• 한국환경보건학회지
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• 제34권4호
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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.

• 한국환경보건학회지
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• 제19권2호
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• pp.10-15
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• 1993

Hygienic condition of farm waters has an effect on the hygiene of dairy foods. So we examined Standard Plate Count, coliform, E. coli, heat-resistant bacteria, psychrophilic bacteria, Pseudomonas aeruginosa and enterococcus for the bacterial sanitation of 78 farm waters in Kyunggi Province. Of the 78 farm waters, the average number of psychrophilic bacteria was 750 $\pm$ 170/ml, SPC 440 $\pm$ 130/ml, Pseudomonas aeruginosa 130 $\pm$ 97/100/ml, Coliform 22 $\pm$ 17/ml, E. coli 10 $\pm$ 6/100/ml, Heatresistant bacteria 5 $\pm$ 1ml, and Enterococcus 2 $\pm$ 1/100/ml. The percent of over than 1000/ml in SPC and psychrophilic bacteria of 78 farm water was 11.5% and 23.1%, respectively. The rate of over than 10/ml in coliform and heat-resistant bacteria was 12.8% and 15.4%, respectively and the rate of over than 10/100 ml in E. coli, Pseudomonas aeruginosa and enterococcus was 8.9%, 33.3%, and 2.6%, respectively. Pseudomonas aeruginosa was no significant between any other indicator organisms, and psychrophilic bacteria was significant with only SPC but other indicator organisms were highly significant with each other.

• 대한영양사협회학술지
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• 제9권4호
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• pp.316-325
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• 2003

This study was carried out to compare the characteristics of the over weight elementary school students with those of desirable-weight children. Anthropometric parameters such as height, weight, BMI, body fat percentile, triceps skin fold thickness were measured. Dietary assessment and blood analysis were performed. The average ages of over weight children and desirable-weight children were 10.9$\pm$2.5 and 10.2$\pm$2.8 years, respectively. The means body fat percentile of over weight children and desirable-weight children were 27.5$\pm$3.7% and 20.2$\pm$3.8%. respectively. Plasma levels of TG, total cholesterol, LDL cholesterol, and HDL cholesterol of over weight children and desirable-weight children were 179.3$\pm$30.0, 104.9$\pm$26.6, 52.3$\pm$6.7 and 178.3$\pm$84.1 mg/dl, and those of desirable-weight children were 86.1$\pm$43.5, 183.7$\pm$16.5, 101.0$\pm$2.1 and 67.7$\pm$20.0 mg/dl, respectively. Plasma TG levels of over weight children were significantly higher than those of desirable weight children. On the other hand, plasma HDL-cholesterol levels of over weight children were significantly lower than those of desirable-weight children. Plasma levels of GOT and GPT were in normal range in both group however, GPT level of over weight children was higher than that of desirable weight children. Plasma levels of albumin, globulin, and BUN were all in normal range and no differences were found in both groups. Hematologic data did not show any difference between two groups except WBC, RBC and Hgb levels which were significantly higher in over weight group than those of desirable-weight children. Daily nutrients intake of over weight children and desirable-weight children were very similar and they were around the Korean RDA levels for each nutrients. However the intake of calcium of both groups were little over 50% of RDA. The consumption of dietary fiber was very low and the cholesterol intake was very high showing that the habitual meals of Korean school children were not well balanced.

• 한국대기환경학회지
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• 제24권2호
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• pp.176-188
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• 2008

Anthropogenic emissions of nitrogen oxides and sulfur dioxide in Northeast Asia are of great concern because of their impact on air quality and atmospheric chemistry on regional and intercontinental scales. Satellite remote sensing based on DOAS (Differential Optical Absorption Spectroscopy) technique has been preferred to measure atmospheric trace species and to investigate their emission characteristics on regional and global scales. Absorption spectra obtained by the satellite-born instrument, SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) have been utilized to retrieve the information of $SO_2$ and $NO_2$ over Northeast Asia. $SO_2$ levels over Northeast Asia were in order of East China, Yellow Sea, South Sea and Korean Peninsula with mean vertical columns of $1.78({\pm}1.0){\times}10^{16}$, $1.11({\pm}0.67){\times}10^{16}$, $0.60({\pm}0.63){\times}10^{16}$, $0.71({\pm}0.65){\times}10^{16}\;molecules/cm^2$, respectively. $NO_2$ levels were in order of East China, Yellow Sea, Korean Peninsula, and South Sea with mean vertical columns of $1.2({\pm}0.56){\times}10^{16}$, $0.38({\pm}0.19){\times}10^{16}$, $0.48({\pm}0.28){\times}10^{16}$, $0.26({\pm}0.16){\times}10^{16}\;molecules/cm^2$, respectively. High levels of $SO_2$ and $NO_2$ were observed over East China, in particular in winter by the contribution of heating fuel combustion exhausts. The $SO_2$ and $NO_2$ levels over East China were the highest in January with 34% and 42% higher over the annual means. Low levels of $SO_2$ ranged over Korean peninsula, while $NO_2$ levels were relatively high, in particular in winter. The $SO_2$ and $NO_2$ levels over Yellow Sea were relatively higher compared to those over Korean peninsula and South Sea, which could be mainly attributed to their transport from East China.

• 한국환경과학회지
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• 제29권5호
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• pp.495-506
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• 2020

This study investigated the nitrate formation process, and mass closure of Particulate Matter (PM) were calculated over the urbanized area of Jeju Island. The data for eight water-soluble inorganic ions and nineteen elements in PM_2.5 and PM₁₀ were used. The results show that the nitrate concentration increased as excess ammonium increased in ammonium-rich samples. Furthermore, nitrate formation was not as important in ammonium-poor samples as it was in previous studies. According to the sum of the measured species, approximately 45~53% of gravimetric mass of PM remained unidentified. To calculate the mass closure for both PM_2.5 and PM₁₀, PM chemical components were categorized into secondary inorganic aerosol, crustal matter, sea salt, trace matter and unidentified matter. The results by the mass reconstruction of PM components show that the portion of unidentified matter was decreased from 52.7% to 44.0% in PM_2.5 and from 45.1% to 29.1% in PM₁₀, despite the exclusion of organic matter and elemental carbon.

• 한국대기환경학회지
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• 제32권4호
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• pp.360-371
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• 2016

The goal of this research is to examine the recent decade-long (2000~2014) trends of national background concentrations over China, Japan, and Korea. Based on the Long-range Transboundary Air Pollutants in Northeast Asia (LTP) project, which is three-party collaboration project among three countries, we investigated the long-term trends of national background $PM_{10}$ concentrations in three countries over the recent 15 years, including the 2008 Beijing Olympic Game period. In accordance with the agreement among three countries, a total of 8 national background sites: three national background monitoring sites in China (2 sites in Dalian, and 1 in Xiamen), three sites in Korea (Ganghwa, Gosan, and Taean), and two sites in Japan (Oki and Rishiri), were chosen for the trend analysis. The results showed that Chinese background concentration recorded the highest level overall. However, the rapid declining recent trends of annual median ($50^{th}$-percentile) values were surprisingly detected since 2006 or 2007 in every site in China, with the most rapidly decreasing rate (- $18.6{\pm}10.3%$/year) over 2006~2007, and the second most rapidly decreasing rate (- $18.0{\pm}1.5%$/year) over 2007~2008. Based on the previous statistical literature, we concluded that this declining trends were due to the emission reduction of $PM_{10}$ concentrations in China for 2008 Beijing Olympic Game. In Korea, Ganghwa was also showing the decreasing trends over the recent years since 2006, which is also well accorded with the decreasing period of Chinese background concentrations. Taean also implied some impact of Beijing Olympic Game, showing small but detectable decreasing trends, while Gosan showed the increasing tendencies probably due to the near-urban influences. However, since 2012, most sites in both China and Korea showed strong increasing trends, undoubtedly implying the increasement of both emission in China and its long-range transport process toward Korea. Two sites in Japan, Oki and Rishiri recorded the lowest level of $PM_{10}$ level during whole period with the smallest deviations of measurements. Other discussions including the decade-long trends of $5^{th}$, $10^{th}$, $25^{th}$, $50^{th}$, $75^{th}$, $90^{th}$, $95^{th}$-percentiles of $PM_{10}$ background concentrations in three countries were also comparatively addressed here.

• 한국농공학회논문집
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• 제56권3호
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• pp.39-45
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• 2014

Dust is mostly caused by human activity. The effect of natural factors on dust emission were studied in many research, but the little effort in researching artificial factors of dust emission. The object of study is to analysis dust emission characteristic by drop impact. Particle matter $10{\mu}m$ ($PM_{10}$) was measured by drop impact on paved soil with changing drop height, weight and drop size. Increasing drop height cause more $PM_{10}$ emission. Increasing drop weight cause more $PM_{10}$ emission but had limit weight for increasing dust emission. Because the exceed kinetic energy of drop weight penetrate the soil surface. The limit perimeter was exist that separating $PM_{10}$ emission aspect. Under limit perimeter, $PM_{10}$ emission was increasing while perimeter was increasing, but over limit perimeter showed the opposite aspect. Regression equations for estimating $PM_{10}$ with kinetic energy and perimeter were made under limit perimeter and over limit perimeter. The $R^2$ of those equations were 0.784, 0.743. The error has occurred between measured $PM_{10}$ and calculated $PM_{10}$ in the equation under limit perimeter. But using equation of case for over limit perimeter, PM10 can be estimated with kinetic energy and drop perimeter.

• 한국지구과학회지
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• 제37권7호
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• pp.434-447
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• 2016

2011-2015년 동안 한국 중부 태안과 청주 강내의 배경 관측지점에서 측정한 PM10, PM2.5 질량 농도를 분석하였다. 황사 사례를 제외한 PM10 질량 농도의 계절변동에서 겨울-봄 동안 높은 농도는 서풍 기류에 의한 영향이 반영되고 있으며, 여름에는 북태평양 기단과 잦은 강수로 낮은 수준을 보이고 있었다. 따라서, 일평균 PM10 질량 농도 $81{\mu}gm^{-3}$ (미세먼지 예보 '약간 나쁨' 이상) 이상의 사례도 겨울-봄 동안에 발생이 많으며, 특히 중국 동부 배출원에 가까운 태안에서 더 많은 사례가 발생하고 있었다. 인위적으로 발생한 연무는 입경 $2.5{\mu}m$ 미만 입자의 구성 비율이 높다. 천리안 위성의 밝기온도차 분석에서 대기와 입자가 작은 연무는 $-0.5^{\circ}K$ 이상에서 관측된다. 2011-2015년 동안 태안과 청주 강내에서 관측한 연무 사례일의 PM10 질량 농도와 NOAA 19 위성 밝기온도차를 분석하였다. PM10 질량 농도는 $200{\mu}g\;m^{-3}$ 보다 낮지만, PM2.5/PM10 질량 농도비는 0.4보다 높고 밝기온도차는 $-0.3-0.5^{\circ}K$ 범위에 분포하고 있었다. 그러나, PM10 질량 농도 $190{\mu}g\;m^{-3}$ 이상인 황사 사례의 밝기온도차는 PM2.5/PM10 질량 농도비가 0.4보다 낮고, 밝기온도차는 $-0.7^{\circ}K$ 이하의 범위에 분포하고 있었다. 이러한 연무의 밝기온도차 경계값 범위를 적용한 결과는 MODIS AOD, OMI AI의 에어로졸 분포 범위와 일치하였다.

• 한국지구과학회지
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• 제43권1호
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• pp.77-90
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• 2022

최근 동아시아 지역에서 인위적 배출량의 감소에도 불구하고, 봄철에 한국에서는 잦은 연무 사례가 발생하고 있다. 북동 태평양에서 자주 발생하는 대기 블로킹은 지구 규모 대기 변동과 동아시아 지역의 서풍 기류를 정체시키기도 한다. 2019년 3월 동아시아 지역의 온난하고 정체적인 종관 기상 특성이 알래스카 대기 블로킹이 발생한 6-7일 후에 일어나고 있었다. 특히, 2019년 3월 18-24일에 발생한 알래스카 대기 블로킹은 3월 25-28일 동안 한국에서 일평균 미세먼지(particulate matter; PM₁₀) 질량농도가 50 ㎍ m^-3을 넘는 고농도 PM₁₀ 연무 사례가 발생하는 데 영향을 미치고 있었다. 한편, WRF-Chem 모델을 활용하여 한국의 고농도 PM₁₀ 연무 사례에 대한 인위적 배출의 장거리 수송 기여도는 30-40%를 나타내고 있었다. PM₁₀ 에어로졸 구성 성분인 황산염, 질산염, 암모늄, 블랙 카본, 유기 탄소, 기타 무기물의 장거리 수송 기여도는 각각 10-15, 20-25, 5-10, 5-10, 5-10, 15-20%를 나타내었다. 질소 산화물이 온난하고 정체적인 대기에서 암모늄과의 광화학 반응으로 형성된 질산암모늄은 한국의 고농도 PM₁₀ 연무 사례에 대한 장거리 수송 기여도가 PM₁₀ 에어로졸 중 가장 큰 비중을 나타내고 있었다.

• Journal of Preventive Medicine and Public Health
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• 제26권3호
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• pp.387-399
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• 1993

This study was conducted to analyze blood lipid profile and other risk factors among crew members who are currently active and had more than 10 years of experience as crew members. Data was analyzed using medical record files in an airline medical department. The results are as follows. 1. The total number of crew members studied was 392. Among age groups, those below age 40 consisted of 26(6.9% of the total), those in age $41{\sim}50$ were 135 (34.4%) and those over age 51 were 230 (58.7%). 263 were former air force pilots consisting 66.9%. Those who had captain status numbered 21 I comprising 53.7% of the total. The type of aircraft most of the crew members involved were large size aircraft which totaled 268 (68.2%). With respect to the number of working years as crew members, 488(48.9%) comprised the largest group with $11{\sim}15$ years. 2. The rate of smoking among crew members has shown gradual decrease with 50.3% smoking in 1983 to 33.6% in 1993. Among $41{\sim}50$ age group the rate has shown a decrease from 20.9% to 13.3% In those group over age 51 it decreased from 25.5% to 16.6%. But group below age 40 were within the range of 3.6~3.8% with no significant change in the rate of smoking. 3. Body Mass Index in age group over 51 was slightly higher than other age groups. On the whole, BMI over 25 was not found. 4. The total cholesterol levels of those below age 40 were $196.9{\pm}38.5mg/dl,\;216.2{\pm}39.2mg/dl$ in ages $41{\sim}50$, and $225.1{\pm}42.5mg/dl$ in age group over 51. No significant difference was found among age groups. 5. HDL-cholesterol levels of over age 50 were higher than other age group and ranged from $40{\sim}55mg/dl$. 6. LDL-cholesterol levels of those over 51 were $126.7{\pm}37.7mg/dl$ higher than other age groups. But there were no significant changes in all age during 10 years of follow up. 7. Cardiac index of age group below age 40 was 3.8, 4.3 in age group $41{\sim}50$ and 4.5 in those over age 51 group. No significant changes among groups were found during the follow up period. 8. Triglyceride levels of age group below age 40 was $142.2{\pm}70.1,\;167.3{\pm}77.5$ in age group of $41{\sim}50$ and $113.6{\pm}897$ in age group over 50 showing that triglyceride levels increased with age. No significant changes in pattern were noted.