• Proceedings of the Korea Air Pollution Research Association Conference
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• 2008.04a
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• pp.139-141
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• 2008

• Journal of Environmental Science International
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• v.25 no.10
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• pp.1349-1368
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• 2016

Concentrations of fine particulate matter ($PM_{2.5}$) and several of its particle constituents measured outside homes in Houston, Texas, and Los Angeles, California, were characterized using multiple regression analysis with proximity to point and mobile sources and meteorological factors as the independent variables. $PM_{2.5}$ mass and the concentrations of organic carbon (OC), elemental carbon (EC), benzo-[a]-pyrene (BaP), perylene (Per), benzo-[g,h,i]-perylene (BghiP), and coronene (Cor) were examined. Negative associations of wind speed with concentrations demonstrated the effect of dilution by high wind speed. Atmospheric stability increase was associated with concentration increase. Petrochemical source proximity was included in the EC model in Houston. Area source proximity was not selected for any of the $PM_{2.5}$ constituents' regression models. When the median values of the meteorological factors were used and the proximity to sources varied, the air concentrations calculated using the models for the eleven $PM_{2.5}$ constituents outside the homes closest to influential highways were 1.5-15.8 fold higher than those outside homes furthest from the highway emission sources. When the median distance to the sources was used in the models, the concentrations of the $PM_{2.5}$ constituents varied 2 to 82 fold, as the meteorological conditions varied over the observed range. We found different relationships between the two urban areas, illustrating the unique nature of urban sources and suggesting that localized sources need to be evaluated carefully to understand their potential contributions to $PM_{2.5}$ mass and its particle constituents concentrations near residences, which influence baseline indoor air concentrations and personal exposures. The results of this study could assist in the appropriate design of monitoring networks for community-level sampling and help improve the accuracy of exposure models linking emission sources with estimated pollutant concentrations at the residential level.

• Environmental Engineering Research
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• v.23 no.3
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• pp.265-270
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• 2018

This study was to measure the exposure of diesel vehicle drivers to elemental carbon (EC) as an indicator of diesel particulate matter (DPM) emitted from diesel vehicles in an underground coal mine over 3 years as per NIOSH Method 5040. Our study results (range $10{\mu}g/m^3-377{\mu}g/m^3$ for the loader drivers, $19{\mu}g/m^3-162{\mu}g/m^3$ for the SMV drivers) were similar or less than previous study results (range $5{\mu}g/m^3-2,200{\mu}g/m^3$) for normal mine operations. From this study results, it appeared that the exposures decreased in the second and the third year. It is thought that the reasons for the decreased personal DPM (EC) exposures over the 3 years were related to the following recommendations; more frequent monitoring and maintenance of the diesel vehicles and their DPM filtration systems, more consistent monitoring of the mine's ventilation system and changes of work practices such as minimizing the opening of diesel vehicle windows. An educational program on adverse health effects of exposure to DPM and use of respiratory protection (P2 respirators) also assisted in minimizing driver exposure to DPM.

• Journal of the Korean Society of Safety
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• v.35 no.6
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• pp.9-14
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• 2020

This study was to compare the sampling efficiencies for monitoring of diesel particulate matter (DPM) using two different sampling methods; In-House PVC cyclone sampling heads and commercial airborne DPM (EC) sampling heads mounted on Dorr-Oliver cyclone heads. Personal exposure levels of DPM, analysed for elemental carbon (EC) were 0.004 - 0.2 mg/m³ for the loader drivers and 0.005 - 0.34 mg/m³ for the specialised mining vehicle (SMV) drivers were similar to previous study results. The highest result (0.34 mg/m³) might be from an irregular production schedule and multiple job tasks requested. The results using the two sampling heads were not significantly different and it is thought that the In-House PVC cyclone with 37 mm quartz filter could be used in place of the commercial sampler as a preliminary screen in place of using the commercial sampler.

• Atmosphere
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• v.25 no.1
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• pp.141-148
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• 2015

Recently increased anthropogenic aerosols change the radiative energy balance and affect human life. The management of air quality requires monitoring both the local emissions and transported pollutants. In order to estimate the quantitative contribution of long-range transport from remote sources on aerosol concentrations in Seoul, the airmasses were classified into five types with respect to their pathways. When airmass came from west over strong emission regions in China, high concentrations of $PM_{10}$, $PM_{2.5}$, black carbon (BC), organic carbon (OC), and elemental carbon (EC) were found, even higher than those for the stagnated airmass. High OC concentrations were found when airmass came from north while BC, EC, and $PM_{2.5}$ concentrations were lower than those of the stagnated airmasses. During dust events, the $PM_{2.5}$ and $PM_{10}$ concentrations increased significantly while carbonaceous aerosol concentrations did not increased. The temporal variations of aerosol concentrations in Seoul were affected by the seasonal variations of airmass pathways. The high $PM_{2.5}$ concentrations over $100{\mu}g\;m^{-3}$ appeared most frequently when the airmasses came from west.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.6
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• pp.571-578
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• 2009

$PM_{2.5}$ black carbon (BC) concentrations were measured to investigate the filter spot loading effect in raw BC data at 5-minute time-based resolution using a single-wavelength aethalometer at a Gwangju site. Also the elemental carbon (EC) concentrations from 24-hr integrated filter-based measurements of $PM_{2.5}$ particles were determined to compare with the loading compensated BC values. Close examination of the time-series BC data showed clearly the "gaps" when the filter tape advances, suggesting the correction of raw BC data. Therefore, we calculated the average BC concentration in each range of attenuation (ATN) to decide if there was (or was not) an effect on the aethalometer data according to the loading of the filter spot. A consistent decrease of average BC concentration was found with increasing ATN values for every month, suggesting there was a consistent "spot loading effect" in the raw BC data. The loading compensated BC concentration according to a simple compensation model with loading effect was 1.01~1.15 times greater than the raw BC data. The 24-hr average concentration of EC observed during summer sampling period was about 3% higher than the original 24-hr average BC value and 2% lower than the loading compensated BC concentration.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.1
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• pp.131-140
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• 2005

To investigate secondary carbonaceous species within PM$_{10}$ and PM$_{2.5}$ in Seoul urban Metropolitan Area (SMA), Korea. atmospheric particulate matters samples were collected at two sites of SMA at UOS (The University Of Seoul station) sites and IHU (InHa University of Incheon station) during the period of 4 to 14 January and 12 to 22 May, 11 to 15 August 2004, and their characteristics were qualitatively discussed. during January and May and August of 2004. Daily average mass concentration 0.095 mg/㎥ in PM$_{10}$ and 0.053 mg/㎥ in PM$_{2.5}$ for mass respectively. were observed in SMA. The concentrations of carbonaceous species contributed 18.4% and 16.4% of PM$_{2.5}$ and PM$_{10}$ during the sampling period, respectively, of which OC accounted for 68% and 52% more of the total carbon (TC). OC and EC concentrations and their mass percentages were higher in PM$_{2.5}$ than in PM$_{10}$ which could be attributed to generation process. Organic aerosols would constitute up to 38% of PM$_{2.5}$ based on the evaluation of 1.6 for the ratio of OC to organic particulate. Secondary organic carbon (SOC) were estimated to be more than 13% and up to 68% of total OC based on the minimum OC/EC ratio of 1.06/1.11 using least square method. Comparisons of OC and EC with trace elements. As results of carbonaceous species analysis, the dominant factor in view of fine particle (PM$_{10}$/PM$_{2.5}$) is primary emission source such as mobile, fossil fuel combustion etc. during winter time in SMA. But in summer periods, remarkable fine particle increasing factor was secondary organic carbon dependent to photochemical reaction. reaction.n. reaction.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.1
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• pp.21-31
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• 2016

Organic carbon (OC) and elemental carbon (EC) in $PM_{2.5}$ were measured with Sunset OC/EC Field Analyzer at Taehwa Research Forest (TRF) near Seoul metropolitan area from May 2013 to April 2014. During the study period, the mean concentrations of OC and EC were $5.0{\pm}3.2{\mu}gC/m^3$ and $1.7{\pm}1.0{\mu}gC/m^3$, respectively. They showed clear seasonality reaching their maximum in winter ($6.5{\mu}gC/m^3$ and $1.9{\mu}gC/m^3$) and minimum in wet summer ($2.5{\mu}gC/m^3$ and $1.4{\mu}gC/m^3$). While OC showed greater seasonal variation, the diurnal variation was more noticeable for EC through all seasons with a clear maximum in the morning, which reveals the influence of vehicle emissions. In contrast, OC exhibited a broad second peak in the afternoon during May~June, when biological activities were the highest. Using the morning peaks of EC and OC, primary OC/EC ratio was assessed, which was assumed to be anthropogenic origin. It was the greatest in winter followed by spring and the lowest in wet summer. The seasonal difference in primary OC/EC ratio implies the influence of non-local sources of OC at the Mt. Taehwa.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.4
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• pp.309-316
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• 2000

Chemical compositions of air pollutants with fine particles (<2.5 ${\mu}{\textrm}{m}$, PB2.5) were evaluated at background site. Kangwha. in Korea during the winter season. The data set was obtained for seventeed days with 24-hour sampling from December 11 to 16, 1996 and from January 9 to 1997. The chemical species have been measured {{{{ {SO }`_{4 } ^{2- } }}}}, {{{{ { NO}`_{3 } ^{- } }}}}, {{{{ { NH}`_{4 } ^{+ } }}}}. OC and EC in the particulate phase, NH3 HNO3, HCl and SO2 in the gas phase using the three stage filter pack method. Mean concentration ($\mu\textrm{g}$/m3) of this study were : 35.42 for PM2.5 8.78 for organic carbon (OC) 7.25 for nss {{{{ {SO }`_{4 } ^{2- } }}}}, 4.94 for {{{{ { NO}`_{3 } ^{- } }}}}, 3.58 for {{{{ { NH}`_{4 } ^{+ } }}}} and 1.48 for elemental carbon (EC) respectively. Contributive rates of major particulate components in PM2.5 were OC (25%) nss- {{{{ {SO }`_{4 } ^{2- } }}}}(20%) ,{{{{ { NO}`_{3 } ^{- } }}}}(14%) {{{{ { NH}`_{4 } ^{+ } }}}}(10%) and EC (4%) respectively and these components could be accounted for 73% of PM2.5 mass. Reactive forms of {{{{ { NH}`_{4 } ^{+ } }}}} were considered as NH4HO3 and NH4{{{{ {SO }`_{4 } ^{2- } }}}} during the sampling periods. {{{{ { NO}`_{3 } ^{- } }}}}/({{{{ { NO}`_{3 } ^{- } }}}} + HNO3) and {{{{ {SO }`_{4 } ^{2- } }}}}/({{{{ {SO }`_{4 } ^{2- } }}}} + SO2) were calculated 0.8 and 0.9 respectively. Most of these compounds might be formed in partiiculate phase in the air. Correlation coefficient between OC and EC was 0.866 which might have the same sources during the sampling periods,.

• Atmosphere
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• v.29 no.4
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• pp.429-438
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• 2019

Organic carbon (OC) and elemental carbon (EC) in PM_2.5 were measured with Sunset Laboratory Model-5 Semi-Continuous OC/EC Field Analyzer by NIOSH/TOT method at Anmyeondo Global Atmosphere Watch (GAW) Regional Station (37°32'N, 127°19'E) in July and August, 2017. The mean values of OC and EC were 3.7 ㎍ m^-3 and 0.7 ㎍ m^-3, respectively. During the study period, the concentrations of reactive gases and aerosol compositions were evidently lower than those of other seasons. It is mostly due to meteorological setting of the northeast Asia, where the influence of continental outflow is at its minimum during this season under southwesterly wind. While the diurnal variation of OC and EC were not clear, the concentrations of O₃, CO, NOx, EC, and OC were evidently enhanced under easterly wind at night from 20:00 to 8:00. However, the high concentration of EC was observed concurrently with CO and NOx under northerly wind during 20:00~24:00. It indicates the influence of thermal power plant and industrial facilities, which was recognized as a major emission source during KORUS-AQ campaign. The diurnal variations of pollutants clearly showed the influence of land-sea breeze, in which OC showed good correlation between EC and O₃ in seabreeze. It is estimated to be the recirculation of pollutants in land-sea breeze cycle. This study suggests that in general, Anmyeondo station serves well as a background monitoring station. However, the variation in meteorological condition is so dynamic that it is primary factor to determine the concentrations of secondary species as well as primary pollutants at Anmyeondo station.