• Title/Summary/Keyword: Urban Air pollutants

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Analysis of the Correlation between Urban High Temperature Phenomenon and Air Pollution during Summer in Daegu

  • An, Eun-Ji;Kim, Hae-Dong
    • 한국환경과학회지
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    • 제28권10호
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    • pp.831-840
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    • 2019
  • Recently, summer high temperature events caused by climate change and urban heat island phenomenon have become a serious social problem around the world. Urban areas have low albedo and huge heat storage, resulting in higher temperatures and longer lasting characteristics. To effectively consider the urban heat island measures, it is important to quantitatively grasp the impact of urban high temperatures on the society. Until now, the study of urban heat island phenomenon had been carried out focusing only on the effects of urban high temperature on human health (such as heat stroke and sleep disturbance). In this study, we focus on the effect of urban heat island phenomenon on air pollution. In particular, the relationship between high temperature phenomena in urban areas during summer and the concentration of photochemical oxidant is investigated. High concentrations of ozone during summer are confirmed to coincide with a day when the causative substances (NO2,VOCs) are high in urban areas during the early morning hours. Further, it is noted that the night urban heat island intensity is large.. Finally, although the concentration of other air pollutants has been decreasing in the long term, the concentration of photochemical oxidant gradually increases in Daegu.

건물 밀집 지역에서 대기오염물질 분포에 미치는 건물과 지형의 영향에 관한 수치 연구 (A Numerical Study on the Effects of Buildings and Topography on the Spatial Distributions of Air Pollutants in a Building-Congested District)

  • 강건;김재진;이재범
    • 대한원격탐사학회지
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    • 제36권2_1호
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    • pp.139-153
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    • 2020
  • 본 연구는 전산유체역학(computational fluid dynamics, CFD) 모델을 이용하여 도시 지역에 위치한 도시 대기측정소의 대기질 대표성을 평가하고, 측정 목적에 따른 측정소 위치 선정에 대한 방법론을 제시하였다. 이를 위하여 대상 지역을 은평구 도시대기측정소(air quality monitoring system, AQMS)로 선정하였고 두 가지배출 시나리오(대기오염물질이 배경에서 수송되는 경우, 도로에서 배출되는 경우에 대한 수치 실험을 수행하였다. 대기 흐름은 대상 지역의 북동쪽과 남동쪽에 위치한 산악 지형의 영향을 크게 받고, 건물이 밀집한 지역에서는 2차 순환에 의한 복잡한 흐름이 나타났다. 대기오염물질이 배경에서 수송되는 경우에, 대기오염물질 분포는 지형(산)의 영향을 크게 받았다. 선오염(도로)에서 배출되는 경우에는 도로 위치와 건물 분포/높이 영향을 크게 받았다. 은평구 AQMS 위치에서 수치 모의된 농도는 지형보다 건물의 영향이 크게 나타났다. 배출 시나리오 결과를 이용하여 은평구 AQMS가 대상 지역의 대기질을 대표할 수 있는지에 대하여 평가하였다. 은평구 AQMS 위치에서 모의되는 농도는 두 시나리오의 층 평균 농도와 유사한 크기를 가지고 있어 측정 높이에서의 대기질을 대표할 수 있다고 판단된다. 대기오염물질은 시·공간적으로 비균질적이기 때문에 측정 목적에 따른 고도 별 측정망 위치 선정에 대한 가이드라인을 제시하였다. 측정망을 고농도가 나타나는 지역(hot spot)과 청정 지역(clean zone), 각 층의 평균 농도가 나타나는 지역(average zone), 건물/지형에 가로막혀 흐름의 유입과 유출이 활발하지 않는 안락처 지역(shelter zone), 외부에서 수송되는 배경 농도를 대표할 수 있는 지역(equi-background zone) 등 총 5가지로 분류하여 조사하였다.

자동차에서 배출되는 가스상 유해대기오염물질 (HAPs) 배출량 추정 (Estimation of Gaseous Hazardous Air Pollutants Emission from Vehicles)

  • 김정;장영기;최상진;김정수;서충열;손지환
    • 한국대기환경학회지
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    • 제29권1호
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    • pp.1-9
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    • 2013
  • Hazardous Air Pollutants (HAPs) are difficult to measure, analyze and assess for risk because of low ambient concentrations and varieties. Types of HAPs are Volatile organic compounds (VOCs), Polycyclic aromatic hydrocarbon (PAHs) and Aldehydes. HAP emissions from vehicles are a contributor to serious adverse health effects in urban areas. In this study, hazardous air pollutant emissions from road transport vehicles by Non-methane volatile organic compounds (NMVOC) weight fraction and PAHs emission factors are estimated in 2008. The top-five-most hazardous air pollutant emissions were estimated to toluene 864.3 ton/yr, acrolein 690.6 ton/yr, acetaldehyde 554.5 ton/yr, formaldehyde 498.7 ton/yr, propionaldehyde 421.6 ton/yr in 2008. The results for a cancer and non-cancer risk assessment of HAPs emissions show that the major cancer driver is formaldehyde and the non-cancer driver is acrolein.

In situ measurement-based partitioning behavior of perfluoroalkyl acids in the atmosphere

  • Kim, Seung-Kyu;Li, Donghao;Kannan, Kurunthachalam
    • Environmental Engineering Research
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    • 제25권3호
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    • pp.281-289
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    • 2020
  • Environmental fate of ionizable organic pollutants such as perfluoroalkyl acids (PFAAs) are of increasing interest but has not been well understood because of uncertain values for parameters related with atmospheric interphase partitioning behavior. In the present study, not only the values for air-water partition coefficient (KAW) and dissociation constant (pKa) of PFAAs were induced by adjusting to in situ measurements of air-water distribution coefficient between vapor phase and rainwater but also gas-particle partition coefficients were also estimated using three-phase partitioning model of ionizable organic pollutants, in situ measurements of PFAAs in aerosol and air vapor phase, and obtained parameter values. The pKa values of PFAAs we obtained were close to the minimum values suggested in literature except for perfluorooctane sulfonic acids, and COSMOtherm-modeled KAW values were assessed to more appropriate among suggested values. When applying parameter values we obtained, it was predicted that air particle-associated fate and transport of PFAAs could be negligible and PFAAs could distribute ubiquitously along the transection from urban to rural region by pH-dependent phase transfer in air. Our study is expected to have some implications in prediction of the environmental redistribution of other ionizable organic compounds.

유해대기오염물질 모니터링을 위한 대도시 우선순위 측정지점 선정기법 제안 (Suggestions on the Selection Method of Priority Monitoring Sites for Hazardous Air Pollutants in Megacities)

  • 권혜옥;김성준;김용표;김상균;홍지형;최성득
    • 한국대기환경학회지
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    • 제33권6호
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    • pp.544-553
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    • 2017
  • There is an overall guideline of the installation of air quality monitoring stations in Korea, but specified steps for the selection of monitoring sites for hazardous air pollutants(HAPs) are not provided. In this study, we proposed a systematic method for the selection of monitoring sites for HAPs using geographic information system (GIS). As a case study, the Seoul metropolitan area (Seoul, Incheon, and Gyeonggi Province) was chosen, and 15 factors including population, vehicle registration, and emission data were compiled for each grid cell ($7km{\times}7km$). The number of factors above the top 30% of individual data for each grid cell was used to select priority monitoring sites for HAPs. In addition, several background sites were added for data comparison and source identification. Three scenarios were suggested: Scenario 1 with 7 sites, Scenario 2 with 17 sites, and Scenario 3 with 30 sites. This proposal is not the final result for an intensive monitoring program, but it is an example of method development for selecting appropriate sampling sites. These results can be applied not only to HAPs monitoring in megacities but also to the national HAPs monitoring network.

부산지역 도심하천 복원에 따른 기온변화 효과 분석 (An Analysis of the Temperature Change Effects of Restoring Urban Streams in Busan Area)

  • 정우식;도우곤
    • 한국환경과학회지
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    • 제21권8호
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    • pp.939-951
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    • 2012
  • This study is conducted to estimate the air temperature decreasing effects by restoring urban streams using WRF/CALMET coupled system. The types of land use on covered streams are constructed with the land cover map from Korea ministry of environment. Restoring covered streams changes the types of land use on covered areas to water. Two different types of land use(CASE 1 and CASE 2) are inputted to the WRF/CALMET coupled system in order to calculate the temperature difference. The results of the WRF/CALMET coupled system are similar to the observed values at automatic weather stations(AWS) in Busan area. Restoring covered streams causes temperature to be decreased by about $0.34{\sim}2^{\circ}C$ according to the locations of streams and the regions that temperature is reduced are widely distributed over the restored area. Reduction of temperature is increased rapidly from morning and maximus at 13LST. Natural restoration of streams will reduce the built-up area within urban. With this, temperature reductions which are the cause to weaken the urban heat island appear. Relief of urban heat island will help to improve the air quality such as accumulation of air pollutants in within urban area.

국내 적용을 위한 Miller-Holzworth 모델의 수정 (Modification of Miller-Holzworth model for Korea)

  • 장영기
    • 한국대기환경학회지
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    • 제11권3호
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    • pp.299-302
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    • 1995
  • Many air quality models have been used for Environmental impact assessments. Miller-Holzworth model suggested by Holzworth is a simple air quality model is frequently used for air quality assessments in korea. Miller-Holzworth model suggested by Holzworth is a simple air quality model for the ground-level area source, The model estimates the pollutants concentration averaged over the wind centerline. An error involved in the Miller-Holzworth model was first indentified by Calder in 1977. But the model has been used without correction for unsuitable cases in Korea. This paper corrected that error and modified model formulation for application to urban and rural areas.

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In vitro mutagenicity and genotoxicity study of PAHs and nitro-PAHs using the bacterial revertant (Ames) test and alkaline single cell gel electrophorosis (Comet) assay

  • Kim, Soung-Ho;Oh, Seung-Min;Chung, Kyu-Hyuck
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.284.1-284.1
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    • 2002
  • In previous studies, we demonstrated that ambient PM collected from urban site of Korea air could induce DNA damage, Various mutagens and carcinogens present in the urban air differ according to the source of the pollutants. Polycyclic aromatic hydrocarbons (PAHs) and their nitrated compound are produced in the combustion of fossil fuels as diesel emission exhausts. In recent, PAH and nitro-PAH have been identified in urban air particulate matter (PM). and some of them were found to be tumorigenic in experimental animals and humans. (omitted)

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