• Toxicological Research
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• v.29 no.2
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• pp.121-127
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• 2013

Nanotoxicological research has shown toxicity of nanomaterials to be inversely related to particle size. However, the contribution of agglomeration to the toxicity of nanomaterials has not been sufficiently studied, although it is known that agglomeration is associated with increased nanomaterial size. In this study, we prepared aerosols of nano-sized carbon black by 2 different ways to verify the effects of agglomeration on the toxicity and deposition of nano-sized carbon black. The 2 methods of preparation included the carbon black dispersion method that facilitated clustering without sonication and the carbon black dispersion method involving sonication to achieve scattering and deagglomeration. Male Sprague-Dawley rats were exposed to carbon black aerosols 6 hr a day for 3 days or for 2 weeks. The median mass aerodynamic diameter of carbon black aerosols averaged $2.08{\mu}m$ (for aerosol prepared without sonication; group N) and $1.79{\mu}m$ (for aerosol prepared without sonication; group S). The average concentration of carbon black during the exposure period for group N and group S was $13.08{\pm}3.18mg/m^3$ and $13.67{\pm}3.54mg/m^3$, respectively, in the 3-day experiment. The average concentration during the 2-week experiment was $9.83{\pm}3.42mg/m^3$ and $9.08{\pm}4.49mg/m^3$ for group N and group S, respectively. The amount of carbon black deposition in the lungs was significantly higher in group S than in group N in both 3-day and 2-week experiments. The number of total cells, macrophages and polymorphonuclear leukocytes in the bronchoalveolar lavage (BAL) fluid, and the number of total white blood cells and neutrophils in the blood in the 2-week experiment were significantly higher in group S than in normal control. However, differences were not found in the inflammatory cytokine levels (IL-$1{\beta}$, TNF-${\alpha}$, IL-6, etc.) and protein indicators of cell damage (albumin and lactate dehydrogenase) in the BAL fluid of both group N and group S as compared to the normal control. In conclusion, carbon black aerosol generated by sonication possesses smaller nanoparticles that are deposited to a greater extent in the lungs than is aerosol formulated without sonication. Additionally, rats were narrowly more affected when exposed to carbon black aerosol generated by sonication as compared to that produced without sonication.

• Journal of Preventive Medicine and Public Health
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• v.49 no.5
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• pp.329-341
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• 2016

Objectives: The goal of this study was to investigate the short-term effect of ambient air pollution on emergency department (ED) visits in Seoul for asthma according to patients' prior history of allergic diseases. Methods: Data on ED visits from 2005 to 2009 were obtained from the Health Insurance Review and Assessment Service. To evaluate the risk of ED visits for asthma related to ambient air pollutants (carbon monoxide [CO], nitrogen dioxide [$NO_2$], ozone [$O_3$], sulfur dioxide [$SO_2$], and particulate matter with an aerodynamic diameter <$10{\mu}m$ [$PM_{10}$]), a generalized additive model with a Poisson distribution was used; a single-lag model and a cumulative-effect model (average concentration over the previous 1-7 days) were also explored. The percent increase and 95% confidence interval (CI) were calculated for each interquartile range (IQR) increment in the concentration of each air pollutant. Subgroup analyses were done by age, gender, the presence of allergic disease, and season. Results: A total of 33 751 asthma attack cases were observed during the study period. The strongest association was a 9.6% increase (95% CI, 6.9% to 12.3%) in the risk of ED visits for asthma per IQR increase in $O_3$ concentration. IQR changes in $NO_2$ and $PM_{10}$ concentrations were also significantly associated with ED visits in the cumulative lag 7 model. Among patients with a prior history of allergic rhinitis or atopic dermatitis, the risk of ED visits for asthma per IQR increase in $PM_{10}$ concentration was higher (3.9%; 95% CI, 1.2% to 6.7%) than in patients with no such history. Conclusions: Ambient air pollutants were positively associated with ED visits for asthma, especially among subjects with a prior history of allergic rhinitis or atopic dermatitis.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.5 no.2
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• pp.160-171
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• 1995

The size characteristics of lead particle which is one of the important factors associated with absorption of lead were ignored in establishing lead standard. This study was conducted to investigate distribution of lead particles by operation of industry. Aerodynamic Mass Median Diameters (MMD) of airborne lead particles in the battery and litharge manufacturing industry were $14.1{\mu}m$ and $15.1{\mu}m$, respectively. There was no significant difference between those two values(p>0.05). However, the diameters in radiator manufacturing and secondary smelting industry were $1.3{\mu}m$, $4.9{\mu}m$, respectively. Those were significantly smaller than the particle sizes in other industries(p<0.05). 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). Concentrations of lead particles smaller than $1{\mu}m$ defined as respirable fraction by OSHA's CPA model assumption were $72.4{\mu}g/m^3$ in the secondary smelting industry, exceeding $50{\mu}g/m^3$. The relationship of concentrations between total lead and lead of particles smaller than $1{\mu}m$ was log Y = 0.46 logX + 0.06(n=119, $r^2=0.44$, p=0.0001). Relationship of respirable lead concentrations between OSHA and ACGIH was significantly detected in the litharge and battery manufacturing industry(p=0.0001), but was not significant in the radiator(p=0.2720) and secondary smelting manufacturing industry(p=0.2394). As MMDs of lead particles generated in industry were small, difference of respirable lead concentration between OSHA and ACGIH became smaller. There was a significant difference between concentrations respirable lead defined by two organizations such as OSHA and ACGIH in the battery and litharge manufacturing industry. Average concentration of respirable lead by ACGIH definition was 43.3 % of total lead in secondary smelting and 48.9 % in radiator manufacturing industry, and lower fractions were indicated in battery and litharge manufacturing industry. Relationships of total lead with IPM, TPM, and RPM were significant respectively(p=0.0001) and lead concentrations by particle size could be estimated using this relationship. Linear regression equation between total lead concentration(X) and ACGIH-RPM concentration(Y) was log Y = 0.76 log X - 0.40($r^2=0.89$, p=0.0001).

• Journal of Environmental Science International
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• v.25 no.8
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• pp.1065-1076
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• 2016

This study analyzes the $PM_{10}$ characteristics (particulate matter with aerodynamic diameter less than $10{\mu}m$), concentration, and emissions in eight large South Korean cities (Seoul, Incheon, Daejeon, Daegu, Gwangju, Ulsan, Busan, Jeju). The annual median of $PM_{10}$ concentration showed a decline of $0.02{\sim}1.97{\mu}g/m^3$ in the regions, except for Incheon, which recorded an annual $0.02{\mu}g/m^3$ increase. The monthly distribution levels were high in spring, winter, fall, and the summer, but were lower in summer for all regions except for Ulsan. These differences are thought to be due to the dust in spring and the cleaning effect of precipitation in summer. The variation in concentrations during the day (diurnal variation) showed that $PM_{10}$ levels were very high during the rush hour and that this was most extreme in the cities (10.00 and 18.00-21.00). The total annual $PM_{10}$ emissions analysis suggested that there had been a general decrease, except for Jeju. On-road mobile (OM) sources, which contributed a large proportion of the particulates in most regions, decreased, but fugitive dust (FD) sources increased in the remaining regions, except for Daegu. The correlation analysis between $PM_{10}$ concentrations and emissions showed that FD could be used as a valid, positive predictor of $PM_{10}$ emissions in Seoul (74.5% (p<0.05)), Dajeon (47.2% (p<0.05)), and Busan (59.1% (p<0.01)). Furthermore, industrial combustion (IC) was also a significant predictor in Incheon (61.7% (p<0.01)), and on-road mobile (OC) sources were a valid predictor in Daegu (24.8% (p<0.05)).

• Journal of Korean Society for Atmospheric Environment
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• v.33 no.6
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• pp.616-625
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• 2017

Measurements using five real-time particle samplers were compared to measurements using three NRM (National Reference Method system) filter-based samplers(Gravimetric method) at Incheon, Korea, between May and August, 2014. The purpose of this study was to suggest the quality assurance/quality control (QA/QC) method of each instrument for use in a real-time continuous particle sampler to measure the mass of airborne particles with an aerodynamic diameter less than $2.5{\mu}m$ ($PM_{2.5}$). Five real-time particle samplers of BAM1020, FH62C_14, TEOM, PM-711 and SPM-613 were evaluated by comparing its measured 23 hr average $PM_{2.5}$ concentrations with those measured with NRM filter-based samplers simultaneously. The parameters(e.g. Inlet heating condition, Slope factor, Film response, Intercept, Background, Span value) of the real-time samplers were optimized respectively by conducting test performance evaluation during 7 days in field sampling. For example, inlet heating temperature of TEOM sampler controls $35{\sim}40^{\circ}C$ to minimize the fluctuation of the real-time measurement data and background value of BAM1020 is the key factor affecting the accuracy of $PM_{2.5}$ mass concentration. We classified the $PM_{2.5}$ concentration according to relative humidity (80%) to identify water absorbed in aerosols by measuring the ${\beta}$-ray samplers(BAM1020, FH62C_14) and TEOM. ${\beta}$-ray samplers were not strongly affected by relative humidity that the difference of the average $PM_{2.5}$ concentration was about 5%. On the other hand, The TEOM sampler overestimated $PM_{2.5}$ mass concentration about 15% at low relative humidity (<80%).

• Journal of Korean Society of Environmental Engineers
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• v.30 no.10
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• pp.1006-1012
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• 2008

The effect of small and medium scale shipyard operations on environmental pollutions related with civil appeal of nearby residential areas was estimated. PM-10(particles with an aerodynamic diameter less than or equal to 10 $\mu$m) concentrations were higher, as the sampling sites were nearer from shipyards. PM-10 concentrations of sampling sites closer to shipbuilding companies were higher during the normal operation periods than on vacation at which only small works were done. The larger amount of dry deposition was observed as the sampling sites were closer to shipyards. The odor intensity was highly influenced by ambient temperature. Almost all odor intensities measured by air dilution sensory test went over the emission standard in summer. Odor properties measured by instrumental analysis were observed to exceed the emission standard enforced to the shipyards. Odor compounds such as ammonia, sulfur compounds and trimethylamine went over the standard. Concentrations of styrene and aldehydes were lower than the olfactory threshold. All equivalent sound levels measured at daytime except the value of SP-3 pont were in excess of the environmental standard. Almost all sound levels at nighttime in all measuring sites were higher than the environmental standard. The results of this study shows counterplans need to be established for reducing the civil appeal related pollutions in the research areas.

• Journal of Environmental Health Sciences
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• v.34 no.4
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• pp.300-310
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• 2008

In order to further determine the mass concentration and ion composition of size-segregated particulate matter (PM) during the non-Asian dust storm of spring, $PM_{2.5}$ (fine particle), $PM_{10-2.5}$ (coarse particle), and $PM_{over-10}$ (PM with an aerodynamic diameter larger than $10{\mu}m$) were collected using a MCI (multi-nozzle cascade impactor) sampler of a three-stage filter pack in the spring season of 2007 in the Iksan area. During the sampling period from 5 April to 21 April, a total of 34 samples for size-segregated PM were collected, and then measured for PM mass concentrations by gravimetric measurements and for water-soluble inorganic ion species by using ion chromatography. Average mass concentrations of $PM_{2.5}$, $PM_{10-2.5}$, $PM_{over-10}$ were $35.4{\pm}11.5{\mu}g/m^3$, $13.3{\pm}5.5{\mu}g/m^3$ and $9.5{\pm}4.7{\mu}g/m^3$, respectively. On average, $PM_{2.5}$ accounted for 74% of $PM_{10}$. Compared with the literature from other areas in Korea, the measured concentration of $PM_{2.5}$ were relatively high. Water-soluble inorganic ion fractions in $PM_{2.5}$, $PM_{10-2.5}$, and $PM_{over-10}$ were found to be 47.8%, 28.5%, and 14.7%, respectively. Among the water-soluble inorganic ion species, $SO_4^{2-}$, $NO_3^-$ and $NH_4^+$ were the main components in $PM_{2.5}$, while $NO_3^-$ dominantly existed in both $PM_{10-2.5}$ and $PM_{over-10}$. Non-seasalt $SO_4^{2-}$ (nss-$SO_4^{2-}$ and $NO_3^-$ were found to mainly exist as the neutralized chemical components of $(NH_4)_2SO_4$ and $NH_4NO_3$ in fine particles.

• Particle and aerosol research
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• v.14 no.4
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• pp.135-144
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• 2018

Based on a two-year measurement data, major sources for the ambient carbonaceous aerosols at the Anmyeon Global Atmosphere Watch (GAW) station were identified by using the Positive Matrix Factorization (PMF) model. The particulate matter less than or equal to $2.5{\mu}m$ in aerodynamic diameter (PM2.5) aerosols were sampled between June 2015 to May 2017 and carbonaceous species including ~80 organic compounds were analyzed. When the number of factors was 5 or 6, the performance evaluation parameters showed the best results, With 6 factor case, the characteristics of transported factors were clearer. The 6 factors were identified with various analyses including chemical characteristics and air parcel movement analysis. The 6 factors with their relative contributions were (1) anthropogenic Secondary Organic Aerosols (SOA) (10.3%), (2) biogenic sources (24.8%), (3) local biomass burning (26.4%), (4) transported biomass burning (7.3%), (5) combustion related sources (12.0%), and (6) transported sources (19.2%). The air parcel movement analysis result and seasonal variation of the contribution of these factors also supported the identification of these factors. Thus, the Anmyeon Island GAW station has been affected by both regional and local sources for the carbonaceous aerosols.

• Journal of Ginseng Research
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• v.47 no.1
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• pp.81-88
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• 2023

Background: Air pollution has led to an increased exposure of all living organisms to fine dust. Therefore, research efforts are being made to devise preventive and therapeutic remedies against fine dust-induced chronic diseases. Methods: Research of the respiratory protective effects of KRG extract in a particulate matter (PM; aerodynamic diameter of <4 ㎛) plus diesel exhaust particle (DEP) (PM4+D)-induced airway inflammation model. Nitric oxide production, expression of pro-inflammatory mediators and cytokines, and IRAK-1, TAK-1, and MAPK pathways were examined in PM4-stimulated MH-S cells. BALB/c mice exposed to PM4+D mixture by intranasal tracheal injection three times a day for 12 days at 3 day intervals and KRGE were administered orally for 12 days. Histological of lung and trachea, and immune cell subtype analyses were performed. Expression of pro-inflammatory mediators and cytokines in bronchoalveolar lavage fluid (BALF) and lung were measured. Immunohistofluorescence staining for IRAK-1 localization in lung were also evaluated. Results: KRGE inhibited the production of nitric oxide, the expression of pro-inflammatory mediators and cytokines, and expression and phosphorylation of all downstream factors of NF-κB, including IRAK-1 and MAPK/AP1 pathway in PM4-stimulated MH-S cells. KRGE suppressed inflammatory cell infiltration and number of immune cells, histopathologic damage, and inflammatory symptoms in the BALF and lungs induced by PM4+D; these included increased alveolar wall thickness, accumulation of collagen fibers, and TNF-α, MIP2, CXCL-1, IL-1α, and IL-17 cytokine release. Moreover, PM4 participates induce alveolar macrophage death and interleukin-1α release by associating with IRAK-1 localization was also potently inhibited by KRGE in the lungs of PM4+D-induced airway inflammation model. KRGE suppresses airway inflammatory responses, including granulocyte infiltration into the airway, by regulating the expression of chemokines and inflammatory cytokines via inhibition of IRAK-1 and MAPK pathway. Conclusion: Our results indicate the potential of KRGE to serve as an effective therapeutic agent against airway inflammation and respiratory diseases.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1235-1241
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• 2003

Purpose : We assessed the dynamic characteristics of 16 nebulizer/compressor combinations currently available in Korea. Methods : The 16 nebulizer/compressor combinations(Pariboy Type 38/Long life, Pariboy Type N/Long life, Pariboy Type N/Salter 8900, Pariboy Type N/LC, Devilbiss pulmoaid-LT/Hudson, Devilbiss pulmoaid/Hudson, Mesmed neb-300/Own, San-up 3040/Hudson, Midas(Basic)/Own, AirJolie 2/Hudson, Thomas 1127/Salter 8900, Noel NE-2000/Salter 8900, Omron CX3/Hudson, Chang Woo CWN-100/Salter 8900, Voyage/Mefar, Chang Woo ASI-Pro/Medel jet pulse) were evaluated in terms of particle size and mass output. In addition, we determined the effects of nebulizer fill volume on mass output. Results : Pariboy Type N/Long life has the highest respirable mass of 0.184 mg/min and Mesmed Neb-300/Own has the lowest 0.019 mg/min. Pariboy Type N/Long life has the highest mass output of 0.68 mg/min and the shortest mass median aerodynamic diameter(MMAD) of $3.76{\mu}m$. All combinations other than Pariboy Type N/Long life produced a MMAD of over $5{\mu}m$. MMAD over a 5 min nebulization ranged 3.76 to $9.83{\mu}m$. There were no significant effects of fill volume on mass output. Conclusion : We concluded that there is a wide variation in performance of nebulizer/compressor combinations. The characteristics of nebulizer/compressor combinations should be considered in selecting products.