The marine environment is polluted by plastics of all forms and sizes. To reduce this serious pollution, it is important to identify its sources. This work focuses on the me-chanically induced breakdown of plastic into smaller fragments as a source of secondary microplastic, the time scale in which these microplastics are formed as well as the influ-ence of different environmental conditions like matrix conditions, collision potential or UV irradiation on the abrasion and fragmentation behaviour of plastic debris. Since a systematic investigation of parameter influence is not possible in the environ-ment, laboratory experiments were developed to simulate natural conditions such as drift on the beach or wave action in the (low tide) surf and swash zone. For this purpose, selected plastic objects (PET bottles, HDPE caps, PS cups and LDPE bags) were ex-posed to collision and/or friction forces under different conditions. Besides visual in-spection of the destruction procedure, a number of different methods was used to char-acterize the process, e.g., counting of visible fragments (larger than 350 μm), micro-scopic analysis of the surface structure (binocular, SEM) and highly resolved analysis of particle numbers in the size range below 350 μm. In order to extract microplastic parti-cles (<5 mm) from the matrix, extraction methods were developed that were adapted to the given sample properties (matrix volume). Furthermore, based on the particle num-bers, the power law model was applied to analyse the fragmentation process in the con-text of the observed particle size distributions. Plastic samples exhibited various signs of mechanical impairment in form of surface abrasion, cracks, tears, perforation, crumpling and finally fragmentation. The formation of fragments in different sizes (macro-, meso- and microplastics) was observed. The plastic objects were classified according to their degree of destruction to elucidate the effect of the different experimental conditions. Results show that fragmentation and abrasion depend on individual properties of the plastic objects such as thickness or shape and on the potential of weakening the plastic structure by mechanical forces (collisions) or chemical degradation (UV irradiation). Environmental conditions also influence the plastic damage; surface abrasion plays a major role on the beach; fragmentation will most likely happen in the surf- and in the swash zone. However, both processes occur simultaneously and interact with each oth-er. Formation of secondary microplastics was shown to be likely in the marine environ-ment; it must therefore be considered as an important process in the light of microplastic contamination.

No description available.

With increasing global plastics production, the amounts of fragmenting, microscopic plastic debris (microplastics, MPs) are anticipated to rise in aquatic environments. The ecological consequences of this pollution are currently unknown. Studies are being conducted at present to assess these risks but many have been shown to be uninformative from a risk assessment perspective due to flawed and environmentally unrealistic experimental designs; the main problem being confounding effects of food dilution due to the use of particle free controls. Natural particles, such as clay are in the microplastic-size range and ubiquitous in the environment. Hence, to counteract and improve on the poor experimental design to test microplastic effects, the aim of the study was to develop a simple, high throughput screening method which accounts for naturally occurring microparticles like suspended clay in mixtures with MP. Lethal and sub lethal effects of MP alone and in mixtures at different ratios were investigated. Single particle exposures revealed a significant and up to a hundred times higher LC50 for clay compared to the plastics. Among the plastics, weathered plastics were four to five times more toxic than the pristine forms. The mixtures indicated interaction effects of all particles and revealed toxic microplastic-specific effects. A mean decrease of 19 % in the protein content across all particle types was observed after 96 h, however, one plastic type showed a higher reduction in the protein content. Testing MPs effects in mixtures with natural particulates is important due to various interaction effects but more comparative studies with environmental relevant concentrations are required in future. / <p>Master thesis is used for further publication.</p> / WEATHER-MIC, irPLAST, MICROPOLL

Single-use plastic packaging waste is overflowing the Earth’s surface, releasing mi- croplastics that contaminate our food. This poses serious threats and concerns to food safety and security. The project aims to raise public awareness about the issue of microplastic con- tamination in the food system. It will use friendly visual language to help people understand how plastic waste from local recycling stations can end up back on their plates and in their bodies. The outcome of the project is a dining workshop that explores the journey of microplastics into the food system. Visual elements and dishes are used as tools to connect partic- ipants with this complex issue. This enables the audience to learn, think critically and reflect on their daily plastic consumption habits. It inspires them to take responsibility and makea change towards reducing plastic waste. Currently, there is no clear scientific literature on whether there is a potential risk to humans associated with exposure to microplastics in food.

A method with the potential for comprehensive microplastic monitoring in river sediments is presented in this study. We introduce a novel combination of electrostatic separation, density separation, and differential scanning calorimetry (DSC). Currently, microplastic analysis in sediments is limited in terms of sample masses, processing time, and analytical robustness. This work evaluated a method to process large sample masses efficiently and still obtain robust results. Four particulate matrices, including commercial sands and river sediments, were spiked with PCL, LD-PE, and PET microplastic particles (63–200 µm). Samples with a mass of 100 g and 1,000 g (sand only) contained 75 mg of each microplastic. After electrostatic separation, the mass of sand samples was reduced by 98%. Sediment samples showed a mass reduction of 70–78%. After density separation, the total mass reduction of sediment samples was above 99%. The increased concentration of total organic carbon seems to have the highest impact on mass reduction by electrostatic separation. Nevertheless, the recovery of microplastic was independent of the particulate matrix and was polymer-specific. In 100 g samples, the average recovery rates for PCL, LD-PE, and PET were 74 ± 9%, 93 ± 9%, and 120 ± 18%, respectively. The recoveries of microplastic from 1,000 g samples were 50 ± 8%, 114 ± 9%, and 82 ± 11%, respectively. In scale up experiments, high recoveries of all microplastics were observed with a decrease in standard deviation. Moreover, the biodegradable polymer PCL could be used as an internal standard to provide quality assurance of the process. This method can overcome the current limitations of routine microplastic analysis in particulate matrices. We conclude that this method can be applied for comprehensive microplastic monitoring in highly polluted sediments. More studies on electrostatic separation and polymer-specific recovery rates in complex matrices are proposed.

No description available.

Dagens intensiva användning av plast genererar mikroplaster som på olika sätt sprids ut i vår omgivning och medför risker för naturliga system världen över. Dessa mikroplaster härrör från bland annat hushåll, industrier och deponier, och färdas ofta med avloppsvattten och i viss utsträckning dagvatten till reningsverk. Där renas vattnet och en stor del av mikroplasterna ansamlas i det slam som bildas i samband med vattenreningen. Slammet består till stora delar av organiskt material och näring, och betraktas ofta som en resurssnarare än avfall. Cirka 50 % av det slam som bildas i europeiska reningsverk används som gödningsmedel inom jordbruk. Det innebär att slamgivor potentiellt är källor för spridning av stora mängder mikroplast. Idag är kunskapen om mikroplaster i slam relativt liten och en standardiserad metod för extrahering av mikroplaster ur slam saknas, vilket begränsar möjligheten att se problemets magnitud. Detta examensarbete strävar efter att bidra till utformandet av en sådan metod, och undersöker förekomsten av mikroplaster i slam från Ekeby reningsverk i Eskilstuna och Käppalaverket på Lidingö utanför Stockholm med hjälp av två olika metoder. De båda metoderna kombinerar oxidativ nedbrytning med hjälp av fenton-reagens och densitetseparering för att skilja mikroplaster från organiskt och inorganiskt material. Skillnaden mellan de olika metoderna är att den ena innehåller ett oxiderande moment och den andra två. Rapporten behandlar huruvida det extra oxiderande momentet har någon betydande skillnad för utvinningen av mikroplaster ur slam, samt om förekomsten av mikroplasterskiljer sig åt mellan slam från de två olika reningsverken. Resultaten visar att det finns en skillnad mellan de två extraheringsmetoderna samt viss skillnad mellan förekomsten av mikroplaster i de olika slammen. I rapporten diskuteras huruvida skillnaden mellan resultaten av de två olika metoderna beror på det extra oxiderande momentet, eller andra tillkommande effekter. Vad gäller mikroplasters förekomst i slam från de olika reningsverken fastslås att de skiljer sig åt kvantitativt, och i viss mån även kvalitativt.

Over the past decade, research on microplastic pollution has gained significant attention. Research regarding microplastic occurrence in freshwater fish, however is still scarce. While possible pathways have been investigated, passive transfer via ingestion of prey, and possible bioaccumulation in different organs remains relatively unstudied. The scope of the work presented here was to examine microplastic occurrence in brown trout (Salmo trutta) and its main prey European smelt (Osmerus eperlanus) from Lake Vänern, Sweden. Further, my aim was to investigate for microplastics different organs such as stomach, liver, heart and intestine. Brown trout were collected by sport fishermen at sport fishing contests in Lake Vänern. All dissected organs were treated with hydrogen peroxide (H2O2) and particles were analysed and identified using Fourier transform infrared spectroscopy (FTIR). Microplastics were found in 94% of brown trout with 43% coming from the intestine, 41% from the stomach and 16% from the gastrointestinal tract of smelt. There was a significant difference in microplastic abundance between organs. No microplastics were fund in the liver or heart of brown trout. Fibres were the most abundant shape (95%) and black the most occurring colour (44%). The most abundant polymer types were neoprene, chlorosulfonated polyethylene and hydrogenated nitrile rubber and the smallest analysed particle was 100 m while the largest was 4.9 mm. In conclusion, my study confirmed the presence of microplastics in brown trout and its main prey from Lake Vänern, Sweden. Future research should focus on prey fish and different organs to give a better understanding of trophic transfer within the aquatic food web, and its possible bioaccumulation. / Under det senaste decenniet har forskningen om mikroplastföroreningar fått stor uppmärksamhet, men det finns fortfarande få undersökningar om mikroplastens förekomst i sötvattensfisk. Även om möjliga vägar har undersökts, är forskning på passiv överföring via intag av bytesdjur och eventuell bioackumulering i olika organ fortfarande relativt outforskat. Syftet med det arbete som presenteras här var att undersöka förekomsten av mikroplaster i öring (Salmo trutta) och dess huvudsakliga bytesdjur europeisk nors (Osmerus eperlanus) från Vänern, Sverige. Vidare var mitt mål att undersöka om det fanns mikroplaster i olika organ som mage, lever, hjärta och tarm. Öring samlades in av sportfiskare vid olika sportfisketävlingar i Vänern. Alla dissekerade organ behandlades med väteperoxid (H2O2) och partiklar analyserades och identifierades med hjälp av Fourier transform infraröd spektroskopi (FTIR). Mikroplaster hittades i 94 % av öringarna, där 43% kom från tarmen, 41% från magsäcken och 16% från mag- och tarmkanalen hos nors. Det fanns en signifikant skillnad i mikroplastmängden mellan organen. Inga mikroplaster hittades i lever eller hjärta hos öring. Fibrer var den vanligaste formen (95%) och svart den vanligaste färgen (44%). De vanligaste polymertyperna var neopren, klorsulfonerad polyeten och hydrerat nitrilgummi. Den minsta analyserade partikeln var 100 m medan den största var 4,9 mm. Sammanfattningsvis bekräftar min studie förekomsten av mikroplaster i öring och dess huvudsakliga föda från Vänern, Sverige. Framtida forskning bör fokusera på bytesfiskar och olika organ för att ge en bättre förståelse för trofisk överföring inom den akvatiska näringsväven, såsom möjlig bioackumulering.

京都大学 / 新制・課程博士 / 博士(地球環境学) / 甲第25467号 / 地環博第253号 / 新制||地環||51(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)准教授 田中 周平, 教授 越後 信哉, 教授 梶井 克純 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

Material av plast är praktiska och användbara, vilket medför att de återfinns i många produkter som används i vardagen. På grund av dess egenskaper har framställning av produkter och användning av plast ökat sedan massproduktionen av plast började. Mikroplast definieras som plastobjekt med en storlek mindre än 5 millimeter. Eftersom att material av plast förekommer i många produkter så har det lett till en spridning av mikroplast som påträffas på flertalet platser i naturen runtom i världen. Svenska Miljöinstitutet, IVL, har granskat kartlagda uppkomstkällor till och spridningen av mikroplaster i Sverige. De två största landbaserade källorna till mikroplast är slitage av vägbanor och däck respektive mikroplast från konstgräsplaner. Utifrån kartläggningen sker spridning vidare till omgivningen och därför är det angeläget att undersöka belastningen som kan förekomma i dagvattnet från dessa källor. I den här studien har mängden mikroplast undersökts med en minsta storleksfraktion på 100 mikrometer i dagvatten från trafikvägen Bolandsgatan och konstgräsplanen Stenhagens IP i Uppsala. Provtagning utfördes på dagvatten i dagvattenbrunnar genom att ta stickprov och med en provtagare som möjliggjorde flödesproportionell provtagning. Insamlade prover filtrerades där mikroplast sedan analyserades visuellt i stereomikroskop. Analysen av mikroplast kombinerades även med ett smälttest. I undersökningen av den trafikerade vägen Bolandsgatan var 98 % av alla partiklar svarta. De svarta partiklarna kategoriserades som mikroplast som har uppkommit i samband med slitage av vägtrafik. Vid undersökning av konstgräsplanen Stenhagens IP påträffades ett gräsfragment som kategoriserades som mikroplast från konstgräsplanen.  Mikroplastmängden i dagvatten från den trafikerade vägen Bolandsgatan erhölls till 33 kg/år. Emissionsfaktorn för blandad trafik beräknades till 2,2∙10-5 kg/fordonskm. Emissionsfaktor för mikroplast från däck, som beräknats utifrån mätningar i dagvatten från vägtrafik, har inte presenterats i tidigare studier. Från vägtrafiken i Uppsala kommun och Sverige erhölls mängden till 27 000 kg/år respektive 1,5∙106 kg/år. Från konstgräsplanen Stenhagens IP var mängden mikroplast 6,3∙10-2 kg/år. Från konstgräsplaner i Uppsala kommun och Sverige erhölls mängden till 0,56 kg/år respektive 48 kg/år. Vid beräkning av mikroplastmängder finns det en osäkerhet i bestämningen av volymen, ökar partikelradien med en faktor 2 så ökar volymen 8 gånger. Enligt den här studien är mikroplastmängder från vägtrafik i Sverige ungefär 5 gånger mindre än Naturvårdsverkets uppskattning, mängder från konstgräsplaner i Sverige är ungefär 30-50 gånger mindre än Naturvårdsverkets resultat. / Materials made from plastic are practical and durable, therefore plastic is found in many every day products. Because of the properties of plastics, the manufacturing of products and usage of the material has increased consequently leading to the creations of microplastics in varying sizes. The definition of microplastics is plastic materials with a size smaller than 5 millimeters. Because of a huge prevalence in products the consequence is microplastics being found on many places in nature around the world. The Swedish Environmental Research Institute, IVL, has been assigned by the Swedish Environmental Protection Agency to review identified origins and the pathways of microplastics in Sweden. According to the study the largest source of microplastics from outdoor activities on land is from road wear and the abrasion of tyres followed by artificial turfs. Since microplastics are presumed to be spread to the environment, it is of concern to investigate potential microplastic load in storm water from these sources. The investigation of microplastic amounts has been studied in sizes ≥100 micrometres in storm water from the traffic road Bolandsgatan and the artificial turf Stenhagens IP in Uppsala. Samples were collected, using random sampling and with an automatic sampler enabling flow proportional sampling. Filtration of collected water samples were carried out followed by analysing microplastic visually in a stereo microscope. The analyses of microplastics were also combined with a melting test. In the study of the traffic road Bolandsgatan 98 % of all particles were black colored. The black colored particles were identified as microplastic originated from road wear. When studying the artificial turf Stenhagens IP a grass fragment was identified as microplastic originated from the artifical turf. Microplastic amounts from the traffic road Bolandsgatan are 33 kg/year. The emission factor for mixed fleet is 2.2∙10-5 kg/vehicle km. An emission factor for microplastic from road traffic has not been presented in other studies before. The amount of microplastics from road traffic in Uppsala was estimated to 27 000 kg/year and in Sweden to 1.5∙106 kg/year. From the artificial turf Stenhagens IP the amount was 6.3∙10-2 kg/year. By upscaling the amounts of microplastics from artificial turfs in Uppsala and Sweden the amounts were estimated to 0.56 and 48 kg/year, respectively. According to this study, the spread of microplastic from road traffic in Sweden is 5 times less than the estimated value and the amount from artificial turfs is 30-50 times less compared to the investigation by the Swedish Environmental Protection Agency.