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>

Assessment of the indoor air quality based on airborne bacteria and fungi measurements in a public school of Istanbul

2020 ◽  
Vol 13 (24) ◽  
Author(s):  
Nuket Sivri ◽  
Ahmet Ozgur Dogru ◽  
Arzu Funda Bagcigil ◽  
Kemal Metiner ◽  
Dursun Zafer Seker
Keyword(s):  
Air Quality ◽  
Public School ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Airborne Bacteria ◽  
Bacteria And Fungi

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).

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.

Assessment of Airborne Bacteria and Fungi in Various University Indoor Environments: A Case Study in Chang'an University, China

2015 ◽  
Vol 32 (4) ◽  
pp. 273-283 ◽  
Author(s):  
Yanpeng Li ◽  
Wei Wang ◽  
Xiao Guo ◽  
Tinglu Wang ◽  
Honglei Fu ◽  
...  
Keyword(s):  
Airborne Bacteria ◽  
Indoor Environments ◽  
Bacteria And Fungi

scholarly journals Microbial Assessment of Indoor Air Quality of Ventilation Systems

2019 ◽  
pp. 1-7
Author(s):  
H. O. Stanley ◽  
B. Onwuna ◽  
C. J. Ugboma
Keyword(s):  
Indoor Air ◽  
Natural Ventilation ◽  
Airborne Bacteria ◽  
Fungal Isolates ◽  
Enterococcus Spp ◽  
Bacillus Spp ◽  
Bacteria And Fungi ◽  
Klebsiella Spp

The aim of the study was to compare the indoor levels of airborne bacteria and fungi of air conditioned (AC) buildings and naturally ventilated (NV) buildings using a Supermarket, a Laboratory and an Eatery as a case study. The predominant bacterial isolates were Staphylococcus, Micrococcus spp., Escherichia coli, Bacillus spp., Streptococcus spp., Enterococcus spp., Klebsiella spp. The fungal isolates belong to the genera Penicillium, Aspergillus, Mucor, Trichophyton, Fusarium, Candida and Chaetomium. The levels of airborne bacteria and fungi were determined using settle plate method. In AC buildings the average air levels of bacteria (supermarket: 24.2 CFU m-3; laboratory: 29.2 CFU m-3; eatery: 51.0 CFU m-3 air) were higher than in NV (respectively: 54.3 CFU m-3; 100.7 CFU m-3; 134.3 CFU m-3 air). The average air levels for fungal isolates were higher in the eatery due to presence of poorly maintained AC system (supermarket: 7.8 CFU m-3; laboratory: 11.5 CFU m-3; eatery: 56.7 CFU m-3 air) than in NV (28.6 CFU m-3; 19.6 CFU m-3; 13.5 CFU m-3 air respectively). Findings from this study showed that AC buildings had lower levels of bacterial and fungal contamination compared to buildings with natural ventilation.

Association Between Levels of Radon And Bioaerosols (Bacteria And Fungi) By Living Conditions

2022 ◽  
Author(s):  
Sung Ho Hwang ◽  
Sangwon Lee ◽  
Jong-Uk Won ◽  
Hyo Soung Cha ◽  
Wha Me Park
Keyword(s):  
Relative Humidity ◽  
Airborne Fungi ◽  
Health Condition ◽  
Living Conditions ◽  
Self Report ◽  
Airborne Bacteria ◽  
Indoor Environments ◽  
Colony Forming Unit ◽  
Residential Environments ◽  
Bacteria And Fungi

Abstract This study aimed to measure the levels of airborne radon (Rn) and bioaerosols—culturable airborne bacteria (CAB) and culturable airborne fungi (CAF)—in South Korea’s residential environments, considering living conditions such as the number of ventilations, number of windows, floors, temperature, and relative humidity. These levels were evaluated for 32 houses of residents from the socially vulnerable class. Rn gas and bioaerosols were sampled twice: in fall and summer. A self-report survey gathered residents’ information on their general characteristics (daily residence time, heating and cooking type, cleaning and washing cycle, etc.) and health condition scores (0–100 points) on the day of sampling. The range of Rn levels was 0.43–7.439 pCi/L with a median of 0.70 pCi/L. The CAB levels were 239–488 colony-forming unit (CFU)/m3 with a median of 309 CFU/m3, and CAF levels were 174–366 CFU/m3 with a median of 233 CFU/m3. Thus, this study found that semi-basement residential indoor environments negatively affected Rn and bioaerosol levels, and living in such residences resulted in high health condition scores.

Relationships Between Aerosol Particles and Airborne Bacteria and their Dependence on Environmental Factors in a Dairy Calf House

2019 ◽  
Vol 62 (6) ◽  
pp. 1819-1828 ◽  
Author(s):  
Md. Aminul Islam ◽  
Atsuo Ikeguchi ◽  
Takanori Naide
Keyword(s):  
Indoor Air ◽  
Aerosol Particles ◽  
Aerobic Bacteria ◽  
Airborne Bacteria ◽  
Dairy Calf ◽  
Outdoor Temperature ◽  
The Mean ◽  
High Concentrations ◽  
Mean Concentration ◽  
Indoor And Outdoor

Abstract. The quality of indoor air dramatically affects the health of animals and humans. An investigation was conducted into the relationships among the total number of aerosol particles and different types of airborne bacteria and their dependence on indoor and outdoor environmental factors, including air temperature and relative humidity (RH), in the indoor air of a dairy calf house in Tochigi, Japan, during the summer season. The concentrations of aerosol particles, the concentrations of airborne total aerobic bacteria (, , and spp.) in the indoor air, and the indoor and outdoor temperature and RH were evaluated from 14 weekly measurements. The mean concentration of small aerosol particles (0.3 to 2.0 µm) was higher than the mean concentration of large aerosol particles (2.0 to 10.0 µm) in the summer season. The mean concentration of airborne total aerobic bacteria was higher than the concentrations of airborne , , and spp. Airborne and were positively correlated with the number of 2.0 to 10.0 µm aerosol particles, i.e., high concentrations of 2.0 to 10.0 µm particles were correlated with high concentrations of airborne and . Airborne total aerobic bacteria did not correlate with the number of aerosol particles of any size, but spp. was negatively correlated with the number of 1.0 to 2.0 µm aerosol particles, i.e., high concentrations of 1.0 to 2.0 µm particles were correlated with low concentrations of airborne spp. The indoor temperature and indoor and outdoor RH did not correlate with any airborne bacteria. The outdoor temperature was negatively correlated with spp., i.e., high outdoor temperature was correlated with a low concentration of spp. in the indoor air of the dairy calf house. Both indoor and outdoor temperatures were positively correlated with the number of 0.5 to 5.0 µm aerosol particles, and indoor RH was negatively correlated with the number of 5.0 to 10.0 µm aerosol particles. These findings will be important for elucidating the role of aerosol particles in the transmission of airborne bacteria and ultimately for the mitigation of aerosol particles and airborne bacteria in dairy houses. HighlightsThe number of fine aerosol particles increased with increasing temperatures.Environmental factors had a less critical effect on airborne bacteria than aerosol particles.Airborne E. coli strongly positively correlated with 5.0 to 10.0 µm aerosol particles.Airborne Salmonella spp. negatively correlated with 1.0 to 2.0 µm aerosol particles.Relative humidity did not affect any airborne bacteria. Keywords: Aerosol particle number, Airborne bacteria, Dairy calf, Indoor air, Relationship, Summer season.

scholarly journals Behavior of the cultivable airborne mycobiota in air-conditioned environments of three Havanan archives, Cuba.

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Sofia Flavia Borrego Alonso ◽  
Alian Molina
Keyword(s):  
Indoor Air ◽  
Pathogenic Fungi ◽  
The Other ◽  
Indoor Environments ◽  
Outdoor Environments ◽  
High Concentrations ◽  
Opportunistic Pathogenic ◽  
Indoor And Outdoor Environments ◽  
Principal Species ◽  
Indoor And Outdoor

High concentrations of environmental fungi in the archives repositories are dangerous for the documents preserved in those places and for the workers' health. The aims of this work were to evaluate the behavior of the fungal concentration and diversity in the indoor air of repositories of 3 archives located in Havana, Cuba, and to demonstrate the potential risk that these taxa represent for the documentary heritage preserved in these institutions. The indoor and outdoor environments were sampled with a biocollector. From the I/O ratios, it was evident that two of the studied archives were not contaminated, while one of them did show contamination despite having temperature and relative humidity values very similar to the other two. Aspergillus, Penicillium and Cladosporium were the predominant genera in the indoor environments. New finds for archival environments were the genera Harposporium and Scolecobasidium. The principal species classified ecologically as abundant were C. cladosporioides and P. citrinum. They are known as opportunistic pathogenic fungi. All the analyzed taxa excreted acids, the most of them degraded cellulose, starch and gelatin while about 48% excreted different pigments. But 33% of them showed the highest biodeteriogenic potential, evidencing that they are the most dangerous for the documentary collections.

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