• Journal of Environmental Health Sciences
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• v.36 no.4
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• pp.306-312
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• 2010

This field study was performed to evaluate the efficiency of a plasma ion-operated air cleaner in temporal reduction of airborne pollutants emitted from a pig housing facility. In the case of gaseous pollutants, the plasma ion air cleaner was not effective in reducing levels of ammonia, hydrogen sulfide, nitrogen dioxide, or sulfur dioxide (p>0.05). In the case of particulate pollutants, however, the air cleaner was effective in reducing levels of particulate matter ($PM_{2.5}$ and $PM_1$) by 79(${\pm}6.1$) and 78(${\pm}3.0$)%, respectively. Unlike the case of these fine particle fractions, the reduction of total suspended particles (TSP) and $PM_{10}$ following treatment was almost negligible. In the case of biological pollutants, the mean reduction efficiencies for airborne bacteria and fungi were relatively low at 22(${\pm}6.6$) and 25(${\pm}8.7$)%, respectively. Taken together, these results indicate that in terms of air pollutants released from this pig housing facility, the plasma ion air cleaner was primarily effective in reducing levels of $PM_{2.5}$ and $PM_1$.

• Journal of Environmental Health Sciences
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• v.40 no.2
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• pp.88-97
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• 2014

Objectives: The aim of this study was to evaluate the occurrence of microbiological contamination of kitchen utensils and environments of food service operations at university located in Seoul, Korea. Methods: We collected swab samples from the surfaces of knives, chopping boards, floors, and drains, as well as drinking water and airborne bacteria samples from 20 food service operations. Three bacterial indicators and five food poisoning bacteria were measured quantitatively and qualitatively, respectively. We used selective culture media and the PCR assay targeting 16S rRNA gene for the microbiological analysis. Results: We detected bacterial indicators on knives or chopping boards in eight different food service operations and, three food service operations (I, M, and O) showed more than 3 log colony forming units $(CFU)/100cm^2$ on their knives, significantly higher than the others. The levels of bacterial indicators on the floors and drains in the cooking areas were much higher than those on the cooking utensils. S. aureus was detected on 10 floors and 8 drains. Culturable bacteria were identified in 5 drinking water samples, and food service operation B ($431.1CFU/m^3$) and C ($551.2CFU/m^3$) showed more than $400CFU/m^3$ of total airborne bacteria. Conclusions: These results suggest that some of food service operations in this study may require additional investigation to secure the microbial safety of cooking environments. In addition, further actions including hygiene education for employees and proper guidelines to maintain clean cooking environments should be prepared.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.395-402
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• 2023

Objectives: Microbial contamination of face masks used by healthcare professionals can vary depending on the degree of exposure to bioaerosols in various healthcare environments. However, research on this topic is limited. Therefore, we analyzed microbial contamination of N95 respirators used in hospital offices, wards, and outpatient settings. Methods: Samples isolated from N95 respirators worn for 2, 4, and 6 hours were incubated at a temperature of 35-37℃ or 25-28℃ for 24 hours or for 3-7 days, and colony-forming units were counted in chocolate agar, tryptic soy agar, and Sabouraud dextrose agar plates. Total indoor airborne bacteria were also measured in the healthcare environments. Finally, microbial species were identified using Gram staining with a microscopic speculum. Results: The three types of environments did not deviate from the maintenance of standard indoor air quality. There was no difference between the microbial species identified in the healthcare environment and mask contamination. However, the number of bacteria in the masks worn in each environment differed, and the degree of contamination increased with mask-wearing time (p<0.05). Conclusions: Therefore, care must be taken to avoid recontamination of masks due to improper use and exposure to biological hazards in healthcare environments. In conclusion, scientific evidence is necessary for safe mask-wearing times. Based on the results of this study, we hope to conduct further research to establish guidelines for the safe use of face masks during respiratory disease epidemics.

• Journal of Mushroom
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• v.13 no.1
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• pp.26-29
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• 2015

Since button mushroom (Agaricus bisporus) cultivation is performed in closed environment, the understanding of indoor environment becomes essential for the quality and quantitative production of the greenhouse-grown mushroom. To generate information on indoor environmental factors affecting on fruiting body quality, we investigated temperature, humidity, and bacterial concentration and species in a greenhouse located in Buyeo, Chungnam Province. Temperature and humidity were recorded as $19.75{\pm}0.35^{\circ}C$ and $87{\pm}3.67%$, respectively. The total concentration of bacteria was measured as $3.84{\times}10^3CFU/M^3$. Advenella kashmirensis, Bacillus vietnamensism, B. licheniformis, Burkholderia sordidicola, Fictibacillus phosphorivorans, Lysobacter daejeonensis, Microbacterium esteraromaticum, Pseudomonas aeruginosa, P. protegens, P. gessardii, P. mosseli were identified from indoor air of the greenhouse.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.789-799
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• 1998

Literatures on microorganisms of traditional Korean nuruk published since 1945 were reviewed in this paper. Traditional Korean nuruk consists of raw barley and various grains. Traditional Korean nuruk consists of unbolied raw barely and various grains. They are ground to paste and moistened, and then naturally inoculated by airborne microorganisms. Therefore, many kinds of microorganisms such as fungi, yeast, and bacteria grwo in nuruk. Since 1945, new 14 species of Aspergillus and 9 species of Penicillium have been identified from traditional Korean nuruk. Total number of fungal species identified so far is now up to 38 species among 12 different genus. Among newly isolated fungal species, Aspergillus penicilloides and Penicillium, expansum showed not only high production rate of acid and amylase but also extreme stability of the enzyme at room temperature for 3 months. As examples of newly isolated yeast species, there are 5 species of Candida, 4 species of Hansenula, 1 species of Pichia and 1 species of Schizosaccharomyces. Total number of yeast species isolated so far is up to 18 species from different 8 genus. Newly isolated bacteria, were Bacillus pumilus, Lactobacillus casei and Leuconostoc mesenteroides.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.117-123
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• 2022

Recently, due to COV ID-19, many people are spending most of their time indoors. So, there is a rising interest on the indoor air quality in the field of building construction. The main sources for the indoor air pollution are human indoors activity, building materials, living supplies and the polluted air from outdoor. The Korean government has designated 17 indoor air pollutants including fine dust, total airborne bacteria, fungi and carbon dioxide, etc.. Most people are always exposed to assorted bacteria and molds in our daily life, because indoor environment for human, moderate temperature are humidity, it is favourable to the growth of most of bacteria and fungi. Pine needles have an antibacterial effect against bacteria and fungi. In this study, the antibacterial activity against bacteria and fungi was tested by cement matrix using pine needle extract. As a result, the cement matrix using pine needle extract showed antibacterial activities against bacteria, but in the case of fungi, it did not show antifungal activity.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.283-294
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• 2004

Air quality in the livestock waste compost pilot plant at the Colligate Livestock Station was assessed to quantity the emissions of aerial contaminants and evaluate the degree of correlation between them for different operation strategies; with the ventilation types and agitation of compost pile, in this study. The parameters analyzed to reflect the level of air quality in the livestock waste compost pilot plant were the gaseous contaminants; ammonia, hydrogen sulfide, and odor concentration, the particulate contaminants; inhalable dust and respirable dust, and the biological contaminants; total airborne bacteria and fungi. The mean concentrations of ammonia, hydrogen sulfide, and odor concentration in the compost pilot plant without agitation were 2.45ppm, 19.96ppb, and 15.8 when it was naturally ventilated, and 7.61ppm, 31.36ppb, and 30.2 when mechanically ventilated. Those with agitation were 5.50ppm, 14.69ppb, and 46.4 when naturally ventilated, and 30.12ppm, 39.91ppb, and 205.5 when mechanically ventilated. The mean concentrations of inhalable and respirable dust in the compost pilot plant without agitation were 368.6${\mu}g$/$m^3$ and 96.0${\mu}g$/$m^3$ with natural ventilation, and 283.9${\mu}g$/$m^3$ and 119.5${\mu}g$/$m^3$ with mechanical ventilation. They were also observed with agitation to 208.7${\mu}g$/$m^3$ and 139.8${\mu}g$/$m^3$ with natural ventilation, and 209.2${\mu}g$/$m^3$ and 131.7${\mu}g$/$m^3$ with mechanical ventilation. Averaged concentrations of total airborne bacteria and fungi in the compost pilot plant without agitation were observed to 28,673cfu/$m^3$ and 22,507cfu/$m^3$ with natural ventilation, and 7,462cfu/$m^3$ and 3,228cfu/$m^3$ with mechanical ventilation. They were also observed with agitation to 19,592cfu/$m^3$ and 26,376cfu/$m^3$ with the natural ventilation, and 18,645cfu/$m^3$ and 24,581cfu/$m^3$ with the mechanical ventilation. It showed that the emission rates of gaseous pollutants, such as ammonia, hydrogen sulfide, and odor concentration, in the compost pilot plant operated with the mechanical ventilation and with the agitation of compost pile were higher than those with the natural ventilation and without the agitation. While the concentrations of inhalable dust and total airborne bacteria in the compost pilot plant with the natural ventilation and with the agitation, the concentrations of respirable dust and total airborne fungi in the compost pilot plant with the mechanical ventilation and agitation were higher than those with the natural ventilation and without the agitation of compost pile. It was statistically proved that indoor temperature and relative humidity affected the release of particulates and biological pollutants, and ammonia and hydrogen sulfide were believed primary malodorous compounds emitted from the compost pilot plant.

• Tuberculosis and Respiratory Diseases
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• v.58 no.2
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• pp.167-173
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• 2005

Background : Airborne particles during Yellow Sand phenomena are known to be associated with the respiratory disease. The purpose of this study was to evaluate the concentration and metal component properties of Yellow Sand particles and compare with airborne microbial concentration and species in non Yellow Sand and Yellow Sand phenomena. Methods : Samplings were carried out in 2002 in Seosan, during non Yellow Sand and Yellow Sand phenomena. Samples were taken using the 8-stage Cascade impactor and metallic elements were analyzed by XRF. Those were culture on the media for bacterial and fungal culture and celline for virus. Results : The concentration of total suspended particulate matter were respectively $80.2{\mu}g/m^3$, $40.3{\mu}g/m^3$ in non Yellow Sand and Yellow Sand phenomena. The concentration of metallic elements such as Ca, Fe, Cu and Zn in Yellow Sand phenomena were higher than its in non Yellow Sand. Two bacteria, Bacillus species and Staphylococcus were grown in two periods. In both periods, several fungal spores(Mucor species, Cladosporum, Alternaria, Aspergillus, Penicillium, and Alternaria species) were identified. The differences of bacteria and fungus species not observed in Yellow Sand and non Yellow Sand. Any viruses were not isolated in between both periods. Conclusions : The concentration of total suspended particulate matter and some metallic elements in Yellow Sand phenomena were higher than its in non Yellow Sand. The difference of bacteria and fungus species was not observed in non Yellow Sand and Yellow Sand phenomena.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.120-129
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• 2017

This study assessed the safety of raw oysters Crassostrea gigas for consumption during processing in a processing plant. Bacterial contamination (e.g., viable cell counts, coliform groups, Escherichia. coli and pathogenic bacteria) and chemical contamination (e.g., heavy metals and shellfish toxins) were measured on raw oysters, a processing equipment, employees and work areas. No total mercury, lead, paralytic shellfish poison, diarrheic shellfish poison or norovirus was detected in any post-harvested oyster samples. However, the cadmium level ranged from 0.1-0.2 mg/kg. The viable cell count, E. coli and coliform group levels in post-harvested oysters ranged from 4.00-4.54 log CFU/g, ND-210 MPN/100 g and 110-410 MPN/100 g, respectively. The viable contaminating cell counts on employees, equipment and work areas were in the range of $0.90-3.46log\;CFU/100cm^2$. Airborne bacteria in the work areas ranged from 0.60 to 1.81 log CFU/plate/15 min. Thus, no significant health risks were detected in the processing plant.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.1
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• pp.70-76
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• 2017

Objectives: This on-site study was performed to evaluate the reduction efficiency of an air cleaner on particulate matters and biological agents in a swine facility. Materials and Methods: Particulate matter was measured using a real-time monitoring recorder and biological agents were sampled with a one-stage impactor and then analyzed based on the microbial culture method. An experimental process for the reduction effect on airborne pollutants through air cleaner operation consisted of three conditions: no treatment, wet scrapper by water spray and wet scrapper by disinfectant spray. Results: Geometric mean levels of particulate matter(TSP, $PM_{10}$, $PM_{2.5}$ and $PM_1$) were presented at $1,608{\mu}g/m^3$, $1,373.8{\mu}g/m^3$, $401.8{\mu}g/m^3$ and $144.5{\mu}g/m^3$ for no treatment; $1,503{\mu}g/m^3$, $1,017{\mu}g/m^3$, $159.4{\mu}g/m^3$ and $69.8{\mu}g/m^3$ for wet scrapper by water spray; and $1,222.17{\mu}g/m^3$, $477.17{\mu}g/m^3$, $33.2{\mu}g/m^3$ and $11.1{\mu}g/m^3$ for wet scrapper by disinfectant spray, respectively. In the case of biological agents, the geometric averaged concentrations of total airborne bacteria and fungi were as follows: $45,371cfu/m^3$ and $13,474cfu/m^3$ for no treatment, $43,286cfu/m^3$ and $8,610cfu/m^3$ for wet scrapper by water spray, and $2,440cfu/m^3$ and 1,867 cfu/ for wet scrapper by disinfectant spray, respectively. Regardless of particulate matter and biological agent, the highest concentrations were found for no treatment, while the lowest concentrations were found with wet scrapper by disinfectant spray. Conclusions: Based on the results obtained from this on-site evaluation, there was a significant reduction effect on particulate matter and biological agents through the application of an air cleaner in this study.