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As part of the handover of the research vessel Belgica recently renamed to "Boris Aleksandrov" from Belgium to Ukraine in autumn 2021, the transfer from Zeebrugge to Odessa was undertaken - the Cruise of Three European Seas of the RV Belgica (funded by European Union and the United Nations Development programme in the framework of the EU4EMBLAS project). This cruise was used to carry out measurement campaigns of various aspects, including the analysis of sediment and water samples for microplastics (MP). A special focus was put on the sampling of surface waters in a comparative study of three sampling systems: (1) Manta trawl, (2) volume water pump, and (3) Slurp system, a newly constructed pump system, providing a kind of basin where the surface water layer converges before being pumped off. During the cruise traversing the Atlantic Ocean, the Mediterranean Sea and the Black Sea a total number of 6 sediment samples and 23 water samples with different sampling systems were taken. Due to weather conditions, all three devices for water sampling could only be applied at two of the 18 stations simultaneously. At the MRC laboratory (Hamburg) sample preparation was done via digestion of the biogenic organic material (KOH/NaClO) and subsequent density separation (NaI ¿1.7 g/cm³) of sediment samples. Samples were transferred over a 40 µm sieve with Ethanol and stained with Nile Red (1 ml/mg in chloroform). Suspensions were transferred to aluminium oxide filters (Anodisc, 0.2 µm retention, 25/47 mm diameter) and investigated via fluorescence microscopy (AxioLab A.1, Zeiss, TRITC HC Filterset (AHF), 2.5x) for potential MP particles (numbers and dimensions). A subset of particles were investigated for their polymer composition with µRaman spectroscopy (DXR2xi Raman Imaging Microscope, Thermo Fisher Scientific). Results on MP abundance in sediments and water comparing different sampling devices will be introduced and discussed. Also see: https://micro2022.sciencesconf.org/426797/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

The magnitude and patterns of atmospheric microplastic deposition rates are crucial factors for calculating the input of microplastics in the environment. Nevertheless, long-term and spatially diverse studies are scarce. In this study, the spatial distribution of atmospheric microplastic particles in urban, sub-urban and rural areas of Northern Germany was investigated in cooperation with the Hamburg Luftmessnetz and as part of the MICROLIM project (German Research Foundation, DFG). Therefore, eleven structurally diverse locations in Hamburg and Mecklenburg-Western Pomerania were equipped with bulk-deposition samplers in triplicates and sampled monthly between August 2019 and July 2020. The resulting 306 samples were treated with hydrogen peroxide (30%) and sodium hypochlorite (6-14%) to digest biological organic matter. The filters were subsequently stained with the lipophilic dye Nile Red (1 mg/ml in chloroform) and underwent microplastic identification via fluorescence microscopy (Axioscope 7, Zeiss). A subset of particles identified as synthetic particles were analysed for their composition using μRaman spectroscopy (DXR2xi Raman Imaging Microscope, Thermo Fisher Scientific). Particles and fibers were quantified down to a cut-off size of 10 µm. The results were compared to the small-scale meteorological data recorded at each investigation site. The study shows that the microplastic deposition rate for Northern Germany (89 ± 61 MP/m²/day) is in the same order of magnitude as those reported by previous studies. Significant differences in microplastic deposition rates and particle morphology were found between urban, sub-urban and rural sampling sites. Population density was identified as an important factor for larger amounts of microplastics and higher shares of fibers in urban samples. Special attention was given to the canopy cover at two forested sampling sites. Sampling throughout the leaf-bearing and leafless period revealed an influence of the comb-out effect on atmospheric microplastic deposition rates for deciduous forests. Also see: https://micro2022.sciencesconf.org/424719/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Harbors pose an unique environment of increased anthropogenic pressure and artificial river morphology that are of specific interest concerning microplastic release and accumulation. To address the specific situation in the Hamburg port area we conducted a study in cooperation with the Hamburg Port Authority (HPA). Sediment samples in depth profiles were taken at seven sites with similar flow velocity and underlying morphology. Two sites are located upstream and downstream of the port of Hamburg, while four sites are located in the center area of the port. One additional site takes into account an estuary of a receiving stream flowing into the Upper river Elbe. For the analysis of microplastic concentrations in the samples, the biogenic organic matter was removed by digestion (H2O2 10% and NaClO 6-14%) followed by wet sieving and a density separation with NaI (density: 1.5 - 1.6 g/cm3). For identification the Nile red staining method in combination with fluorescence microscopy (AxioLab A.1, Zeiss, TRITC HC Filterset (AHF), 2.5x) was applied. A subset of 101 identified synthetic polymers was investigated for polymer composition via µRaman spectroscopy (DXR2xi Raman Imaging Microscope, Thermo Fisher Scientific). A total number of 31 sediment samples divided into different depths below riverbed level were examined. Detailed results of sites and depths concentrations, morphologies and polymer composition will be presented during the conference. In brief, 11,280 microplastic particles could be found in total. Both the highest and lowest number of particles were detected at center port sites ranging from 60 to 21,799. Fragments are the dominating particle morphology throughout all locations, except for one center harbor site where microbeads are most common. Most common synthetic polymers were detected to be PVC (34 %) and PET (28 %). Also see: https://micro2022.sciencesconf.org/426148/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Recent proof of the presence of microplastics (MP) in the human body, especially in the digestive system and stool, support the theory of ingestion being a viable route for MP uptake in humans. This raises food safety concerns, particularly for seafood, as studies around the world frequently report the ingestion of plastic particles by aquatic organisms. However, for risk assessment detailed information on the occurrence of MP in edible tissues is required. Despite first quantitative assessments of MP in the edible parts of several seafood products, comparing results of different studies is difficult due to the diversity of methods and their validity. In recent years interlaboratory comparison studies highlighted the need for method harmonisation and standardisation. This study aimed to contribute to method development and standardisation by evaluating and optimising promising approaches for analysing small plastic particles in the edible part of seafood products. Numerous techniques are described in literature; however, they are often time consuming, or require exclusive equipment, thus, limiting their applicability for routine analysis e.g., in food control. Consequently, methods are not only compared regarding analytical performance (e.g., sensitivity, precision), but also regarding complexity, accessibility and sample throughput. For sample preparation, a combined enzymatic-alkaline digestion with consecutive filtration and oxidative treatment of the filters was the most promising approach; suitable for MP analysis with optical and mass-based methods. Within on-going research activities, the potential of fast and/or easily accessible analytical techniques, including methods like fluorescence microscopy, confocal laser scan, differential scanning calorimetry and quantitative NMR-spectroscopy, is compared to currently often applied techniques (FTIR, Raman, Pyrolysis-GC/MS). Preliminary results indicate, that there is no "one-fits-all"-method for all analytical needs yet. In particular, in the case of nanoplastic analysis, significant method development is still required. Also see: https://micro2022.sciencesconf.org/424833/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Within the HELCOM BLUES project Activity 3 "Marine Litter" aims to support the work of the EU's MSFD Technical Group on Marine Litter (TG Litter), as well as to promote the harmonisation of regional work on marine litter indicators and threshold values with TG Litter work. Therefore, guidelines on monitoring microlitter in seabed sediments and surface water have been drafted according to existing approaches and feasibility. These draft guidelines are currently applied within a case study to seabed sediments from the southern Baltic Sea. In total, 29 grab sediment samples were taken in cooperation with Federal Agencies of Schleswig-Holstein and Mecklenburg Western-Pomerania in 2021 and 2022. Sampling areas were located in Flensburg fjord, Kiel fjord, Lübeck bay, Warnow estuary and Pomeranian bay. Three samples with increasing distance to the coastline were taken within each area. Additionally, three offshore stations within the Exclusive Economic Zone (EEZ) were included in the study. Sample preparation consisted of biogenic organic matter removal by adding a digestion solution (NaClO 6-14 % and KOH 10M) with subsequent wet sieving (20 µm) and density separation with NaI (density: 1.7 g/cm3). Sample suspensions were stained with Nile red (1 mg/ml in chloroform) and transferred to aluminium oxide filters (Anodisc 25, Whatman, 0.2 µm retention). Potential microplastic particles were detected via fluorescence microscopy (Axioscope 5/7 KMAT, Zeiss). A subset of identified microplastic particles were investigated for their polymer composition via µRaman spectroscopy (DXR2xi Raman Imaging Microscope, Thermo Fisher Scientific). According to preliminary results, a total of 7,688 particles are recorded comprising predominately fragments (89 %), followed by microbeads (9 %) and fibers (4 %). Within the areas of Flensburg fjord, Kiel fjord, Lübeck bay and Pomeranian bay decreasing microplastic particles per kg dry weight with increasing distance from the coastline are detected. Also see: https://micro2022.sciencesconf.org/425647/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Recent studies on the atmospheric deposition of microplastic particles in the greater Hamburg area, showed evidence of particle retention within the canopy of forests. That is what set us off to investigate the canopy of urban trees in parallel to further atmospheric investigations. Four sampling stations were selected representing different anthropogenic pressures. At each sampling station, fresh leaves from the outer crown area of two individuals of lime (Tilia spp.) or oak (Quercus robur) were taken in three different expositions to the adjacent road once in early summer and once in autumn 2021. Furthermore, the underlying sediment or soil was sampled in early summer in 4 replicates each. In the MRC laboratory, leave samples were put into (1) filtered MilliQ water and (2) SDS solution and subsequently shaken in a standardised manner over 30 minutes. Concerning sediment samples the biogenic organic matter was digested (H2O2 - NaClO), and samples underwent density separation (NaI, ¿1.5 g/cm3). Sample suspensions were transferred to cellulose filters, stained with Nile Red (1 mg/ml in chloroform) and investigated with fluorescence microscopy (Axioscope 5/7 KMAT, Zeiss) for microplastic particle counts and dimensions. A subset of potentially identified synthetic particles were investigated for their polymer composition via Raman spectroscopy (DXR2xi Raman Imaging Microscope, Thermo Fisher Scientific). Microplastics are found in all samples investigated. Microplastic mean concentrations in leaf samples are 493 ± 231 particles per m2 of leaf surface. Mean concentrations of microplastics in associated sediments are 17.174,2 (±11.643) per kg dry weight. Both for leaf and sediment samples, highest concentrations are found at a central investigation site affected by high anthropogenic pressure. Results are closely linked to the findings on microplastics in atmospheric deposition (see talk given by Malin Klein, MRC, Hamburg). Also see: https://micro2022.sciencesconf.org/425652/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

Recent studies on plastic particle release from baby feeding bottles have shown conflicting results. In order to gain further insights here, we conducted this comparative study in cooperation with Greenpeace e.V. and the German Midwifery Association. We included eleven bottles from different brands and models with different bottle materials (plastic, glass, and stainless steel). In order to mimic realistic conditions, the bottles were exposed to different conditions of use. This included the sterilization of the bottles, the shaking of bottles with filtered MilliQ water at different temperatures (20, 45 and 70 °C), a long-time exposure to continuous shaking over 28 d and mechanical stress of repeated screwing and unscrewing of the bottle cap (20, 40 and 60 times). All tests have been carried out in triplicates, all experimental scenarios included the analysis of blank samples. The resulting sample suspensions were transferred onto glass fibre filters and further analysed applying Nile Red staining, fluorescence microscopy (AxioLab A.1, Zeiss, TRITC HC Filterset (AHF), 2.5x) for counting and measuring of microplastic particles ¿4 µm. Polymer composition was recorded on a subset of particles via μRaman spectroscopy (DXR2xi Raman Imaging Microscope, Thermo Fisher Scientific). The study shows that the release of microplastic particles is above all a factor of the brand and to a lesser extent the bottle material. With regard to the scenarios investigated, the factor of temperature has the greatest influence on particle release. The duration of use (simulated in the shaking test) does not show any temporal trends, which speaks for a continuous, uniform release. The test for release through mechanical stress (simulated in the screw test) indicates that a relevant proportion of microplastic particles are introduced into the bottle by screwing and unscrewing the cap, though, this value does not increase through further repetitions. Also see: https://micro2022.sciencesconf.org/425650/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano

The potential uptake of microplastics by humans is currently in the focus of many studies dealing on croplands. For our study we chose the seasonal crops asparagus and strawberries, as their cultivation usually require the use of plastic mulch film and thus, fruits are expected to be prone for microplastic contamination. Samples of asparagus and strawberries were collected during the growing season of 2021 around the Hamburg region in northern Germany. Sample category groups included freshly harvested and packaged (fresh versus frozen) products. Packaging consisted both of paper and plastics. Overall, 36 different samples were analyzed at the MRC laboratory. In brief, fresh asparagus were peeled and peels and peeled fruit were treated separately. Concerning strawberries, the fruit and the calyx leaves were treated accordingly. Sample suspensions were prepared by adding samples to (1) filtered MilliQ water and (2) ethanol followed by shaking the suspensions in a standardized manner. Suspensions were transferred to filters followed by staining with Nile Red (1 mg/ml in chloroform) and fluorescence microscopy (Axioscope 5/7 KMAT, Zeiss). A subset of identified microplastic particles were randomly selected and investigated for their polymer composition via µRaman spectroscopy (DXR2xi Raman Imaging Microscope, Thermo Fisher Scientific). Microplastics are detected within all samples investigated, concentrations however differ between categories, most notably between fresh and frozen products. Within asparagus samples, lower concentrations were detected in freshly harvested samples compared to packaged samples. Peeling asparagus results in a distinct reduction of microplastic contamination. Strawberry samples show significantly higher concentrations in frozen products compared to their fresh counterpart. The predominant morphology within all samples consisted of fragments, though, the share of fibers in fresh samples of strawberries is elevated compared to frozen samples. Polymer composition of microplastics found were predominately PE and PA (fragments) or PET (fibers). Also see: https://micro2022.sciencesconf.org/425648/document, In MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nano