• Safety and Health at Work
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• 제5권1호
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• pp.23-26
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• 2014

Background: The purpose of this study was to compare the concentration of total airborne bacteria (TAB) in biosafety cabinets (BSCs) at universities and hospital microbial laboratories to assess the performance of BSCs. Methods: TAB was determined by using the single-stage Anderson sampler (BioStage Viable Cascade Impactor). The samples were obtained three times (with the BSC turned off and the shield open; with the BSC turned off and the shield closed; and with the BSC tuned on and operating) from the areas in front of 11 BSCs. Results: TAB concentrations of accredited and nonaccredited BSCs were determined. No significant differences were observed in the TAB concentrations of the accredited BSCs and the nonaccredited BSCs for the areas outside the BSCs in the laboratories (p > 0.05). TAB concentrations for the BSCs sampled with the shield open and the instrument turned off showed differences based on the sampling site outside the BSC in each laboratory. Conclusion: These results imply that TAB concentration is not altered by the performance of the BSCs or TAB itself and/or concentration of TAB outside the BSC is not a good index of BSC performance.

• Journal of Microbiology
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• 제35권1호
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• pp.1-9
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• 1997

Distribution of airborne microorganisms was determined with two different types of air samplers, the Anderson cascade sampler and the Aerobioscope sampler, in the vicinity of Taejon. The size distribution of particles carrying bacteria and fungi was concurrently measured. The concentration of detected viable airborne particles was greatly varied. It was observed that the number of microbial particles increased in April and October. The most isze o particles carrying bacteria was larger than 4.7 .mu.m in mean aerodiameter, which made up 69.8% of the total particle fraction. About 63.2% of fungi-carrying particles were smaller than 4.7 .mu.m in aerodiameter. The distribution of particles on Yellow Sand Phenomena days was also analyzed. The number of fine particles having mass median aero-diameter from 1.0 to 10.mu.m increased on Yellow Sand Phenomena days to about 6 times that on normal days and the n umber of colony forming unit (CFU/$\textrm{m}^3$) of airborne bacteria also increased by 4.3 times in April. The reuslts from the Anderson sampler showed that the concentration of bacteria increased greatly on the fraction of fine particles ranging from 0.6 $\mu$m to 4.7 $\mu$m in diameter. Unlike the increase in bacterial floraon Yellow Sand Phenomena days, the fungal concentration slightly decreased and showed a normal size distribution parttern. This study suggests that a long-range transmission of bacteria results form bacteria adsorbing onto the fine particles during the Yellow Sand Phenomena.

• 한국미생물·생명공학회지
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• 제50권2호
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• pp.165-192
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• 2022

본 논문에서는 실외 대기 환경의 바이오에어로졸 혹은 입자상물질의 미생물 메타게놈 특성과 이에 영향을 미치는 기후 및 환경 인자의 영향을 고찰하였다. 시료 채취 지역 및 환경 조건 특성별 대기 중 세균과 곰팡이 농도를 요약 하고, 에어로졸과 PM 시료의 세균과 곰팡이의 메타게놈 특성을 조사하기 위한 비배양법 기반 분석방법과 메타게놈 특성을 정리하였다. 또한, 세균과 곰팡이의 메타게놈 특성과 다양성 및 특성에 미치는 기상 인자와 환경 인자의 영향을 고찰하였다. 대기 중 미생물의 생존, 생장과 분산은 지역 기상 조건 및 대기 오염 물질에 의해 크게 영향을 받았다. 일반적으로 기온이 상승함에 따라 AM 농도는 증가하지만, 여름에는 고온과 강한 자외선의 영향으로 AM 농도가 감소하였다. 습도와 미생물 농도는 양의 상관성을 보이나, 습도가 너무 높으면 AM의 분산이 지연되었다. 이러한 종합적인 고찰 결과는 대기권에서 미생물의 역할과 기능을 이해하고, 이들 미생물에 의해 야기되는 환경 및 공중보건 문제를 해결하기 위한 전략 수립 및 저감 기술 개발에 활용될 수 있다.

• Environmental Engineering Research
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• 제17권4호
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• pp.211-216
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• 2012

Quantification of the airborne microorganisms (bacteria and fungi) at a swine wastewater treatment plant was performed. Microbial samples were collected at three different phases of the treatment process over a 1-yr period. Cultivation methods based on the viable counts of mesophilic heterotrophic bacteria and fungi were performed. The concentrations of airborne bacteria ranged up to about $5{\times}10^3$ colony-forming unit (CFU)/$m^3$, and those of airborne fungi ranged up to about $9{\times}10^2CFU/m^3$. The primary treatment (e.g., screen, grit removal, and primary sedimentation) was found to be the major source of airborne microorganisms at the site studied, and higher levels of airborne bacteria and fungi were observed in summer. High levels of the respirable bioaerosol (0.65 to $4.7{\mu}m$ in size) were detected in the aeration phase. Among the environmental factors studied, temperature was strongly associated with fungal aerosol generation (with a Spearman correlation coefficient of 0.90 and p-value <0.01). Occupational biorisks are discussed based on the observed field data.

• 한국입자에어로졸학회지
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• 제19권3호
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• pp.77-87
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• 2023

We present the development of a wetcyclone sampler designed for the sampling of airborne bacteria. The wetcyclone design involves a combination of two traditional cyclone shapes and computational fluid dynamics (CFD) analysis to validate its effectiveness in terms of pressure drop and collection efficiency. The wetcyclone exhibits a collection efficiency of over 90% for bacteria, specifically targeting Staphylococcus aureus. Additionally, the wetcyclone enables continuous bioaerosol sampling using a liquid medium (deionized water), demonstrating a concentration ratio exceeding >105 and a stable microbial recovery rate of 81.9%. The application of real-time quantitative polymerase chain reaction (qPCR) and the colony counting method ensures precise measurement of the concentration ratio and microbial recovery rate.

• 한국산업보건학회지
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• 제24권3호
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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.

• Journal of Korean Society for Atmospheric Environment
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• 제23권E1호
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• pp.1-9
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• 2007

In Korea, there is only a limited amount of information currently available on the levels of airborne bacteria and fungi of cattle sheds, although certain portions of people are potentially exposed to these bioaerosols in cattle sheds. Accordingly, the current study measured them inside cattle sheds, inside and outside farmers' houses near the sheds, and/or inside residential houses far away from the sheds during winter, 2004 and summer, 2005. The airborne bacteria and fungi were detected in most samples in the cattle farmers' houses as well as in the cattle sheds. Aspergillus, Cladosporium, and Penicillium, which have been associated with adverse health effects, were three most prevalent fungal genera, and they took most of the total fungi (more than 69%). The microbial concentrations measured inside the cattle sheds were comparable to those in other reports. Nevertheless, the present arithmetic and geometric mean (GM) microbial concentrations exceeded the Korean guideline for total airborne bacteria at medical facilities ($800\;CFU\;m^{-3}$), the current GM residential indoor concentrations at houses, and the residential indoor levels reported in other countries. The present findings suggest the need for a strategy to reduce Korean cattle farmers' exposure to these microorganisms. In contrast to the microbes, it is suggested that the cattle shed is not an important microenvironment for $PM_{10}$ exposure. Two characteristics examined in this study (seasonal variation and summer survey period, i.e., temperature and humidity) were all important for the cattle farmers' occupational exposure to airborne microbes. The lack of constancy between highest and lowest concentrations of bioaerosols over the survey period further suggests the necessity of performing a long-term survey to better examine farmer exposure levels and their variability.

• 한국환경보건학회지
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• 제29권1호
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• pp.1-7
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• 2003

서울에 위치한 20개 종합병원의 중환자실, 일반병동 입원실, 환자대기실과 병원 실외 4곳 공기중의 일반 세균수와 곰팡이수를 측정하였으며, 기회 감염균을 검출하였다. 97-410 cfu/㎥의 일반세균수와 37-77 cfu/㎥의 진균이 검출되었으며 중환자실이 가장 낮은 미생물의 오염도를 보였으며 환자대기실이 가장 높은 오염도를 나타내었다. 18종의 진균이 분리되었으며 Aspergillus spp.가 가장 높은 빈도로 검출되었으며, 그 다음으로 Penicillium, Alternaria, Cladosporium 속 등이 검출되었다. Staphylococcus spp. 중에서는 S. haemolyticus와 S. epidermis가 가장 높은 빈도로 검출되었으며 검출된 Staphylococcus spp. 중 47%가 중환자실에서 검출되었다.

• 보존과학회지
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• 제38권1호
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• pp.64-71
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• 2022

Many investigations have been conducted on the biological damage and environmental conditions necessary to preserve the Janggyeong Panjeon and Daejanggyeongpan (woodblocks). We performed a survey on the concentration and diversity of airborne fungi in the Janggyeong Panjeon and compared them with the results of a survey from 2012. The temperature of the Beopbojeon building was slightly lower, while the relative humidity was higher than those found at the Sudarajang building. The concentration of airborne fungi in the Beopbojeon was 1.44-fold that of the Sudarajang. It was confirmed that the concentration and diversity of airborne fungi in the Janggyeong Panjeon differed depending on the sampling site. In total, 23 fungal genera were identified from the air samples, and 11 fungal and 1 bacterial genera were identified from the surface of the woodblocks. Among these, only five types of fungi were commonly distributed in the indoor air and surface of the Daejanggyeongpan; however, 58.3% of the fungi identified on the surface of the woodblocks were not observed in the in the air samples. The surface-dwelling fungi may accumulate dust to form microbial communities over time.

• 한국산업보건학회지
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• 제20권1호
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• pp.41-46
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• 2010

The purpose of this study is to assess the level of fungi concentration in the university laboratories in Seoul, Korea, and to investigate factors contributing to these concentrations. The samples were taken from three spots in each laboratory; the top of sink, the center of laboratory, and the front of ventilation system, i.e fume hood at the chemical laboratory and clean bench/biosafety cabinet at the microbial laboratory. Air samples were collected using the single-stage Anderson sampler (Quick Take 30) at a flow rate of 28.3 l/min for 5 min on nutrient media in Petri-dishes located on the impactor. Fifty-two air samples were collected from 19 different laboratories (13 microbiology laboratories, 6 chemistry laboratories) in the university, and concentrations of airborne fungi showed no significant difference (p>0.05) between microbiology and chemistry laboratory, and also no significant difference at three locations (sink, center, front of ventilation system) in microbiology and chemistry laboratories. Average concentrations of fungi in 19 laboratories ranged from 7 to 459 cfu/$m^3$, with an overall Geometric Mean of 52 cfu/$m^3$. Airborne fungi concentrations of 6 samples (12 %) exceeded 150 cfu/$m^3$, the guideline of WHO. The ratios of Indoor/Outdoor for airborne fungi ranged from 0.2 to 4.8 (mean = 1.6). Related factors were measured such as relative humidity, temperature, and laboratory area. Temperature and laboratory area showed no significant relations to concentrations of airborne fungi except for relative humidity in the laboratory Concentrations of fungi were significant different (p<0.01) between rainy or cloudy and sunny. However, there was no significant difference between general ventilation and nongeneral ventilation.