• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.273-278
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• 2005

This study was performed to investigate the characteristics of distribution for airborne bio aerosol in 11 public facilities in Seoul from June to July. The collected samples are total suspended bacteria in indoor and outdoor Anderson six stage air sampler by the IAQ standard method of Ministry of Environment in Korea. The concentration of total suspended bacteria in the theater higher than IAQ standards. As the results of the survey, the most high indoor air mean concentration of bacteria $1273CFU/m^3$ was theater and the most high outdoor air mean concentration of bacteria $^229 CFU/m3$was Kindergarten. The mean concentration of bacteria in the theater was higher than the IAQ standards established by the Ministry of Environment, Republic of Korea. Moreover, this study was for investigation a part of indoor air pollution condition in public facilities. It means that this study can't represent fDr all of public facilities. Therefore, we suggest that long and middle term country plan for management of IAQ should be established through long-term and continuous investigation of IAQ condition. Also above consideration in mind, it is suggest that the research for source contribution of the results on these need further study.

• 생명과학회지
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• 제10권1호
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• pp.74-78
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• 2000

This study was investigated to evaluate the distribution of airborne microorganisms at underground shops in Seomyun and Nampodong, Pusan. The number of bacterial colonies on the nutrient agar plate plates were calculated by the open petri dish method for 30 minutes in indoor air of underground shops at every seasons in a year. There was no statistically significant difference between Seomyun and Nampodong in mean colony counts. Isolation rates of Gram positive rods was highest, and Gram positive cocci and Gram negative rods were followed. In Nampodong underground shops, Enterobacteriaceae strains was isolated. Mean colony counts according to seasons was higher at summer and autumn in Seomyun, and spring and winter in Nampodong. In near future, a study on the distribution of bacteria causing respiratory infection should be followed.

• 한국산학기술학회논문지
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• 제16권1호
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• pp.868-876
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• 2015

실내 공기 중 부유세균은 실내공기오염을 유발하고 재실자의 건강상 위해를 초래할 수 있다. 본 연구는 다중이용시설을 대상으로 주요목적으로 사용되는 실내에서 부유세균의 농도와 세균의 종류를 동정하고 실내공기오염물질 중 부유세균에 대한 기초정보 제공을 목적으로 한다. 노인시설 7개소 (노인요양시설, 노인전문병원, 복지관 포함), 대규모점포 4개소, 대학병원 4개소, 어린이집 7개소 (유치원, 어린이집, 보육원 포함), 지하역사 4개소 및 버스터미널 4개소 등 총 30개소 120개 지점에서 총부유세균의 농도를 측정 분석하고 세균의 종류를 동정하였다. 모든 시설군에서 측정된 실내 부유세균의 농도는 유지기준 $800CFU/m^3$이하 이었으나, I/O비가 1.09-2.36으로 실내의 총부유세균의 농도가 실외에 비해 높았고, 어린이집, 대학병원, 노인시설에서 동정된 세균의 종류별 높은 검출빈도 보였다. 국내 다중이용시설의 주요목적에 따른 실내 부유세균에 대한 지속적 관찰이 필요하며, 특히 어린이집, 대학병원, 노인시설 등에 대한 관심이 요구되고, 추후 배양 가능한 세균 뿐 아니라 알레르겐 등을 포함한 미생물학적 실내오염물질에 대한 추가 연구가 필요할 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권11호
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• pp.1858-1865
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• 2020

Objective: The microbiota of dairy cow milk varies with the season, and this accounts in part for the seasonal variation in mastitis-causing bacteria and milk spoilage. The microbiota of the cowshed may be the most important factor because the teats of a dairy cow contact bedding material when the cow is resting. The objectives of the present study were to determine whether the microbiota of the milk and the cowshed vary between seasons, and to elucidate the relationship between the microbiota. Methods: We used 16S rRNA gene amplicon sequencing to investigate the microbiota of milk, feces, bedding, and airborne dust collected at a dairy farm during summer and winter. Results: The seasonal differences in the milk yield and milk composition were marginal. The fecal microbiota was stable across the two seasons. Many bacterial taxa of the bedding and airborne dust microbiota exhibited distinctive seasonal variation. In the milk microbiota, the abundances of Staphylococcaceae, Bacillaceae, Streptococcaceae, Microbacteriaceae, and Micrococcaceae were affected by the seasons; however, only Micrococcaceae had the same seasonal variation pattern as the bedding and airborne dust microbiota. Nevertheless, canonical analysis of principle coordinates revealed a distinctive group comprising the milk, bedding, and airborne dust microbiota. Conclusion: Although the milk microbiota is related to the bedding and airborne dust microbiota, the relationship may not account for the seasonal variation in the milk microbiota. Some major bacterial families stably found in the bedding and airborne dust microbiota, e.g., Staphylococcaceae, Moraxellaceae, Ruminococcaceae, and Bacteroidaceae, may have greater influences than those that varied between seasons.

• 한국산업보건학회지
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• 제22권4호
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• pp.284-292
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• 2012

Objectives: The objective of this study was to investigate the relations between the bacterial concentration and the environmental factors in the water soluble metal working fluids at factories. Methods: The bacterial concentrations for airborne and fluid samples of 7 factories were quantified during the summer season. And we statistically analysed the relations between the bacterial concentrations and the factors such as temperature, relative humidity, usage quantity, mixing ratio and exchange interval. Results: The geometric mean levels of the airborne bacterial concentrations were 79.1(range : N.D.~686) $CFU/m^{3}$ and 68.1(range: N.D.~919) $CFU/m^{3}$ in the process and outdoor. The airborne bacterial concentrations showed no statistical difference by process, usage quantity, mixing ratio and exchange interval. The airborne bacterial concentrations had negatively weak correlations with air temperature and relative air humidity(p<0.05). The bacterial concentrations and pH showed significantly negative correlations in the fluids(p<0.05). And the airborne bacterial concentrations in factories and those in metal working fluids showed no statistical relationship. Conclusions: In the water soluble metal working fluids using factories, the airborne bacterial concentrations of the process were related to those of the outdoor and environmental factors, rather than the onsite contaminated metal working fluids.

• 설비공학논문집
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• 제28권12호
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• pp.509-514
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• 2016

From the point of view to prevent airborne infection-related diseases such as H1N1, SARS, and MERS, an actual application of air cleaning and purification systems including technologies like UVGI has become increasingly important. Recently, an air purification system using REME (Reflective Electro Magnetic Energy) developed in the U.S. is applied for indoor air purification and sterilization technology to counteract the outbreak of new airborne infections. In this study, an air sterilization performance experiment using REME was carried out. The results verified that air sterilization performance in the case of installing a REME system in a medical center was 31%, namely the number of floating bacteria decreased by 31% after only a five-day operation. In addition, the number of culture collections in the REME operating air conditioning systems using nonpathogenic Geobacillus stearothemophilus as a biological indicator decreased maximally to 67%. A field application of REME technology will be useful to prevent airborne infection-related diseases, especially in response to public health crises due to the advent of emerging diseases.

• Safety and Health at Work
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• 제1권2호
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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.

• 한국입자에어로졸학회지
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• 제10권2호
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• pp.83-91
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• 2014

Since airborne bacteria have been known to aggravate indoor air quality, studies on reducing bacteria particles increase recently. In this study, a chamber(0.8m x 0.8m x 1.56m) system was built in order to simulate real conditions for reducing airborne bacteria, and evaluated by a simple aerosol reduction test. A method utilizing CFD(Computational Fluid Dynamics) simulation was used to detect the horizontal cross-sectional area which represents particle distribution in the chamber. Then an air-cleaner with HEPA filter and Carbon Fiber Ionizer was located on that area for aerosol reduction test. The CFD result found the area was located at 0.2m height from the bottom of the chamber, and the test showed aerosol reduction efficiencies using measurements of number concentration and CFU(colony forming unit) per each case. At the measurement of number concentration, the reduction efficiency of air-cleaner with filter and ionizer(Case 3) was about 90% after 4 minutes from the stop of the bacteria injection, and that with only filter(Case 2) was about 90% after 8 minutes from the beginning. Lastly, that without filter and ionizer(Case 1) was about 30% after 10 minutes. At the measurement of CFU, it shows similar results but it is related to viability of bio-aerosol.

• 한국산업보건학회지
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• 제22권4호
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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.

• 한국환경보건학회지
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• 제31권2호
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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.