Seasonal and Spatial Variations of Bioaerosols in Indoor Urban Environments, Ankara, Turkey

2011 ◽  
Vol 21 (6) ◽  
pp. 797-810 ◽  
Author(s):  
Sibel Mentese ◽  
Abbas Yousefi Rad ◽  
Münevver Arısoy ◽  
Gülen Güllü
Keyword(s):  
Large Scale ◽  
Climatic Factors ◽  
Sampling Site ◽  
Urban Environments ◽  
Spatial Variations ◽  
Indoor Environments ◽  
Seasonal And Spatial Variations ◽  
Bacillus Spp ◽  
Bacteria And Fungi ◽  
Indoor And Outdoor

Seasonal and spatial variations of both levels and characteristics of airborne bacteria and fungi in various types of non-complaint indoor environments and their outdoors were investigated. Bioaerosol samples were collected by the single-stage Andersen sampler during the winter and summer seasons in Ankara, Turkey. Indoor and outdoor temperature, relative humidity (RH) and CO2 concentrations were also monitored online during the sampling. Bacteria levels in apartments were found to be considerably elevated when people were present. Significant relationships between bioaerosol levels and RH and CO2 concentrations ( p<0.05) were found. Bacteria levels exhibited a seasonal variation, while fungi levels did not, probably due to lower fungi concentrations occurrence as a result of lower RH values (median: 30%). Measured low levels of fungi in this study may be due to geographical conditions, climatic factors, and other environmental conditions. The indoor to outdoor (I/O) ratio for bacteria levels were found to be significantly higher than 1.0, while indoor and outdoor fungi levels were similar. Winter to summer (W/S) ratios in the sampling site groups varied on a large scale for both culturable fungi concentrations (0.24–19.59) and total bacteria count (0.16–6.59). The most prominent bacteria were Micrococcus spp., Staphylococcus spp. and Bacillus spp., while the most predominant fungi were Penicillium spp., Aspergillus spp. and Cladosporium spp.

Characterization of Bacteria and Fungi Bioaerosol in the Indoor Air of selected Primary Schools in Malaysia

2011 ◽  
Vol 20 (6) ◽  
pp. 607-617 ◽  
Author(s):  
Nor Husna Mat Hussin ◽  
Lye Munn Sann ◽  
Mariana Nor Shamsudin ◽  
Zailina Hashim
Keyword(s):  
Indoor Air ◽  
Primary Schools ◽  
Average Concentration ◽  
Outdoor Air ◽  
Inadequate Ventilation ◽  
Bacillus Spp ◽  
Bacteria And Fungi ◽  
Staphylococcus Spp ◽  
Indoor And Outdoor

This study reports the types and concentrations of bacterial and fungal bioaerosols found in five randomly selected primary schools in Malaysia. Normal flora bacteria was the most frequently isolated bacteria including Staphylococcus spp., Pseudomonas spp. and Bacillus spp. Terribacillus spp. found in this study had never been reported before. The most frequently isolated fungal genera were Aspergillus, Penicillium, Fusarium, Rhizopus and Zygomycetes. The average concentration of bacteria in indoor and outdoor air were 1025 ± 612 CFU/m3 and 1473 ± 1261 CFU/m3, respectively, while the average concentration of fungal bioaerosol in indoor and outdoor air were 292 ± 83 CFU/m3 and 401 ± 235 CFU/m3, respectively. The percentages of bacterial and fungal samples that were within the American Conference of Industrial Hygenists (ACGIH) recommended levels were 44% and 33.8%, respectively. The ratio of indoor to outdoor fungi concentration was below 1.0, suggesting minimal indoor generative source for fungal bioaerosols. However, the ratio of indoor to outdoor bacteria concentration was approaching 1.0, suggesting the presence of potential internal generative source and inadequate ventilation. Building occupants might be one of the potential sources of bacteria in the indoor air as the bacteria concentrations without occupants were significantly lower than with occupants (p < 0.05).

scholarly journals Indoor and Outdoor Backpack Mapping with Calibrated Pair of Velodyne LiDARs

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3944 ◽  
Author(s):  
Martin Velas ◽  
Michal Spanel ◽  
Tomas Sleziak ◽  
Jiri Habrovec ◽  
Adam Herout
Keyword(s):  
Point Cloud ◽  
Large Scale ◽  
Laser Intensity ◽  
Information Modeling ◽  
Indoor Environments ◽  
Data Density ◽  
Universal Solution ◽  
Building Information ◽  
Sufficient Precision ◽  
Indoor And Outdoor

This paper presents a human-carried mapping backpack based on a pair of Velodyne LiDAR scanners. Our system is a universal solution for both large scale outdoor and smaller indoor environments. It benefits from a combination of two LiDAR scanners, which makes the odometry estimation more precise. The scanners are mounted under different angles, thus a larger space around the backpack is scanned. By fusion with GNSS/INS sub-system, the mapping of featureless environments and the georeferencing of resulting point cloud is possible. By deploying SoA methods for registration and the loop closure optimization, it provides sufficient precision for many applications in BIM (Building Information Modeling), inventory check, construction planning, etc. In our indoor experiments, we evaluated our proposed backpack against ZEB-1 solution, using FARO terrestrial scanner as the reference, yielding similar results in terms of precision, while our system provides higher data density, laser intensity readings, and scalability for large environments.

scholarly journals Indoor Air Quality in New Zealand Office Buildings: Studies of Airborne Bacteria and Fungi

2021 ◽  
Author(s):  
◽  
Hany George Fouad
Keyword(s):  
New Zealand ◽  
Indoor Air ◽  
Environmental Science ◽  
Airborne Bacteria ◽  
Indoor Environments ◽  
Evaluation Tool ◽  
Mechanically Ventilated ◽  
Carbon Dioxide Levels ◽  
Bacteria And Fungi ◽  
Indoor And Outdoor

<p>The aim of this thesis was to investigate the levels of indoor airborne bacteria and fungi in fully sealed mechanically ventilated offices in New Zealand. One of the main objectives was to examine the indoor airborne bacterial and fungal levels in Auckland and Wellington offices and to compare the quality of indoor air in offices in both cities. Examining the differences in indoor airborne bacterial and fungal levels between complaint and non-complaint offices as well as comparing those levels with those of similar indoor environments overseas was also one of the main objectives of this thesis. Indoor and outdoor air data used in this thesis were recorded during commercial investigation of 235 offices in Auckland and Wellington by the Institute of Environmental Science and Research (ESR) and Advanced Building Services (ABS). This data included measurements of indoor microclimatic parameters (temperature and relative humidity), indoor and outdoor airborne bacterial and fungal concentrations and indoor carbon dioxide levels. Statistical analyses showed the indoor bacterial levels in Auckland offices were significantly higher than those of Wellington offices. Indoor fungal levels in Auckland offices, on the other hand, were significantly below those of Wellington offices despite the fact that outdoor fungal levels in Auckland were at least three times higher than those of Wellington. No significant differences have been observed between airborne bacterial and fungal levels in complaint and non-complaint offices. Indoor airborne bacterial and fungal levels in New Zealand offices appeared also to be within the levels of those of overseas offices. However, as the bacterial and fungal sampling techniques used by ESR and ABS were different from those used in overseas studies and this can affect airborne bacterial and fungal absolute counts significantly, care is needed in making such comparisons. Finally, an evaluation tool has been developed to overcome the difficulties associated with comparison between indoor airborne fungal levels obtained using different measurements techniques. This tool can be used to establish whether elevated fungal problems exist in an office environment and the likely causes of these problems.</p>

scholarly journals Indoor Air Quality in New Zealand Office Buildings: Studies of Airborne Bacteria and Fungi

2021 ◽  
Author(s):  
◽  
Hany George Fouad
Keyword(s):  
New Zealand ◽  
Indoor Air ◽  
Environmental Science ◽  
Airborne Bacteria ◽  
Indoor Environments ◽  
Evaluation Tool ◽  
Mechanically Ventilated ◽  
Carbon Dioxide Levels ◽  
Bacteria And Fungi ◽  
Indoor And Outdoor

<p>The aim of this thesis was to investigate the levels of indoor airborne bacteria and fungi in fully sealed mechanically ventilated offices in New Zealand. One of the main objectives was to examine the indoor airborne bacterial and fungal levels in Auckland and Wellington offices and to compare the quality of indoor air in offices in both cities. Examining the differences in indoor airborne bacterial and fungal levels between complaint and non-complaint offices as well as comparing those levels with those of similar indoor environments overseas was also one of the main objectives of this thesis. Indoor and outdoor air data used in this thesis were recorded during commercial investigation of 235 offices in Auckland and Wellington by the Institute of Environmental Science and Research (ESR) and Advanced Building Services (ABS). This data included measurements of indoor microclimatic parameters (temperature and relative humidity), indoor and outdoor airborne bacterial and fungal concentrations and indoor carbon dioxide levels. Statistical analyses showed the indoor bacterial levels in Auckland offices were significantly higher than those of Wellington offices. Indoor fungal levels in Auckland offices, on the other hand, were significantly below those of Wellington offices despite the fact that outdoor fungal levels in Auckland were at least three times higher than those of Wellington. No significant differences have been observed between airborne bacterial and fungal levels in complaint and non-complaint offices. Indoor airborne bacterial and fungal levels in New Zealand offices appeared also to be within the levels of those of overseas offices. However, as the bacterial and fungal sampling techniques used by ESR and ABS were different from those used in overseas studies and this can affect airborne bacterial and fungal absolute counts significantly, care is needed in making such comparisons. Finally, an evaluation tool has been developed to overcome the difficulties associated with comparison between indoor airborne fungal levels obtained using different measurements techniques. This tool can be used to establish whether elevated fungal problems exist in an office environment and the likely causes of these problems.</p>

Contribution of large bacteria to bacterial biomass in a deep freshwater lake (Lake Biwa, Japan)

2020 ◽  
Vol 85 ◽  
pp. 131-139
Author(s):  
S Shen ◽  
Y Shimizu
Keyword(s):  
Cell Volume ◽  
Bacterial Cell ◽  
Lake Biwa ◽  
Bacterial Biomass ◽  
Spatial Variations ◽  
Freshwater Lake ◽  
Heterotrophic Nanoflagellates ◽  
Bacterial Productivity ◽  
Transmission Electron ◽  
Seasonal And Spatial Variations

Despite the importance of bacterial cell volume in microbial ecology in aquatic environments, literature regarding the effects of seasonal and spatial variations on bacterial cell volume remains scarce. We used transmission electron microscopy to examine seasonal and spatial variations in bacterial cell size for 18 mo in 2 layers (epilimnion 0.5 m and hypolimnion 60 m) of Lake Biwa, Japan, a large and deep freshwater lake. During the stratified period, we found that the bacterial cell volume in the hypolimnion ranged from 0.017 to 0.12 µm3 (median), whereas that in the epilimnion was less variable (0.016 to 0.033 µm3, median) and much lower than that in the hypolimnion. Additionally, in the hypolimnion, cell volume during the stratified period was greater than that during the mixing period (up to 5.7-fold). These differences in cell volume resulted in comparable bacterial biomass in the hypolimnion and epilimnion, despite the fact that there was lower bacterial abundance in the hypolimnion than in the epilimnion. We also found that the biomass of larger bacteria, which are not likely to be grazed by heterotrophic nanoflagellates, increased in the hypolimnion during the stratified period. Our data suggest that estimation of carbon flux (e.g. bacterial productivity) needs to be interpreted cautiously when cell volume is used as a constant parametric value. In deep freshwater lakes, a difference in cell volume with seasonal and spatial variation may largely affect estimations.

scholarly journals Species and characteristics of volatile organic compounds emitted from an auto-repair painting workshop

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Y. Song ◽  
H. Chun
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Large Scale ◽  
Butyl Acetate ◽  
Small Scale ◽  
Indoor Environments ◽  
Voc Emissions ◽  
Volatile Organic ◽  
Before And After ◽  
Adsorption Systems

AbstractVolatile organic compounds (VOCs) are secondary pollutant precursors having adverse impacts on the environment and human health. Although VOC emissions, their sources, and impacts have been investigated, the focus has been on large-scale industrial sources or indoor environments; studies on relatively small-scale enterprises (e.g., auto-repair workshops) are lacking. Here, we performed field VOC measurements for an auto-repair painting facility in Korea and analyzed the characteristics of VOCs emitted from the main painting workshop (top coat). The total VOC concentration was 5069–8058 ppb, and 24–35 species were detected. The VOCs were mainly identified as butyl acetate, toluene, ethylbenzene, and xylene compounds. VOC characteristics differed depending on the paint type. Butyl acetate had the highest concentration in both water- and oil-based paints; however, its concentration and proportion were higher in the former (3256 ppb, 65.5%) than in the latter (2449 ppb, 31.1%). Comparing VOC concentration before and after passing through adsorption systems, concentrations of most VOCs were lower at the outlets than the inlets of the adsorption systems, but were found to be high at the outlets in some workshops. These results provide a theoretical basis for developing effective VOC control systems and managing VOC emissions from auto-repair painting workshops.

scholarly journals Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 135
Author(s):  
Keng-Lou James Hung ◽  
Sara S. Sandoval ◽  
John S. Ascher ◽  
David A. Holway
Keyword(s):  
Habitat Fragmentation ◽  
Large Scale ◽  
Global Climate ◽  
Relative Magnitude ◽  
Urban Environments ◽  
Floral Resources ◽  
Severe Drought ◽  
Drought Event ◽  
Fragmented Habitat ◽  
Native Bee

Global climate change is causing more frequent and severe droughts, which could have serious repercussions for the maintenance of biodiversity. Here, we compare native bee assemblages collected via bowl traps before and after a severe drought event in 2014 in San Diego, California, and examine the relative magnitude of impacts from drought in fragmented habitat patches versus unfragmented natural reserves. Bee richness and diversity were higher in assemblages surveyed before the drought compared to those surveyed after the drought. However, bees belonging to the Lasioglossum subgenus Dialictus increased in abundance after the drought, driving increased representation by small-bodied, primitively eusocial, and generalist bees in post-drought assemblages. Conversely, among non-Dialictus bees, post-drought years were associated with decreased abundance and reduced representation by eusocial species. Drought effects were consistently greater in reserves, which supported more bee species, than in fragments, suggesting that fragmentation either had redundant impacts with drought, or ameliorated effects of drought by enhancing bees’ access to floral resources in irrigated urban environments. Shifts in assemblage composition associated with drought were three times greater compared to those associated with habitat fragmentation, highlighting the importance of understanding the impacts of large-scale climatic events relative to those associated with land use change.

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