• Journal of agricultural medicine and community health
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• v.29 no.2
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• pp.303-314
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• 2004

Objectives: This study was carried out to assess exposure levels of organic dusts and ammonia in poultry farms in Korea. Methods: A total of six poultry farms were investigated. The farms were located in Namwon, Chonlabuk-do and in Kae-San, Chungchongbuk-do. This study consisted of a questionnaire and measuring organic dusts and ammonia. The questionnaire included the characteristics of the farms, work patterns and the tasks of the poultry farms. Results and Conclusions: The farmers raised the chickens 45 times a year and the average number of years in the poultry farm were eight years ranging from 2 to 12 years. They worked for seven days per week and the average hours spent caring the chickens are 6.3 hours per day. The duration of staying in the confinement buildings was 3.3 hours per day. The work time in summer was longest. The feed and the water supply systems were automatic and the control of ventilation windows used "winch curtain" was semiautomatic. They used mechanical ventilation system in winter and used dilution ventilation system in the other seasons. The geometric mean concentration of total and respirable dust sampled in the poultry confinement buildings was 4.0 mg/$m^3$and 0.9 mg/$m^3$ respectively. The ratio of respirable to total dusts range from 9 to 49 percent. There was no sample exceeding the criteria 10 mg/$m^3$ for total dust and 3 mg/$m^3$ for respirable dust in farms. The criteria have been recommended by Korean Ministry of Labor and American Conference of Governmental Industrial Hygienist. The personal respirable dusts measured during a circle work averaged geometric mean concentration 1.4 mg/$m^3$ Two personal samples were exceeded the threshold 3 mg/$m^3$. There was a positive relation between an index and the personal samples of respirable dusts($R^2$=0.98). The index is calculated by multipling the total number of chickens in the farm by the age of the chickens and then dividing by the volume of the confinement building. The geometric mean concentration of area and personal ammonia samples was 23.3 ppm and 22.2 ppm, respectively. Some of the ammonia samples, both area and personal samples, exceeded the short term exposure limit value 35 ppm.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.2
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• pp.265-271
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• 1996

This study was conducted to investigate distribution of lead particles by operation of industry, to evaluate the effect of particle size on the absorption to workers, and to recommend the Occupational Health Standard for lead. Total lead concentrations in the secondary smelting industry were higher than those in the battery and litharge manufacturing industry. Total lead concentrations in other industries except radiator manufacturing industry exceeded the standard of $50{\mu}g/m^3$. Only radiator manufacturing industry indicated lead concentrations significantly lower than those in other industries(p<0.05). Average blood lead level of workers was $85.1{\mu}g/dl$ in secondary smelting manufacturing, $51.3{\mu}g/dl$ in the battery manufacturing, and below $40{\mu}g/dl$ in the litharge and radiator manufacturing industry. Blood lead levels of workers by industry were significantly different(p<0.05). From relationship between airborne lead concentrations by size and lead in blood, confidence limits of airborne lead concentration equivalent to $40{\mu}g/dl$ of permissible limit in blood, was $147.9-489.8{\mu}g/m^3$ as total lead and $28.8-79.4{\mu}g/m^3$ as ACGIH-RPM. It is recommended that two separate occupational health standards for lead should be established by particle size. Airborne concentration of $150{\mu}g/m^3$ as fatal lead dust and $30{\mu}g/m^3$ as respirable lead dust was recommended.

• Journal of Environmental Health Sciences
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• v.41 no.6
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• pp.369-379
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• 2015

Objectives: The lack of reliable information on environmental pollution and health impacts related to asbestos contamination from abandoned mines has drawn attention to the need for a community health study. This study was performed to evaluate asbestos-related health symptoms among residents near abandoned asbestos mines located in the Chungcheong Provinces. In addition, exposure assessment for asbestos is needed although the exposure to asbestos was in the past. Methods: Past exposure to asbestos among inhabitants near abandoned asbestos mines was estimated by using surface sampling of deposited dust in indoor and outdoor residences. A total of 54 participants were divided into two groups with (34 cases) and without (20 controls) diseases related to asbestos. Surface sampling of deposited dust was carried out in indoor and outdoor residences by collecting 105 samples. Deposited dust for sampling was analyzed by polarization microscope (PLM) and scanning electron microscope?energy dispersive x-ray spectrometer (SEM-EDX) to detect asbestos. Subsequently, the elements of the deposited dust with asbestos were analyzed by SEM-EDX to assess the contribution of sources such as abandoned mines, slate and soil. Results: Among the 105 samples, asbestos was detected by PLM in 29 (27.6%) sampling points, and detected by SEM in 56 (48.6%) sampling points. Asbestos in indoor residences was detected by PLM in four sampling points, and by SEM in 12 sampling points. Asbestos detection in indoor residences may be due to ventilation between indoors and outdoors, and indicates long-term exposure. The asbestos detection rate for outdoor residences in the case group was higher than that in the control group. This can be explained as the case group having had higher exposure to asbestos, and there has been continuous exposure to asbestos in the control group as well as the case group. Conclusion: Past residential asbestos exposure may be associated with asbestosis among local residents near abandoned asbestos mines. Odds ratios were calculated for asbestos detection in outdoor residence by logistic regression analysis. Odds ratio between asbestos detection and asbestosis pulmonum was 3.36 (95% CI 0.90-12.53) (p=0.072), adjusting for age, sex, smoking status and work history with multi-variable logistic regression by PLM analysis method.

• Journal of Preventive Medicine and Public Health
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• v.14 no.1
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• pp.97-110
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• 1981

This study was conducted in order to investigate the status of harmful working environ ment on twelve rubber and ten chemical products manufacturing industries in Busan area over a period of five months from lune 1 to October 31, 1980. The summarized results were as follows: 1. The highest and lowest mean values of harmful environmental elements in workroom of rubber products manufacturing industries were noted in twisting (98.7dB) and coating department (77.3dB) to noise, molding ($6.43mg/m^3$) and forming ($1.33mg/m^3$) to dust, bonding (toluene 463.7ppm, xylene 457.8ppm and benzene 111.8ppm, respectively) and splicing (toluene 90.0ppm, xylene 83.3ppm and benzene 6.7ppm, respectively) to organic solvents, respectively. Also in chemical products manufacturing, they were noted in grinding (95.1dB) and shining department (76.8dB) to noise, packing ($4.30mg/m^3$) and staining ($3.20mg/m^3$) to dust, shining (393.3ppm and 375.0ppm, respectively) and varnishing(125.5ppm and 121.7ppm, respectively) to toluene and xylene, and scattering (51.8ppm) and mixing (23.9ppm) to benzene, respectively. 2. The mean values of harmful elements in workroom of rubber products manufacturing were 86.3dB to noise, $4.16mg/m^3$ to dust, 258.2ppm to toluene, 230.3ppm to xylene, and 5 4.0ppm to benzene, respectively. Also in chemical products manufacturing, they were 85.2dB to noise, $3.69mg/m^3$ to dust, 227.9ppm to toluene, 213.2ppm to xylene, and 36.3ppm to benzene, respectively. 3. Number of workers exposed to harmful working environment, over TLV, of a total 10,195 workers in rubber products manufacturing were 1,002(9.8%) to noise, 212 (2.1%) to dust, 1,581(15.5%) to toluene, 1,509(14,8%) to xylene, and 1,524(15.0%) to benzene, respectively. Number of workers exposed to harmful working environment, over TLV, of a 1,913 workers in chemical products manufacturing were 112(5.9%) to noise, 132(6.9%) to each organic solvent, respectively. 4. The values of noise and dust of rubber and chemical products manufacturing in 1980 were lower then those in 1977, but the value of organic solvent in 1980 was similar with that in 1977.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.119-129
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• 2005

The ambient TSP data measured at Seoul, Incheon. Taean, Daegu, Busan in Korea were used to explain the chemical composition and general features of Asian Dust (AD) observed in Korea. 9 episodes out of 19 were sampled from 2000 through May 2002, and measurements were conducted covering ionic and metal components with mass concentration. The results showed that daily averaged mass concentration (TSP) during the AD episodes was 458 $\mu\textrm{g}$/㎥, and ionic and metal concentrations were 27.93 $\mu\textrm{g}$/㎥ and 71.7 $\mu\textrm{g}$/㎥, respectively, accounting for 6.1 % and 15.5% of the total aerosol mass. TSP concentrations during episodes were varied from 120 to 1742 $\mu\textrm{g}$/㎥ according to the impact of Asian Dusts and had a tendency of showing higher values at sites in the west side of Korea, which can be explained by the effect of diffusion and deposition. In this study, ionic components like Ca (NO$_3$)$_2$, CaSO$_4$, NaNO$_3$, Na$_2$SO$_4$ were prominent types in secondary aerosol during AD periods and also indicated that V, Co as well as soil elements such as Ca, Fe, Mg, Mn, K correlated well with Al, while Cu, Cd, Pb, Zn didn't agree well with it. In addition, enrichment factors (EFs) for each metal component were obtained to provide simple information about source contribution of Asian Dust, and the results were compared with those from other AD studies. In this study, the results showed that aerosol properties in Korea during the Asian Dust were considerably different from those of general atmospheric condition and specially varied from case to case rather than site to site, which implies that there are certain variations in the soil of source region, pathways of air mass, and meteorological condition. For the enhanced study, those factors should be combined with the features of Asian Dust resolved from this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.192-199
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• 2020

The blower erosion phenomenon was investigated to develop a long-life blower with a volume flow rate of 10,000 ㎥/min with the required total pressure efficiency of 83% or more. The blower performance and blower erosion were predicted through numerical analysis by computational fluid dynamics(CFD). The conditions used for numerical analysis were an air volume of 16,200 ㎥/min, a rotation speed of 893 rpm, and a temperature of 330℃. The specific gravity, particle size, and amount of the dust was 3.15, 90 ㎛~212 ㎛, and is 265 kg/min, respectively. To examine the effects of a dust deflector on erosion, erosion analysis was performed by comparing the models with and without a dust deflector. Numerical analysis showed that when the dust deflector is installed, the average tended to decrease by 167% in the impeller and 133% in the boss. CFD using the Finne's model for erosion revealed a parallel restitution coefficient of 1 and a perpendicular restitution coefficient of 0.1. The blower performance of case 5 was 691.7 mmAq, and the efficiency was 83.3% when the rotation speed and the air volume flow rate were 880 rpm and 16,200 ㎥/min, respectively.

• Ocean and Polar Research
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• v.44 no.4
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• pp.297-310
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• 2022

To understand the chemical composition of aerosols in the Cheju-Korea Straits and their contribution to the ocean by deposition, aerosol samples were collected on board R/V Eardo from November 1997 to May 1999. The average concentrations of Al, NO₃^-, non-sea-salt (nss)-SO₄^2-, and NH₄⁺ in aerosols were 2.19, 5.59, 6.16 and 2.08 ㎍ m^-3, respectively. The Al concentration in the high yellow dust period was about 100 times higher than that in the non-yellow dust period. The concentration ratio of NO₃^-/nss-SO₄^2- ranged between 0.47 and 1.5, indicating that the aerosols in the Cheju-Korea Straits are under the effects of NO_x and SO_x emitted from China, Korea and Japan. The equivalent concentration ratio of [NH₄⁺]/[nss-SO₄^2-+ NO₃^-] with the average of 0.58±0.29 indicates that nss-SO₄^2- and NO₃^- are not neutralized by NH₄⁺. A high activity concentration of ²¹⁰Pb with 1.13-1.23 mBq m^-3 was observed during the high yellow dust period, indicating that ²¹⁰Pb is easily adsorbed in the yellow dust originating from the continent of Asia. The distribution of ⁷Be and NH₄⁺ concentrations showed a strong negative linear correlation during the low yellow dust period, April 1998. The total mineral dust flux in the Cheju-Korea Straits was estimated to be 1.21×10⁶ tons yr^-1, accounting for about 12% of the annual sediment discharge via the Nakdong River. The combined annual deposition of NH₄⁺ and NO₃^- was 0.103 mole N m^-2 yr^-1 was estimated to support 4% of the annual primary productivity in the East China Sea.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.398-422
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• 2017

Objectives: The major aim of this study is to construct the database of retrospective exposure assessment for crystalline silica through reviews of literatures in South Korea. Methods: Airborne concentrations of crystalline silica were collected using an academic information search engine, Research Information Service System(RISS), operated by the Korea Education & Research Information Service(KERIS). The key words used for the literature search were 'silica', 'crystalline silica', 'cristobalite', 'quartz' and 'tridymite'. A total number of 18 published documents with the information of crystalline silica level in air or bulk samples were selected and used to estimate retrospective exposures to crystalline silica. Weighted arithmetic mean(WAM) calculated across studies was summarized by industry type. Industries were classified according to Korea Standard Industrial Classification(KSIC) using information provided in the literature. Results: A total of 2,131 individual air sampling data measured from 1987 to 2012 were compiled. Compiled individual measurement data consisted of 827 respirable crystalline silica (RCS), 31 total crystalline silica(TCS), 24 crystalline silica(CS), 778 respirable dust(RD) and 471 total dust(TD). Most of RCS measurements(68.9%) were collected from 'cast of metals(KSIC 243)'. Comparing industry types, 'mining coal and lignite(KISC 051)' showed the highest WAM concentration of RCS, $0.14mg/m^3$, followed by $0.11mg/m^3$ of 'manufacture of other non-metallic mineral products(KSIC 239)', $0.108mg/m^3$ of 'manufacture of ceramic ware(KSIC 232)', $0.098mg/m^3$ of 'heavy construction(KSIC 412)' and $0.062mg/m^3$ of 'cast of metals(KSIC 243)'. In terms of crystalline silica contents in airborne dust, 'manufacture of other non-metallic mineral products(KSIC 239)' showed the highest value of 7.3%(wt/wt), followed by 6.8% of 'manufacture of ceramic ware(KSIC 232)', 5.8% of 'mining of iron ores(KSIC 061)', 4.9% of 'cast of metals(KSIC 243)' and 4.5% of 'heavy construction(KSIC 412)'. WAM concentrations of RCS had no consistent trends over time from 1994 ($0.26mg/m^3$) to 2012 ($0.12mg/m^3$). Conclusion: The data set related RCS exposure level by industries can be used to determine not only the possibility of retrospective exposure to RCS, but also to evaluate the level of quantitative retrospective exposure to RCS.

• Economic and Environmental Geology
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• v.45 no.3
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• pp.217-235
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• 2012

We evaluated the geochemical characteristics and their potential pollution of Asian Dusts in Daejeon, Korea during spring 2007. Compared with the chemical compositions of soils in source area of Asian Dust, those of aerosols in Daejeon were enriched with trace elements (ten to hundred fold), inferring that pollutants from China have affected on local environment in adjoining country such as Korea. Chemical analysis of aerosols during Asian dust showed that fine particles ($PM_{2.5}$) contained high contents of trace elements such as Cr, Cu, Pb, Zn, V, S, As, Cd, Co, Ni, Mo, Sb, Cs, Rb, Th, Sc and Y. In the case of TSP (Total Suspended Particle), Zr, Sr, Ba, Li, Th and U were contained much more than other trace elements. The contents of some elements (i.e. Li, Cs, Co, U, Cr, Ni, Rb, V, Th, Y, Sr and Sc) in aerosols collected in Asian Dust period, which are not likely enriched by air pollutants, were higher (2 - 4.2 fold) than those in Non Asian Dust period, indicating that these elements could be used as indicator elements for determining the occurrence of Asian Dust phenomena (especially, Sr, V, Cr & Li). In the case of Asian Dust coming through the big cities and/or industrial areas of China, the domestic aerosols had higher contents of trace elements (such as S, Cd, Zn, Pb, Cu, Mo and As) than those from Northeastern China via North Korea, indicating that the transportation courses of air mass are very important to determine the pollution degrees. Using the enrichment factors of trace elements in aerosols during Asian Dust and Non Asian Dust, we identified that some elements (i.e. S, Zn, Cu, Pb, As, Mo and Cd) were most problematic in terms of environmental hazard aspects, and these elements could affect adverse effects on human health as well as ecosystem and surface environment (soil and water) through long-lived precipitation.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.97-104
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• 2007

This study was carried out to develop the modified cyclone dust collector in windowless broiler building measuring 12 m wide, 46 m long, with a side wall height of 3 m and a capacity of 12,800 birds. Ventilation rate in windowless broiler building was $0.014{\sim}0.015\;and\;0.158{\sim}0.181cmm$ in second weeks and fifth weeks of age, respectively. Ammonia concentration was $13{\sim}16\;and\;20{\sim}24\;ppm$ in first and second weeks of age, respectively. Amount of dust collected in dust collector each week was 104.1, 274.7 and 388.6g in first, second and third weeks of age. But it was decreased from fourth weeks of age because of the increased ventilation rate. Total suspended particulate(TSP) of polluted air was $3,111.7{\sim}8,745.2{\mu}g/m^3$, but it was decreased to $530.8{\sim}2,264.4{\mu}g/m^3$ when it passed through the dust collector. Collecting efficiency was $54.2{\sim}82.9%$ in TSP. But collecting efficiency of Particulate matter smaller than $1{\mu}g$ (PM1.0) was $7.6{\sim}33.8%$, and lower than TSP. TSP concentration in control broiler house was 1,387.6 and $4,210.1{\mu}g/m^3$ in first and fourth weeks of age, respectively. But it was decreased to 876.3 and $2,535.3{\mu}g/m^3$ in broiler house operated dust collector in first and fourth weeks of age, respectively. Dust collecting efficiency for TSP was $36.8{\sim}39.8%$, and it was decreased to $11.4{\sim}39.8%$ in smaller dust size.