• 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.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.103-107
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• 2013

Objectives: The principal purpose of this study is to statistically compare dust levels among farmers with and without feeding in a nursery pig building. Methods: Total dust and respirable dust were measured by personal sampling method, and TSP and PM10 were monitored by the direct recording method in the pig building. Results: IIn the personal samples, mean exposure levels of total and respirable dust were higher among the farmers who conducted feeding compared to farmers who did not. A significant difference between farmers with feeding and farmers without feeding was found in total dust concentration(p<0.05), whereas there was no significant difference in respirable dust concentrations. In real-time monitoring of dust based on area sampling, the highest levels of total and respirable dust were detected in the feeding time periods; $4.33{\pm}2.57mg/m^3$ for TSP and $2.53{\pm}1.02mg/m^3$ for PM10, respectively. During time periods without feeding, the levels of total and respirable dust ranged from 1 to $2mg/m^3$ and from 0.5 to $1.5mg/m^3$, respectively. Conclusions: In terms of association of feeding work and air sampling location, the mean concentrations of total and respirable dust were highest in area sampling with feeding and lowest in personal sampling without feeding. However, a significant difference among groups investigated according to air sampling condition was found in total dust.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.4
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• pp.574-579
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• 2005

Optimal management of indoor air quality in a confined pig house, especially in winter, is indispensable for preventing infectious respiratory disease to workers and animals. This study was performed to elucidate the correlation of aerial contaminants and climate factors in a confinement. It was observed that indoor air contaminants ion in the confinement was the highest at 2:00-5:00 pm in a day, followed by 8:00-11:00 pm and 8:00-11:00 am. This was attributed to the increase of pig activities in the afternoon. The concentration of total dust and total airborne bacteria was found to have a significant correlation with temperature and relative humidity (p<0.05). Correlation of total dust and total airborne bacteria, total dust and ammonia, and total dust and odor were shown statistically significant at 95% confidence level. In conclusion, temperature and total dust concentration correlated significantly with all the parameters except for hydrogen sulfide ($H_2S$). This could be explained by the fact the dryness of pig feces by increase of interior temperature and resuspension of feed deposited on the floor by the pig activity, resulted in high generation of dust which adsorbed and carried the airborne bacteria and odor compounds in a confined pig house. It was proved that the adsorptive capacity of dust with ammonia ($NH_3$) was higher than that with hydrogen sulfide ($H_2S$).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.390-397
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• 2017

Objectives: The purpose of this study was to evaluate concentrations in airborne total and respirable dusts in the cement manufacturing and handling industries. Methods: Fifty-three total dust and 42 respirable dustsamples were collected from 24 work places. Total dust samples were collected using a three-stage cassette. Respirable dust samples were collected using a cyclone equipped with a 37 mm, $5{\mu}m$ pore size PVC filter. Results: The geometric means of the dust concentrations were $0.10mg/m^3$ and $0.08mg/m^3$ in total dust and respirable dust, respectively. The Korean Occupational Exposure Limit($10mg/m^3$) was not exceeded, but the rate of exceeding the American Conference of Governmental Industrial Hygienist(ACGIH) Threshold Limit Value($1mg/m^3$) was 16.7%. Conclusion: When measuring the level of dust at cement manufacturers, the airborne concentration of respirable dust should be evaluated. In order to protect the health of workers exposed to cement dust, it is necessary to actively consider strengthening the Korean Occupational Exposure Limit.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.158-166
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• 1999

The purpose of this study was to investigate the correlation between airborne total dust and man-made mineral fibers (MMMF), and to estimate total dust concentration to maintain below the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV$^{(R)}$) for the MMMF. The regression coefficients between airborne total dust concentrations and fiber concentrations determined in the industries producing glass fibers, rock wool. refractory ceramic and continuous filament glass fibers products were 0.41, 0.42, 0.20 and 0.19, respectively. The size characteristics of fibers as well as the amounts of contaminated non-fibrous dusts could affect the correlation intensities. When total dust and fiber exposure data were compared with the occupational exposure limits, there was a large gap between two evaluation results. The regression coefficient between total dust and fiber data was increased ($r^2=0.88$) in the process of insulation installation generating in the higher levels of glass or rock wool fibers. In this case, an estimated total dust concentration of glass wool or rock wool fibers complying with the ACGIH TLV (1 f/cc) was $1.7mg/m^3$. In conclusion, the total dust and fibers concentrations was highly correlated at the higher exposure levels so that total dust-monitoring data could be used to control simply and economically and to estimate worker's exposure to fibers.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.1
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• pp.10-17
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• 2020

Objectives: This study was performed to evaluate the total dust, size-selective dust, and heavy metal concentrations generated inside and outside toll booths on an expressway and to identify the source through analysis of the components of the deposited dust. Methods: A total of 32 samples were collected from eight expressway toll booths. Each total dust sample was collected using a 37 mm PVC filter attached to a personal air sampler. Heavy metal samples were collected according to NIOSH method 7300. The size-selective dust concentrations were identified using a DustMate, and deposited dust was analyzed by WD-XRF and UHR-FE-SEM. Results: The geometric mean concentrations of the total dust inside and outside the toll booths were 337.5 ㎍/㎥ and 342.7 ㎍/㎥, respectively. The overall concentrations of TSP, PM₁₀, PM_2.5, and PM1 were higher on the outside of the toll booths, as the particle size of dust was larger, and higher in the underground passage as the dust size was smaller. The real-time analysis of the dust concentrations of TSP, PM₁₀, PM_2.5, and PM1 revealed to be higher at morning and evening times than other times because of heavy traffic. The element components of deposited dust in the toll booth were related to natural sources rather than artificial sources. Among the chemical components in the deposited dust analyzed by WD-XRF, SiO₂ was the highest. For the elements analyzed by UHR-FE-SEM, C was the highest, followed by O, and Si. Conclusions: In order to reduce the dust concentrations around toll booths on an expressway, it is necessary to periodically clean surrounding areas such as underground passages, and it is also necessary to remove deposited dust inside the toll booth from time to time.

• Journal of Environmental Health Sciences
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• v.43 no.3
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• pp.185-193
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• 2017

Objectives: An on-site study was conducted in order to quantify indoor exposure levels and the emission rate of particulate matter for domestic poultry buildings. Materials and methods: Three types of poultry building (caged layer house, broiler house, and layer house with manure belt) as classified by mode of manure treatment and ventilation were investigated in this study. Nine sites per each poultry building were selected and visited for measuring exposure levels and emission rate of particulate matter. Total dust and respirable dust among the particulate matter were analyzed based on the weight method. Emission rates were estimated by dividing emission amount, which was calculated through multiplying indoor concentration ($mg/m^3$), by the ventilation rate ($m^3/h$), into indoor area ($m^2$) and number of poultry reared in the poultry building. Results: Mean exposure levels for total dust and respirable dust in the poultry buildings were $3.91({\pm}1.99)mg/m^3$ and $1.99({\pm}0.89)mg/m^3$, respectively. The emission rates of particulate matter in the poultry buildings were estimated as $4.75({\pm}1.22)mg\;head^{-1}h^{-1}$ and $64.39({\pm}24.95)g\;m^{-2}h^{-1}$ for total dust and $0.58({\pm}0.23)mg\;head^{-1}h^{-1}$ and $7.52({\pm}2.51)mg\;m^{-2}h^{-1}$ for respirable dust, respectively. The distribution patterns for total dust and respirable dust were similar regardless of poultry building type. Among poultry buildings, broiler house showed the highest exposure level and emission rate of total dust and respirable dust, followed by layer house with manure belt and caged layer house. Conclusions: The finding that the broiler house showed the highest exposure level and emission rate of particulate matter can be attributed to sawdust utilized as bedding material, which can be dispersed into the air by movements of the chickens. Thus, a work environmental management solution for optimally reducing dust concentrations is necessary for broiler houses.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.3
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• pp.177-183
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• 2011

Occupational exposure to silicon carbide dust of manufacturing industries has seldom been evaluated in Korea. Accordingly, we evaluated various silicon carbide dust concentrations in the breathing zone of workers between May 2010 and July 2010. To compare silicon carbide dust concentrations, three dust samplers including the Institute of Occupational Medicine (IOM) sampler, 37mm cassette sampler, and Aluminum cyclone sampler were used. A total of 5 manufacturing industries producing abrasive and refractory materials using silicon carbide were investigated. The geometric mean concentrations were 2.04, 0.97, and $0.48mg/m^3$ in inhalable, total and respirable silicon carbide dust, respectively. The geometric mean concentrations of silicon carbide in abrasive material manufacturing industries were slightly higher than that of refractory manufacturing industries, and finishing operations were higher than that of other operations. It was found that the results of exposure assessment in airborne dust at manufacturing industries using silicon carbide in Korea showed exceeding rate to American Conference of Governmental Industrial Hygienists Threshold Limit Value ($3mg/m^3$) was 10% in respirable dust samples. Therefore, with the consideration of the close relationship between smaller dust size and the occurrence of occupational respiratory diseases, it is suggested to promulgate the new occupational exposure limit for respirable silicon carbide dust.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.3 no.2
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• pp.227-239
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• 1993

The author selected 77 dust emissing processes from 71 types of industries which placed in Sasang Industrial Complex in Pusan. The level of total dust was measured as areal concentration and personal exposure concentration by low volume air sampler and personal air sampler, respectively. Collected samples were classified into 5 groups (chemicals and rubber product, metal product, sawmills and wood, foundries and others). Respirable particulate and total dust of areal and personal exposure were analyzed. The results were as follows; 1. All of the respirable dust concentration and total dust of areal and personal concentration were log-normally distributed. 2. Geometric mean of respirable particulate of personal exposure concentration measured $0.55mg/m^3$ in the first group, $0.86mg/m^3$ in the second group, $0.39mg/m^3$ in the third group, $0.81mg/m^3$ in the forth group and $0.52mg/m^3$ in the fifith group. The exceed rates over TLV (thehold limit values) of total dust were 31.3% in the first group, 31.3% in the second group, 70% in the third group, 80% in the forth group and 13.3% in the fifth group. 3. There were singnificant difference between areal and personal exposure concentration and personal exposure concentration was higher than that of area. 4. In the case of high ratio of respirable particulate to total dust, pneumoconiosis incidence was high even though the workshop was opened and emissing dust concentration was low. These findings suggest that it is desirable to measure respirable particulate in environmental assessment of dust emissing workshops.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.471-477
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• 2014

Objectives: This study was conducted to evaluate area exposure of airborne dust and organic gas during entrance and shipment of chicken in poultry farms Methods: Total dust was measured with NIOSH method 0500. The volume of distributed dust and organic gas(Ammonia, TVOC, Hydrogen Sulfide) were measured using direct reading instrument. Results: The range of concentrations of total dust in area sample was $0.07{\sim}4.91mg/m^3$ during the entrance of chicks and $4.37{\sim}9.4mg/m^3$ during shipment respectively. Concentration of ammonia reached approximately 9 ppm during shipment. There was a difference of concentration of total dust in the area sample between shipment and entrance tasks. Conclusions: It was found that the development of a special intervention program by type of task should be considered for reducing respiratory health effects among poultry farmers.