Assessment of microbiological indoor air quality in an Italian office building equipped with an HVAC system

The purpose of this study was to evaluate the level and composition of bacteria and fungi in the indoor air of an Italian office building equipped with a heating, ventilation and air conditioning (HVAC) system. Airborne bacteria and fungi were collected in three open-space offices during different seasons. The microbial levels in the outdoor air, supply air diffusers, fan coil air flow and air treatment unit humidification water tank were used to evaluate the influence of the HVAC system on indoor air quality (IAQ). A medium–low level of bacterial contamination (50–500 CFU/m³) was found in indoor air. Staphylococcus and Micrococcus were the most commonly found genera, probably due to human presence. A high fungal concentration was measured due to a flood that occurred during the winter. The indoor seasonal distribution of fungal genera was related to the fungal outdoor distribution. Significant seasonal and daily variation in airborne microorganisms was found, underlining a relationship with the frequency of HVAC system switching on/off. The results of this monitoring highlight the role of the HVAC system on IAQ and could be useful to better characterise bacterial and fungal population in the indoor air of office buildings.     

Airborne fungi and bacteria in indoor and outdoor environment of the Pediatric Unit of Edirne Government Hospital

This study was performed between January 2004 and December 2004 in 13 stations in the Pediatric Unit of Edirne Government Hospital in order to determine the outdoor and indoor airborne microfungal and bacterial contents. The results of air samplings revealed that 1,376 microfungal and 2,429 bacterial colonies in total were isolated. The isolated microfungal specimens were identified and 65 species from 16 genera were determined. Among these, the most frequent genus was Cladosporium with 462 colonies (33.58%) followed by Alternaria with 310 (22.53%) and Penicillium with 280 (20.35%) colonies. The isolated bacterial samples were grouped based on their Gram-staining properties. The most frequent ones were Gram (+) cocci with 1,527 colonies (62.87%) followed by Gram (+) bacilli with 828 colonies (34.09%) and Gram (−) bacilli with 74 colonies (3.05%). Staphylococcus, Bacillus, Corynebacterium, and Microccus appeared to be the common genera isolated for all months. Statistical analyses were performed in order to see if there existed a relationship between meteorological conditions and the microfungal and bacterial species and their concentrations.     

Indoor air quality in university environments

This study evaluates the airborne microflora in research laboratories of the University of Chieti (Italy). A quali-quantitative evaluation of the index microbial air contamination was performed using the settle plate method. The microbial air contamination was evaluated during 6 months in three university buildings (A, B, and C). Nutrient agar plates were exposed, monthly, for 1 h at the morning and the afternoon to evaluate the colony forming units per plate per hour. Together with the quantitative analysis, the most frequent bacterial and fungal colonies isolated were also characterized. Moreover, in each sampling, the number of the occupants in each room was recorded to evaluate a possible relationship with the microbial pollution. The microbial concentration was always within the limit values defined for these environments. Buildings A and C displayed a seasonal fluctuation of airborne microflora with the increase in microbial concentration in the warmer season (April to June) in respect to the colder period (October to December). The most common microorganisms detected in the indoor air of the examined buildings were Gram-positive bacteria, belonged to the genera Staphylococcus, Bacillus, and Actinomyces. Data presented here underline the useful monitoring of the research university laboratories also emphasizing the effectiveness of the settle plate method.     

Airborne fungi in child day care centers in Edirne City, Turkey

The purpose of this study was to determine the concentration, in terms of monthly and seasonal distribution and in relation to meteorological factors, of indoor and outdoor microfungi at selected sites in several child day care centers in the city of Edirne, Turkey. Samples were collected at one month intervals over a period of 12 months between January-December 2004, by exposing petri plates containing Peptone Dextrose Agar with Rose-Bengal and Streptomycin medium to the air for 10-15 min. A total of 2,071 microfungal colonies were counted on 192 petri plates. Thirty microfungal genera (Acremonium, Alternaria, Arthrinium, Aspergillus, Bahusakala, Beauveria, Ceuthospora, Chaetomium, Cladosporium, Curvularia, Drechslera, Epicoccum, Eurotium, Fusarium, Mycotypha, Myrotechium, Paecilomyces, Penicillium, Pestalotiopsis, Phoma, Ramichloridium, Rhizopus, Scopulariopsis, Stachybotrys, Stemphylium, Torula, Trichoderma, Trichothecium, Ulocladium, Verticillium) and 75 microfungal species were isolated from the air indoor and outdoor of the day care centers. The dominant microfungal genera were Cladosporium, Penicillium and Alternaria (44.11%, 18.94%, 14.67% of the total respectively), while the genus with the most species richness was Penicillium (26 species). Alternaria, Cladosporium, Penicillium and non-sporulating microfungi were found every month. Cladosporium was the dominant genus in both indoor and outdoor air. Although the predominant genus was the same in both indoor and outdoor air, Cladosporium was followed by Penicillium, Alternaria and Aspergillus genera in indoor air and by Alternaria, Penicillium and Aspergillus genera in outdoor air. While a positive correlation was found between the concentration of monthly outdoor microfungi and monthly average temperature, a negative correlation was found between the concentration of monthly outdoor microfungi and monthly average wind velocity. Also, some relationships were found between the monthly concentrations of the most predominant microfungal genera (Cladosporium, Penicillium and Alternaria) and various meteorological factors.     

Seasonal evaluation of bioaerosols from indoor air of residential apartments within the metropolitan area in South Korea

The aims of the present study were to determine the levels of bioaerosols including airborne culturable bacteria (total suspended bacteria, Gram-positive bacteria, Staphylococcus, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), and Gram-negative bacteria), fungi, endotoxin, and viruses (influenza A, influenza B, respiratory syncytial virus types A/B, parainfluenza virus types 1/2/3, metapnemovirus, and adenovirus) and their seasonal variations in indoor air of residential apartments. Of the total suspended bacteria cultured in an indoor environment, Staphylococcus was dominant and occupied 49.0 to 61.3 % of indoor air. Among Staphylococcus, S. aureus were detected in 100 % of households' indoor air ranging from 4 to 140 CFU/m³, and 66 % of households were positive for MRSA ranging from 2 to 80 CFU/m³. Staphylococcus and S. aureus concentrations correlated with indoor temperature (adjusted β: 0.4440 and 0.403, p?<?0.0001). Among respiratory viruses, adenovirus was detected in 14 (14 %) samples and influenza A virus was detected in 3 (3 %) samples regarding the indoor air of apartments. Adenovirus concentrations were generally higher in winter (mean concentration was 2,106 copies/m³) than in spring (mean concentration was 173 copies/m³), with concentrations ranging between 12 and 560 copies/m³. Also, a strong negative correlation between adenovirus concentrations and relative humidity in indoor air was observed (r?=??0.808, p?<?0.01). Furthermore, temperature also negatively correlated with adenovirus concentrations (r?=??0.559, p?<?0.05).     

Fungal flora in indoor and outdoor air of different residential houses in Tekirdag City (Turkey): Seasonal distribution and relationship with climatic factors

This study was investigated the density and monthly distribution of indoor and outdoor microfungi in six different residential houses in Tekirdag City through the exposure of Petri dishes containing Rose-Bengal Streptomycin Agar media. Samples were collected in 1-month intervals over a period of 12 months between March, 2001, and February, 2002. We used 432 Petri dishes and counted a total of 4,205 microfungi colonies, 1,790 from indoor air and 2,415 from outdoor air. As a result, 42 species belonging to 12 genera were identified. The most frequent fungal genera were Penicillium (28.61%), Cladosporium (16.08%) and Alternaria (15.98%). While Penicillium (40.61%) and Cladosporium (15.92%) were the dominant genera of indoor air, Alternaria (20.62%) and Penicillium (19.71%) were isolated most frequently from outdoor air (Table 3). Alternaria citri (10.15%) and Penicillium brevicompactum (10.15%) were found to be the most frequent among the 42 identified species. While P. brevicompactum (19.55%) and Aspergillus niger (6.37%) were the most frequent indoor species, A. citri (13.37%) and Cladosporium cladosporioides (8.20%) were the most frequent outdoor species. Linear Regression Analysis was applied to determine whether or not there was a relationship between the number of colonies of isolated fungal genera and meteorological factors during the research period. Correlations between the presence of Aspergillus and temperature, relative humidity, duration of sunny periods and agents of air pollution such as SO(2) and PM were statistically significant. No significant correlations, however, were found between other fungal genera and environmental variables.     

Determination of potential allergenic fungal flora and its clinical reflection in suburban elementary schools in Izmir

In this research, in order to determine mean fungus counts, indoor and outdoor air samples were taken in five elementary school buildings located in the city center of Seferihisar, Izmir (45 km from Izmir) within a 1-year period between March and April 2004, and between January and February 2005 representing similar climatic characteristics. Five samples, three from three classes where 5–8, 10–12, and 12–15 age group students attended, one from the corridors, and one from outside the buildings in all the schools, were taken for each period. Within the period of the study, in indoor and outdoor air samples, 7,122 microfungus colonies were counted. Sixty-four species were identified that belong to 17 genera as a result of the identification of isolates obtained. Skin prick tests were applied to 55 out of a total of 117 teachers by the clinicians. According to these test results, 24 teachers were sensitive to at least one agent. Results revealed that, in terms of mold counts, the difference between the schools and the difference between the times (periods) were statistically significant (p?< 0.05).     

Microbial contamination of dental unit waterlines and effect on quality of indoor air

The microbiological quality in dental unit waterlines (DUWLs) is considered to be important because patients and dental staff with suppressed immune systems are regularly exposed to water and aerosols generated from dental units (DUs). Opportunistic pathogens like Pseudomonas, Legionella, Candida, and Aspergillus can be present in DUWLs, while during consultations, bioaerosols can be dispersed in the air, thus resulting in effects on microbiological quality of indoor air. This present study represents microbiological air and water quality in dental offices (DOs) and also concerns the relationship between the quality of DO air and dental unit water. This study aimed to assess both the microbial quality of dental unit water and the indoor air in 20 DOs and to survey the effect on the quality of the indoor air with the existing microorganisms in dental unit water. Fourteen out of 20 (70 %) DUWLs were found to be contaminated with a high number of aerobic mesophilic heterotrophic bacteria. In terms of bacterial air contamination levels, in 90 % of DOs, a medium level (<500 colony-forming units (CFU)/m³) of contamination was determined, while in terms of microfungal air contamination, in all DOs, a low level (<100 CFU/m³) of contamination was determined. Potential infection or allergen agents, such as Pseudomonas, Micrococcus, Staphylococcus, Alternaria, Cladosporium, Penicillium, Aspergillus, and Paecilomyces were isolated from water and air samples. This study’s determination of contamination sources and evaluation of microbial load in DOs could contribute to the development of quality control methods in the future.     

A study on Aspergillus species in houses of asthmatic patients from Sari City, Iran and a brief review of the health effects of exposure to indoor Aspergillus

To study the distribution of Aspergillus spp. in outdoor and indoor air of asthmatic patients’ houses, as well as a review on the health effects of exposure to indoor Aspergillus. Open plates containing malt extract agar media were used to isolate fungi from the indoor (n?=?360) and outdoor (n?=?180) air of 90 asthmatic patients’ houses living in Sari City, Iran. Plates were incubated at room temperature for 7–14 days. Cultured Aspergillus spp. were identified by standard mycological techniques. All culture plates grew fungi, a testament to the ubiquitous nature of fungal exposure. Cladosporium spp. (29.2%), Aspergillus spp. (19.0%), and Penicillium spp. (18.3%) were most common inside the houses while Cladosporium spp. (44.5%), Aspergillus spp. (12.4%), and Alternaria spp. (11.1%) were most common outside the houses. Aspergillus flavus (30.1%) and A. fumigatus (23.1%) are the most commonly isolated species in indoor air. Aspergillus flavus (44.5%) and A. fumigatus (42.6%) were the most prevalent Aspergillus spp. outside. The most colony numbers of Aspergillus were isolated from kitchens (30.4%) and the least from bedrooms (21.1%). Aspergillus flavus was the most prevalent specie in all sampled rooms except in the kitchen where A. fumigatus was the most common. Aspergillus flavus is the most prevalent species among the Aspergillus spp. in the indoor and outdoor of a warm climate area. In these areas, A. flavus can be a major source of allergen in the air. Therefore, minimizing indoor fungal exposure could play an important role in reducing allergic symptoms in susceptible persons.     

Airborne and soilborne microfungi in the vicinity Hamitabat Thermic Power Plant in Kirklareli City (Turkey), their seasonal distributions and relations with climatological factors

Soil and air samples of seven different localities around Hamitabat Thermic Power Plant, 10 km far away from Luleburgaz/Kirklareli (Turkey), were taken between the years 2003 and 2004 with seasonal intervals. The samples were brought to the laboratory and their microfungal identifications were done. From the air samples, 737 microfungi colonies were isolated comprising 26 species belonging to eight genera. From soil samples, 170.6 × 10⁴ colony-forming unit (CFU)/g was isolated from 33 species belonging to 16 genera. The most isolated genus from air samples was Alternaria (324 CFU, 43.96%), followed by Cladosporium (208 CFU, 25.52%) and Phoma (44 CFU, 5.40%). Penicillium was the most isolated genus from the soil samples with a value of 560,000 CFU/g (32.8%), followed by Fusarium (226,000 CFU/g, 13.12%) and Aspergillus (154,000 CFU/g, 9.03%). Among these species, Alternaria citri and Alternaria alternata are the most abundant species in air with 164 and 107 CFU, respectively, whereas Fusarium graminearum and Penicillium citrinum are the most abundant species in soil with CFU per gram values of 17.8 × 10⁴ and 1.3 × 10⁵. Correlation analysis was applied to determine whether or not there was a relationship between colony number of isolated fungal genera and meteorological factors. Some parameters of soil samples’ incontent during the research period were calculated using a computer analysis program. From the air samples, a positive correlation was found between relative humidity and Alternaria colonial counts and Cladosporium spore counts (r?=?0.912 and r?=?1.000, respectively). Similarly, with the analysis of soil samples, a positive correlation between colonial counts of Alternaria and soil pH and a positive correlation between colonial counts of Aspergillus and Penicillium and salt percentage concentration of soil were found.     

某石化化工行业聚集区室内外PM2.5中多环芳烃分布特征及来源

于非采暖季和采暖季分别采集某石化化工行业聚集城市中心城区室内外PM_(2.5)样品,采用高效液相色谱法分析PM_(2.5)上载带的16种PAHs,对其分布特征、来源以及室外PAHs污染对室内污染的贡献进行了初步探讨。结果表明,研究区域非采暖季和采暖季室外PM_(2.5)中ΣPAHs浓度日均值分别为36.3、294 ng/m~3,室内PM_(2.5)中ΣPAHs浓度分别为14.8、84.6 ng/m~3,均以4、5环PAHs为主;室内PAHs主要来自室外渗透污染,但同时明显存在室内排放源贡献;PAHs来源分析进一步证实研究区域PAHs主要来自煤炭、石油等不完全燃烧,采暖季煤炭燃烧源贡献更突出。     

Assessment of indoor airborne contamination in a wastewater treatment plant

The main objective of this work was to quantify and characterize the major indoor air contaminants present in different stages of a municipal WWTP, including microorganisms (bacteria and fungi), carbon dioxide, carbon monoxide, hydrogen sulfide ammonia, formaldehyde, and volatile organic compounds (VOCs). In general, the total bacteria concentration was found to vary from 60 to >52,560 colony-forming units (CFU)/m³, and the total fungi concentration ranged from 369 to 14,068 CFU/m³. Generally, Gram-positive bacteria were observed in higher number than Gram-negative bacteria. CO₂ concentration ranged from 251 to 9,710 ppm, and CO concentration was either not detected or presented a level of 1 ppm. H₂S concentration ranged from 0.1 to 6.0 ppm. NH₃ concentration was <2 ppm in most samples. Formaldehyde was <0.01 ppm at all sampling sites. The total VOC concentration ranged from 36 to 1,724 μg/m³. Among the VOCs, toluene presented the highest concentration. Results point to indoor/outdoor ratios higher than one. In general, the highest levels of airborne contaminants were detected at the primary treatment (SEDIPAC 3D), secondary sedimentation, and sludge dehydration. At most sampling sites, the concentrations of airborne contaminants were below the occupational exposure limits (OELs) for all the campaigns. However, a few contaminants were above OELs in some sampling sites.     

Levels, sources, and health risks of carbonyls in residential indoor air in Hangzhou, China

Concentrations of formaldehyde, acetaldehyde, acetone, propionaldehyde, i-pentanal, and butyraldehyde in residential indoor air in Hangzhou were determined. The mean concentration of the total carbonyl compounds in summer was 222.6 μg/m³, higher than that in winter (68.5 μg/m³). The concentration of a specific carbonyl in indoor air was higher than the outdoor air measurement, indicating the release of carbonyls from the indoor sources. Formaldehyde and acetone were the most abundant carbonyls detected in summer and winter, respectively. Multiple regression analysis indicated that carbonyl concentrations in residential indoor air depended on the age of decoration and furniture, as well as their concentrations in outdoor air. In addition, a primary estimation showed that the health risks of carbonyls in summer were higher than those in winter.     

Bacteriological safety assessment,hygienic habits and cross-contamination risks in a Nigerian urban sample of household kitchen environment

Urban household kitchen environment was assessed for safety by determining their levels of indicator bacteria, hygienic habits and risk of cross-contamination. Household kitchens (60) were selected in Warri Town, Nigeria, by the multi-stage sampling technique. Contact surfaces, water and indoor kitchen air were analysed for aerobic plate counts, total and faecal coliforms using Nutrient and McConkey media by swab/rinse method, membrane filtration and sedimentation methods, respectively. Hygienic habits and risk of cross-contamination were assessed with structured questionnaire which included socio-demographic variables. On the basis of median counts, the prevalence of high counts (log cfu/cm²/m³/100 mL) of aerobic plate counts (>3.0), total coliforms (>1.0) and faecal coliforms (>0) on contact surfaces and air was high (58.0–92.0%), but low in water (30.0–40.0%). Pots, plates and cutleries were the contact surfaces with low counts. Prevalence of poor hygienic habits and high risk of cross-contamination was 38.6 and 67.5%, respectively. Education, occupation and kitchen type were associated with cross-contamination risk (P = 0.002–0.022), while only education was associated with hygienic habits (P = 0.03). Cross-contamination risk was related (P = 0.01–0.05) to aerobic plate counts (OR 2.30; CL 1.30–3.17), total coliforms (OR 5.63; CL 2.76–8.25) and faecal coliforms (OR 4.24; CL 2.87–6.24), while hygienic habit was not. It can be concluded that urban household kitchens in the Nigerian setting are vulnerable to pathogens likely to cause food-borne infections.     

Assessment of indoor and outdoor particulate air pollution at an urban background site in Iran

The relationship between indoor and outdoor particulate air pollution was investigated at an urban background site on the Payambar Azam Campus of Mazandaran University of Medical Sciences in Sari, Northern Iran. The concentration of particulate matter sized with a diameter less than 1 μm (PM_1.0), 2.5 μm (PM_2.5), and 10 μm (PM₁₀) was evaluated at 5 outdoor and 12 indoor locations. Indoor sites included classrooms, corridors, and office sites in four university buildings. Outdoor PM concentrations were characterized at five locations around the university campus. Indoor and outdoor PM measurements (1-min resolution) were conducted in parallel during weekday mornings and afternoons. No difference found between indoor PM₁₀ (50.1 ± 32.1 μg/m³) and outdoor PM₁₀ concentrations (46.5 ± 26.0 μg/m³), indoor PM_2.5 (22.6 ± 17.4 μg/m³) and outdoor PM_2.5 concentration (22.2 ± 15.4 μg/m³), or indoor PM_1.0 (14.5 ± 13.4 μg/m³) and outdoor mean PM_1.0 concentrations (14.2 ± 12.3 μg/m³). Despite these similar concentrations, no correlations were found between outdoor and indoor PM levels. The present findings are not only of importance for the potential health effects of particulate air pollution on people who spend their daytime over a period of several hours in closed and confined spaces located at a university campus but also can inform regulatory about the improvement of indoor air quality, especially in developing countries.     

Assessing indoor air quality of school environments: transplanted lichen <Emphasis Type="Italic">Pseudovernia furfuracea</Emphasis> as a new tool for biomonitoring and bioaccumulation

The aim of this research is to evaluate the ability of transplanted lichen Pseudovernia (P). furfuracea to biomonitor and bioaccumulate in urban indoor environments. The elements As, Cd, Cr, Cu, Hg, Ni and Pb and 12 selected polycyclic aromatic hydrocarbons (PAHs) were used to assess P. furfuracea as a biomonitoring tool for the indoor air quality of school environments. To achieve this purpose, lichen samples were exposed for 2 months in the outdoor and indoor environments of five school settings located in urban and rural areas. The results demonstrated that transplanted lichen P. furfuracea is a suitable biomonitoring tool for metals and PAHs in indoor settings and can discriminate between different levels of air pollution related to urbanisation and indoor conditions, such as those characterised by school environments. A transplanted lichen biomonitoring strategy is cost-effective, “green”, educational for attending children and less “invasive” than traditional air sampling methods. The feasibility of indoor monitoring by P. furfuracea is a relevant finding and could be a key tool to improve air quality monitoring programmes in school scenarios and thus focus on health prevention interventions for children, who are one of the most susceptible groups in the population.     

Outdoor-indoor air quality in Riyadh: SO2, NH3, and HCHO

A funded research project was conducted during the period July1992 through November 1994. The project was designed to evaluateindoor and ambient air quality in and around buildings of different types and uses in Riyadh, the capital of Saudi Arabia.Thirty intercity buildings and two outercity (background) siteswere carefully selected and monitored for air quality. Ten airpollutants, together with relevant meteorological parameters, were monitored indoor and outdoor at each site continuously andsimultaneously for a period of two weeks covering summer and winter seasons.This article discusses the results obtained for sulfur dioxide (SO₂), ammonia (NH₃) and formaldehyde (HCHO). Results of this investigation revealed that most sites had on the averageexceeded the recommended standards for SO₂ and NH₃ bothindoor and outdoor, with indoor levels being worse than outdoorduring winter time. Several sites also showed high levels of HCHO, with outdoor levels being consistently higher than indoor.Statistical and frequency analyses were performed on the collected data, showing seasonal and sector by sector variability, and outdoor-indoor correlations.     

Personal, indoor, and outdoor exposure to VOCs in the immediate vicinity of a local airport

This study measures the effect of emissions from an airport on the air quality of surrounding neighborhoods. The ambient concentrations of benzene, toluene, ethylbenzene, and o-, m-, and p-xylene (BTEX) were measured using passive samplers at 15 households located close to the airport (indoor, outdoor, and personal), at the end of airport runways and an out-of-neighborhood location. Measurements occurred over a 48-h period during summer 2006 and winter 2006?C2007. The average concentrations were 0.84, 3.21, 0.30, 0.99, and 0.34 ??g/m³ at the airport runways and 0.84, 3.76, 0.39, 1.22, and 0.39 ??g/m³ in the neighborhood for benzene, toluene, ethylbenzene, m-, p-, and o-xylene. The average neighborhood concentrations were not significantly different to those measured at the airport runways and were higher than the out-of-neighborhood location (0.48, 1.09, 0.15, 0.78, and 0.43 ??g/m³, each BTEX). B/T ratios were used as a tracer for emission sources and the average B/T ratio at the airport and outdoors were 0.20 and 0.23 for the summer and 0.40 and 0.42 for the winter, suggesting that both areas are affected by the same emission source. Personal exposure was closely related to levels in the indoor environment where subjects spent most of their time. Indoor/outdoor (I/O) ratios for BTEX ranged from 1.13 to 2.60 and 1.41 to 3.02 for summer and winter. The seasonal differences in I/O ratios reflected residential ventilation patterns, resulting in increased indoor concentrations of volatile organic compounds during winter.     

Indoor airborne fungal pollution in newborn units in Turkey

Pathogenic and/or opportunistic fungal species are major causes of nosocomial infections, especially in controlled environments where immunocompromised patients are hospitalized. Indoor fungal contamination in hospital air is associated with a wide range of adverse health effects. Regular determination of fungal spore counts in controlled hospital environments may help reduce the risk of fungal infections. Because infants have inchoate immune systems, they are given immunocompromised patient status. The aim of the present study was to evaluate culturable airborne fungi in the air of hospital newborn units in the Thrace, Marmara, Aegean, and Central Anatolia regions of Turkey. A total of 108 air samples were collected seasonally from newborn units in July 2012, October 2012, January 2013, and April 2013 by using an air sampler and dichloran 18% glycerol agar (DG18) as isolation media. We obtained 2593 fungal colonies comprising 370 fungal isolates representing 109 species of 28 genera, which were identified through multi-loci gene sequencing. Penicillium, Aspergillus, Cladosporium, Talaromyces, and Alternaria were the most abundant genera identified (35.14, 25.40, 17.57, 2.70, and 6.22% of the total, respectively).     

Indoor air pollution by 2-ethyl-1-hexanol in non-domestic buildings in Nagoya, Japan

2-Ethyl-1-hexanol is a possibly causative chemical in sick building symptoms, although 2-ethyl-1-hexanol has received little attention as a hazardous substance in studies on indoor air pollution. Airborne 2-ethyl-1-hexanol concentrations were measured from 2002 to 2004 in 99 rooms of 42 non-domestic buildings in Nagoya, Japan. The diffusive sampling method is effective for the measurement of a low level of 2-ethyl-1-hexanol in indoor air. The geometric mean (geometric standard deviation) of 2-ethyl-1-hexanol concentrations was 16.5 (5.4) microg m(-3) in indoor air and 1.9 (2.2) microg m(-3) in outdoor air. The maximum concentration of 2-ethyl-1-hexanol in indoor air and outdoor air was 2709 microg m(-3) and 12.4 microg m(-3), respectively. Fewer rooms in a small number of new buildings showed high concentrations of 2-ethyl-1-hexanol, while low concentrations were observed in many rooms of these buildings as well as the other new buildings. The room-to-room concentrations of 2-ethyl-1-hexanol in each building exhibited a wide variation. The geometric mean of the 2-ethyl-1-hexanol concentrations was significantly higher for indoor air than for outdoor air (p < 0.01). The correlation of the 2-ethyl-1-hexanol concentrations between indoor and outdoor air was not significant. Mechanical ventilation was effective in the temporary reduction of indoor 2-ethyl-1-hexanol level. These results suggest that the predominant source of 2-ethyl-1-hexanol was indoor areas.