• Safety and Health at Work
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• v.13 no.4
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• pp.487-492
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• 2022

Objective: The exposure levels of disease-causing bacteria and germs were assessed on aircraft cleaning workers on multiple different aircrafts. Method: Five measuring points were selected depending on the aircraft types. Four aircraft cleaning agencies were selected for the test. Aircraft cleaning work was classified as intensive cleaning and general cleaning work. Ventilation in aircraft when sampling during the cleaning operation was categorized into forced ventilation and natural ventilation. The collection of airborne microorganisms was made through inertial impactors which were installed 1.5 meters above the bottom of the aircraft. The airborne bacteria and fungus growth badges were selected by Trytpic Soy Agar and Sabouraud Dextrose Agar. Results: The average concentrations of bacteria in the air were higher in the order of small, medium, and large airplanes. Rainy days had higher concentrations inside and outside the aircraft as compared to those in sunny days. Regarding ventilation, concentrations in natural ventilation were higher than concentrations in forced ventilation. According to the type of work, the concentrations in the intensive cleaning groups (cleaning one plane a day) were lower than those of the ordinary cleaning groups (cleaning several planes per day). Conclusion: The concentration levels of airborne bacteria and fungi in the aircraft surveyed were lower than the indoor environmental standards of Korea (800 cfu/m³ and 500 cfu/m³). The average concentrations of bacteria in the air and fungi in the air were highest in small aircraft owned by Company D.

• Mycobiology
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• v.42 no.3
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• pp.286-290
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• 2014

Fungi are the known sources of irritation associated with atopic diseases (e.g., asthma, allergic rhinoconjunctivitis, and atopic eczema). To quantitatively estimate their presence in the indoor environment of atopic dermatitis-inflicted child patient's houses (ADCPHs), the high-efficiency particulate air (HEPA) filters installed inside the air cleaners of three different ADCPHs were investigated for the presence of mold. The air cleaner HEPA filters obtained from the three different ADCPHs were coded as HEPA-A, -B, and -C, respectively, and tested for the presence of mold. The colony forming units (CFUs) corresponding to the HEPA-A, -B, and -C filters were estimated to be $6.51{\times}10^2{\pm}1.50{\times}10^2CFU/cm^2$, $8.72{\times}10^2{\pm}1.69{\times}10^2CFU/cm^2$, and $9.71{\times}10^2{\pm}1.35{\times}10^2CFU/cm^2$, respectively. Aspergillus, Penicillium, Alternaria, Cladosporium, Trichoderma, and other fungal groups were detected in the 2,494 isolates. The distribution of these fungal groups differed among the three filters. Cladosporium was the major fungal group in filters HEPA-A and -C, whereas Penicillium was the major fungal group in the filter HEPA-B. Nine fungal species, including some of the known allergenic species, were identified in these isolates. Cladosporium cladosporioides was the most common mold among all the three filters. This is the first report on the presence of fungi in the air cleaner HEPA filters from ADCPHs in Korea.

• Safety and Health at Work
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• v.11 no.4
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• pp.517-525
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• 2020

Background: The study was planned to show the status of indoor microorganisms and the status of the reduction device in the military dog clinic. Methods: Airborne microbes were analyzed according to the number of daily patient canines. For identification of bacteria, sampled bacteria was identified using VITEK^®2 and molecular method. The status of indoor microorganisms according to the operation of the ventilation system was analyzed. Results: Airborne bacteria and fungi concentrations were 1000.6 ± 800.7 CFU/m³ and 324.7 ± 245.8 CFU/m³. In the analysis using automated identification system, based on fluorescence biochemical test, VITEK^®2, mainly human pathogenic bacteria were identified. The three most frequently isolated genera were Kocuria (26.6%), Staphylococcus (24.48%), and Granulicatella (12.7%). The results analyzed by molecular method were detected in the order of Kocuria (22.6%), followed by Macrococcus (18.1%), Glutamicibacter (11.1%), and so on. When the ventilation system was operated appropriately, the airborne bacteria and fungi level were significantly decreased. Conclusion: Airborne bacteria in the clinic tend to increase with the number of canines. Human pathogenic bacteria were mainly detected in VITEK^®2, and relatively various bacteria were detected in molecular analysis. A decrease in the level of bacteria and fungi was observed with proper operation of the ventilation system.

• The Korean Journal of Mycology
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• v.43 no.1
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• pp.58-63
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• 2015

Mold contamination is one of the detrimental factors affecting sawdust media-based shiitake cultivation in greenhouses. During mold monitoring of indoor air of greenhouses, several fungi were isolated. Among them, Aspergillus pulverulentus and Cosmospora butyri were found to be new in Korea and Lecanicillium psalliotae and L. antillanum were known in Korea without taxonomic validation. In this study the morphological characteristics and phylogenetic analysis based on the internal transcribed spacer (ITS) rDNA region or ${\beta}$-tubulin gene of the four identified species were described.

• Journal of Environmental Health Sciences
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• v.38 no.6
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• pp.510-519
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• 2012

Objectives: This study was conducted in order to evaluate the microbiological contamination of the indoor air of the lunchrooms at child care centers and investigate the toxin genes and toxin production ability of food-borne pathogens. Methods: A total of 64 child care centers were sampled to test total aerobic bacteria, coliform bacteria, fungi, Staphylococcus aureus, Bacillus cereus and Salmonella spp. according to the Korea Food Code. All toxin genes of pathogens were detected using the Polymerase Chain Reaction method. The Sthaph. aureus enterotoxin was detected by a Staphylococcus aureus enterotoxin-reversed passive latex agglutination kit. The heamolysin BL (HBL) and non-heamolytic enterotoxin (NHE) produced by B. cereus were detected using a B. cereus enterotoxin-reversed passive latex agglutination kit and Bacillus diarrheal enterotoxin visual immunoassay kit, respectively. Results: The means of total aerobic bacteria and coliform bacteria were $1.91{\pm}1.84$ log CFU/plate and $0.47{\pm}0.62$ log CFU/plate, respectively. The mean of fungi also showed $0.59{\pm}0.71$ log CFU/plate. Among the pathogenic bacteria tested in this study, Staphy. aureus and B. cereus were detected in four (6.3%) and 21 (32.8%) out of 64 indoor air samples from lunchrooms in child care centers, respectively. All Staphy. aureus tested in this study possessed no toxin genes and did not produce enterotoxin. The detection rate of nheABC, hblCDA, entFM and ces toxin gene in B. cereus was 100, 57.1, 76.2 and 0%, respectively. B. cereus isolates were classified into four groups according to the presence or absence of toxin genes. The nheABC gene was the major toxin gene among B. cereus tested in this study. The HBL was detected in 11 out of 21 B. cereus isolates (52.4%) and three B. cereus isolates produced NHE (14.3%). Conclusion: The results indicated that the contamination by microorganisms in the indoor air of lunchrooms was unqualified to supply safe catering in child care centers. The ongoing control of indoor air quality is required.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2485-2491
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• 2009

Culture was performed by using Sheep Blood Agar Plate (BAP, Asan Pharmaceutical) and Sabouraud Dextrose Ager (SDA, Asan Pharmaceutical) along with air $IDEAL^{TM}$ (Biomerieux), which is a microbe interceptor based on inertial impaction interception, in order to investigate bioaerosol in indoor and outdoor air at five elderly care facilities in a metropolis and an urban-rural consolidated city for two months from April 1 to May 31, 2007. From the culture followed by isolation and identification, the following conclusions were drawn. 1. As for the general isolation of microbes in each facility, care center S had the largest amount of microbes (263 cfu/$m^3$) isolated in a 300L room, followed by care center U having 123 cfu/$m^3$ isolated. 2. As for the number of bacteria isolated from a medium intercepting 300 L indoor, the largest amount of other unidentified or non-pathogenic Gram positive cocci (321 cfu/$m^3$) was isolated and most of the other Gram positive cocci were CNS (Coagulase Negative Staphylococcus). 3. As for the number of fungi isolated from a medium intercepting 300 L in a room, the largest number of Aspergillus spp. (66) was isolated, followed by Mucor spp. (62 cfu/$m^3$), Penicillium spp. (53 cfu/$m^3$), Alternaria spp. (50), and other unidentified or non-pathogenic fungi (42 cfu/$m^3$). 4. As for the rate of indoor and outdoor pollution, the average number of interceptions was all larger indoor than outdoor; the research differentiating the amount of air into 300 L and 500 L demonstrated that the larger amount of air led to more bacteria, making no great variation in the species.

• 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 the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.311-316
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• 2018

As the lives of people have improved, the demand for improved indoor air quality has increased. Various methods are used to remove biological air pollutants, such as UV/photocatalytic devices and ozone generators. However, these methods have disadvantages such as energy consumption, high corrosivity and toxicity. To overcome these disadvantages, an antibacterial copper filter was fabricated and its antimicrobial activity was then tested against two fungi (P. pinophilum, C. globosum) and one bacteria (S. aureus) Moreover, the ability to remove suspended microorganisms was tested step by step from the chamber stage to the air conditioning system. The results revealed 100% antimicrobial activity after 24 hours for the two fungi, while this value was 99.9% after 18 hours for the bacteria. Moreover, the antibacterial activity was higher when the chamber and air purifier were used than was obtained using a general antibacterial HEPA filter. Also, as a filter for system air conditioner, the antibacterial activity was lowered in offices and hospitals. In conclusion, the copper filter was found to have sufficient antibacterial activity for use as an antibacterial filter; however, further research on its preparation methods and materials is warranted.

• Journal of Environmental Health Sciences
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• v.36 no.1
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• pp.27-32
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• 2010

The indoor environmental condition was assessed in houses with allergy (asthma and atopy) patients by use of a fungal detector. The fungal index was calculated from the growth rate of the sensor fungi in a fungal detector encapsulating the spores, Alternaria alternata S-78, Eurotium herbariorum J-183 and Aspergillus penicillioides K-712. Fungal indices were higher in asthma patient's houses than in control houses and Eurotium herbariorum showed the highest growth response among the sensor fungi. Dust mites allergen, Der f1, was also significantly high in allergy patient's houses where fungal indices above 10 were detected. A correlation was observed between the fungal indices and dust mite allergen proliferations in examined houses. Therefore, the fungal index can be a useful tool as an indirect indication for detecting chronic dampness that brings both contaminations by fungi and dust mite.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.1
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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.