Seasonal and intradiurnal variation of allergenic fungal spores in urban and rural areas of the North of Portugal

Because fungal spore emission intensity varies throughout the year and even throughout the day, study of the hourly distribution is an important aspect of aerobiological monitoring. The objective of this work was to determine seasonal and intradiurnal variation of allergenic airborne fungal spores in urban and rural areas. The aerobiological study was performed from 2005 to 2007 using Hirst-type volumetric spore traps. Fungal spore types (Cladosporium, Alternaria, and Aspergillus/Penicillium) were selected according to their allergenic capacity and their frequency in the atmosphere. Cladosporium was the most frequent fungal spore in both locations, together with Alternaria; its concentration was higher during summer whereas Aspergillus/Penicillium was more abundant during autumn. Alternaria and Cladosporium maximum daily spore concentration was reached from 16.00 to 20.00 h. Aspergillus/Penicillium spore distribution differed in the two locations, and although it was difficult to establish a distribution pattern the highest concentration were found during the night. Determination of periods of high concentration may help allergic patients to avoid the daily periods when the allergen concentration is highest.     

Main airborne Ascomycota spores: characterization by culture, spore morphology, ribosomal DNA sequences and enzymatic analysis

The aim of this work was to identify the main allergy-related Ascomycetes fungal spores present in the atmosphere of Porto, using different and complementary techniques. The atmospheric sampling, performed in the atmosphere of Porto (Portugal) from August 2006 to July 2008, indicated Cladosporium, Penicillium, Aspergillus and Alternaria as the main fungal spore taxa. Alternaria and Cladosporium peaks were registered during summer. Aspergillus and Penicillium highest values were registered from late winter to early spring. Additionally, the Andersen sampler allowed the culture and isolation of the collected viable spores subsequently used for different identification approaches. The internal-transcribed spacer region of the nuclear ribosomal repeat unit sequences of airborne Ascomycetes fungi isolates revealed 11 taxonomically related fungal species. Among the identified taxa, Penicillum and Aspergillus presented the highest diversity, while only one species of Cladosporium and Alternaria, respectively, were identified. All selected fungal spore taxa possessed phosphatase, esterase, leucine arylamidase and β-glucosidase enzymatic activity, while none had lipase, cystine arylamidase, trypsin or β-glucuronidase activity. The association between the spore cell wall morphology, DNA-based techniques and enzymatic activity approaches allowed a more reliable identification procedure of the airborne Ascomycota fungal spores.     

Vegetation: A source of air fungal bio-contaminant

Airborne fungal counts and types were examined in three selected regions in Egypt. Two of the sampling sites are rural areas, one cultivated with chamomile and the second with vegetable. The third site is located in an urban area. A sedimentation method was used to isolate airborne fungal spores. Airborne fungal spore counts averaged 71\pm 19, 64\pm 14 and 175\pm 79 cfu/p/h in the urban, vegetable and chamomile growing areas, respectively. A total of 1486 fungal colonies belonging to 32 genera were identified. Alternaria (7.5–59.9%), Aspergillus (11.2–38.9%), Penicillium (9.5–15%) and Cladosporium (7.78–17.5%) were the predominant fungal genera found in all sampling sites. Alternaria (42–59.9%) and Aspergillus (38.9%) were the common fungal genera in the cultivated and urban areas, respectively. Vegetation is considered the main source of Alternaria, whereas Aspergillus, Penicillium and Cladosporium are related to local microenvironments and urbanization. Acremonium, Aureobasidium, Botrytis, Beauveria, Chlamydomyces, Chalara, Curvularia, Fusarium, Geotrichum, Trichothecium, Oidiodendron, Scopulariopsis, Spicaria, Stachybotrys chartarum, Torula and Thamnidium, were only detected in low percentages (0.11–1.8%) in the cultivated areas. Vegetation adds different fungal types into the air and their numbers vary according to vegetation type and weather conditions. Airborne fungal counts increased with temperature and decreased with rainfall and relative humidity. Airborne fungal spores have many implications in the spread of human and plant diseases. The presence of fungal spores in air, in spite of their counts, may raise arguments about their role in health complaints in a particular region, „i.e., the fungal concentration may be low but the predominant aeroallergen may be dangerous”.     

Airborne fungal spores colonising marbles exposed in the terrace of Messina Museum, Sicily

Studies were carried out on the air and on Carraramarble blocks located in the terrace of MessinaMuseum, in order to know the likelihood of airbornefungal spores coming into contact with and colonisingtridimensional objects. Our results showed there were not significantdifferences between airborne fungi circulating inspring and in autumn; Aspergillus, Penicillium,Fusarium, Alternaria, Cladosporium,Ulocladium, Aureobasidium, Phoma were themost common isolates. However, only few species wereable to settle on the marble surfaces as demonstratedby their isolation after 2 and 6 years of exposition.     

Diversity and spatial–temporal distribution of airborne fungi at the world culture heritage site Maijishan Grottoes in China

The deposition of the airborne microorganisms onto cultural heritage is associated closely with the subsequent biodeterioration. In this study, a systematic investigation was carried out to detect the seasonal variation and diversity of airborne fungal concentration at the World Cultural Heritage Site Maijishan Grottoes in western China. A bio-aerosol sampler was deployed to collect samples over four seasons in 2016. The culturable airborne fungi were isolated, purified and then identified with the extraction of genomic DNA, PCR amplification of ITS rRNA region, sequencing, and phylogenetic analysis. The concentrations of culturable fungi ranged from 216 to 1389 CFU/m³, which varied seasonally with significant differences among the sampling sites. Fifteen different fungal genera were confirmed, among them, Cladosporium was the most predominant fungal genus, followed by Penicillium. The fungal community structure and their relationship with environmental factors were also delineated. The spatial–temporal differences of airborne fungi at Maijishan Grottoes were mainly due to height, rainfall, relative humidity, and temperature. The dominant genera Cladosporium and Penicillium may pose potential threats to the ancient painted sculptures and murals, and monitoring of the airborne fungi at such a heritage site could provide supporting data for the pre-warning and control of fungal outbreaks inside the caves for better management.

     

A study of fungal spore poupulations in the atmosphere of Kuwait

The fungal air-spora of Kuwait was investigated using the Petri-dish trapping technique. During the period from 1st April, 1974 to 30th June, 1975, a total of 3685 colonies were recorded from 2 % malt agar plates. Fifty-five genera and 116 species were identified. Alternaria occupied the first place in the order of percentage incidence, being represented by 18.3% of the entire catch, followed by Aspergillus (17.1%), Penicillium (14%), Cladosporium (13.6%), Drechslera (13.3%), and Ulocladium (7.1%). The widest spectrum of species was displayed by Aspergillus (possessed 19 species) followed by Penicillium (17 species), Alternaria (6 species), Drechslera (5 species), and Ulocladium (4 species). The monthly total number of fungi showed marked seasonal periodicity with the greatest number of colonies occurring in March–April and November. The lowest counts were recorded in mid-summer (July) and mid-winter (January). Only 220 colonies and 17 species of thermophilous fungi were reported from plates incubated at 45 °C. The most common species were Aspergillus fumigatus and A. terreus.     

Study of bioaerosols and site influence in the La Plata area (Argentina) using conventional and DNA (fingerprint) based methods

The present study approaches the characterization of seasonal samples of bioaerosols taken during 2005–2006 in rural, urban, industrial, coastal and residential sites within La Plata area, Buenos Aires, Argentina. Culturable airborne fungal and bacterial communities were collected on DG18 agar and R2 Agar plates respectively, using a single-stage SKC sampling device. Fungal genera were identified based on their micro- and macro-morphological characteristics. Bacterial populations were analyzed by denaturing gradient gel electrophoresis (DGGE) of PCR 16SrDNA bacterial amplification. Geometric mean concentration of bacteria and fungi ranged from 10 to 10³ CFU m⁻³ and were comparable with those from other reports. No differences were observed among sites for fungi and Cladosporium sp. was predominant, with 85.7% of total concentration counts; secondary genera that contributed were Alternaria (6.7%), Penicillium (1.8%), Aspergillus (1.3%), Epicoccum (1.0%) and the group of yeasts (1.9%). The dominance of Cladosporium in all sites suggests that the most abundant fungal aerosol was neither significantly affected nor primarily generated by any anthropogenic area source more than the natural ambience present in the La Plata area. With regard to bacteria, the results showed on several occasions differences in concentration among sites during sampling events, but these differences were not observed when the community structure was analyzed by means of DGGE. Bacterial DGGE banding profiles from all sites revealed the existence of a relatively diversified, culture-based airborne community. Construction of similarity dendrograms exposed a distribution of site samples in which replicates intra-site equalled those encountered among sites, rendering substantial inference of site distinction unfeasible.     

Contribution of leaf surface fungi to the air spora

High concentrations of airborne fungal spores frequently occur from spring through fall in temperate areas of the world. Although it is generally assumed that fungi on leaf surfaces are contributors to the air spora, little data are available comparing the types of fungi found on leaf surfaces with those in the atmosphere. Air sampling was carried out with a Burkard Spore Trap located on the roof of a building on the University of Tulsa campus using standard methods. Leaf samples were aseptically collected from Ulmus americana and Quercus palustris trees on campus, placed in sterile plastic bags, and brought to the lab. For each leaf, 4 cm² areas of both upper and lower leaf surfaces were swabbed and plated on malt extract agar with streptomycin. Cultures were incubated at room temperature for 5–7 days and then examined microscopically. Results were expressed as colony forming units (CFU)/cm². Twenty-one fungal taxa were identified from the air samples. The most abundant taxa were Cladosporium, ascospores, basidiospores, and Alternaria; together these four spore types comprised over 90% of the yearly total. Yeasts were the most abundant fungi isolated from both leaf types. Among the mycelial fungi were Phoma species, followed by Cladosporium and Alternaria. Overall twenty genera of filamentous fungi were identified. Yeasts and Phoma are normally splash dispersed and were not identified in the Burkard air samples. However, 10 taxa isolated from leaf surfaces were registered in air samples. Crude estimates of the leaf surface area of each tree suggest that the total fungal load was approximately 5.04×10⁸ CFU for Ulmus and 2.71×10⁸ CFU for Quercus. Of these levels, 19% were from fungi also detected in air samples. The data suggest that some leaf-surface fungi are major contributors to the air spora.     

夏季故宫养心殿空气中真菌的调查与分析

【目的】在无法实现洁净环境的古建筑内,文物易遭受霉菌的破坏,尤其是在闷热的夏季。探明空气中真菌的种类对文物、游客的安全具有重要意义。【方法】采用自然沉降法与撞击法对夏季养心殿正殿内代表性的6个取样位置的气生真菌进行培养并进行ITS1 rDNA序列分析。【结果】利用自然沉降法测得气生真菌22种,以枝孢属(Cladosporium)、曲霉属(Aspergillus)和青霉属(Penicillium)为优势类群,在2个位置(佛堂二层与西暖阁)空气真菌污染超标;而撞击法测得100余种,腐生营养型真菌比例较高,优势类群为链格孢属(Alternaria)、Cladosporium、木霉属 (Trichoderma)、根霉属(Rhizopus)、Aspergillus和Penicillium,所有6个位置均超标。通过对环境因子与真菌多样性的相关性分析发现,养心殿内真菌丰度与温度、湿度及悬浮颗粒物有着密切关系。在相对湿度较低的6月,温度对丰度影响较大;高湿度时,悬浮颗粒物与湿度对真菌丰度影响更大。丝状真菌的丰度与小粒径悬浮颗粒物、相对湿度存在显著正相关,而空气中的酵母菌与温度相关性更高。【结论】本研究对养心殿正殿空气中真菌的种属进行了鉴定,并分析了与环境因子的相关性,为预防、开放展览以及修缮提供了科学依据。     

Prevalence and distribution of airborne and waterborne fungi and actinomycetes in the Nile river

The objective of this research was to investigate the prevalence and distribution of airborne and waterborne fungi and actinomycetes along the main stream of the Nile river during April to July, 2005. Air and water samples were collected at eight sites within a ~50 km stretch of the river. The distribution and prevalence of air and water microorganisms varied with location. The highest counts of airborne fungi (516 CFU/p/h) and actinomycetes (222 CFU/p/h) were detected at suburban sites near cultivated areas. However, the highest counts of waterborne fungi (56.4 CFU/ml) and actinomycetes (15.4 CFU/ml) were detected at Al-Galaa (city centre) and Kafr-El-elwe (south Cairo), respectively. A total of 1,816 fungal colonies (943 isolates from air and 873 from water samples) belonging to 27 genera were identified. Aspergillus, Alternaria, Cladosporium, and yeasts were the predominant fungal types in both air and water environments. Dreschlera, Emericella, Nigrospora, Spicaria, Stachybotrys, and Verticillium were only detected in the air, and Epicoccum, Philaphora, Phoma and Ulocladium were only detected in the water. Mycotoxin-producing fungi represented by Aspergillus flavus, Aspergillus parasiticus, Penicillium, Fusarium, and Trichoderma were found in the air and water environments. Significant differences (P ≤ 0.05) were found between fungal populations in air and water at different sampling sites. No significant differences (P ≥ 0.05) were found between waterborne actinomycetes. Sampling location, human activity, and pollution load are the main factors affecting the variability and biodiversity of microorganisms in different microenvironments.     

Continually Measured Fungal Profiles in Sick Building Syndrome

Buildings with indoor air quality (IAQ) complaints frequently have high airborne concentrations of Penicillium species, while buildings with few IAQ complaints have an indoor air (IDA) fungal ecology similar to outdoor air (ODA), where Cladosporium species is usually the dominant microorganism. These studies compared fungal air profiles, measured continually over 6 h in a documented sick building, in IDA in a room experiencing IAQ problems with fungal profiles measured concurrently in ODA. The dominant species collected at both sites were Penicillium species, Cladosporium species, and Alternaria species. In the IDA, Penicillium species were always the dominant organisms, ranging from 150 to 567 cfu/m³ (89.8–100% of the total fungi). In the ODA, Cladosporium species were dominant in four samples (40.0–70.6%), while Penicillium species were dominant (52.7–79.6%) in two. These data demonstrate that, even though ODA fungal profiles are changing continuously, IDA fungal profiles in “sick” buildings tend to remain unchanged. Received: 6 July 1998 / Accepted: 12 August 1998     

Studies on seed-borne fungi of wheat in seed health testing programme

Seed mycoflora associated with wheat was studied on different media with a particular reference to Blotter and potato dextrose agar (PDA) procedures of ISTA. Seed-borne fungi, viz. Fusarium moniliforme, Rhizopus spp., Mucor spp., Alternaria alternata, Aspergillus niger, Aspergillus flavus, Curvularia lunata, Drechslera spp, Alternaria spp. and Penicillium spp., were isolated from the variety HD264. Blotter method was found to be the best media for the isolation of mycoflora whether borne externally or internally. Total number and frequency of occurrence of fungi were recorded. The effect of seed treatment with different chemicals and eco-friendly botanicals was analysed on germination, and growth, better percentage of seed germination and reduction in fungal pathogen were due to biochemical seed treatment.     

Survey of airborne fungus spores at Taif,Saudi Arabia

Fifty-eight species and one variety belonging to 25 genera were collected from the atmosphere of Taif from August 1981 to July 1982 (12 exposures for each type of media) on glucose- and cellulose-Czapek's agar plates at 28 °C.The total counts of sugar and cellulose-decomposing airborne fungi showed seasonal fluctuations; the maxima were recorded in winter, and the minima in summer months. Aspergillus (16.23% and 13.22% of total fungi on glucose and cellulose media, respectively), Alternaria (11.52% and 15.7%), Cladosporium (18.59% and 9.5%), Drechslera (4.7% and 10.74%), Scopulariopsis (7.33% and 6.6%) and phoma (8.12% and 11.98%) were recovered in high seasonal occurrence on the two media. Also, Penicillium (on glucose) and Ulocladium (on cellulose) were common in the air accounting for 10.73% and 7.44% of total fungi, respectively.     

A comparative study on the airborne fungi in Athens,Greece, by viable and non-viable sampling methods

Airborne fungi were studied in the city of Athens using two complementary methods in which 136 concurrent samplings were carried out during the 12-month period from January until December 1998. A portable Burkard air sampler for agar plates was used for trapping the culturable portion of the mycobiota. Nineteen genera of fungi were identified and assessed in terms of total numbers and fluctuations in concentration (Alternaria, Arthrinium, Aspergillus, Aureobasidium, Botrytis, Chrysonilia, Cladosporium, Drechslera, Epicoccum, Fusarium, Mucor, Nigrospora, Paecilomyces, Penicillium, Rhizopus, Sclerotinia, Scopulariopsis, Trichoderma and Ulocladium), with the exception of those included in the Sphaeropsidales, the yeasts, and the non-sporulating fungi, which were counted as groups. A volumetric Burkard air sampler for glass slides was operating simultaneously for detecting the total mycobiota, including the non-culturable and the non-viable portion. Ascospores, basidiospores, spores of Myxomycetes, Ustilaginales, Uredinales and Erysiphales, teliospores of Puccinia, as well as conidia of the genera Curvularia, Helminthosporium, Periconia, Pestalotiopsis, Pithomyces, Polythrincium, Stachybotrys, Stemphylium and Torula were also recorded. Only seven of the genera were recovered by both samplers. The total numbers of fungal spores, which had a maximum concentration of 3,175 spores/m³, as well as the spore concentrations of the genera Cladosporium (2,565 spores/m³) and Alternaria (280 spores/m³) were underestimated by the viable method (2,435 CFU/m³ for the total, 2,169 CFU/m³ for Cladosporium and 180 CFU/m³ for Alternaria). The non-viable method fails to resolve the identification of the genera Penicillium and Aspergillus, which are major components of the airborne mycobiota (1,068 CFU/m³ and 204 CFU/m³, respectively) based on recovery by the viable method.     

Fungal spores prevalent in the aerosol of the city of Caxias do Sul, Rio Grande do Sul, Brazil, over a 2-year period (2001–2002)

This study was carried out over a 2-year period (2001 and 2002) with the aim of identifying the fungal population in the aerosol of the Southern city of Caxias do Sul, RS, Brazil. Sampling was performed using Hirstȁ9s non-viable volumetric method. Our results show the presence of a large number of fungal spore types, a total of 41. Three groups were predominant: Deuteromycotina, Ascomycotina and Basidiomycotina. In 2001, Deuteromycotina taxa represented 44.61% of the total annual spore counts, with the largest concentration occurring in the fall (58,637 spores); in 2002, it represented 40.03% of the total annual spore counts, and the largest concentration was obtained in the summer (68,317 spores). Ascomycotina was present at the same level (24.5%) in both years of sampling, and the highest concentrations were found out in the summer (2001: 42,183 spores; 2002: 29,461 spores). Basidiomycotina represented 22.37% of the total annual spore counts in 2001, and 20.41% in 2002, with the largest concentrations found in the summer (2001: 35,988 spores; 2002: 30,212 spores). The most frequent fungi found during the study period were Cladosporium, Coprinus, Leptosphaeria, Aspergillus/Penicillium and Ganoderma. Permanent aerobiological monitoring would be necessary to detect associated environmental variations.     

Indoor airborne fungi as risk factors in IgE-mediated respiratory allergy

The purpose of this epidemiological study was to assess respiratory allergy in relation to the presence of indoor airborne fungi. The relationship between IgE-mediated respiratory allergy (skin test positivity) and the presence of fungi (CFU/m³) in the indoor environments of 104 subjects was assessed in a cross-sectional study by controlling for extraneous variables (age, gender, predisposition, asthma, rhinitis, skin positivity to ragweed and mite, and smoking). The qualitative and quantitative measurements of airborne seasonal fungi (Alternaria spp. andCladosporium spp.) and non-seasonal airborne fungi (Penicillium spp. andAspergillus spp.) were taken in the subjects’ indoor environments twice in a 2-year period by volumetric methods (Burkard Personal Sampler). There was a significant association between skin test positivity to seasonal fungi and to ragweed (Adj. OR=3.42, CI=1.76–6.66). There was no association between skin test positivity to seasonal fungi and asthma (Adj. OR=0.52, CI=0.28–0.98), but a significant association was found between skin test positivity to seasonal fungi and rhinitis (Adj. OR=5, CI=2.03–12.32). In a logistic regression analysis (maximum likelihood estimates—model A), no statistical association was found indoors between skin prick test positivity to seasonal fungi (Alternaria and/orCladosporium) and airborneAlternaria and/orCladosporium concentrations (Adj. OR=1.18, CI=0.66–2.07). There was a significant association between skin prick test positivity to seasonal fungi and to non-seasonal fungi (Adj. OR=12.81, CI=1.67–98.34). There was no association between asthma and airbornePenicillium concentrations (Adj. OR=1.86, CI=0.47–7.33) nor between rhinitis and airbornePenicillium concentrations (Adj. OR=0.18, CI=0.03–1.19). In another logistic regression analysis (maximum likelihood estimates — model B) using non-seasonal fungi (Aspergillus andPenicillium), no statistical association was found indoors between skin prick test positivity to non-seasonal fungi and airbornePenicillium concentrations (Adj. OR=0.33, CI=0.07–1.69). These findings suggest an association between rhinitis and seasonal fungi. In the rhinitis stratum, subjects who had skin test positivity to ragweed had a higher risk of being sensitive to seasonal airborne fungal allergens. Subjects with non-seasonal fungal allergy had a high relative risk if they were also allergic to seasonal fungi. There was no association between asthma and airborne fungi, as the epidemiological study (cross-sectional design), by definition, does not allow an etiological evaluation of chronic disease. This would require a longitudinal study, i.e. the measurement of repeated exposure as an independent variable (allergen) and repeated measurement as a function of the disease as outcome in humans as a dependent variable.     

Fungi Isolated from Damaged Flue-cured Tobacco

Species of Aspergillus were the most prevalent fungi isolated from 51 samples of damaged flue-cured tobacco of the 1966 U.S. crop, comprising 57% of the total isolates. Other prevalent fungi were Penicillium (16%), Alternaria (8%), Cladosporium (4%), and Chaetomium (4%). Members of the Aspergillus glaucus group were isolated most frequently from samples with moisture contents ranging from 18 to 28%, whereas Alternaria, Cladosporium, and Penicillium were isolated consistently from samples containing 24 to 32% moisture. Aspergillus niger was prevalent in tobacco ranging in moisture content from 18 to 30%.     

Fungal colonization of automobile air conditioning systems

Air samples and swab samples of the air conditioning vents were collected from 29 automobiles in the metropolitan region of Atlanta, GA, and cultured for fungi. Among the fungi observed, species of Acremonium, Aspergillus, Alternaria, Aureobasidium, Cladosporium, and Penicillium were in the highest densities. Transparent adhesive tape imprints, SEM observations, and enrichment culture of components of five systems demonstrated fungal hyphae on the metal surfaces and within the matrix of various insulation materials. The evaporator removed from one automobile because of a series of complaints of noxious odors was densely colonized by Penicillium viridicatum. The amplification of known allergenic and odor-producing fungi occurred within the automobile air conditioning systems. Received 27 May 1997/ Accepted in revised form 16 July 1997     

Airborne fungi associated with ornamental plant propagation in greenhouses

The objective was to determine potential exposure to airborne fungi in greenhouses and to characterize the temporal patterns of airborne fungi in relation to environmental conditions. We analyzed air samples collected in two greenhouses. Results showed that the top 5 fungi in greenhouse 1 were Trichoderma, hyphal fragments, Aspergillus/Penicillium-like, Cladosporium, and Botrytis in a descending order. Those in greenhouse 2 were Aspergillus/Penicillium-like, Cladosporium, Botrytis, yeast-like, and hyphal fragments. Maximum concentrations of Trichoderma and total spores in greenhouse 1 were 36,426 and 49,729 spores/m³, respectively. Maximum concentrations of Aspergillus/Penicillium and total spores in greenhouse 2 were 46,961 and 71,037 spores/m³, respectively. Airborne fungal populations fluctuated dramatically within 2 h during work hours, tenfold for Aspergillus/Penicillium, 66-fold for Trichoderma, and sevenfold for total spores. QPCR detected Trichoderma harzianum ranging from 7 to 3,500 conidia E/m³. Aspergillus/Penicillium and Botrytis showed diurnal patterns, but not Trichoderma. Aspergillus/Penicillium and Cladosporium were positively correlated with temperature, relative humidity, dew point, heat index, and light and negatively with air movement and air pressure. Botrytis and Trichoderma were not correlated with the environmental factors. Greenhouse workers were potentially exposed up to 71,037 spores/m³ of airborne fungi.     

Fungal spores are an important component of library air

The airborne fungal spore types were studied in different libraries in Delhi, using an Andersen sampler and a Burkard personal sampler, for culturable and non-culturable fungi respectively. The concentration inside the libraries, before and after the agitation of books, were compared with outside air. The major contributors to the library air areCladosporium, aspergilli/penicillia, smuts andAlternaria, varying from 50 to 14%. Some fungi (Cladosporium, Alternaria, smut,Penicillium chrysogenum andnigricans) showed seasonal occurrence, corresponding to their occurrence in the extramural environment. Aspergilli/penicillia,Drechslera, Curvularia andAspergillus flavus had a significantly higher concentration (P<0.01) inside the library, and recorded a significant increase in concentration after agitation of books. Air-conditioned libraries have low fungal spore concentrations, as compared to naturally ventilated libraries.