Status of airborne spores and pollen in a coir factory in Kerala,India

The prevalence of airborne fungal spores and pollen grains in the indoor and outdoor environments of a coir factory in Thiruvananthapuram district of Kerala state, India was studied using the Burkard Personal Sampler and the Andersen 2-stage Sampler for 2 years (September 1997 to August 1999). The concentration of pollen grains was remarkably lower than that of fungal spores (ratio of 1:28). There was no large difference in the concentrations and types of fungal spores between the indoor and outdoor environments, with 26 spore types found to be present indoors and 27 types outdoors; of these, 22 were common to both the environments. Aspergillus/Penicillium, Cladosporium, ‘other basidiospores’ and ascospores were the dominant spore types. The total spore concentration was highest in February and lowest in September, and it was significantly higher in 1998–1999 than in 1997–1998. Twenty viable colony-forming types were isolated from inside the coir factory. The most dominant viable fungi isolated were Penicillium citrinum, Aspergillus flavus and Aspergillus niger. The total pollen concentration was higher in the outdoor environment of the coir factory than indoors, with 15 and 17 pollen types, respectively. Grass and Cocos nucifera pollen types were dominant. The dominant spore and pollen types trapped in the two environments of the coir factory are reportedly allergenic and, consequently, workers are at risk of catching respiratory/allergic diseases.     

Airborne fungal spores in a sawmill environment in Palakkad District, Kerala, India

Concentration of airborne fungal spores inindoor and outdoor environments of a sawmill in Palakkad district of Kerala, India was studied with Burkard Personal Slide Sampler from January to December 1997. Total spore concentration in the indoor and outdoor showed a 3:2 ratio. Higher spore count was observed in indoor in January and in outdoor in October. Thirty three fungal spore types were identified from the indoor and twenty six from the outdoor. Aspergillus/Penicillium, Cladosporium, Nigrospora, Ganoderma, `other basidiospores' and ascospores were the dominant components of the airspora. Aspergillus/Penicillium, the most dominant spore type in the indoor contributed 51.19% and Cladosporium, the most dominant spore type in the outdoor contributed 44.75% of the total spores. The study revealed high prevalence of predominantly allergenic fungal spores in the sawmill environment.     

Relationship between indoor and outdoor airborne fungal spores, pollen, and (1→3)-β-D-glucan in homes without visible mold growth

In this exploratory study, indoor and outdoor airborne fungal spores, pollen, and (1→3)-β-D-glucan levels were determined through long-term sampling (24-h) using a Button Personal Inhalable Aerosol Sampler. The air samples were collected in five Cincinnati area homes that had no visible mold growth. The total count of fungal spores and pollen in the collected samples was conducted under the microscope and Limulus Amebocyte Lysate (LAL) chromogenic assay method was utilized for the determination of the (1→3)-β-D-glucan concentration. For the combined number concentration of fungal spores and pollen, the indoor and outdoor geometric mean values were 573 and 6,435 m⁻³, respectively, with a geometric mean of the Indoor/Outdoor (I/O) ratio of .09. The geometric means of indoor and outdoor (1→3)-β-D-glucan concentrations were .92 and 6.44 ng m⁻³, respectively, with a geometric mean of the I/O ratio equal to .14. The I/O ratio of (1→3)-β-D-glucan concentration was found to be marginally greater than that calculated based on the combined number concentration of fungal spores and pollen. This suggests that (1→3)-β-D-glucan data are affected not only by intact spores and pollen grains but also by the airborne fragments of fungi, pollen, and plant material, which are ignored by traditional enumeration methodologies. Since the (1→3)-β-D-glucan level may elucidate the total exposure to fungal spores, pollen, and fungal fragments, its I/O ratio may be used as a risk marker for mold and pollen exposure in indoor environments.     

Allergic potential of someAspergilli on saw mill workers in Lucknow,India

Fifty fungal types were isolated from the indoor atmosphere of saw mills by exposing Petri plates containing Czapek-dox Agar, Potato-dextrose Agar and Sabouraud Agar media for 5 min. The fungal flora of the outdoor surroundings was also studied for comparison. Species ofAspergilli dominated in the saw mills, being represented by 16 species including one ascosporic form. Other fungi were species ofCladosporium, Alternaria, Curvularia, Penicillium, Fusarium, etc. Variations in the fungal population in different months were also observed. Fungal spores recovered using the Rotorod Sampler wereAlternaria, Curvalaria lunata, Curvularia tetramera, Cladosporium, Dreschslera sp.,Epicoccum sp.,Pithomyes sp.,Nigrospora, Stemphylium sp. andTorula sp. Mycelial fragments and unidentifiable spores were also seen in abundance. Varying allergic responses of patients were also recorded by testing intradermally, the antigens of nineAspergilli, vizAspergillus flavus, A. fumigatus, A. japonicus, A. melleus, A. nidulans, A. niger, A. niveus, A. tammarii and A. terreus.     

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.     

Allergic potential of someAspergilli on saw mill workers in Lucknow,India

Fifty fungal types were isolated from the indoor atmosphere of saw mills by exposing Petri plates containing Czapek-dox Agar, Potato-dextrose Agar and Sabouraud Agar media for 5 min. The fungal flora of the outdoor surroundings was also studied for comparison. Species ofAspergilli dominated in the saw mills, being represented by 16 species including one ascosporic form. Other fungi were species ofCladosporium, Alternaria, Curvularia, Penicillium, Fusarium, etc. Variations in the fungal population in different months were also observed. Fungal spores recovered using the Rotorod Sampler wereAlternaria, Curvalaria lunata, Curvularia tetramera, Cladosporium, Dreschslera sp.,Epicoccum sp.,Pithomyes sp.,Nigrospora, Stemphylium sp. andTorula sp. Mycelial fragments and unidentifiable spores were also seen in abundance. Varying allergic responses of patients were also recorded by testing intradermally, the antigens of nineAspergilli, vizAspergillus flavus, A. fumigatus, A. japonicus, A. melleus, A. nidulans, A. niger, A. niveus, A. tammarii and A. terreus.     

Annual pollen spectrum in the air of Palma de Mallorca (Balearic Islands, Spain)

This aeropalynological study documented the pollen of 13 taxa with the highest concentration in the air of Palma de Mallorca during the years 2004–2010, using a Hirst-type volumetric spore trap. The taxa were Cupressaceae, Olea europaea, Platanus hispanica, Pinus spp., Parietaria judaica, Urtica membranacea, Quercus ilex, Poaceae, Chenopodiaceae/Amaranthaceae, Plantago spp., Castanea sativa, Pistacia lentiscus and Betula spp. These taxa accounted for 91.85 % of the total annual pollen recorded during the period. The mean annual pollen index was 20,027. The highest pollen counts occurred in February–June, representing 88.74 % of the annual total collected. Every year, there was a substantial increase in the concentration and types of pollen from March to May, followed by a decrease from July to January. The maximum annual total pollen count was recorded in 2005 with 25,870 and the minimum in 2009 with 14,726. The mean daily average pollen concentration count showed a declining trend over the study period. With respect to seasonal phases analysed, the later phase of the pollen season is more variable than the beginning. To observe the overall dynamics of the different pollen types better, a pollen calendar was established for Palma de Mallorca. The pollen calendar had typical Mediterranean features and is a useful tool for allergological and botanical awareness.     

Aspergillus and other moulds in the air of Kuwait

A one-year survey was carried out to study the aerial prevalence of Aspergillus species and other moulds in the outdoor and indoor environments of Kuwait. Petri plates containing rose-Bengal medium were exposed for 20 minutes twice a month using a six-stage Andersen air sampler at the pre-determined sites. The exposed plates were incubated at 28 °C ± 1 °C up to 5 days and colonies were enumerated and identified by colonial and microscopic morphology. The data revealed that Aspergillus species were the predominant component (27.7%) of the outdoor aerospora of Kuwait and A. fumigatus alone accounted for 21.3% of the total aspergilli. In contrast, Cladosporium species formed the major component of the indoor aerospora (22.8%), followed by Aspergillus species (20.9%), Penicillium species (14.6%), and Bipolaris species (10.6%). A comparison of the fungi recorded in the outdoor and in the indoor air revealed that Aspergillus, Alternaria and Fusarium were significantly higher in the outdoor environment, whereas Cladosporium, Penicillium, and Bipolaris were significantly higher in the indoor environment. The relative prevalence of Aspergillus species and other moulds in the outdoor and indoor air of Kuwait was as follows: A. fumigatus 5.9 and 9.8%, A. flavus 4.9 and 3.9%, other aspergilli 16.8 and 7.0%, Alternaria species 19.8 and 7.9%, Cladosporium species 13.7 and 22.8%, Penicillium species 7.6 and 14.6%, and other moulds 31.2 and 34.1%, respectively. During the study, 25 different genera were identified, indicating a wide diversity in the spectrum of local fungal aerospora. The study provides useful information on the prevalence of allergenic fungi in the outdoor and indoor environments of Kuwait. This revised version was published online in June 2006 with corrections to the Cover Date.     

The Diversity and Distribution of Fungi on Residential Surfaces

The predominant hypothesis regarding the composition of microbial assemblages in indoor environments is that fungal assemblages are structured by outdoor air with a moderate contribution by surface growth, whereas indoor bacterial assemblages represent a mixture of bacteria entered from outdoor air, shed by building inhabitants, and grown on surfaces. To test the fungal aspect of this hypothesis, we sampled fungi from three surface types likely to support growth and therefore possible contributors of fungi to indoor air: drains in kitchens and bathrooms, sills beneath condensation-prone windows, and skin of human inhabitants. Sampling was done in replicated units of a university-housing complex without reported mold problems, and sequences were analyzed using both QIIME and the new UPARSE approach to OTU-binning, to the same result. Surfaces demonstrated a mycological profile similar to that of outdoor air from the same locality, and assemblages clustered by surface type. “Weedy” genera typical of indoor air, such as Cladosporium and Cryptococcus, were abundant on sills, as were a diverse set of fungi of likely outdoor origin. Drains supported more depauperate assemblages than the other surfaces and contained thermotolerant genera such as Exophiala, Candida, and Fusarium. Most surprising was the composition detected on residents’ foreheads. In addition to harboring Malassezia, a known human commensal, skin also possessed a surprising richness of non-resident fungi, including plant pathogens such as ergot (Claviceps purperea). Overall, fungal richness across indoor surfaces was high, but based on known autecologies, most of these fungi were unlikely to be growing on surfaces. We conclude that while some endogenous fungal growth on typical household surfaces does occur, particularly on drains and skin, all residential surfaces appear – to varying degrees – to be passive collectors of airborne fungi of putative outdoor origin, a view of the origins of the indoor microbiome quite different from bacteria.     

The incidence of fungal spores in the ambient air and inside homes: Evidence from London

Little research has been carried out in London concerning fungal spore prevalence yet this information may help to elucidate geographical patterns of asthma and hay fever. Although many types of spore reach peak concentrations outdoors in late-summer, the incidences in the indoor environment may be more important through the winter because of heating and poor ventilation. Daily average concentrations of fungal spores in the ambient atmosphere were monitored with a Burkard volumetric spore trap on an exposed roof in North London from autumn 1991 until the summer of 1992. Indoor spore measurements were taken in 19 homes in the vicinity through the winter months, both by direct air sampling using a portable Burkard sampler and by dust culture. Trends in the occurrence and concentrations of fungal spores indoors and outdoors were examined. Relationships between the abundance of selected allergenic fungi and features of the houses were analysed including age of dwelling, dampness, cleanliness and presence of pets.Aspergillus andPenicillium were the most frequently occurring spore types in the homes. Overall, high spore incidence was associated with dampness and dust accumulation. The outdoor spore samples revealed generally low concentrations through the winter until March when concentrations of many types includingCladosporium, Epicoccum andAlternaria increased in abundance in response to the warmer weather. Even during the late-spring and early-summer, concentrations of most fungal spores were notably below those reported for rural sites.     

Effects of weather conditions on selected airborne fungal spores in the southern part of the state of Enugu,Nigeria

A study of airborne fungal spore was carried out at nine locations in the southern part of the state of Enugu, Nigeria, from March 2005 to February 2006. The aim of the study was to ascertain the variations in selected fungal spore types at the sites owing to weather conditions. The variation in airborne fungal spores of 14 taxa was studied using modified Tauber pollen traps including Alternaria, Corynespora, Curvularia, Drechslera type, Endophragmiella, Botryodiplodia, Ganoderma, Gliomastrix, Nigrospora, Pithomyces, Spegazzinia, Sporidesmium, Tetraploa and Ustilago. The frequency of the spore types recorded showed considerable variation. The highest spore counts were recorded in July, June and October. The highest numbers of fungal spores were recorded during the rainy season (June–October) to early dry season (November–December). The peak of occurrence of most selected fungal spore types was July. The highest percentages of fungal spores were documented at the recording stations Mgbowo Junction, UNTH Ituku Ozalla and Oji River Express Junction. Spearman’s correlation analyses were performed for the monthly amounts of the fungal spore types and monthly meteorological factors. The numbers of Curvularia, Nigrospora and Sporidesmium was significantly correlated with relative humidity, while those of Endophragmiella, Pithomyces and Nigrospora were significantly correlated with temperature. A significant correlation was also found between the number of Nigrospora spores and light intensity and Sporidesmium spores and wind velocity. Relative humidity and temperature seem to be the most important weather conditions affecting the frequency of the selected spore types in the atmosphere.     

Profiles of Airborne Fungi in Buildings and Outdoor Environments in the United States

We examined 12,026 fungal air samples (9,619 indoor samples and 2,407 outdoor samples) from 1,717 buildings located across the United States; these samples were collected during indoor air quality investigations performed from 1996 to 1998. For all buildings, both indoor and outdoor air samples were collected with an Andersen N6 sampler. The culturable airborne fungal concentrations in indoor air were lower than those in outdoor air. The fungal levels were highest in the fall and summer and lowest in the winter and spring. Geographically, the highest fungal levels were found in the Southwest, Far West, and Southeast. The most common culturable airborne fungi, both indoors and outdoors and in all seasons and regions, were Cladosporium, Penicillium, nonsporulating fungi, and Aspergillus. Stachybotrys chartarum was identified in the indoor air in 6% of the buildings studied and in the outdoor air of 1% of the buildings studied. This study provides industrial hygienists, allergists, and other public health practitioners with comparative information on common culturable airborne fungi in the United States. This is the largest study of airborne indoor and outdoor fungal species and concentrations conducted with a standardized protocol to date.     

Some components of the air spora in Jamaica and their possible medical application

A knowledge of the pollen and fungal spores which comprise the air spora is useful as a preliminary approach to the problem of respiratory allergy. Therefore, this study of the qualitative and quantitative aspects of the air spora was done. Fungal spores were found to be numerically dominant, comprising 97.73% whilst pollen comprised 0.40% of the total material observed. A small number of types made up the majority of the fungal air spora, namely, Cladosporium, the Sporobolomycetaceae group, Diatrype, Glomerella, hyaline and coloured basidiospores, and septate fusiform spores. Seasonal periodicity studies on twenty-five fungal types showed that a high number of spores were trapped for sixteen during wet months, four during cooler months, and that five showed no seasonal trends. Mean diurnal periodicity studies for the year on the same twenty-five spore types showed that all had a maximum number of spores trapped at some time during the day. Investigation of the effect of rainfall on the numbers of spores released showed that the amount and duration of rainfall, the time of day rain occurs, and the length of the dry period preceding rain were of varying importance to particular spore types.     

Changes in airborne pollen concentrations in Delhi,India

In order to find the qualitative and quantitative changes in airborne pollen concentrations in Delhi metropolis area an aerobiological survey was undertaken from September 1990 to August 1997. Air samples were collected daily using a Rotorod Aeroallergen Sampler at 10?m above the ground level. Ninety-four pollen types were recorded and the major contributors include Morus, Cannabis, Chenopod/Amaranth, Prosopis, Artemisia, and Eucalyptus. Ten pollen types contributed 90% of the total pollen load. Two major pollen seasons were recorded each year (February–April and September–November), although pollen grains in low frequency were recorded throughout the whole year. A significant reduction in pollen concentration was observed in subsequent years. The number of Morus, Cannabis, Prosopis, and Artemisia pollen decreased considerably while the number of Ricinus communis pollen did not show any considerable change during the study period. It is suggested that the reduction in pollen numbers from 1990 to 1997 in Delhi is due to massive clearing of vegetation for developmental activities of the city.     

Exposure to indoor fungi in different working environments: A comparative study

In this study an attempt was made to evaluate the qualitative and quantitative fungal burden (load) in five different working environments of South Assam (India) and the possible risks of indoor fungi to employees and stored products. Fungal concentrations in different working environments were studied using a Burkard personal petriplate sampler. The survey was done in five different working environments for one year. A total of 76 fungal types were recorded in the indoor air of South Assam during the survey period. The maximum fungal concentration (5,437.6 ± 145.3 CFU m⁻³ air) was recorded in the indoor air of medical wards, followed by the paper-processing industry (3,871.7 ± 93.4 CFU m⁻³ air). However the lowest concentration was observed in the indoor air of a bakery (1,796.8 ± 54.4 CFU m⁻³ air). The most dominant fungal genera were Aspergillus (34.2%) followed by Penicillium (17.8%), Geotrichum (7.0%) and the most dominant fungal species were Aspergillus fumigatus (2,650.4 CFU m⁻³ air) followed by Aspergillus flavus (1,388.2 CFU m⁻³ air), Geotrichum candidum (1,280.3 CFU m⁻³ air), Aspergillus niger (783.3 CFU m⁻³ air), and Penicillium aurantiovirens (774.0 CFU m⁻³ air). The fungal species viz., Aspergillus fumigatus, Penicillium aurantiovirens, Aspergillus flavus, Aspergillus niger, Geotrichum candidum, and Penicillium thomii, which were recorded well above threshold levels, may lead to adverse health hazards to indoor workers. Setting occupational exposure limits for indoor fungal spores as reference values is obligatory for prevention and control of adverse effects of indoor fungal exposure.     

Preliminary surveys of outdoor and indoor aeromycobiota in Uganda

This investigation was conducted during the period of March through June 1998 to trap, enumerate and identify the different airborne fungi in a variety of microhabitats of outdoor and indoor environments in different localities of Uganda. The settle plate method was used and Czapek-Dox agar was the isolation medium. A total of 47 genera and 61 species in addition to some other unidentified airborne fungi were trapped from all exposures at outdoor (39 genera and 52 species) and indoor (35 and 49) environments. The total fungal catches of outdoor airspora obtained from all exposures (and even in most individual exposures) were more than twice (5222 colonies) of that of the indoor ones (4361) when the exposure periods are taken into consideration. It is worth mentioning that the most highly polluted sites were either parks, forests or river banks for outdoor exposures, or teaching laboratory, library, laterines or bathrooms for indoor exposures. The most prevalent fungi from both outdoor and indoor microhabitats being species of Mycosphaerella, Yeasts, Penicillium, Fusarium, Aspergillus,Cochliobolus and Alternaria. However, several others were trapped frequently from either outdoor or indoor environments. On the other hand, several others were trapped only, but not frequently (in low or rare instances) from either outdoor or indoor microhabitats. The implications of these airborne spores are also discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Atmospheric concentration of pollen grains at human height

An atmospheric survey at human height (1.5–1.8 ft) was carried out from February 1988 to January 1990, in four different ecozones of the Delhi metropolis. The samples were collected by using Burkard Personal Volumetric Sampler at weekly intervals. The sampler was operating for 15 min three times a day (07, 14, 20 hrs). Altogether, 84 pollen types were identified. Some of the dominant pollen types recorded were Poaceae (25.1%), Cheno/Amaranthaceae (14.5%) and Ricinus communis (12.3%) followed by Morus, Cannabis, Prosopis, Parthenium and Artemisia. Weekly variations were recorded for the total number of pollen of different types in different months. Two major pollen seasons 1. February — April and 2. August — October were observed, although pollen was recorded throughout the year. Significant variation in total and individual pollen concentration was recorded from different inhabited areas in the same urban locality. Any definite daily pattern in the occurrence of pollen was not recorded. The concentration at lower height was also poor.     

Fungal population in the atmosphere of Ismailia City

Fungal spore populations in the outdoor and indoor atmosphere of Ismailia have been studied during the period from March 1992 to May 1993. A total of 23 350 cfu and 73 species were recorded.Cladosporium cladosporioides, Aureobasidium pullulans andAspergillus flavus were the most abundant. The indoor and outdoor mycoflora showed marked quantitative and qualitative differences. In view of count, recorded species could be categorized into three groups as follows: (a) species showing higher counts in out-than indoor, (b) species showing the opposite trend i.e. lower counts in out-door than indoor, (c) species showing approximately equal counts in out- and indoor. Regarding seasonal periodicity, March and either September or October showed the highest count for both normal fungal flora (NFF) and opportunistic fungal flora (OFF). While January and July showed the lowest count of them both, May but not July was the lowest as for outdoor NFF.     

Fungal population in the atmosphere of Ismailia City

Fungal spore populations in the outdoor and indoor atmosphere of Ismailia have been studied during the period from March 1992 to May 1993. A total of 23 350 cfu and 73 species were recorded,Cladosporium cladosporioides, Aureobasidium pullulans andAspergillus flavus were the most abundant. The indoor and outdoor mycoflora showed marked quantitative and qualitative differences. In view of count, recorded species could be categorized into three groups as follows: (a) species showing higher counts in out- than indoor, (b) species showing the opposite trend i.e. lower counts in out-door than indoor, (c) species showing approximately equal counts in out- and indoor. Regarding seasonal periodicity, March and either September or October showed the highest count for both normal fungal flora (NFF) and opportunistic fungal flora (OFF). While January and July showed the lowest count of them both, May but not July was the lowest as for outdoor NFF.     

Introducing DNA-based methods to compare fungal microbiota and concentrations in indoor,outdoor, and personal air

Inhalation of airborne fungi is known to cause respiratory illnesses such as allergies. However, the association between exposure and health outcomes remains largely unclear, in part due to lack of knowledge about fungal exposure in daily life. This study aims to introduce DNA-based methods such as high-throughput sequencing (HTS) and quantitative polymerase chain reaction (qPCR) to compare fungal microbiota and concentrations in indoor, outdoor, and personal air. Five sets of concurrent indoor, outdoor, and personal air samples were collected, each with duration of 4 days. Sequencing analysis revealed greater species richness in personal than indoor air for four out of the five sets, indicating that people are exposed to outdoor species that are not in indoor air. The personal–indoor (P/I) and personal–outdoor (P/O) ratios of total fungi were 1.2 and 0.15, respectively, suggesting that personal exposure to total fungi is better represented by indoor than outdoor concentrations. However, the ratios were taxon dependent, highlighting the complexity of generalizing personal exposure to the diverse kingdom Fungi. These results demonstrate that the HTS/qPCR method is useful for assessing taxon-specific fungal exposure, which might be difficult to achieve effectively using conventional, non-DNA-based techniques.