• Safety and Health at Work
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• v.1 no.2
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• pp.183-191
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• 2010

Objectives: The objective of this study is to investigate the distribution patterns and exposure concentrations of bioaerosols in industries suspected to have high levels of bioaerosol exposure. Methods: We selected 11 plants including 3 livestock feed plants (LF industry), 3 metal working fluids handling plants (MWFs industry), and 5 sawmills and measured total airborne bacteria, fungi, endotoxins, as well as dust. Airborne bacteria and fungi were measured with one stage impactor, six stage cascade impactor, and gelatin filters. Endotoxins were measured with polycarbonate filters. Results: The geometric means (GM) of the airborne concentrations of bacteria, fungi, and endotoxins were 1,864, $2,252\;CFU/m^3$, and $31.5\;EU/m^3$, respectively at the sawmills, followed by the LF industry (535, $585\;CFU/m^3$, and $22.0\;EU/m^3$) and MWFs industry (258, $331\;CFU/m^3$, and $8.7\;EU/m^3$). These concentrations by industry type were significantly statistically different (p < 0.01). The ratio of indoor to outdoor concentration was 6.2, 1.9, 3.2, and 3.2 for bacteria, fungi, endotoxins, and dust in the LF industry, 5.0, 0.9, 2.3, and 12.5 in the MWFs industry, and 3.7, 4.1, 3.3, and 9.7 in sawmills. The respiratory fractions of bioaerosols were differentiated by bioaerosol types and industry types: the respiratory fraction of bacteria in the LF industry, MWF industry, and sawmills was 59.4%, 72.0%, and 57.7%, respectively, and that of fungi was 77.3%, 89.5%, and 83.7% in the same order. Conclusion: We found that bioaerosol concentration was the highest in sawmills, followed by LF industry facilities and MWFs industry facilities. The indoor/outdoor ratio of microorganisms was larger than 1 and respiratory fraction of microorganisms was more than 50% of the total microorganism concentrations which might penetrate respiratory tract easily. All these findings suggest that bioaerosol in the surveyed industries should be controlled to prevent worker respiratory diseases.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.4
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• pp.265-275
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• 2012

Objectives: The aim of this study was to investigate the distribution patterns and exposure concentrations of biological hazards in waste handling industries. Methods: We selected 3 recyclable waste sorting plants(RWS), 2 food recycling plants(FR), 1 landfill area(LA) and 1 waste incineration plant(WI). Total airborne bacteria and fungi were measured with single stage impactor and gelatin filters. Endotoxin and glucan were measured with polycarbonate filters in total and respirable dust. Results: The geometric mean of airborne bacterial concentration was the highest in FR($3,273CFU/m^3$), followed by LA, RWS, and WI as 1,334, 934, and $860CFU/m^3$. The fungal concentrations were 6,031, 5,052, 3,307, and $713CFU/m^3$ in RWS, WI, FR, and LA, respectively. By process, WI pit showed the highest concentrations of bacteria, fungi, and endotoxin, followed by inside of bulldozer in LA. The indoor to outdoor ratios of bacteria, fungi, endotoxin and glucan were 2.3, 4.0, 2.3, and 5.0 in RWS, 29.5, 4.9, 7.6, and 5.0 in FR, 5.3, 8.7, 26.8, and 9.5 in WI, respectively. Conclusions: We found that biological hazards, specifically bacteria in FR, fungi in RWS and endotoxin in WI pit and bulldozer at LA, should be controlled to prevent worker's respiratory diseases.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.120-126
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• 2005

To assess exposure of allergy patients to a biological environment, measurements were made of levels of airborne bacteria and fungi, house dust endotoxin and mite allergens in homes of 7 allergy patients and 12 healthy families. Concentrations of airborne total bacteria and the ratio of indoor and outdoor concentrations(I/O) in allergy patient's homes were high compared to non-allergy houses. But no significant differences could be shown for the concentration of spores of viable fungi and staphylococcus in indoor air between the homes of allergic patients and healthy families. The results of investigation on house dust mites, Dermatophagoids farinae were detected in all mattress samples and the levels in the allergy patient's homes were generally high, with individual measurements exceeding $2{\mu}g/g$ dust found in $30\%$ samples. In contrast with, Dermatophagoids pteronyssinus were detected in only $60\%$ samples and the concentrations were very low. The levels of endotoxin in dust samples collected from the allergy patient's home mattresses were higher than those of control houses. There was a positive correlation between the endotoxin levels and the house dust mite allergens.

• The Korean Journal of Mycology
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• v.47 no.2
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• pp.131-142
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• 2019

The Bupjusa and Seonamsa temples are located at places with geographically different condition, and therefore, differ with respect to building's structure and layout. In addition, evident difference can be appeared by the regional climate. For the 2 years, we studied the concentration and diversity of the seasonal airborne fungi inside and outside of the 2 temples. In Seonamsa temple, airborne fungi concentration in the indoor and outdoor air was higher and the species diversity in the indoor air was lower, whereas, concentration variation was larger than that of Bupjusa temple. A total of 173 fungal isolates (including 54 genera) and 162 isolated (including 49 genera) were obtained from the indoor air of Bupjusa and Seonamsa temple, respectively. Whereas, 80 fungal isolates (including 33 genera) and 74 isolates (including 39 genera) were collected form the outdoor air of Bupjusa and Seonamsa temple, respectively. However, more fungal varieties were observed to be distributed inside Bupjusa and outside Seonamsa temples. Amongst all the fungi identified, ascomycetes were more dominant (plus or minus 90% points), followed by basidiomycetes and zygomycetes; which more presented in outdoor air than in indoor air. The airborne fungi concentration in spring (month of April) and autumn was higher than in any other season, for Seonamsa and Bupjusa temples, repectively. Genus Cladosporium was isolated from each site and season, with its dramatic increase noted in autumn. In addition, the highest basidiospore(s) number was obtained after the rain. Consequently, the results suggest that Seonamsa temple was more susceptible to biological damage than Bupjusa temple was.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.300-309
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• 2014

Objectives: The objective of this study is to evaluate microbial exposure hazards in the metal-working fluids(MWF) handling industry. Methods: Air quality parameters(airborne bacteria, fungi, endotoxin and oil mist) and bulk MWF in storage tanks were evaluated at 54 points at nine sites in South Korea. Results: The geometric means(GM) of culturable airborne bacteria, fungi, endotoxin and oil mist concentration were $133CFU/m^3$(n=376, range $7{\sim}6,510CFU/m^3$), $159CFU/m^3$(n=381, range $7{\sim}8,469CFU/m^3$), $8.06EU/m^3$(n=103, range $0.34{\sim}280.4EU/m^3$) and $0.20mg/m^3$(n=104, range $0.01{\sim}2.87mg/m^3$), respectively. The ratio of indoor to outdoor concentration was 2.7 for bacteria, 6.1 for endotoxin, and 4.8 for oil mist. Even though average airborne bacteria concentration did not exceed recommended exposure limits($1,000CFU/m^3$), MWF in the storage tanks was highly contaminated with bacteria(arithmetic mean $2.1{\times}10^6CFU/ml$) and exceeded recommended bacteria limits($10^5CFU/ml$). Conclusions: It is necessary for MWF handling workplaces to conduct periodical biohazard inspection of MWF storage tanks. Additionally, further research may be necessary to establish biological occupational exposure limits.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.253-259
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• 2003

To assess microbiological indoor air quality in kindergartens, concentrations of viable airborne microorganisms were seasonally determined at three kindergartens in Ulsan from April, 2002 to January, 2003. Sampling was performed with an impaction-type air sampler and three different media. The numbers of bacteria grown on Staphylococcus medium were between 84 and 4,150 MPN/m3 with an average of 827 MPN/m3, and those on standard method agar ranged from 50 to 2,636 MPN/m3 with an average of 580 MPN/m3. The bacterial concentrations were highest in summer, followed by fall, spring, and winter, and were significantly correlated with indoor temperature. Among the colonies, 45.6~61.0% were observed as Gram-positive cocci and 8.5~20.6% were Gramnegative rods. Micrococcus species were the dominant organisms. The numbers of fungi ranged from 0 to 1,888 MPN/m3(661 MPN/m3 average) based on colony counts with dichloran rose bengal chloramphenicol agar. On average, the fungal concentrations were highest in summer and lowest in winter. Penicillium species and Aspergillus species were identified from the colonies. The obtained data can be utilized as a step to set a guideline for bioaerosols in indoor environment of schools.

• Microbiology and Biotechnology Letters
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• v.50 no.2
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• pp.165-192
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• 2022

The microbial metagenome characteristics of bioaerosols and particulate matter (PM) in the outdoor atmospheric environment and the effects of climate and environmental factors on the metagenome were analyzed. The concentrations of bacteria and fungi in bioaerosols and PM were determined by sampling different regions with different environmental properties. A variety of culture-independent methods were used to analyze the microbial metagenome in aerosols and PM samples. In addition, the effects of meteorological and environmental factors on the diversity and metagenomes of bacteria and fungi were investigated. The survival, growth, and dispersal of the microorganisms in the atmosphere were markedly affected by local weather conditions and the air pollutant concentration. The concentration of airborne microorganisms increased as the temperature increased, but their concentration decreased in summer, due to the effects of high temperatures and strong ultraviolet rays. Humidity and microbial concentration were positively correlated, but when the humidity was too high, the dispersion of airborne microorganisms was inhibited. These comprehensive data on the microbial metagenome in bioaerosols and PM may be used to understand the roles and functions of microorganisms in the atmosphere, and to develop strategies and abatement techniques to address the environmental and public health problems caused by these microorganisms.

• Advances in environmental research
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• v.2 no.1
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.393-403
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• 2018

Bio-aerosols transported by the air have been considered as the major source of dispersal agents that contaminate agricultural products. Unseen fungal spores are known sources of bio-aerosols that harm mushroom and human health during mushroom cultivation. This study was conducted to obtain basic data on the concentration and species distribution of fungi present in the indoor air of oak mushroom cultivation houses in Korea. In 2015 and 2016, we sampled and analyzed indoor airborne fungal spores 21 times from 13 oak mushroom cultivation farms located in six different provinces. The concentration of airborne fungi ranged from $1.30{\times}10^2$ to $1.59{\times}10^4cfu/m^3$. Surprisingly, in 20 sampling cases, the fungal concentration exceeded $500cfu/m^3$, which is recommended as the indoor air quality standard by the Ministry of Environment, Korea. A total of 450 fungi were isolated and identified to belong to 33 genera and 46 species. Among the identified fungi, human pathogens (4 genera and 4 species) and plant pathogens (10 genera and 13 species) were present. In addition, Trichoderma harzianum, Trichoderma atroviride, and Trichoderma longibrachiatum, which are detrimental species that affect mushroom health, were found 17 out of 21 sampling times. Our results provide evidence that indoor air quality should be improved for better management of mushroom cultivation houses.

• Korean Journal of Microbiology
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• v.48 no.1
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• pp.8-15
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• 2012

Bioaerosols generated from composting facilities and landfills may create health risks for workers and nearby residents. To determine the levels of culturable airborne bacteria and fungi in bioaerosols, samples were seasonally collected at a composting facility and a landfill in Ulsan, Korea with an impaction-type sampler. Concentrations of heterotrophic bacteria averaged (in $MPN/m^3$) $6.5{\times}10^3$ (range $1.5{\times}10^2-1.5{\times}10^4$) in the composting facility and $3.9{\times}10^3$ (range $6.0{\times}10^1-9.3{\times}10^3$) at the entrance of the facility. These concentrations were 460 and 280 times higher than those of reference sites. Coliform bacteria were detected both inside and entrance of the facility. On the landfill, heterotrophic bacterial concentrations averaged (in $MPN/m^3$) $4.9{\times}10^2$ (range $1.7{\times}10^2-1.0{\times}10^3$), while they averaged $3.7{\times}10^2$ (range $4.8{\times}10^1-1.3{\times}10^3$) at the parking lot of the landfill. These concentrations were 35 and 26 times higher than those of reference sites. When we isolated and tentatively identified heterotrophic bacteria, Pseudomonas luteola was the most dominant species in bioaerosols from the composting facility, whereas the most abundant one in reference samples was Micrococcus sp. Average concentrations of airborne fungi were measured between $4.8{\times}10^2$ and $7.9{\times}10^2\;MPN/m^3$ depending on sites, which were 2.1-3.4 times higher compared to those of reference sites. While Cladosporium, Alternaria, and Penicillium were commonly identified fungal genera, genus Aspergillus was identified only in bioaerosols from the composting facility.