 samplings with both concentrations within the range for class 8 clean rooms were positive for fungi. The association between fungal detection and higher particle counts was statistically significant, both for P05 (p=.004) and P1 (p=.003). There was a partial overlap between the concentrations of particles of samplings which were positive or negative for fungi. ConclusionsThere is a relationship between the concentrations of P05 and P1 and airborne fungi in hospital rooms. When both P05 and P1 concentrations are below the maximum for class 6 clean rooms, a negative fungal detection can be predicted.

Influence of dust storms on concentration and content of fungi in the atmosphere of Haifa, Israel

Dust storms originating primarily in the Saharan desert heavily affect the Eastern Mediterranean, mostly during the winter and spring season. The main goal of our study addresses the qualitative and quantitative aspects of dust-associated fungal communities sampled during dust events in the years 2004–2005 in Haifa, Israel, and their comparison with the communities sampled on adjacent clear days. The effect of particulate matter concentrations and elemental composition of the atmospheric particles on fungal communities was also estimated. Airborne fungi were collected with the Six Stage Andersen Viable Impactor. Their taxonomic identification was based mainly on morphological characteristics; one repeatedly isolated type of non-sporulated colonies was identified employing the polymerase chain reaction. During six dust events and the adjacent clear days, 98 species were collected—79 and 32 species in dusty and clear days, respectively. The dust-associated fungal communities were significantly richer than the communities of clear days (Wilcoxon signed-rank test, p = 0.03). Remarkable increases in the concentration of airborne fungi during the dust events compared to the adjacent clear days have been also revealed. The canonical correspondence analysis showed that the concentration of fine atmospheric particles was the dominant environmental factor influencing the distribution of most common fungal species followed by the concentration of geological elements and coarse particles. Overall, the study revealed a distinct pattern of distribution of fungi in the atmosphere of Haifa that was strongly related to Saharan dust storms.

퇴비화 시설과 매립장에서 배양 가능한 공기중 미생물의 분포 및 특성

3(range 6.0×10 1 –9.3×10 3 ) at the entrance of the facility. These concentrations were 460 and 280 times higher than those of reference sites. Coliform bacteria were detected both inside and entrance of the facility. On the landfill, heterotrophic bacterial concentrations averaged (in MPN/m 3 ) 4.9×10 2 (range 1.7×10 2 –1.0×10 3 ), while they averaged 3.7×10 2 (range 4.8×10 1 –1.3×10 3 ) at the parking lot of the landfill. These concentrations were 35 and 26 times higher than those of reference sites. When we isolated and tentatively identified heterotrophic bacteria, Pseudomonas luteola was the most dominant species in bioaerosols from the composting facility, whereas the most abundant one in reference samples was Micrococcus sp. Average concentrations of airborne fungi were measured between 4.8×10 2 and 7.9×10 2 MPN/m 3 depending on sites, which were 2.1–3.4 times higher compared to those of reference sites. While Cladosporium, Alternaria, and Penicillium were commonly identified fungal genera, genus Aspergillus was identified only in bioaerosols from the composting facility.

Workplace Exposure to Bioaerosols in Podiatry Clinics

The aim of this study was to design and execute a pilot study to collect information on the personal exposure levels of podiatrists to microbial hazards in podiatry clinics and also to assess health and safety knowledge within the sector using a questionnaire survey. A self-report quantitative questionnaire dealing with health and safety/health issues was issued to 250 podiatrist clinics. Fifteen podiatry clinics were randomly recruited to participate in the exposure study. Concentrations of airborne bacteria, fungi, yeasts, and moulds were assessed using a six-stage viable microbial cascade impactor. Personal samples of total inhalable dust and endotoxin were measured in the breathing zone of the podiatrist. A questionnaire response rate of 42% (N = 101) was achieved. Thirty-two per cent of respondents indicated that they had a respiratory condition; asthma was the most prevalent condition reported. The most frequently employed control measures reported were use of disposable gloves during patient treatments (73.3%), use of respiratory protective equipment (34.6%), use of protective aprons (16.8%), and eye protection (15.8%). A total of 15.8% of respondents used mechanical room ventilation, 47.5% used nail drills with local exhaust ventilation systems, and 11% used nail drills with water spray dust suppression. The geometric mean concentrations of bacteria, Staphylococci, fungi, and yeasts/moulds were 590, 190, 422, and 59 CFU m(-3), respectively. The geometric mean endotoxin exposure was 9.6 EU m(-3). A significant percentage of all the bioaerosols that were in the respirable fraction was representative of yeasts and moulds (65%) and Fungi (87%). Even if statistical analysis of data is limited by low sample numbers, this study showed that the frequency of cleaning and use of RPE varied between clinics sampled, and it is likely that refresher health and safety training focusing on health and safety hazards inherent in podiatry work and practical control measures is warranted.

Diurnal variations of airborne fungal spores concentration in the town and rural area

Airborne fungal spores were monitored in 2001-2002 in Rzeszów (town) and its neighborhood. The aim of investigations was to ascertain if there were differences in diurnal variations of airborne fungal spores concentration between town and rural area. The sampling was carried out using volumetric method. Traps were located at the same heights - app. 12 m. Airborne spores were sampled continuously. Microscopical slides were prepared for each day. Analysis was carried out on one longitudinal band of 48 mm long divided into 24 segments corresponding following hours of day. The results were expressed as mean number of fungal spores per cubic meter per 24 hours. For this survey, five geni of allergenic fungi were selected: &lt;i&gt;Alternaria&lt;/i&gt;, &lt;i&gt;Botrytis&lt;/i&gt;, &lt;i&gt;Cladosporium&lt;/i&gt;, &lt;i&gt;Epicoccum&lt;/i&gt;, &lt;i&gt;Ganoderma&lt;/i&gt;. The concentrations of their airborne spores were high or very high. It was calculated theoretical day, where the hourly count was the percentage mean of number of spores at that time every chosen day without rainfall from 2001 and 2001 years. The diurnal periodicity of &lt;i&gt;Alternaria&lt;/i&gt;, &lt;i&gt;Cladosporium&lt;/i&gt;, &lt;i&gt;Epicoccum&lt;/i&gt; and &lt;i&gt;Ganoderma&lt;/i&gt; showed one peak, while &lt;i&gt;Botrytis&lt;/i&gt; two. Anamorphic spores peaked in the afternoon, while their minima occurred in the morning. The highest concentrations of &lt;i&gt;Ganoderma&lt;/i&gt; basidiospores were at down or at night, but minima during the day. There were no clear differences in the peak values between two studied sites. The results indicate that maximum concentrations of all spores generally occurred a few hour earlier in the rural area than in the town. Probably, in the rural area airborne spores came from many local sources and their diurnal periodicity reflected rhythm of spore liberation. Towns are characterized by specific microclimate with higher temperature and wind blowing to the centre. In Rzeszów fungal spores could be transported outside and carried out by wind from distant sources. This study showed, among others, that habitat conditions are an important factors influenced diurnal periodicity of airborne fungal spores.

VERIFICATION OF INDOOR AIR QUALITY BEFORE AND AFTER MOVING IN THE HOUSE EQUIPPED WITH THE AIR-CLEANING SYSTEM

The concentrations of fine-particles and airborne fungi, the amount of mite allergen were measured before and after moving in the houses equipped with the air-cleaning system for the countermeasure against allergy. As a result, the concentration of fine-particles and airborne fungi in the houses for the countermeasure against allergy were lower than that of the houses before moving. Amount of mite allergens was also lower. The particle collection efficiency of the air-cleaning system was calculated from the measurement results.

초등학생 가정을 대상으로 한 바이오에어로졸 노출과 아토피와의 연관성 평가

Objectives: Exposure to bioaerosols in the indoor environment could be associated with a variety adverse health effects, including allergic disease such atopy. The objectives of this study were to assess children's exposure to bioaerosol in home indoor environments and to evaluate the association between atopy and bioaerosol, environmental, and social factors in Ulsan, Korea. Methods: Samples of viable airborne bacteria and fungi were collected by impaction onto agar plates using a Quick Take TM 30 and were counted as colony forming units per cubic meter of air (CFU/). Bioaerosols were identified using standard microbial techniques by differential stains and/or microscopy. The environmental factors and possible causes of atopy based on ISAAC (International Study of Allergy and Asthma in Childhood) were collected by questionnaire. Results: The bioaerosol concentrations in indoor environments showed log-normal distribution (p , respectively. Indoor fungal levels were significantly higher than those of bacteria (p , in three out of 92 samples (3.3%) from 52 homes. The means of indoor to outdoor ratio (I/O) for airborne bacteria and fungi were 8.15 and 1.13, respectively. The source of airborne bacteria was not outdoors but indoors. GM of airborne bacteria and fungi were 217.6, 291.8 CFU/ in the case's home and 162.0, 415.2 CFU/ in the control's home respectively. The difference in fungal distributions between case and control were significant (p = 0.004) and the odds ratio was 0.996 (p = 0.027). Atopy was significantly associated with type of house (odds ratio = 1.723, p = 0.047) and income (odds ratio = 1.891, p = 0.041). Some of the potential allergic fungal genera isolated in homes were Cladosporium spp., Botrytis spp., Aspergillus spp., Penicillium spp., and Alternatia spp. Conclusions: These results suggest that there this should be either 'was little' meaning 'basically no significant association was found' or 'was a small negative' mean that an association was found but it was minor. It's a very improtant distinction. Association between airborne fungal concentrations and atopy and certain socioeconomic factors may affect the prevalence of childhood atopy.

Airborne bacteria, fungi, and endotoxin levels in residential microenvironments: a case study

Limited data are currently available on the concentrations of airborne bacteria, fungi, and endotoxins in indoor environments. The levels of aerial bacteria and fungi were measured at several microenvironments within a well-ventilated residential apartment in Singapore including the living room, kitchen, bedroom, toilet, and at a workplace environment by sampling indoor air onto culture medium plates using the 6-stage Andersen sampler. Total microbial counts were determined by collecting the air samples in water with the Andersen sampler, staining the resultant extracts with a fluorescent dye, acridine orange, and counting the microbes using a fluorescent microscope. The levels of airborne endotoxins were also determined by sampling the airborne microorganisms onto 0.4 μm polycarbonate membrane filter using the MiniVol sampler at 5 l/min for 20 h with a PM2.5 cut-off device. The aerial bacterial and fungal concentrations were found to be in the ranges of 117–2,873 CFU/m3 and 160–1,897 CFU/m3, respectively. The total microbial levels ranged from 49,000 to 218,000 microbes/m3. The predominant fungi occurring in the apartment were Aspergillus and Penicillium while the predominant bacterial strains appeared to be Staphylococcus and Micrococcus. The average indoor endotoxin level was detectable in the range of 6–39 EU/m3. The amount of ventilation and the types of human activities carried out in the indoor environment appeared to be important factors affecting the level of these airborne biological contaminants.

Airborne Microorganisms at a Senior High School in Chang-Hua County, Taiwan

Bioaerosols are a type of suspended sediments that contribute to poor air quality in Taiwan. Bioaerosols include allergens such as fungi, bacteria, actinomycetes, arthropods, and protozoa, as well as microbial products such as mycotoxins, endotoxins and glucans. When allergens and microbial products are suspended in the air, local air quality is adversely influenced. In addition, when the particle size is small enough to pass through the human respiratory tract, the health of the local population is also threatened. The classroom is where students spend a large portion of weekday time and thus could play an important role in student's exposure to potential threatening bioaerosols. The purpose of this study was to understand the airborne bacteria and fungi concentrations at a sampling classroom (with the windows opened and closed) from a senior high school in Chang-Hua County, Taiwan. The results indicate that the total average bacterial concentrations were 2.2 × 103, 1.7 × 103, 7.8 × 102, 1.2 × 103, 7.4 × 102 and 7.6 × 102 cfu/m3 using tryptic soy agar (TSA)-medium incubated for 48 hr under various sampling conditions in the morning, afternoon, and evening with windows closed and opened, respectively (i.e., morning with windows closed [MC], afternoon with windows closed [AC], evening with windows closed [EC], morning with windows opened [MO], afternoon with windows opened [AO], and evening with windows opened [EO]) at the sampling classroom. Moreover, the total average fungi concentrations were 1.1×103, 7.3×102, 6.3×102, 7.4×102, 5.8×102, and 6.2×102 cfu/m3 using malt extract agar (MEA) medium incubated for 96 hr under the same various sampling conditions (MC, AC, EC, MO, AO, and EO). The total average bacterial and fungi concentrations were higher with windows closed than with windows opened during any sampling period. Ventilation is the possible reason for the above finding. The highest average bacterial or fungi concentrations was found in the particle size of 0.53 mm (average bioaerosol size was in the range of 2.1–3.3 μm) for any sampling condition. These findings may be relevant in a forensic investigation related to a potential bioattack, since it provides baseline information of bioaerosols composition (e.g., before an attack is initiated) within the tested environment.

Monitoring and assessment of airborne fungi in Kolkata, India, by viable and non-viable air sampling methods

The composition and variability of airborne fungal spores were studied using two complementary sampling methods in an outdoor environment in Kolkata suburb for 2 years, from November 2002 to October 2004. For monitoring the total fungal spore burden in the air, Burkard 7-day volumetric sampler was used, whereas Andersen two-sage viable sampler was used for isolating the cultivable airborne fungi. Among the 37 fungal spore types identified in the air samples, the predominant ones were Cladosporium, unidentified ascospores, unidentified basidiospores, Aspergilli/Penicilli, Nigrospora, Periconia, Chaetomium, Drechslera, Alternaria, Coprinus, Ganoderma, Pithomyces, and rust spores. Only six fungal spore types (Alternaria, Aspergilli/Penicilli, Cladosporium, Curvularia, Drechslera, and Nigrospora) were recovered in common by the two samplers. For Aspergilli/Penicilli, Drechslera, and Nigrospora, the spore concentration was underestimated in the non-viable sampling method (Burkard sampler). In general, higher spore count was recorded in winter. The highest fungal species variability was observed in early monsoon (June). Relative humidity could significantly predict the seasonal periodicity of the maximum number of airborne spores. The total airborne fungi concentration recorded in the study (15-16 × 10(3) spores m(-3) of air) was lower than the proposed threshold limit value for clinical significance, suggesting apparently no or less airborne-fungi-exposure-related health risk in the sampling area. Cladosporium cladosporioides was recorded beyond the proposed threshold limit value in January 2003 and March 2004; Aspergillus fumigatus and Aspergillus nidulans in winter that might have posed considerable health risk to sensitized individuals.

Volumetric Assessment of Airborne Indoor and Outdoor Fungi at Poultry and Cattle Houses in the Mazandaran Province, Iran

The aim of this study was to assess the volume of airborne fungi in the indoor and outdoor environment of poultry and cattle houses in the Mazandaran Province in Iran. Indoor and outdoor air of twenty cattle houses and twenty-five poultry houses were sampled using a single-stage impactor, which draws air at 20 L min-1 and impacts sampled material onto Petri plates containing malt extract agar. The plates were incubated at 30 °C for seven days, after which the resulting colonies were counted. The fungi were identified and counted microscopically and macroscopically. A total of 4,662 fungal colonies were isolated from 90 plates collected from indoor and outdoor air of cattle and poultry houses. Cladosporium (55.3 %), yeast (10.0 %), and Aspergillus (9.4 %) were the most common findings. The concentration of airborne fungi in cattle and poultry houses ranged from 10 CFU m-3 to 1700 CFU m-3 in indoor and 10 CFU m-3 to 2170 CFU m-3 in outdoor environments. Cladosporium had the highest mean indoor (424.5 CFU m-3) and outdoor (449.7 CFU m-3) air concentration in the cattle houses. In the poultry houses, the highest mean concentrations were measured for Cladosporium (551.0 CFU m-3) outdoors and yeast (440.7 CFU m-3) indoors. These levels might present an occupational risk, but threshold levels for these environments have yet to be established worldwide.