(The) liability of online service provider for a third party`s tort

학위논문(석사) --서울대학교 대학원 :법학과(지적소유권법전공),Maste

Development of Analytical Method for Microplastics in Seawater

미세플라스틱의 분포, 거동, 생태계 영향 등은 해양생태계 보전을 위한 중요한 연구관심사가 되고 있다. 그러나 국내외적으로 통일된 조사 및 정성 정량 분석법이 제시되어 있지 않아 자료들의 비교에 한계가 있다. 본 연구는 해수에 잔류하는 미세플라스틱에 대한 국내외 조사방법들을 고찰하고, 불확실성을 증가시킬 수 있는 과정들에 대해 재현성여부를 평가하여 적용가능한 조사 및 정성 정량 분석법을 확립하였다. 또, 확립된 방법을 적용해 인천경기연안 해수에 잔류하는 미세플라스틱의 분포특성에 대한 사전조사 결과를 제시하였다. 해수는 표면해수층(surface microlayer; SML)과 해수층(subsurface water; SSW)로 나누어 SML층은 2 mm mesh screen를 이용해서 채취하였고 SSW층은 동물플랑크톤채집용 trawl net(mesh size= 330μm )과 식물플랑크톤채집용 hand net(mesh size= 20μm )을 이용해서 채취하였다. 채취된 양에 기초해 계산된 SML층은 대략 100μm 로써 SML층을 잘 반영하는 것으로 판단된다. 미세플라스틱의 우점적인 크기는 300μm 으로 관측되어 SSW층에 대한 채취는 trawl-net보다는 hand-net이 더 적절한 것으로 판단된다. 적외선 분광분석(IR)을 통해 플라스틱 여부와 polymer성분을 결정하였는데, SML에 대해서는 IR분석결과에 기초해 계수한 농도와 육안계수법에 기초한 농도가 잘 일치하였으나 SSW에 대해서는 그렇지 못해서 기존 연구들의 육안계수에 의한 결과 값들이 불확실할 수 있음이 관측되었다. 본 연구에서 확립된 방법을 적용해서 사전조사한 결과 인천경기연안 지역 해수 중 잔류하는 미세플라스틱 농도는 낙동강 하구연안에서 관측된 값과 유사한 범위에 있었다. 본 연구에서 확립된 분석방법은 미세플라스틱에 대한 향후 연구를 위해 중요한 기초자료로 활용되리라 사료된다. Despite of emerging and increasing concerns to microplastics, no standard methodology has not been proposed for determination of microplastics. This study aims to develop the analysis method for microplastics in seawater by overviewing methodologies proposed by previous studies and by assessing some processes in those methodologies which possibly cause uncertainties in microplastic determination. Furthermore, we present preliminary results of distribution characteristics of microplastics in seawater of Incheon/Kyeonggi coastal region which is based on our new methodology. Microplastics in surface microlayer (SML) and subsurface water (SSW) were collected using mesh screen and planktonic nets (trawl net with 330μm mesh size and hand net with 20μm mesh size), respectively. Microplastics with 300μm was predominant, indicating hand net as the better collection tool for SSW. As for SML, FT-IR based microplastic concentration was well matched with naked-eye based concentration which has been used in most of previous studies. However, a poor relationship was observed for SSW, indicating that concentration data of previous SSW studies should be corrected. Incheon/Kyeonggi bay seawater contained the similar concentration range with those in coastal region of the Nakdong River. Our methodology can be used as a basic tool for further microplatic studies.22Nkc

Micro and Nano-fragmentation of expanded polystyrene ?exposed to sunlight

1. Approximately 50 to 80 million nano-expanded polystyrene (EPS) particles per cm2 were produced by 2 to 8 months of sunlight exposure. 2. The EPS particles less than 100 nm in size obviously increased according to sunlight exposure duration. 3. Microplastics larger than 10 mm accounted for over 90% of total weight of the fragmented particles. 4. Approximately 4.7 years are required to fragment 50% of EPS cube by sunlight weathering.ion. 3. Microplastics larger than 10 mm accounted for over 90% of total weight of the fragmented particles. 4. Approximately 4.7 years are required to fragment 50% of EPS cube by sunlight weathering.1

Ecological risk assessment of microplastics in salt water envionment

Microplastic in surface water, water column and bottom water of Korean coastal waters were determined down to 20 mm in size. Along with this in-situ observation data and microplastic abundance data reported in the world and bioassay data available in literature, preliminary ecological risk assessment was conducted. The highest microplastic abundance observed in saltwater environment is about three orders of magnitude lower than the most sensitive toxic effects reported for water flea. However, microplastic abundance in seawater is likely to increase with current increasing rate of plastic production. Precautionary approach is highly required to reduce input or standing stock of plastic debris. In addition, big uncertainty still exists for assessment of ecological risk due to limited taxa in bioassay especially saltwater species, limited chronic toxicity data, and data based on non-standardized bioassays. It is highly recommended to conduct harmonized and well-designed microplastic monitoring and bioassay for ecological risk assessment.available in literature, preliminary ecological risk assessment was conducted. The highest microplastic abundance observed in saltwater environment is about three orders of magnitude lower than the most sensitive toxic effects reported for water flea. However, microplastic abundance in seawater is likely to increase with current increasing rate of plastic production. Precautionary approach is highly required to reduce input or standing stock of plastic debris. In addition, big uncertainty still exists for assessment of ecological risk due to limited taxa in bioassay especially saltwater species, limited chronic toxicity data, and data based on non-standardized bioassays. It is highly recommended to conduct harmonized and well-designed microplastic monitoring and bioassay for ecological risk assessment.1

Organic micropollutants in plastic resin pellets from sand beaches of South Korea

In order to assess the occurrence and distribution of microplastic debris in the coastal regions of South Korea, beach monitoring survey was conducted at four beaches in September and October, 2011. Among the plastic samples collected in that survey, plastic resin pellet was selected and used for the chemical analysis of persistent organic pollutants (POPs). The FT-IR analysis showed that the primary synthetic polymers collected on the beaches were polypropylene (PP) and polyethylene (PE). According to their polymer type and the degree of weathering, the pellet samples were sorted into four groups: aged PP, fresh PP, aged PE, and fresh PE. The overall concentration (ng/g pellet) of POPs in pellet samples were in the range of 0.06-18.6 (median value: 1.75) for HCB, nd-163 (0.14) for HCHs, nd-116 (0.13) for CHLs, nd-193 (15) for endosulfans, 0.39-6,800 (8.6) for DDTs, 0.3-55.3 (10.3) for PCBs, and 0.25-510 (8.16) for PBDEs. Extremely high concentration of DDT was determined in the aged PE pellets collected from Deokheung and Heungnam beaches. In general, PE accumulated larger amounts of POPs than PP. And aged pellet accumulated more contaminants than the fresh. Among the target compounds, DDTs, PCBs, and endosulfans showed the highest concentration, followed by PBDEs and HCB. Hexachlorocyclohexanes and chlordans were detected with a low concentration. The profile of POPs detected in the pelln that survey, plastic resin pellet was selected and used for the chemical analysis of persistent organic pollutants (POPs). The FT-IR analysis showed that the primary synthetic polymers collected on the beaches were polypropylene (PP) and polyethylene (PE). According to their polymer type and the degree of weathering, the pellet samples were sorted into four groups: aged PP, fresh PP, aged PE, and fresh PE. The overall concentration (ng/g pellet) of POPs in pellet samples were in the range of 0.06-18.6 (median value: 1.75) for HCB, nd-163 (01

Characteristic of spatiotemporal distribution of microplastics in surface microlayer in southern coast of South Korea

Microplastics, less than 1 mm in size, have been recently recognized as marine pollutants of significant concern due to their persistence, ubiquity, toxic potential, and their ability to act as vectors for transfer of absorbed and additive toxic chemicals to marine organisms. Floating of plastics on sea surface is affected by the density of the plastic materials. For example, polyethylene, polypropylene and expanded polystyrene which are generally less dense than sea water is likely to become floating debris. There is a microlayer in the sea surface formed by the surface tension of water with thickness of 1 mm. Sea surface microlayer is a habitat of a variety of life and accumulates light particles as well as pollutants deposited from the atmosphere and buoyant from water column. So the place is used for researching of pollutants. Considering the size and specific gravity of the microplastics, they are also expected to be accumulated within the microlayer. In this study, microplastic debris was quantitatively determined in surface microlayer at 21 stations in southern coast of South Korea in May (dry season) and July (rainy season), 2012, which is receiving Nakdong River discharge. The microplastics in the microlayer samples were extracted using the surface tension. The specially fitted 2 mm mesh sieve was dipped into the sea surface for 100 times, then the trapped water within mesh space was collected in the range of 2.2-2.8 L per site in the stainless steel tray and transferred to the 1 L polyethylene bottle. In the laboratory, the microlayer sample was filtered, using a glass fiber filter and counted using a dissecting microscope. Microplastic abundances in microlayer are in the range of 50-110 particles/L in May and 55-132 particles/L in July. Even if the average of microplastics (110±45 particles/L) in May was higher than those (132±106 particles/L) in July, there is not a statistical signification. Among four categories of microplastics (fragment, fiber, sheet and spherule), fragment type accounted for 80% in May and 98% in July. Small size microplastics down to 0-100 &#61549 m class are dominant in all the samples. Microplastics are relatively abundant at stations near shore in comparison with offshore stations. Abundances of microplastics in microlayer were folders or orders of magnitude higher than those in top 20 cm surface water collected by filtering (0.7 &#61549 m pore), a hand net (50 &#61549 m mesh) and a manta trawl net (330 &#61549 m).1

Abundance, composition and spatial distribution of microplastics on Korean sand beaches

Microplastics are widespread and ubiquitous in the marine environment. Potential ofmicroplastic ingestion by marine organisms increases with decreasing microplastic size.Contamination level of microplastics in various marine compartment are widely reported inthe world, but limited information is available in Korean beaches. The distribution andcomposition of microplastics were investigated in sediments collected from twenty beachesalong the coast of Korea. Three lines parallel to shoreline were selected at a beach, and fourquadrats (0.5 × 0.5 m) were randomly placed in each line. Sand in a quadrat in depth of 2.5cm was scooped and sieved using 1 and 5 mm mesh metal sieves. Solid materials includingplastics in 1-5 mm size range and < 1 mm were separately stored for further analysis.Abundance of large microplastics (L-MP, 1-5 mm in size) was in the range of 0-2,102particles/㎡. The mean abundance of L-MP was 432 ± 624 particles/㎡ for the South coast,132 ± 199 particles/㎡ for the West coast, 6 ± 10 particles/㎡ for the East coast. Wahyunbeach at Geoje showed the highest abundance (2,102 particles/㎡), and it was followed byGosung (555 particles/㎡) and Ansan (527 particles/㎡). The relatively low abundances of 0-2particles/㎡ were found in Gangneung, Sokcho and Uljin in northern part of the East coast.Expanded polystyrene (EPS) beads accounted for 93% in total abundance of L-MP. Small are widely reported inthe world, but limited information is available in Korean beaches. The distribution andcomposition of microplastics were investigated in sediments collected from twenty beachesalong the coast of Korea. Three lines parallel to shoreline were selected at a beach, and fourquadrats (0.5 × 0.5 m) were randomly placed in each line. Sand in a quadrat in depth of 2.5cm was scooped and sieved using 1 and 5 mm mesh metal sieves. Solid materials includingplastics in 1-5 mm size range and < 1 mm were separately stored for further analysis.Abundance of large microplastics (L-MP, 1-5 mm in size) was in the range of 0-2,102particles/㎡. The mean abundance of L-MP was 432 ± 624 particles/㎡ for the South coast,132 ± 199 particles/㎡ for the West coast, 6 ± 10 particles/㎡ for the East coast. Wahyunbeach at Geoje showed the highest abundance (2,102 particles/㎡), and it was followed byGosung (555 particles/㎡) and Ansan (527 particles/㎡). The relatively low abundances of 0-2particles/㎡ were found in Gangneung, Sokcho and Uljin in northern part of the East coast.Expanded polystyrene (EPS) beads accounted for 93% in total abundance of L-MP. Small2

Vertical distribution of microplastics and their presence in marine snow in offshore waters of South Korea

Microplastics can be vertically transported by physical mixing as well as biological interaction. There is, however, still limited in situ observation data in vertical profile and characteristics of microplastics in offshore areas. In this study, the vertical distribution of microplastics larger than 201

Vertical distribution of microplastics in Yellow Sea and South Sea of South Korea

Microplastic can be transferred up or down the water column by vertical mixing. However, there is still a lack of data to understand the vertical distribution of microplastics. In this study, the vertical distribution and characteristics of microplastic larger than 201

Micro and nano-particles of expanded polystyrene exposed to sunlight

Expanded polystyrene (EPS) was used to sunlight exposure because it is one of most common litter items and highly susceptible to UV as well as mechanical weathering. The EPS cube was placed in borosilicate petri-dish and covered with quartz chamber to transmit sunlight and naturally weathered on the roof of our laboratory located at Goeje Island, South Korea. The produced particles by sunlight exposure was confirmed by energy dispersive spectroscopy. Approximately 3-70 million micro sized particles and 20-900 million nano sized particles per square centimeter were produced after 3, 6, 7, 9 and 24-month exposure. The number of particles increased according to the exposure duration. The average size of fragmented particles was comparable by increasing exposure time. By the weight loss of EPS cube, the fragmentation rate was calculated.1