• Asian Journal of Atmospheric Environment
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• v.5 no.1
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• pp.21-28
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• 2011

Occupational nanomaterial exposure is an important issue in the manufacture of such products. People are also exposed to various nanoparticles in their living environments. In this study, we investigated nanoparticle formation during the reaction of ozone and volatile organic compounds (VOCs) emitted from a commercial air freshener, one of many widely used consumer products, in a $1-m^3$ reaction chamber. The air freshener contained various VOCs, particularly terpenes. A petri dish containing 0.5 mL of the air freshener specimen was placed in the bottom of the chamber, and ozone was continuously injected into the center of the chamber at a flow rate of 4 L/min with an ozone concentration of either 50, 100 or 200 ppb. Each test was conducted over a period of about 4 h. The higher ozone concentrations produced larger secondary nanoparticles at a faster rate. The amount of ozone reacted was highly correlated with the amount of aerosol formation. Ratios of reacted ozone concentration and of formed particle mass concentration for the three injected ozone concentrations of 50, 100 and 200 ppb were similar to one other; 4.6 : 1.9 : 1.0 and 4.7 : 2.2 : 1.0 for ozone and aerosol mass, respectively.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.87-100
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• 2018

Fast economic growth and urbanization of China have been causing air pollution not only over its domestic but transboundary atmosphere. Recent high fine particle pollution episodes in China made the government move toward more stringent air pollution control policies - which are mostly fuel switching and emissions control. In this research, we tried to understand characteristics of Chinese emissions and their change by analyzing its emissions inventory by year, sector, and region. From the inter-comparison of existing bottom-up emission inventories, we found relatively good agreements (<20% difference) for $SO_2$ and $NO_x$, but 30% or more discrepancies for some pollutants. Inter-comparison with top-down $NO_x$ emissions estimates also showed 20~50% differences by year. The regional distribution and inter-annual changes of emissions revealed different stages of energy/fuel mix and policy penetration. Early increase of pollutants emissions in the eastern part of China might give strong influences to the Korean peninsular in early 2000s but, more stringent control in that region would help improving air pollution in Korea in near future.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.3
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• pp.263-273
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• 2003

P $M_{2.5}$ fine particles have been collected at the Cosan measurement station in Jeju Island, and the major water-soluble components have been analyzed in order to Investigate the aerosol compositions and pollution characteristics. The mean concentrations of the components were in the order of S $O_4$$^{2-}$> N $H_4$$^{+}$> N $O_3$$^{[-10]}$ > N $a^{+}$> $K^{+}$>C $l^{[-10]}$ >C $a^2$$^{+}$>M $g^2$$^{+}$. The major components were S $O_4$$^{2-}$, N $H_4$$^{+}$ and N $O_3$$^{[-10]}$ , whose compositions were 58％, 18％ and 10％ of the total ions, respectively. Most of the components showed higher concentrations in spring season, and especially $Ca^2$$^{+}$, N $O_3$$^{[-10]}$ and S $O_4$$^{2-}$ concentrations were increased 2.8, 1.9 and 1.2 times higher than the annual mean concentrations. The most parts of S $O_4$$^{2-}$ and N $H_4$$^{+}$ were distributed in fine particles below 2.1 ${\mu}{\textrm}{m}$ size, but the $Ca^2$$^{+}$, N $a^{+}$ and C $l^{[-10]}$ showed relatively higher concentrations in coarse particles. Based on the factor analysis, the P $M_{2.5}$ fine particles were considered to be largely influenced by anthropogenic sources, and followed by sea salt and soil sources. In the variations of concentrations as a function of wind direction, most components have shown higher concentrations notably as the northwesterly prevails.thwesterly prevails.

• Journal of Korean Society for Atmospheric Environment
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• v.10 no.2
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• pp.90-97
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• 1994

PIXE( Proton Induced X- ray Emission ) analysis has been applied to the analysis of aerosol for the Purpose of pollution monitoring. Coarse and fine Particle fractions were sampled selectively, using Nuclepore filter in stacked filter units, once a month from February to September in 1993 at urban and rural sites. Concentration of 9 elements, Si, S, K, Ca, Mn, Fe, Cu, Zn and Pb was determined without Pretreatment of Samples. Comparison of data between urban and rural site revealed higher elemental concentration level in urban aerosol. From April to May aerosol sampling was carried out daily to observe the effect of Yellow Sand on the composition of aerosol in the Korean Peninsula. During the Yellow Sand period, Si, Ca, Fe content level in aerosol became more than 5 times higher than normal. The elemental concentration of the aerosol samples of Daejeon City was compared with that of two foreign cities. S and Pb( which are fuel- derived elements) levels in Daejeon City aerosol appeared to be lower than those of foreign cities. And it may be due to the leaded-fuel restriction policy of Korean government since 1987.

• Asian Journal of Atmospheric Environment
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• v.7 no.1
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• pp.38-47
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• 2013

$PM_{10}$ concentrations were measured at four monitoring sites at the Daechaung station of the Seoul subway. The four locations included two tunnels, a platform, and a waiting room. The outside site of the subway was also monitored for comparison purposes. In addition, the effect of the platform screen doors (PSDs) recently installed to isolate the $PM_{10}$ in a platform from a tunnel were evaluated, and a comparison between $PM_{10}$ levels during rush and non-rush hours was performed. It was observed that $PM_{10}$ levels in the tunnels were generally higher than those in the other locations. This might be associated with the generation of $PM_{10}$ within the tunnel due to the train braking and wear of the subway lines with the motion of the trains, which promotes the mixing and suspension of particulate matter. During this tunnel study, it was observed that the particle size of $PM_{10}$ ranged from 1.8 to 5.6 ${\mu}m$. It was revealed that the $PM_{10}$ levels in the tunnels were significantly increased by the PSDs, while those in the platform and waiting room decreased. As a result, in order to estimate the effect of ventilation system on $PM_{10}$ levels in the tunnels, fans with inverters were operated. It was found that the concentration of $PM_{10}$ was below 150 ${\mu}g/m^3$ when the air flow rate into a tunnel was approximately 210,000-216,000 CMH.

• Journal of Environmental Science International
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• v.16 no.10
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• pp.1157-1167
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• 2007

In an effort to interpret the characteristics of fine particle concentrations in Busan, time variations of hourly monitored concentrations $PM_{10}$ (Particulate Matter with aerodynamic Diameter ${\le}10\;{\mu}m$) in Busan are analyzed for the period from 2000 to 2005. The characteristics of aerosol second generation formation process is also interpreted qualitatively, by using the statistical analysis of the meteorological variables including temperature, wind speed, and relative humidity. The result shows some significant annual, seasonal, weekly and diurnal variations of $PM_{10}$ concentrations. In particular, seasonal(i.e., spring) variations are governed by frequency of yellow sand events even for the non-yellow sand cases where yellow-sand days are eliminated in our analysis. However, in seasonal variation, summer season predominate lower $PM_{10}$ concentrations due to the frequent precipitation, and weekly and diurnal variations are both found to be reflecting the emission rate from traffic amount. Correlation coefficients between $PM_{10}$ concentration and meterological variables for non-yellow sand days show overall negative correlation with visibility, wind speed, cloud amounts, and relative humidity. However for non-precipitation days, during non-yellow sand period positive correlation are found clearly with relative humidity, suggesting the importance of secondary aerosol formation in Busan that can be achieved by both homogeneous aerosol formation and heterogeneous transformations resulting from hygroscopic aerosol characteristics.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.4
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• pp.426-435
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• 2011

In this study, PM emission factors for commercial meat cooking were developed by the experiment using the similar restaurant model. The commercial material types of meat cooking were beef, pork and duck. And meat cooking materials were classified with marinated and raw cooking methods. The marinated and raw cooking methods were flat griddle (LPG) and under fired charbroiling grill. As a results, $PM_{10}$ emission factors for underfired pork cooking was estimated as 7.39 g/kg-meat which was the highest value in this study. The emission factors of under fired charbroiling grill method were higher than that of flat griddle method regardless of meat cooking material types and marinated meat. The particle size distribution of meat cooking was 0.23~5 ${\mu}m$ and median diameter was 2~2.5 ${\mu}m$.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.1
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• pp.30-42
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• 2008

In this study, the chemical compositions of $PM_{2.5}$ samples collected at the Redwood National Park IMPROVE site in California from March 1988 to May 2004 were analyzed to provide source identification and apportionment. A total of 1,640 samples were collected and 33 chemical species were analyzed by particle induced X-ray emission, proton elastic scattering analysis, photon induced X-ray fluorescence, ion chromatography, and thermal optical reflectance methods. Positive matrix factorization (PMF) was used to develop source profiles and to estimate their mass contributions. The PMF modeling identified five sources and the average mass was apportioned to motor vehicle (35.8%, $1.58\;{\mu}g/m^3$), aged sea salt (23.2%, $1.02\;{\mu}g/m^3$), fresh sea salt (21.4%, $0.94\;{\mu}g/m^3$), wood/field burning (16.1%, $0.71\;{\mu}g/m^3$), and airborne soil (3.5%, $0.15\;{\mu}g/m^3$), respectively. To analyze local source impacts from various wind directions, the CPF and NPR analyses were performed using source contribution results with the wind direction values measured at the site. These results suggested that sources of $PM_{2.5}$ are also sources of visibility degradation and then source apportionment studies derived for $PM_{2.5}$ are also used for understanding visibility problem.

• Korean Journal of Remote Sensing
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• v.30 no.5
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• pp.559-570
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• 2014

Backscatter signal observed from the space-borne Light Detection And Ranging (LIDAR) system is providing unique 3-dimensional spatial distribution as well as temporal variations for atmospheric aerosols. In this study, the continuous observations for aerosol profiles were analyzed during a years of 2012 by using a Cloud-Aerosol LIDAR with Orthogonal Polarization (CALIOP), carried on the Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) satellite. The statistical analysis on the particulate extinction coefficient and depolarization ratio for each altitude was conducted according to time and space in order to estimate the variation of optical properties of aerosols over Northeast Asia ($E110^{\circ}-140^{\circ}$, $N20^{\circ}$ $-50^{\circ}$). The most frequent altitudes of aerosols are clearly identified and seasonal mean aerosol profiles vary with season. Since relatively high particle depolarization ratios (>0.5) are found during all seasons, it is considered that the non-spherical aerosols mixed with pollution are mainly exists over study area. This study forms initial regional 3-dimensional aerosol information, which will be extended and improved over time for estimation of aerosol climatology and event cases.

• Journal of the Korean earth science society
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• v.33 no.3
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• pp.259-268
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• 2012

To investigate the fluctuation of marine aerosol number concentration at each different size with vertical winds in ocean area, aerosol particles and vertical wind components were measured in the Ieodo Ocean Research Station, which is located to 419 km southwest of Marado, the southernmost island of Korea, from 8 to 22 June 2009. The Laser Particle Counter (LPC) and ultrasonic anemometer were used to measure the number of aerosol particles and vertical wind speed. Surface weather chart, NCEP/NCAR reanalysis data and sounding data were used to analyze the synoptic condition. The distribution of aerosol number concentration had a large fluctuation of bigger particles more than 1.0 ${\mu}m$ in diameter by vertical wind speed during precipitation. The aerosol particles larger than 1.0 ${\mu}m$ in diameter increased as the wind changed from downward to upward during precipitation. The aerosol number concentration of bigger size than 1.0 ${\mu}m$ in diameter increased about 5 times when vertical velocity was about 0.4 $ms^{-1}$. In addition, the accumulation and coarse mode aerosol number concentration decreased about 45% and 92%, respectively compared to concentrations during precipitation period. It is considered that vertical wind plays an important role for the increasing of coarse mode aerosol number concentration compared to the large aerosol particles sufficiently removed by the scavenging effect of horizontal winds. Therefore, the upward vertical winds highly contribute to the formation and increase in aerosol number concentration below oceanic boundary layer.