• Journal of Microbiology and Biotechnology
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• v.16 no.11
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• pp.1684-1689
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• 2006

Airborne microorganisms, which are currently termed bioaerosols, have received attention owing to the harmful effects they have on human health. As the concern over airborne microorganisms grows, there also grows an urgent need to study and develop efficient methods for controlling them. In this study, thermal energy using a thermal tube was tested as a control method, mainly against airborne E. coli. For a comparison, B. subtilis var. niger spores were utilized in the experimentation. It was found that the widely known inactivation conditions for microorganisms were not adequate against airborne microorganisms. The experimental results demonstrated the need for extensive studies that should investigate adequate and economic conditions to control against airborne bacteria. In this study, thermal energy exposed by the thermal tube demonstrated an inactivation performance for controlling E. coli bioaerosols.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.123-130
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• 2021

Objectives: Control methods against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) aerosols have been introduced. Airborne spreading theories for SARS-CoV-2 were analyzed in this study. Methods: Control methods for airborne microorganisms were discussed. Studies on theoretical estimations for airborne spreading of SARS-CoV-2 were presented and analyzed. Analytic calculations were conducted for explaining control techniques for airborne microorganisms. Results: Control methods for SARS-CoV-2 aerosols can include physical or biological procedures. Characterization of SARS-CoV-2 aerosols and massive clustering infection cases of COVID-19 support the airborne spreading theories of SARS-CoV-2. It is necessary to consider the disadvantages of control methods for airborne microorganisms. Conclusions: A study on control methods against bioaerosols is necessary to prevent the spreading of viruses. Airborne spreading theories of SARS-CoV-2 were supported by the current evidence, but further studies are needed to confirm these theories.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.194-201
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• 2015

Objectives: The purpose of this study is to assess the exposure level to dust and airborne microorganisms among employed workers in a clothing shopping center. Materials and Methods: On-site investigation of a clothing shopping center was performed between October and November 2012. The hazardous substances measured in this study are particulate matter(Total dust, respirable dust) and airborne microorganisms (Total airborne bacteria, total airborne fungi). Results: The highest geometric mean levels of particulate matter(total dust, respirable dust) for personal sampling were $1.735(SD:0.883)mg/m^3$ for total dust and $0.0711(SD:0.008)mg/m^3$ for respirable dust, respectively. Those for area sampling were $0.625(SD:0.091)mg/m^3$ for total dust and $0.0718(SD:0.012)mg/m^3$ for respirable dust, respectively. The highest geometric averaged concentrations of airborne microorganisms(Total airborne bacteria, total airborne fungi) were detected at $1,181(SD:105)cfu/m^3$ for total airborne bacteria and $683(SD:114)cfu/m^3$ for total airborne fungi, respectively. Concentrations of particulate matters and airborne microorganism in clothes shopping center did not correlate significantly with environmental factors such as temperature or relative humidity. Conclusions: Exposure levelshave not been established for service workers. Thus, health risk assessment for this group is very difficult. Health guidelines for service workers should be established as soon as possible.

• Environmental Engineering Research
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• v.17 no.4
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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.

• Journal of Environmental Health Sciences
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• v.33 no.2 s.95
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• pp.104-114
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• 2007

This study evaluated the airborne concentrations of bacteria, Gram-negative bacteria, and fungi in waiting rooms, wards, and outdoors, according to time and particle size between October 17 and November 28, 2003. The geometric mean number of airborne bacteria was highest in the morning. The more people there were, the higher was the total bacteria concentration. The concentration of fungi was also highest in the morning. Temperature and relative humidity affected the concentrations of fungi significantly (p<0.05). This study found relationships between microorganism concentrations and (actors such as time, place, temperature, humidity, ventilation, and number of people. Therefore, to manage the pollution resulting from airborne microorganisms, each time, place, and environmental factor should be examined periodically, and the number, size, and movement of airborne microorganisms should be evaluated.

• Journal of Life Science
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• v.10 no.1
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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.

• 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.

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.288-293
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• 2007

To evaluate effects of airborne microorganisms in fresh cut processing plant, microorganisms in air, equipments, raw material, water and final product were isolated and identified using Vitek (R)2 compact system. Airborne microorganisms were isolated from 1000L air using air sampler for floating microorganisms and plate count agar for falling microorganisms. And contaminated microorganisms of equipment, water, and product were isolated from plate count agar plate. Total plate counts for floating and falling, raw material, equipments and final product were $10^2-10^3CFU/m^3,{\sim}10^1CFU/plate,\;10^3CFU/g,{\sim}10^4CFU/cm^2\;and\;10^4CFU/g$, respectively. From the result of isolated microorganism identification from raw material to final product, airborne microorganisms could affect the flora of final product.

• Journal of Microbiology
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• v.35 no.1
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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.

• Journal of Veterinary Clinics
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• v.34 no.2
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• pp.76-81
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• 2017

Studies on the concentration of airborne microorganisms in human medicine as a part of a study on the nosocomial infections have been conducted properly, but in veterinary medicine, there has been rarely performed in Korea to the best of study's knowledge. The purpose of this study was to evaluate the distribution of airborne microorganisms and to identify their species in different places in the animal hospital to alert the necessity of thorough cleanliness management. This study evaluated the concentrations of airborne bacteria and fungi in hospital areas, such as patient waiting room, internal medicine ward, surgical ward and radiological diagnostic ward. The concentration of bacteria and fungi was significantly lower (p < 0.05) in two operating rooms and higher in the patient waiting room. The dominant species of bacteria were Micrococcus spp., Staphylococcus spp., and fungi were Penicillium spp., Dermatophyte mold. Animal hospitals need to perform proper procedures for disinfection, sterilization, and environmental cleaning as well as appropriate employee training and monitoring in order to the maximum prevention of the risk of nosocomial and surgical infections.