Indoor Fungi Research Articles

Air mycobiome in the National Library of Greece following relocation to novel premises

The aim of this work was to study the diversity and spatiotemporal fluctuations of airborne fungi in the National Library of Greece after its relocation from the Vallianeio historic building in the center of Athens to entirely new premises at the Stavros Niarchos Foundation Cultural Center, and also to compare the fungal aerosol in between the two sites. The air mycobiota were studied by a volumetric culture-based method, during the year 2019 in order to assess their diversity and abundance and to compare with those previously reported in the historic building. Twenty-eight genera of filamentous fungi were recovered indoors and 17 outdoors, in addition to yeasts registered as a group. The number of fungal genera recovered was almost similar in both premises, whereas seventeen genera indoors were identical, dominated by Penicillium, Cladosporium and Aspergillus. The mean daily fungal concentration was found to be 66 CFU m−3 indoors and 927 CFU m−3 outdoors in the new location vs 293 and 428 CFU m−3 indoors and 707 and 648 CFU m−3 outdoors in the previous one. The mean daily concentration indoors was consistently and significantly lower (P < 0.05) in the new building than in the historic one, although it was higher outdoors. The indoor/outdoor ratio for the total fungi was 0.07 in the new vs 0.41 and 0.66 in the previous one and reveals a superior indoor air quality in the new site. Air temperature and occupancy had a statistically significant impact on the concentration of indoor fungi. The remarkably reduced concentration of the mycobiota in the new premises indicated a considerable decline in fungal burden, mainly due to technological excellency of the facility and continuous preventive measures to ensure an enhanced indoor air quality in the National Library of Greece. This case study provides a paradigm about upgrading of indoor air after re-establishment of a facility in another setting.

An Overview of The Effects of Indoor Fungi on Human Health

An Overview of The Effects of Indoor Fungi on Human Health

Culturable Bioaerosols Assessment in a Waste-Sorting Plant and UV-C Decontamination

Waste-Sorting Plant (WSP) workers are exposed to bioaerosols containing a large variety of bacterial and fungal species, posing a critical health risk that needs to be assessed and mitigated. The present study aimed to evaluate the indoor air quality in a Portuguese WSP and the air decontamination efficiency with UV-C. The concentrations of bacteria and fungi and particulate matter (PM2.5 and PM10), CO2, relative humidity, and temperature were determined at different hours in manual sorting areas (cabin and ramp) in autumn and winter in 2022 and in administrative offices and canteen in the autumn of 2023. The PM2.5 and PM10 concentrations in the air increased with the daily waste-sorting activities, especially inside the cabin, averaging 22 and 42 μg/m3, respectively, while the CO2 concentration was in the range of 343–578 ppm in both sampling sites. The bacterial species were mainly environmental (mesophilic bacteria) rather than human sources. In the waste-sorting areas, the concentration of bacteria was often found to exceed outdoor values by more than 1000 CFU/m3 on average. Additionally, the concentration of fungi indoors was consistently higher than outdoor values, in many cases exceeding 500 CFU/m3. These findings suggest that workers in these areas are frequently exposed to high levels of microbes. The indoor-to-outdoor (I/O) contamination ratios revealed that the air quality inside the administrative offices and the canteen had high pollutant concentrations during some time periods. The worst scenarios were observed in the canteen and offices with high occupancy in the afternoon. UV-C lamps at 253.7 nm and with 5.0 W irradiation power were used in the sorting cabin to test the indoor air and surface decontamination, and the results showed a high bacterial removal efficacy of over 87.6% after one hour of exposure to UV-C. The present study raises the question of whether 37 °C is the optimal incubation temperature for WSP samples since the microorganisms’ habitat before the sampling had a much lower temperature. As the waste-sorting industry expands, these findings show that the air quality of WSPs remains concerning and requires a holistic approach, integrating the working conditions of all personnel and the implementation and monitoring of mitigation measures.

A Review of the Role of Indoor Fungi in Sick Building Syndrome

Sick building syndrome (SBS) is a group of non-specific symptoms associated with the built environment, including mucosal symptoms in the eyes, nose, throat, and skin, and general symptoms such as headache and fatigue. Currently, more attention has been paid to the impact of buildings on the health and well-being of occupants, so SBS has become a global concern. Indoor microbial agents such as fungi are important in causing this syndrome. Fungi are eukaryotic microorganisms that occur in indoor air. Among the fungi, Cladosporium, Aspergillus, Stachybotrys, and Penicillium have a significant role in causing SBS. Fungi can contribute to this syndrome in different ways. Thus, this review article attempts to investigate the role of fungi and how to intervene in these microorganisms in SBS. To this end, keywords such as: "air," "indoor," "fungi," and "sick building syndrome" were searched. Articles published in scientific databases, such as Google Scholar, PubMed/MEDLINE, Elsevier, and Scopus were used.

The air and dust invisible mycobiome of urban domestic environments

Air and dust harbor a dynamic fungal biome that interacts with residential environment inhabitants usually with negative implications for human health. Fungal air and dust synthesis were investigated in houses across the Athens Metropolitan area. Active and passive culture dependent methods were employed to sample airborne and dustborne fungi for two sampling periods, one in winter and the other in summer. A core mycobiome was revealed both in air and dust constituted of the dominant Penicillium, Cladosporium, Aspergillus, Alternaria and yeasts and accompanied by several common and rare components. Penicillium and Aspergillus diversity included 22 cosmopolitan species, except the rarely found Penicillium citreonigrum, P. corylophilum, P. pagulum and Talaromyces albobiverticillius which are reported for the first time from Greece. Fungal concentrations were significantly higher during summer for both air and dust. Excessive levels of inhalable aerosol constituted mainly by certain Penicillium species were associated with indoor emission sources as these species are household molds related to food commodities rot. The ambient air fungal profile is a determinant factor of indoor fungal aerosol which subsequently shapes dustborne mycobiota. Indoor fungi can be useful bioindicators for indoor environment quality and at the same time provide insight to indoor fungal ecology.

Environmental factors influencing indoor airborne fungi in students dormitory - a case study in Nakhon Sithammarat, Thailand.

Indoor airborne fungi are a significant health concern that can cause respiratory symptoms and other health problems. Indoor fungi are influenced by various factors such as meteorological conditions and dwelling characteristics. This study aims to evaluate the association between indoor airborne fungi and environmental factors in a student dormitory in southern Thailand. The study was conducted at Walailak University in southern Thailand from September toDecember 2020. Air samples were collected from rooms in thirteen dormitories, and the fungal load was determined using the passive air sampling method. The study also measured meteorological parameters and gathered data on occupant behaviors and exposure-related symptoms through a self-administered questionnaire. In a total of 135 student rooms, the average concentration (mean ± SD) of indoor airborne fungi was 409.72±176.22 CFU/m3, which showed the highest concentration on the first floor. For meteorological parameters, the averages of RH (%), temperature (°C), and CO2 (ppm) were 70.99±2.37, 31.11±0.56 and 413.29±76.72, respectively. The abundance of indoor airborne fungi was positively associated with an increase in RH (β=0.267, 95% CI: 5.288, 34.401) and building height (β=0.269, 95% CI: 16.283, 105.873), with values of 19.845 and 61.078, respectively. Conversely, temperature exhibited a negative effect on indoor airborne fungi (-92.224, β=-0.292, 95% CI: -150.052, -34.396). The findings highlight the influence of RH, temperature and building height on indoor airborne fungi in the student dormitory. Therefore, effective management strategies are necessary to improve indoor air quality and reduce associated health risks in student dormitories.

Indoor Bacterial and Fungal Burden in "Moldy" versus "Non-Moldy" Homes: A Case Study Employing Advanced Sequencing Techniques in a US Metropolitan Area.

The presence of fungi in the indoor environment is associated with allergies and other respiratory symptoms. The aim of this study was to use sequencing and molecular methods, including next-generation sequencing (NGS) approaches, to explore the bacterial and fungal communities and their abundance in the indoor environment of houses (n = 20) with visible "moldy" (HVM) and nonvisible "non-moldy" (HNM) in Memphis, TN, USA. Dust samples were collected from air vents and ground surfaces, and the total DNA was analyzed for bacteria and fungi by amplifying 16S rRNA and ITS genes on the Illumina Miseq. Results indicated that Leptosphaerulina was the most abundant fungal genus present in the air vent and ground samples from HNM and HVM. At the same time, the most abundant bacterial genera in the air vent and ground samples were Propionibacterium and Streptococcus. The fungi community diversity was significantly different in the air vent samples. The abundance of fungal species known to be associated with respiratory diseases in indoor dust samples was similar, regardless of the visibility of fungi in the houses. The existence of fungi associated with respiratory symptoms was compared with several parameters like dust particulate matter (PM), CO2 level, temperature, and humidity. Most of these parameters are either positively or negatively correlated with the existence of fungi associated with respiratory diseases; however, none of these correlations were significant at p = 0.05. Our results indicate that implementing molecular methods for detecting indoor fungi may strengthen common exposure and risk assessment practices.

Fungal indoor Air Quality and Associated Factors in Prison Inmate Cells of East Hararghe Zone and Harari Regional State, Eastern Ethiopia, 2020

The presence of fungi inside of buildings and structures is referred to as fungal indoor air quality. Infections, fragments of fungal cells, and metabolites of fungal organisms can all provide significant challenges in indoor structures, including prison inmate cells. In East Hararghe and Harari regional state, there is no evidence of a fungal load or associated factors in prisons. The purpose of this study was to evaluate the fungal indoor air quality and related factors in prison inmate cells. An Institution based cross-sectional study was conducted. The source and study population were all prisoner cells located in the East Hararghe zone and Harari regional state prisons. 62 prisoner cells were used in the investigation. The approach of non-random sampling was applied. Passively settle able plates were used to collect the samples (Koch sedimentation method). ANOVA, correlation, and chi-square statistical tests were used to examine the row data using SPSS statistical software and Microsoft Excel. The fungal concentrations were highest at 8:00 pm (537 CFU/m³) and lowest at 2:00 pm (115 CFU/m³), respectively. The number of people was poorly connected with the fungal load (r=0.192 and p=0.039), and there was a significant positive weak correlation between the fungal load and temperature (r= 0.275, P=0.031). In contrast, a significant positive correlation between the fungal load and relative humidity in prisoner cells was discovered (r = 0.983; p = 0.004). In conclusion, the fungal concentrations were in the intermediate region (<500CFU/m³) except in one inmate cell of the investigated prisons. This study indicates that, it may pose threats to inmates. As a result, both the Harari region and the eastern Haragie zone prison offices should take action to address the issue. The prison facility needs to be restructured in accordance with current requirements.

Characterizing seasonal dynamics of indoor fungal exposure and its relations with allergic diseases/symptoms of children - A case-control based investigation in residences

While most epidemiological surveys reported the effects of indoor fungi on causing building materials deterioration, air quality problems and health risks on occupants, the temporal variations of indoor fungal exposure and verification of the adverse health effects are still not well understood. This study conducted a case-control survey and multiple measurements in 23 homes (11 case and 12 reference) in different seasons. Seasonal dynamics significantly affect the indoor airborne fungal concentrations, with the highest in summer (1467 ± 751 CFU/m3) and the lowest in winter (462 ± 356 CFU/m3). The proportions for the airborne fungi at respirable size <4.7 μm accounted for 82.8%, 87.9% and 89.8% in summer, autumn and winter respectively, indicating a higher inhalable fraction into the lower respiratory system of children. With the high-throughput sequencing, the Aspergillus was the dominant genus and the Aspergillus_penicillioides was the prevailing species without seasonal differences. While the logistic regression presented positive associations with exposing to high fungal concentrations (aORs >1), no significant differences were found of airborne fungal concentrations and relative abundance of dust fungi between case and reference groups. The average exposure doses by inhalation for reference and case children were higher in summer under sleeping state, about 263 CFU/kg·d and 321 CFU/kg·d. These findings reveal the seasonal dynamical characteristics of household fungi and the associations with children's allergic diseases/symptoms, providing practical information for future health-based guidelines/standards and effective protection measures in buildings.

Evaluation of VOCs from fungal strains, building insulation materials and indoor air by solid phase microextraction arrow, thermal desorption–gas chromatography-mass spectrometry and machine learning approaches

Solid phase microextraction Arrow and thermal desorption–gas chromatography–mass spectrometry allowed the collection and evaluation of volatile organic compounds (VOCs) emitted by fungal cultures from building insulation materials and in indoor air. Principal component analysis, linear discriminant analysis and supported vector machine were used for visualization and statistical assessment of differences between samples. In addition, a screening tool based on the soft independent modelling of class analogies (SIMCA) was developed for identification of fungal contamination of indoor air. Ten different fungal strains, incubated under ambient and microaerophilic conditions, were analyzed for time period ranging from 5 to 29 days after inoculation resulting in a total of 140 samples. In addition, the effect of additives on the fungal growing media was studied. The total number of compounds and concentration values were used for the evaluation of the results. Clear differences were observed for VOC profiles emitted by different fungal strains by exploiting long chain alcohols (3-octanol, 1-hexanol and 2-octen-1-ol) and sesquiterpenes (farnesene, cuprene). The analysis of glass-wool and cellulose based building insulation materials (3 samples) gave clear differences, mainly for oxygenated compounds (ethyl acetate and hexanal) and benzenoids (benzaldehyde). Moreover, the comparison of indoor air and insulation materials collected from a house with fungal indoor air problems indicated that 42% of the VOCs were found in both samples. The analysis of 52 indoor air samples demonstrated clear differences in their VOC profiles, especially for hydrocarbons, and between control (44 samples) and indoor air problem houses (8 samples). Finally, the SIMCA model enabled to recognize differences between control and fungi contaminated houses with a prediction capacity over 84%.

Fungal Catastrophe of a Specimen Room: Just One Week is Enough to Eradicate Traces of Thousands of Animals.

Indoor fungi obtain carbon sources from natural sources and even recalcitrant biodegradable materials, such as plastics and synthetic dye. Their vigorous activity may have negative consequences, such as structural damage to building materials or the destruction of precious cultural materials. The animal specimen room of the Seoul National University stocked 36,000 animal resources that had been well-maintained for over 80years. Due to abandonment without the management of temperature and humidity during the rainy summer season, many stuffed animal specimens had been heavily colonized by fungi. To investigate the fungal species responsible for the destruction of the historical specimens, we isolated fungi from the stuffed animal specimens and identified them at the species level based on morphology and molecular analysis of the β-tubulin (BenA) gene. A total of 365 strains were isolated and identified as 26 species in Aspergillus (10 spp.), Penicillium (14 spp.), and Talaromyces (2 spp.). Penicillium brocae and Aspergillus sydowii were isolated from most sections of the animal specimens and have damaged the feathers and beaks of valuable specimens. Our findings indicate that within a week of mismanagement, it takes only a few fungal species to wipe out the decades of history of animal diversity. The important lesson here is to prevent this catastrophe from occurring again through a continued interest, not to put all previous efforts to waste.

Airborne pollen and fungi indoors: Evidence from primary schools in Lithuania

The number of children suffering from respiratory allergies and asthma has been increasing worldwide and, hence, it is crucial to understand the burden of inhalant biological particles present in school facilities, where children spend one third of their life. From the perspective of indoor air quality, while there are numerous studies on outdoor bioaerosol exposure, there are still uncertainties regarding the diversity and deposition of airborne pollen and fungi indoors. When it comes to schools, there is limited research as to the potential bioaerosol exposure. Here we studied the indoor environment of public schools aiming to reveal whether primary schools of different sizes and at localities of different levels of urbanization may exhibit a variability in the biodiversity and abundance of particles of biological origin, which could pose a risk to child health. To achieve this, 11 schools were selected, located in a variety of environments, from downtown, to city centre-periphery, and to the suburbs. Fungal and pollen samples were collected from various surfaces in school classrooms and corridors, using passive air sampling and swab sampling. We demonstrated that fungi and pollen are detected in school premises during and after the vegetation season. The highest diversity of bioaerosols was found on the top of cabinets and windowsills, with Penicillium, Cladosporium and Acremonium being the most abundant indoors. The levels of fungi were higher in schools with more students. The diversity and amount of pollen in the spring were significantly higher than in samples collected in autumn. Our findings complemented existing evidence that bioaerosol measurements in schools (including kindergartens or informal education facilities) are vital. Hence, we here suggest that, in addition to monitoring air quality and bacterial levels indoors, fungi and pollen measurements have to be integrated in the existing regular biomonitoring campaigns so as to prevent exposure, increase awareness and manage efficiently allergic symptomatology.

Prevalence of Mycoses and Investigation of Fungal Indoor Environment

Background and Aims: The incidence of fungal infections in Saudi Arabia is increasing with an increase in the population of high-risk patients. Still, studies highlighting the impact of environmental fungal agents on infections in Saudi are limited, and none have examined the Medina region despite the city’s stature, diversity, and travel flow. This study aims to determine the fungal distribution across the Medina region. Methods: A randomized 212 indoor samples were collected based on analyzed data from 1374 questionnaires. The prevalence of participants to fungal infection was 19.2% and 26.3% in the risk group. Fungal species were identified via macroscopic and microscopic examination. Results: Two hundred and three (96%) samples showed fungal growth. Yeast identified were 78 (34%) Candida species, 56 (25%) non-Candida species. The study identified 13 genera and 20 species for mould, including 38 (17%) Aspergillus spp., 20 (9%) Rhizopus spp. 9(4%) holoarthic/enteroatric conidiogenesis, 7 (3%) Mucor spp. 4 (2%) of both Penicillium spp. and Neurspora spp. and only 2(1%) of Madurella spp., 3(1%) Epidermophyton spp., 2 (1%) Lichtheimia spp., and 1(1%) Peacilomyces spp. Conclusions: This study identified Aspergillus spp. as the most frequent fungi across the Medina region. The characterization of indoor fungal environment enables healthcare practitioners to anticipate fungal infection for individuals at risk. These findings can aid the prediction and prevention of fungal infections and fungal sensitization among the high-risk populations.

Вплив забруднення повітря приміщень мікроскопічними грибами на здоров’я населення

Objective: to determine the impact of mycomycete contamination of air in residential and public buildings on human health. Materials and methods of research: Microbiological and mycological analysis of indoor air was studied by conventional methods. A questionnaire was developed and a survey of residents of the surveyed housing was conducted. Statistical processing of the obtained results, reliability of the obtained data, calculations were performed with using the STATISTICA 8 program and Microsoft Excel program. Results: As a result of field studies of houses’ residential premises of different construction periods and a questionnaire survey of residents, the features of microbiological contamination of the air environment were established. It is shown that in houses commissioned more than twenty years before, air pollution by spores of microscopic fungi was almost twice as high as in the buildings’ air of later development. At the same time, the role of maintenance’s state of the living space, that is, the economic behavior of the residents themselves, was also revealed. Based on the questionnaire, informational characteristics of the relationship between the health status of residential premises residents and objective indicators of the microclimate on the basis of biodamages were developed. The reliability of the obtained data is p&lt;0.001. It has been proven that in the presence of constantly high humidity, leaks and flooding, infection with mold fungi indoors can be overwhelming even with regular ventilation and the use of antiseptics. Conclusions: 1. It has been established that air contamination of living quarters with mold fungi depends on the state of maintenance of the living quarters. 2. The number of mold fungi is affected by the presence of leaks and flooding, the visible growth of mold fungi on the surfaces of the room. 3. A direct correlation of the relationship between the health status of residents and indicators of the microclimate of residential premises was revealed on the basis of the developed questionnaires with informational characteristics.

Spring is associated with increased total and allergenic fungal concentrations in house dust from a pediatric asthma cohort in New York City

IntroductionAsthma and allergy symptoms vary seasonally due to exposure to environmental sources of allergen, including fungi. However, we need an improved understanding of seasonal influence on fungal exposures in the indoor environment. We hypothesized that concentrations of total fungi and allergenic species in vacuumed dust vary significantly by season. ObjectiveAssess seasonal variation of indoor fungi with greater implications related to seasonal asthma control. MethodsWe combined next-generation sequencing with quantitative polymerase chain reaction (qPCR) to measure concentrations of fungal DNA in indoor floor dust samples (n = 298) collected from homes participating in the New York City Neighborhood Asthma and Allergy Study (NAAS). ResultsTotal fungal concentration in spring was significantly higher than the other three seasons (p ≤ 0.005). Mean concentrations for 78% of fungal species were elevated in the spring (26% were significantly highest in spring, p < 0.05). Concentrations of 8 allergenic fungal species were significantly (p < 0.5) higher in spring compared to at least two other seasons. Indoor relative humidity and temperature were significantly highest in spring (p < 0.05) and were associated with total fungal concentration (R2 = 0.049, R2 = 0.11, respectively). ConclusionThere is significant seasonal variation in total fungal concentration and concentration of select allergenic species. Indoor relative humidity and temperature may underlie these associations.

Aspergillus Was the Dominant Genus Found during Diversity Tracking of Potentially Pathogenic Indoor Fungal Isolates.

Viable airborne pathogenic fungi represent a potential health hazard when exposing vulnerable persons in quantities exceeding their resilience. In this study, 284 indoor fungal isolates from a strain collection of indoor fungi were screened for pathogenic potential through the ability to grow in neutral pH at 37 °C and 30 °C. The isolates were collected from 20 locations including 14 problematic and 6 non-problematic ordinary buildings. Out of the screened isolates, 170 isolates were unable to grow at 37 °C, whereas 67 isolates growing at pH 7.2 at 37 °C were considered as potential opportunistic pathogens. Forty-seven isolates growing at 30 °C but not at 37 °C were considered as less likely pathogens. Out of these categories, 33 and 33 strains, respectively, were identified to the species level. The problematic buildings included known opportunistic pathogens: Aspergillus calidoustus, Trichoderma longibrachiatum, Rhizopus arrhizus and Paecilomyces variotii, as well as less likely pathogens: Aspergillus versicolor, Chaetomium cochliodes, Chaetomium globosum and Chaetomium rectangulare. Opportunistic pathogens such as Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger and Aspergillus tubingensis and less likely pathogens such as Aspergillus westerdijkiae, Chaetomium globosum and Dichotomopilus finlandicus were isolated both from ordinary and from problematic buildings. Aspergillus was the dominant, most diverse genus found during screening for potentially pathogenic isolates in the indoor strain collection. Studies on Aspergillus niger and Aspergillus calidodoustus revealed that tolerance to cleaning chemicals may contribute to the adaptation of Aspergillus species to indoor environments.

Season, Vegetation Proximity and Building Age Shape the Indoor Fungal Communities' Composition at City-Scale.

Exposure to particular microbiome compositions in the built environment can affect human health and well-being. Identifying the drivers of these indoor microbial assemblages is key to controlling the microbiota of the built environment. In the present study, we used culture and metabarcoding of the fungal Internal Transcribed Spacer ribosomal RNA region to assess whether small-scale variation in the built environment influences the diversity, composition and structure of indoor air fungal communities between a heating and an unheated season. Passive dust collectors were used to collect airborne fungi from 259 dwellings representative of three major building periods and five building environments in one city—Lausanne (Vaud, Switzerland)—over a heating and an unheated period. A homogenous population (one or two people with an average age of 75 years) inhabited the households. Geographic information systems were used to assess detailed site characteristics (altitude, proximity to forest, fields and parks, proximity to the lake, and density of buildings and roads) for each building. Our analysis indicated that season was the factor that explained most of the variation in colonies forming unit (CFU) concentration and indoor mycobiome composition, followed by the period of building construction. Fungal assemblages were more diverse during the heating season than during the unheated season. Buildings with effective insulation had distinct mycobiome compositions from those built before 1975 — regardless of whether they were constructed with pre-1945 technology and materials or 1945 — 1974 ones. The urban landscape—as a whole—was a significant predictor of cultivable Penicillium load—the closer the building was to the lake, the higher the Penicillium load—but not of fungal community composition. Nevertheless, the relative abundance of eleven fungal taxa detected by metabarcoding decreased significantly with the urbanization gradient. When urban landscape descriptors were analyzed separately, the explanatory power of proximity to vegetation in shaping fungal assemblages become significant, indicating that land cover type had an influence on fungal community structure that was obscured by the effects of building age and sampling season. In conclusion, indoor mycobiomes are strongly modulated by season, and their assemblages are shaped by the effectiveness of building insulation, but are weakly influenced by the urban landscape.

Levels of fungi aerosols in residential houses in Benin City, Southern Nigeria

Lack of monitoring residential homes for fungi contamination, has reportedly resulted in various health outcomes in vulnerable occupants. This study assessed the level of indoor and outdoor airborne fungi contamination and reveal the identity of air borne fungi species in the study area. Forty-five households were randomly selected across the five local council areas in Benin city for airborne sampling. Airborne fungi were assessed bimonthly using the passive sampling technique. Discrete colonies of fungi were enumerated and mean values of triplicate concentrations were expressed in Colony forming unit / m3 (CFU/m3) Airborne fungi isolates were characterized and identified using standard procedures. The mean indoor and outdoor meteorological parameters ranged between 31.2 to 32.3°C and 31.1 to 32.5°C (Temperature); 71.6 to 74.1% and 63.0 to 74.1% (Relative humidity) respectively. The fungi concentrations varied from 301.0 to 747.1 CFU/m3 and 337.67 to 554.6 CFU/m3 (indoor); 223.8 to 450.4 CFU/m3 and 378.64 to 532.7 CFU/m3 (outdoor) in wet and dry seasons. The prevalent fungi genera isolated from the indoor and outdoor air across the sampling sites were Penicillium, Cladosporium, and Aspergillus. The outdoor fungi concentrations showed a significant association (R = 0.360 and 0.260; R2 = 0.130 and 0.032; p&lt; 0.01) with indoor fungi concentrations in both seasons. The study revealed high airborne fungi counts and fungi species of public health interest in the houses. Regular cleaning and maintenance practices to reduce the increasing effect of fungi spores is highly recommended.

In Vitro Metabolism of Phenylspirodrimanes Derived from the Indoor Fungus Stachybotrys.

Fungi belonging to the genus Stachybotrys are frequently detected in water-damaged indoor environments, and a potential correlation between emerging health problems of inhabitants of affected housing and the fungi is controversially discussed. Secondary metabolites (i.e., mycotoxins) produced by Stachybotrys, such as the highly toxic macrocyclic trichothecenes (MCTs), are of potential concern to human health. The present study, however, focused on the potential effects of the more broadly and abundantly formed group of phenylspirodrimanes (PSDs). The phase I and II metabolism of four structurally different PSDs were investigated in vitro using hepatic models in combination with high-performance liquid chromatography high-resolution mass spectrometry (HPLC-HRMS) analysis. In addition to metabolite detection by HRMS, isolation and structure elucidation by nuclear magnetic resonance spectroscopy (NMR) was part of the conducted study as well.

The mysterious mould outbreak - A comprehensive fungal colonisation in a climate-controlled museum repository challenges the environmental guidelines for heritage collections

• The xerophilic Aspergillus halophilicus has colonised a museum repository. • It was climate-controlled; the growth was not detectable with traditional methods. • Fungal growth in museum collections threatens the preservation of cultural heritage. • The massive fungal infestation may cause occupational exposure. • Guidelines for heritage collections do not consider the risk of xerophilic fungi. Within the last decade, fungal colonisations have increased in Danish museum repositories. The growth is unexpected, as many Danish museums strive to comply with the environmental guidelines for heritage collections. When fungal growth develops in heritage collections, it threatens the heritage preservation and occupational health of museum staff. Therefore, it is crucial to prevent. This study characterised a fungal colonisation in a 1450m 2 museum repository, striving to meet the guidelines for heritage collections with relative humidity below 60%. After fungal discovery, the repository was examined twice by an environmental laboratory with morphological identification of fungi and quantification of fungal biomass based on fungal enzyme activity. However, the reports were not sufficient to qualify a recovery process. A research study with a broader approach was conducted to further elucidate the problem. The study included 1) building examination, 2) fungal surface sampling and morphological ID, 3) ID of fungal isolates with DNA sequencing, and 4) activated fungal air sampling and morphological ID. Although the relative humidity was measured to meet the guidelines for heritage collections with no evidence of moisture or microclimate, hyaline and white fungal colonies were distributed on heritage artefacts throughout the repository. There was no growth on interior and building structures. Cultivation of air samples on DG18-agar and V8®agar showed the presence of common indoor fungi, while artefact samples cultivated on the same media showed no growth. In contrast, cultivation of air samples and artefacts samples on the low water activity agar MY50G followed by DNA-sequencing showed high concentrations of the xerophilic fungi A. halophilicus, A. domesticus, A. magnivesiculatus and A. vitricola , belonging to Aspergillus section Restricti . These fungi are characterised by growing at low water activity corresponding to low relative humidity. The museum repository seemed to provide this environment with relative humidity below 60%. The study emphasised that examining the same fungi using different approaches may obtain very different results. Furthermore, the study questioned if the environmental guidelines for heritage collections adequately prevent the risk of xerophilic fungal growth. Xerophilic fungi are not adequately included in the risk assessment underlying the preventive conservation framework. Consequently, the risk is not included in the revised environmental guidelines accepting RH between 40-60% to support more sustainable heritage storage. It has not been studied if the revision would increase the risk of xerophilic fungal growth before it was accepted and implemented. This study indicates that it could be the case. Close collaboration between mycologists and museum professionals may develop more standardised and targeted detection and prevention practices for heritage repositories. The risks of xerophilic fungal growth should be included in the preventive conservation framework ensuring heritage preservation and occupational health of museum staff.