Exposure to Fine Particle along Different Commuting Routes in Urban Area of Fukuoka, Japan

마창진 한국대기환경학회 2015 Asian Journal of Atmospheric Environment (AJAE) Vol.9 No.3

The objective of the current study was to assess the comparative risk associated with exposure to particulate matter (PM) while commuting via different public transport modes in Fukuoka, Japan. For the given routes and measuring days, a trip-maker carried a lightweight portable bag loaded the real-time measurement devices which take simultaneous measurement for size-fractioned particle number concentration, PM2.5 mass concentration, and total suspended particle (TSP) collection. The results of the present study have shown significant differences between public transports as commuting modes in Fukuoka. The PM exposure levels on subway platform and inside subway train were overwhelmingly higher than those of other points on commuting route. The relative ratio between modes (i.e., the ratio of PM2.5 inside subway to that inside bus) provides an idea for choosing a right commuting mode for our health. This study clearly provided evidence of the extremely high levels of iron exposure by subway uses compared to bus uses. The result of theoretically reconstructed mass concentration of PM2.0-0.3 collected on subway platform suggests that the PM of underground subway will be associated with PM both generated in subway system and inleakaged from outdoor environment.

A Combination of the Frozen Raindrop Collection Method and High-performance Capilary Electrophoresis Technique for the Size-resolved Raindrops Study

마창진 한국대기환경학회 2006 한국대기환경학회지 Vol.22 No.E1

Although the importance of size-resolved raindrops study has been known, it has not been popularized up-resolved raindrops study by acombination of the frozen raindrop collection method and a commercially available high-performancecapillary electrophoresis (HPCE). Samplings were carried out at Kyoto, Japan in October 2002. Theinorganic ions (chloride, nitrate, sulphate, calcium, ammonium, sodium, magnesium, potassium) in size-accuracy and precision of HPCE data, t-test was conducted with paired analytical data, which wereexperimentally constructed by analyzing standard solutions with HPCE and IC, respectively. T-test showedthat there is no notable difference between the concentrations determined by the two analytical methods.there was slight increase of sodium and sulphate concentrations between 0.85 mm and 1.15 mm raindropradius, it showed a strong decrease for every ionic component with increasing droplet radius. The combina-tion of the frozen raindrop collection method and a commercially available HPCE can meet the need of size-resolved raindrops study.

Preliminary Study on the Visualization and Quantification of Elemental Compositions in Individual Microdroplets using Solidification and Synchrotron Radiation Techniques

마창진,Susumu Tohno,Mikio Kasahara 한국대기환경학회 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.1

Quantifying the solute composition of a cloud droplet (or a whole droplet) is an important task for understanding formation processes and heating/cooling rates. In this study, a combination of droplet fixation and SR-XRF microprobe analysis was used to visualize and quantify elements in a micro-scale droplet. In this study, we report the preliminary outcome of this experiment. A spherical micro-scale droplet was successfully solidified through exposure to α-cyanoacrylate vapor without affecting its size or shape. An X-ray microprobe system equipped at the beam line 37XU of Super Photon ring 8 GeV (SPring-8)was applied to visualize and quantify the elemental composition in an individual micro-scale droplet. It was possible to reconstruct 2D elemental maps for the K and Cl contained in a microdroplet that was dispensed from the 10-ppm KCl standard solution. Multi-elemental peaks corresponding to X-ray energy were also successfully resolved. Further experiments to determine quantitative measures of elemental mass in individual droplets and high-resolution Xray microtomography (i.e., 3D elemental distribution)are planned for the future.

Particulate Matter in the Korea Train eXpress (KTX) Cabin and its Exposure

마창진,강공언 한국대기환경학회 2022 Asian Journal of Atmospheric Environment (AJAE) Vol.16 No.3

This study aims to assess the particulate matter (PM1, PM2.5, PM10) and black carbon (BC) in the Korea Train eXpress (KTX) cabin during train running, and the personal exposure of PM2.5 for the female/male passengers who use the KTX 20 days a month to commute. Intensive measurements were made on the day when the outside ambient PM concentration was much higher than usual. To compare with the PM concentration in the subway cabin, a measurement was also performed in some sections of the Seoul Metro subway (from Namyoung Station (hereafter referred to as the “Sta.”) to Jonggak Sta.). The amount of PM2.5 exposure (Exposure PM2.5 (μg)) was calculated for the male/female passengers who regularly board the KTX. The Car-exposure PM2.5 (μg), which is the amount of PM2.5 exposure when moving by car in the same section, was also calculated. The PM concentration in the KTX cabin elevated and fallen off at train staying and train running, respectively. The PM2.5 concentrations inside KTX cabin at the stop station exhibited a remarkable positive correlation with those of outdoor. Compared to the PM concentration measured in the cabin of Seoul Metro subway, PM1, PM2.5, and PM10 in the KTX passenger cabin were 74.9%, 73.3%, and 62.7% of those in the cabin of Seoul Metro subway, respectively. The PM2.5 exposure amount (exposure PM2.5 (μg)) when moving the same section using the KTX and passenger cars was calculated, and as a result, the exposure PM2.5 (μg) for both male and female were 5.7 times lower in the KTX than that in car. The mapping result of BC concentration drawn on the KTX line from Iksan Sta. to Gwangmyeong Sta. shows that it fluctuated greatly for each service section or stop station.

Laboratory-scale Experiment and Model Calculation on the Washout Mechanism of Asian Dust Particles

마창진,김기현 한국대기환경학회 2013 Asian Journal of Atmospheric Environment (AJAE) Vol.7 No.3

In this study, an investigation was conducted to assess the washout mechanism of Asian dust particles through both laboratory-scale experiment and model calculation. To artificially simulate Asian dust particle, CaCO3 particles were generated inside an experimental chamber. They were then scavenged by the artificial rain drops. The abundant CaCO3 particles scavenged on a rain drop were successively identified by SEM observation. The concentrations of Ca in residual CaCO3 particles on individual droplet were quantified by PIXE analysis. There was a tendency toward a high accumulation of Ca on a relatively small drop (e.g., ⁄1.0 mm diameter). It is thus suggested that smaller rain drops can effectively scavenge a significant amount of Asian dust particles in ambient atmosphere. The numerical estimation can account for 92.1% and 83.2% of Ca that were measured in small (⁄1.0 mm diameter) and large (¤2.0mm diameter) size drops, respectively.

Development of Acid Rain Model Instrument and Its Application in Environmental Education

마창진,신은상 한국대기환경학회 2015 Asian Journal of Atmospheric Environment (AJAE) Vol.9 No.3

The environmental education with ideal teaching tools (e.g., a small-scaled experimental kit) is essential for raising the public’s, especially student’s, awareness of many environmental issues. This study was undertaken to develop a do-it-yourself model instrument of acid rain and estimating its applicability to the environmental education. Our novel model tool consists of a body (17 cm width, 6 cm depth, and 17 cm height), an acid gas injector, acid four rain reservoirs, and a drop supply pump. An alternative model instrument that can be more readily assembled was also suggested. Based on our novel approach, we carried out several model experiments with educatees (i.e., high school and college students, and adults). The results of questionnaires indicated that educatees achieved a very deep understanding of acid rain through an experienced model experiment. A 77 to 89% of educatees experienced the reappearance experiment of acid rain by our model instrument felt that it was very useful as a teaching tool of environmental education.

Cloud Generation Using a Huge Vertical Mine

마창진 한국대기환경학회 2006 한국대기환경학회지 Vol.22 No.E2

In order to study the characteristics of cloud, a real-scale experiment for cloud generation was carried outusing an extinct vertical mine (430 m height) located in the northeastern Honshu, Japan. The dry particlesgenerated from the three-step concentrations of NaCl solutions were used for cloud generation. The numberSizer (SMPS) and Forward Scattering Spectrometer Probe (FSSP) at bottom and upper sites of pit,respectively. The polymeric water absorbent lm (PWAF) method was employed to measure liquid watercontent (WL) as a function of droplet size. Moreover the chemical properties of individual droplet replicaswere determined by micro-PIXE. The CCN number concentration shows the lognormal form in dependencem and 20m for every case. In comparison to background mineral particles, right shifting of size distri-bution line for NaCl particles was occurred. When NaCl solutions with three-step different concentrationswere nebulized, WLshows the strong droplet size dependence. It varied from 10.0mg m-3 up to 13.6mg m-3with average 11.6 mg m-3. A good relationship between WL and cloud droplet number concentration wasobtained. Both chemical inhomogeneities(mixed components with mineral and Cl) and homogeneities(onlymineral components or Cl) in individual droplet replicas were obviously observed from micro-PIXEelemental images.

Modeling Study on Dispersion and Scavenging of Traffic Pollutants at the Location Near a Busy Road

마창진 한국대기환경학회 2015 Asian Journal of Atmospheric Environment (AJAE) Vol.9 No.4

The information about the dispersion and scavenging of traffic-related pollutants at the locations near busy expressways is very helpful to highway planners for developing better plans to reduce exposures to air pollution for people living as well as children attending schools and child care centers near roadways. The objective of the current study was to give information in the dispersion and scavenging of vehiclederived pollutants at the region near a busy urban expressway by a combination of two different model calculations. The modified Gaussian dispersion model and the Lagrange type below-cloud scavenging model were applied to evaluate NOx dispersion and DEP (Diesel exhaust particles) wet removal, respectively. The highest NOx was marked 53.17 ppb within 20-30 meters from the target urban expressway during the heaviest traffic hours (08:00AM-09:00AM) and it was 2.8 times higher than that of really measured at a nearby ambient measuring station. The calculated DEP concentration in size-resolved raindrops showed a continuous decreasing with increasing raindrop size. Especially, a noticeable decrease was found between 0.2 mm and 1.0 mm raindrop diameter.

Chemical Properties of the Individual Asian Dust Particles Clarified by Micro-PIXE Analytical System

마창진,강공언,MikioKasahara,SusumuTohno 한국대기환경학회 2014 Asian Journal of Atmospheric Environment (AJAE) Vol.8 No.3

The present study was undertaken to evaluate thechemical characteristics of Asian dust (hereafter called“AD”) particles with the aid of the most advancedmicro-PIXE (Particle-induced X-ray emission) analyticaltechnique. To this end, size-selected particleswere sampled on a rural peninsula of Korea (Byunsan,35.37N; 126.27E) during AD and non-AD periods in2004. The coarse particle (¤2 μm) number densityduring an AD event were 170 times higher than thoseof the non-AD counterpart. The average net-count ofsilica in individual particles collected on AD event wasroughly 11 times higher than that of non-AD counterpart. The X-ray net-counts of trace elements (Zn,Co, Mn, and V) were also considerably high in AD relativeto the non-AD day. Particle classification basedon the inter ratio analysis of elemental net-count suggeststhat a large portion of the coarse particles collectedduring AD event underwent chemical transformationto a certain degree. The visual interpretationof micro-PIXE elemental maps and elemental localizationdata in and/or on individual AD particles clarifiedthe internal mixture of AD particles with sea-saltand artificial metallic particles.

High Time-resolution Characterization of PM2.5 Sulfate Measured in a Japanese Urban Site

마창진,강공언,김기현 한국대기환경학회 2015 Asian Journal of Atmospheric Environment (AJAE) Vol.9 No.4

The high time-resolution monitoring data are essential to estimate rapid changes in chemical compositions, concentrations, formation mechanisms, and likely sources of atmospheric particulate matter (PM). In this study, PM2.5 sulfate, PM2.5, PM10, and the number concentration of size-resolved PMs were monitored in Fukuoka, Japan by good time-resolved methods during the springtime. The highest monthly average PM2.5 sulfate was found in May (8.85 μg m-3), followed by April (8.36 μg m-3), March (8.13 μg m-3), and June (7.22 μg m-3). The cases exceed the Japanese central government’s safety standard for PM2.5 (35 μg m-3) reached 10.11% during four months campaign. The fraction of PM2.5 sulfate to PM2.5 varied from 12.05% to 68.11% with average value of 35.49% throughout the entire period of monitoring. This high proportion of sulfate in PM2.5 is an obvious characteristic of the ambient PM2.5 in Fukuoka during the springtime. However, the average fraction of PM2.5 sulfate to PM2.5 in three rain events occurred during our intensive campaign fell right down to 15.53%. Unusually high PM2.5 sulfate (>30 μg m-3) marked on three days were probably affected by the air parcels coming from the Chinese continent, the natural sulfur in the remote marine atmosphere, and a large number of ships sailing on the nearby sea. The theoretical number concentration of (NH4)2SO4 in PM0.5-0.3 was originally calculated and then compared to PM2.5 sulfate. A close resemblance between the diurnal variations of the theoretically calculated number concentration of (NH4)2SO4 in PM0.5-0.3 and PM2.5 sulfate concentration indicates that the secondary formed (NH4)2SO4 was the primary form of sulfate in PM2.5 during our monitoring period.