Seo Park S.,Yonsei University |
Seo Park S.,Kyushu University |
Kim J.,Yonsei University |
Lee H.,Yonsei University |
And 4 more authors.
Atmospheric Chemistry and Physics | Year: 2016
The sensitivities of oxygen-dimer (O4) slant column densities (SCDs) to changes in aerosol layer height are investigated using the simulated radiances by a radiative transfer model, the linearized pseudo-spherical vector discrete ordinate radiative transfer (VLIDORT), and the differential optical absorption spectroscopy (DOAS) technique. The sensitivities of the O4 index (O4I), which is defined as dividing O4 SCD by 1040 molecules2 cm-5, to aerosol types and optical properties are also evaluated and compared. Among the O4 absorption bands at 340, 360, 380, and 477 nm, the O4 absorption band at 477 nm is found to be the most suitable to retrieve the aerosol effective height. However, the O4I at 477 nm is significantly influenced not only by the aerosol layer effective height but also by aerosol vertical profiles, optical properties including single scattering albedo (SSA), aerosol optical depth (AOD), particle size, and surface albedo. Overall, the error of the retrieved aerosol effective height is estimated to be 1276, 846, and 739 m for dust, non-absorbing, and absorbing aerosol, respectively, assuming knowledge on the aerosol vertical distribution shape. Using radiance data from the Ozone Monitoring Instrument (OMI), a new algorithm is developed to derive the aerosol effective height over East Asia after the determination of the aerosol type and AOD from the MODerate resolution Imaging Spectroradiometer (MODIS). About 80 % of retrieved aerosol effective heights are within the error range of 1 km compared to those obtained from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) measurements on thick aerosol layer cases. © 2016 Author(s).
PubMed | Kyungpook National University and National Institute of Environment Research
Type: Journal Article | Journal: International journal of environmental research and public health | Year: 2016
The separation of chiral compounds is an interesting and challenging topic in analytical chemistry, especially in environmental fields. Enantioselective degradation or bioaccumulation has been observed for several chiral pollutants. Polycyclic musks are chiral and are widely used as fragrances in a variety of personal care products such as soaps, shampoos, cosmetics and perfumes. In this study, the gas chromatographic separation of chiral polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclo-penta--2-benzopyrane (HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetra-hydronaphthalene (AHTN), 6-acetyl-1,1,2,3,3,5-hexamethylindane (AHDI), 5-acetyl-1,1,2,6-tetramethyl-3-iso-propylindane (ATII), and 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanone (DPMI) was achieved on modified cyclodextrin stationary phase (heptakis (2,3-di-O-methyl-6-O-tert-butyl-dimethylsilyl--CD in DV-1701)). Separation techniques are coupled to tandem mass spectrometry (MS-MS), as it provides the sensitivity and selectivity needed. River and wastewaters (influents and effluents of wastewater treatment plants (WWTPs)) in the Nakdong River were investigated with regard to the concentrations and the enantiomeric ratios of polycyclic musks. HHCB was most frequently detected in river and wastewaters, and an enantiomeric enrichment was observed in the effluents of one of the investigated wastewater treatment plants (WWTPs). We reported the contamination of river and wastewaters in Korea by chiral polycyclic musks. The results of this investigation suggest that enantioselective transformation may occur during wastewater treatment.
Oh H.-R.,Seoul National University |
Ho C.-H.,Seoul National University |
Kim J.,University of California at Los Angeles |
Chen D.,Gothenburg University |
And 4 more authors.
Atmospheric Environment | Year: 2015
Massive air pollutants originating in China and their trans-boundary transports are an international concern in East Asia. Despite its importance, details in the trans-boundary transport of air pollutants over East Asia and its impact on regional air quality remain to be clarified. This study presents an evidence which strong support that aerosols emitting in China play a major role in the occurrence of multi-day (≥4 days) severe air pollution episodes in cold seasons (October through March) for 2001-2013 in Seoul, Korea, where the concentration of PM10 (particulates with diameters≤10μm) exceeds 100μgm-3. Observations show that these multi-day severe air pollution episodes occur when a strong high-pressure system resides over the eastern China-Korea region. In such weather conditions, air pollutants emitted in eastern China/southwestern Manchuria are trapped within the atmospheric boundary layer, and gradually spread into neighboring countries by weak lower tropospheric westerlies. Understanding of trans-boundary transports of air pollutants will advance the predictability of local air quality, and will encourage the development of international measures to improve air quality. © 2015 Elsevier Ltd.
Park S.S.,Yonsei University |
Kim J.,Yonsei University |
Lee J.,Yonsei University |
Lee S.,National Institute of Environment Research |
And 3 more authors.
Remote Sensing of Environment | Year: 2014
A new dust detection algorithm is developed by combining the results of multiple dust detection methods using IR channels onboard the MODerate resolution Imaging Spectroradiometer (MODIS). Brightness Temperature Difference (BTD) between two wavelength channels has been used widely in previous dust detection methods. However, BTD methods have limitations in identifying the offset values of the BTD to discriminate clear-sky areas. The current algorithm overcomes the disadvantages of previous dust detection methods by considering the Brightness Temperature Ratio (BTR) values of the dual wavelength channels with 30-day composite, the optical properties of the dust particles, the variability of surface properties, and the cloud contamination. Therefore, the current algorithm shows improvements in detecting the dust loaded region over land during daytime. Finally, the confidence index of the current dust algorithm is shown in 10. ×. 10. pixels of the MODIS observations. From January to June, 2006, the results of the current algorithm are within 64 to 81% of those found using the fine mode fraction (FMF) and aerosol index (AI) from the MODIS and Ozone Monitoring Instrument (OMI). The agreement between the results of the current algorithm and the OMI AI over the non-polluted land also ranges from 60 to 67% to avoid errors due to the anthropogenic aerosol. In addition, the developed algorithm shows statistically significant results at four AErosol RObotic NETwork (AERONET) sites in East Asia. © 2013 Elsevier Inc.
An K.-G.,Chungnam National University |
Choi J.-W.,Chungnam National University |
Lee Y.-J.,National Institute of Environment Research
Animal Cells and Systems | Year: 2013
The objectives of this study were to evaluate how chemical gradients and physical habitats influence trophic dynamics and chemical tolerance in relation to ecological health, based on biological integrity model in the absence of cascading pressures (cascading theory) as a control mechanism of aquatic ecosystems. We conducted physical, chemical, and biological surveys from 76 national streams and rivers of four major watersheds during 2004-2005 along with surveys of 80 reference streams. Maximum species richness lines (MSRLs) in reference sites vs. regular sampling sites indicated that the third- to fifth-order streams were evidently impaired in the metrics of trophic and tolerant components. These trophic modifications were linked with land-use patterns, which resulted in differences of nutrients (N, P), organic matter contents and the N:P ratios on trophic structures. Overall, these trophic factors influenced ecological health, based on multimetric index of biological integrity model in these systems, so that trophic compositions and tolerance were regulated by bottom-up hypothesis. © 2013 Copyright Korean Society for Integrative Biology.
Lee S.,Chungnam National University |
Jang Y.-C.,Chungnam National University |
Kim J.-G.,Chonbuk National University |
Park J.-E.,National Institute of Environment Research |
And 3 more authors.
Science of the Total Environment | Year: 2015
This study focused on a quantitative substance flow analysis (SFA) of polybrominated diphenyl ethers (PBDEs) in plastics from obsolete TVs and computer monitors that often contain large amounts of the flame retardants. According to the results of the static SFA study, 1.87. tons and 0.28. tons of PBDEs from newly manufactured TVs and computer monitors were introduced into households in 2011 in Korea, respectively. There were approximately 924. tons and 90.3. tons of PBDEs present in TVs and computer monitors in households during product use, respectively. The results of the dynamic SFA study indicated that in 2017 the amount of PBDEs from TVs and computer monitors in the recycling stage is expected to be 2.63. tons and 0.1. tons, respectively. Large fractions of PBDEs from used TVs are present in recycled plastics, while PBDE-containing computer monitors are exported to Southeast Asian countries. This research indicates that PBDEs were emitted the most from recycled plastic pellet processes upon recycling. Further study may be warranted to focus the flow of PBDEs in recycled plastic products in order to determine the final destination and disposal of these chemicals in the environment. © 2014 Elsevier B.V.
Lee S.-B.,Konkuk University |
Yoon C.-G.,Konkuk University |
Jung K.W.,Korea Water Environment Research Institute |
Hwang H.S.,National Institute of Environment Research
Water Science and Technology | Year: 2010
Stormwater pollution is the untreated contaminated water that drains into natural waterways from land uses within an urban catchment. Several studies have demonstrated the deterioration of water quality in receiving bodies of water caused by stormwater runoff. The data have reported that urban runoff play primary roles in degrading water quality in adjacent aquatic systems. The accurate estimation of non-pollutant loads from urban runoff and the prediction of water quality in receiving waters are important. The objective of this paper is to assess the applicability of the watershed scale hydrologic and water quality simulation models SWMM and HSPF to simulate the hydrology of a small watershed in the Han River Basin. Monitoring was performed in small scale watersheds, which is homogeneous land use. The applicability of SWMM and HSPF model was examined for small watersheds using hourly monitoring data. The results of SWMM were reasonably reflected with observed data in small scale urban area. HSPF model was effective at specifying parameters related to runoff and water quality when using hourly monitoring data. The watershed models used in this study adequately simulated watershed characteristics and are recommended to support watershed management. © IWA Publishing 2010.
Lee J.-W.,University of Sheffield |
Lee Y.-K.,National Institute of Environment Research |
Hatchwell B.J.,University of Sheffield
Animal Behaviour | Year: 2010
Dispersal is a key factor affecting the dynamics and genetic structure of populations. Patterns of natal dispersal vary widely depending on the selection pressures that each species encounters, but the underlying factors determining this variation are poorly understood. We studied the pattern of natal dispersal in a small passerine, the vinous-throated parrotbill, Paradoxornis webbianus, using both direct ringing data and indirect genetic methods. The social structure of this species is characterized by group living without apparent territorial behaviour. The dispersal rate of juveniles from their natal groups was moderate (about 40%) and dispersal distance was short, most individuals moving to neighbouring flocks. Sibling groups that included both sexes usually dispersed or were philopatric together so that they were found in the same winter flock where pairing occurs. Thus, the avoidance of inbreeding or intrasexual competition among siblings appears not to affect natal dispersal in this species. Instead, our results suggest that the benefits of dispersing in groups and/or selection of kin structure within social groups via kin-selected reproductive benefits may promote the observed dispersal pattern: sibling associations without separation of the sexes. This behaviour may have important implications for the kin structure of populations and the evolution of sociality. © 2010 The Association for the Study of Animal Behaviour.
Park J.-E.,National Institute of Environment Research |
Kang Y.-Y.,National Institute of Environment Research |
Kim W.-I.,National Institute of Environment Research |
Jeon T.-W.,National Institute of Environment Research |
And 3 more authors.
Science of the Total Environment | Year: 2014
The emission rates of polybrominated diphenyl ethers (PBDEs) from electric/electronic products during their use and disposal were estimated. E-wastes, including televisions and refrigerators, gathered at recycling centers were also analyzed to estimate their emissions. The average concentrations of PBDEs in TV rear covers produced before and after the year 2000 were 145,027mg/kg and 14,049mg/kg, respectively. The PBDEs concentration in TV front covers was lower than the concentration in TV rear covers. The concentration in the components of the refrigerator samples ranged from ND to 445mg/kg. We estimated the atmospheric emissions of PBDEs based on the concentrations. The annual emissions from TV rear covers produced before 2000 were calculated to be approximately 162.1kg and after 2000, the annual emissions were 18.7kg. Refrigerators showed the lowest annual emissions of PBDEs (0.7kg). The atmospheric concentrations were also measured to calculate emissions generated during the recycling process. The highest concentration was 16.86ng/m3 emitted from the TV sets during the dismantling process. The concentrations of PBDEs generated in the plastic processing field ranged from 2.05 to 5.43ng/m3 depending on the products, and ambient air in open-air yards showed concentrations in the range of 0.32 to 5.55ng/m3. Emission factors for the recycling process were calculated using the observed concentrations. The estimated emissions according to the emission factors ranged from 0.3×10-1 to 90.3kg/year for open-air yards and from 0.1×10-1 to 292.7kg/year for the dismantling and crushing processes of TV set, depending on the production year. © 2013 Elsevier B.V.
PubMed | Chonbuk National University and National Institute of Environment Research
Type: | Journal: The Science of the total environment | Year: 2014
The emission rates of polybrominated diphenyl ethers (PBDEs) from electric/electronic products during their use and disposal were estimated. E-wastes, including televisions and refrigerators, gathered at recycling centers were also analyzed to estimate their emissions. The average concentrations of PBDEs in TV rear covers produced before and after the year 2000 were 145,027 mg/kg and 14,049 mg/kg, respectively. The PBDEs concentration in TV front covers was lower than the concentration in TV rear covers. The concentration in the components of the refrigerator samples ranged from ND to 445 mg/kg. We estimated the atmospheric emissions of PBDEs based on the concentrations. The annual emissions from TV rear covers produced before 2000 were calculated to be approximately 162.1 kg and after 2000, the annual emissions were 18.7 kg. Refrigerators showed the lowest annual emissions of PBDEs (0.7 kg). The atmospheric concentrations were also measured to calculate emissions generated during the recycling process. The highest concentration was 16.86 ng/m(3) emitted from the TV sets during the dismantling process. The concentrations of PBDEs generated in the plastic processing field ranged from 2.05 to 5.43 ng/m(3) depending on the products, and ambient air in open-air yards showed concentrations in the range of 0.32 to 5.55 ng/m(3). Emission factors for the recycling process were calculated using the observed concentrations. The estimated emissions according to the emission factors ranged from 0.310(-1) to 90.3 kg/year for open-air yards and from 0.110(-1) to 292.7 kg/year for the dismantling and crushing processes of TV set, depending on the production year.