Microplastics in beach sediments of the Azores archipelago, NE Atlantic.

Oceanic islands are exposed to plastic debris that has accumulated in the open ocean, particularly in the subtropical gyres. This study investigates the abundance and typology of microplastics (from 0.1 to 5 mm) on 19 sandy beaches spread across 8 oceanic islands of the Azores archipelago. Between January and April 2016, a total of 341 particles retrieved from all beaches, were identified as microplastics. The highest concentration (50.19 ± 21.93 particles kg-1 dw) was found in Terceira Island. Beach morphology and grain size were important factors explaining microplastic concentration. Fibres were the most dominant morphology recovered (80.9 %), followed by fragments (12.3 %). Fourier transform infrared spectroscopy (FTIR) revealed that 41 % of the fibres consisted of polyester and 60 % of the fragments were polyethylene. This research underlines the widespread contamination of microplastics in oceanic islands of the Atlantic Ocean.

Ecotoxicity effect factors for plastic additives on the aquatic environment: a new approach for life cycle impact assessment.

All plastic contains additives. Once in the environment, these will start to leach out and will expose and harm aquatic biota, causing potentially lethal and sub-lethal toxic effects. Even though life cycle assessment covers the toxic impacts of several thousands of chemicals, models to assess the toxic impacts of plastic additives are only emerging. We gathered 461 data points from the literature (266 for freshwater and 195 for marine ecosystems) for 75 species belonging to 9 different phyla. The endpoints effective concentration and lethal concentration, no observed effects concentrations and lowest observed effect concentration tested in acute and chronic exposure, were harmonized into chronic values by applying extrapolation factors. The collected data points covered 75 main plastic additives. This allowed us to calculate 25 Effect factors, 19 for single chemicals and four for overarching categories (alkylphenols, benzophenones, brominated flame retardants and phosphates. In addition, we calculated an aggregated effect factor for chemicals that did not fit in any of the previous groups, as well as a Generic effect factor including 404 gathered data points. The estimated potentially affected fraction (PAF) for the single additives varied between 20.69 PAF·m3·kg-1 for diethyl phthalate and 11081.85 PAF·m3·kg-1 for 4-Nonylphenol. The factors can in future be combined with fate and exposure factors to derive a characterization factor for toxicity caused by additives in aquatic species. This is an important advancement for the assessment of the impacts of plastic debris on aquatic species, thus providing information for decision-makers, as well as guiding policies for the use of additives, ultimately aiming to make the plastic value chain more sustainable.

Nanoplastics activate a TLR4/p38-mediated pro-inflammatory response in human intestinal and mouse microglia cells.

The crescent presence of nanoplastics in the environment raises concerns regarding their potential impact on health. This study exposed human colon adenocarcinoma cells (HT29) and microglia cells (N9) to nanoplastics (25 nm, 50 nm, and 100 nm Polystyrene) to investigate their inflammatory responses, which are vital for body's defence. Although cytotoxicity remained generally low, HT29 cells exhibited a notable upregulation of p50 and p38 expression, concomitant with elevated TLR4 expression, in contrast with N9 cells that showed a less pronounced upregulation of these proteins. Additionally, nanoplastic exposure increased IL-1ß levels, partially attenuated by pre-exposure to TLR4 or p38 inhibitors. Intriguingly, N9 cells exposed to nanoplastics exhibited substantial increases in iNOS mRNA. This effect was entirely prevented by pre-exposure to TLR4 or p38 inhibitors, while TNF-α mRNA levels remained relatively stable. These findings underscore the potential of nanoplastics to activate inflammatory pathways, with response kinetics varying depending on the cell type.

The geographical and seasonal effects on the composition of marine microplastic and its microbial communities: The case study of Israel and Portugal.

Introduction: Floating microplastic debris are found in most marine environments around the world. Due to their low density and high durability, plastic polymers such as polyethylene, polypropylene, and polystyrene serve as stable floating substrates for the colonization of diverse communities of marine organisms. Despite the high abundance of microplastic debris in the oceans, it is not clear how the geographical location and season affect the composition of marine microplastic and its bacterial microbiome in the natural environment. Methods: To address this question, microplastic debris were collected from the sea surface near estuaries in the Mediterranean Sea (Israel) and in the Atlantic Ocean (Portugal) during summer and winter of 2021. The microplastic physical characteristics, including shape, color, and polymer composition, were analyzed and the taxonomic structure of the microplastic bacterial microbiome was characterized using a high-resolution metabarcoding pipeline. Results: Our results, supported by previously published data, suggest that the plastisphere is a highly diverse ecosystem which is strongly shaped by spatial and temporal environmental factors. The geographical location had the highest impact on the plastisphere physical characteristics and its microbiome composition, followed by the season. Our metabarcoding analysis showed great variability between the different marine environments with a very limited microbiome "core." Discussion: This notion further emphasizes the importance of plastisphere studies in different geographical locations and/or seasons for the characterization of the plastisphere and the identification of plastic-associated species.

Beach litter survey by drones: Mini-review and discussion of a potential standardization.

The abundance of beach litter has been increasing globally during the last decades, and it is an issue of global concern. A new survey strategy, based on uncrewed aerial vehicles (UAV, aka drones), has been recently adopted to improve the monitoring of beach macro-litter items abundance and distribution. This work identified and analysed the 15 studies that used drone for beach litter surveys on an operational basis. The analysis of technical parameters for drone flight deployment revealed that flight altitude varied between 5 and 40 m. The analysis of final assessments showed that, through manual and/or automated items detection on images, most of studies provided litter bulk characteristics (type, material and size), along with litter distribution maps. The potential standardization of drone-based litter survey would allow a comparison among surveys, however it seems difficult to propose a standard set of flight parameters, given the wide variety of coastal environments, the different devices available, and the diverse objectives of drone-based litter surveys. On the other hand, in our view, a set of common outcomes can be proposed, based on the grid mapping process, which can be easily generated following the procedure indicated in the paper. This work sets the ground for the development of a standardized protocol for drone litter data collection, analysis and assessments. This would allow the provision of broad scale comparative studies to support coastal management at both national and international scales.

Microplastics and other anthropogenic particles in Antarctica: Using penguins as biological samplers.

Microplastics (< 5 mm in size) are known to be widespread in the marine environment but are still poorly studied in Polar Regions, particularly in the Antarctic. As penguins have a wide distribution around Antarctica, three congeneric species: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarcticus) and gentoo penguins (Pygoscelis papua) were selected to evaluate the occurrence of microplastics across the Antarctic Peninsula and Scotia Sea. Scat samples (used as a proxy of ingestion), were collected from breeding colonies over seven seasons between 2006 and 2016. Antarctic krill (Euphausia superba), present in scat samples, contributed 85%, 66% and 54% of the diet in terms of frequency of occurrence to the diet of Adélie, gentoo and chinstrap penguins, respectively. Microplastics were found in 15%, 28% and 29% scats of Adélie, chinstrap and gentoo penguin respectively. A total of 92 particles were extracted from the scats (n = 317) and 32% (n = 29) were chemically identified via micro-Fourier Transform Infrared Spectroscopy (µ-FTIR). From all the particles extracted, 35% were identified as microplastics, particularly polyethylene (80%) and polyester (10%). It was not possible to ascertain the identification of the remaining 10% of samples. Other anthropogenic particles were identified in 55% of samples, identified as cellulose fibres. The results show a similar frequency of occurrence of particles across all colonies, suggesting there is no particular point source for microplastic pollution in the Scotia Sea. Additionally, no clear temporal variation in the number of microplastics in penguins was observed. Overall, this study reveals the presence of microplastics across Antarctica, in three penguin species and offers evidence of other anthropogenic particles in high numbers. Further research is needed to better understand the spatio-temporal dynamics, fate and effect of microplastics on these ecosystems, and improve plastic pollution policies in Antarctica.

Drones for litter mapping: An inter-operator concordance test in marking beached items on aerial images.

Unmanned aerial systems (UAS, aka drones) are being used to map macro-litter on the environment. Sixteen qualified researchers (operators), with different expertise and nationalities, were invited to identify, mark and categorize the litter items (manual image screening, MS) on three UAS images collected at two beaches. The coefficient of concordance (W) among operators varied between 0.5 and 0.7, depending on the litter parameter (type, material and colour) considered. Highest agreement was obtained for the type of items marked on the highest resolution image, among experts in litter surveys (W = 0.86), and within territorial subgroups (W = 0.85). Therefore, for a detailed categorization of litter on the environment, the MS should be performed by experienced and local operators, familiar with the most common type of litter present in the target area. This work provides insights for future operational improvements and optimizations of UAS-based images analysis to survey environmental pollution.

Spatial and size distribution of macro-litter on coastal dunes from drone images: A case study on the Atlantic coast.

This work analyses the cross-shore (80 m) and long-shore (200 m) spatial and size distribution of macro-litter on coastal dunes, employing a mapping framework based on an Unmanned Aerial System (UAS, aka drone) and a GIS mobile application. Over the cross-shore, plastic percentage increased from 60% to 90% landwards. The largest items (processed wood) were found on the embryo dune. Plastic bottles and paper napkins were trapped by the foredune grass, while the largest fishing-related items were intercepted by the low scrub plant community on the backdune. Over the long-shore, plastic percentage and items size increased from the urbanized area towards the natural dunes. This work assessed the abundance of marine litter on coastal dune sectors, underlining the role of distinct vegetation types in trapping items of different size. The mapping framework can promote further marine litter monitoring programs and support specific strategies for protecting the dune ecosystems.

Application of failure mode and effects analysis to reduce microplastic emissions.

A complete understanding of the occurrence of microplastics and the methods to eliminate their sources is an urgent necessity to minimize the pollution caused by microplastics. The use of plastics in any form releases microplastics to the environment. Existing policy instruments are insufficient to address microplastics pollution and regulatory measures have focussed only on the microbeads and single-use plastics. Fees on the use of plastic products may possibly reduce their usage, but effective management of plastic products at their end-of-life is lacking. Therefore, in this study, the microplastic-failure mode and effect analysis (MP-FMEA) methodology, which is a semi-qualitative approach capable of identifying the causes and proposing solutions for the issue of microplastics pollution, has been proposed. The innovative feature of MP-FMEA is that it has a pre-defined failure mode, that is, the release of microplastics to air, water and soil (depending on the process) or the occurrence of microplastics in the final product. Moreover, a theoretical recycling plant case study was used to demonstrate the advantages and disadvantages of this method. The results revealed that MP-FMEA is an easy and heuristic technique to understand the failure-effect-causes and solutions for reduction of microplastics and can be applied by researchers working in different domains apart from those relating to microplastics. Future studies can include the evaluation of the use of MP-FMEA methodology along with quantitative methods for effective reduction in the release of microplastics.

Beach-dune morphodynamics and marine macro-litter abundance: An integrated approach with Unmanned Aerial System.

This work shows an integrated approach for coastal environmental monitoring, which aimed to understand the relation between beach-dune morphodynamics, marine litter abundance and environmental forcing. Three unmanned aerial system (UAS) flights were deployed on a beach-dune system at the Atlantic Portuguese coast to assess two main goals: (i) quantifying the morphological changes that occurred among flights, with focus on dune erosion, and (ii) mapping the changes of marine macro-litter abundance on the shore. Two most vulnerable-to-erosion sectors of the beach were identified. In the northern sector, the groin affected the downdrift shoreline, with dune erosion of about 1 m. In the central part of the beach, the dunes recessed about 4 m during the winter, being more exposed to environmental forcing due to the absence of dune vegetation. Marine litter occupation area on the beach decreased from 25% to 20% over the winter, with octopus pots (13%) and fragments (69%) being the most abundant items on average. Litter distribution varied in relation to swash elevation, wind speed and direction. With low swash elevation, the wind played a predominant role in moving the stranded items northwards, whereas high swash elevation concentrated the items at the dune foot. This study emphasizes the potential of UAS in allowing an integrated approach for coastal erosion monitoring and marine litter mapping, and set the ground for marine litter dynamic modelling on the shore.

Mapping marine litter on coastal dunes with unmanned aerial systems: A showcase on the Atlantic Coast.

Marine litter pollution on coastal dunes has received limited scientific attention when compared with sandy shores. This paper proposes a new framework based on the combined use of Unmanned Aerial Systems (UAS) and a mobile application to map and quantify marine macro-litter (>2.5 cm) accumulation on coastal dunes. The first application on a dune area of 200 m × 80 m at the north-east Atlantic Portuguese coast is shown. Nine different marine litter categories were found, with styrofoam fragments (23% of the total amount) and plastic bottles (20%) being the most abundant items. Plastic was the most common material (76%). The highest number of items (272) was found on the backdune, mostly related with fishing activities (octopus pots and Styrofoam fragments). In contrast, the highest density (0.031 items/m2) was found on the foredune, with the most abundant items associated with human recreational activities (for example, plastic bottles, bags, papers and napkins). Three major marine litter hotspots (~0.1 items/m2) were identified in correspondence of dune blowouts. The recognition of the primary marine litter pathways highlighted the main role that wind and overwash events play on dune contamination, and suggests that the dune ridge restoration can act as a mitigation measure for preventing marine litter accumulation on the backdune. This study shows how UAS offer the possibility of a detailed non-intrusive survey, and gives a new impulse to coastal dune litter monitoring, where the long residence time of marine debris may threaten the bio-ecological equilibrium of these ecosystems.

Microplastics in gentoo penguins from the Antarctic region.

There is growing evidence that microplastic pollution (<5 mm in size) is now present in virtually all marine ecosystems, even in remote areas, such as the Arctic and the Antarctic. Microplastics have been found in water and sediments of the Antarctic but little is known of their ingestion by higher predators and mechanisms of their entry into Antarctic marine food webs. The goal of this study was to assess the occurrence of microplastics in a top predator, the gentoo penguin Pygoscelis papua from the Antarctic region (Bird Island, South Georgia and Signy Island, South Orkney Islands) and hence assess the potential for microplastic transfer through Antarctic marine food webs. To achieve this, the presence of microplastics in scats (as a proof of ingestion) was investigated to assess the viability of a non-invasive approach for microplastic analyses in Antarctic penguins. A total of 80 penguin scats were collected and any microplastics they contained were extracted. A total of 20% of penguin scats from both islands contained microplastics, consisting mainly of fibers and fragments with different sizes and polymer composition (mean abundance of microplastics: 0.23 ± 0.53 items individual-1 scat, comprising seven different polymers), which were lower values than those found for seabirds in other regions worldwide. No significant differences in microplastic numbers in penguin scats between the two regions were detected. These data highlight the need for further assessment of the levels of microplastics in this sensitive region of the planet, specifically studies on temporal trends and potential effects on penguins and other organisms in the Antarctic marine food web.

An assessment of the ability to ingest and excrete microplastics by filter-feeders: A case study with the Mediterranean mussel.

Plastic debris has been recognized as a growing threat to marine biota due to its widespread distribution and possible interactions with marine species. Concerns over the effects of plastic polymers in marine ecosystems is reflected in the high number of toxicological studies, regarding microplastics (<5 mm) and marine fauna. Although several studies reported that organisms ingest and subsequently eliminate microplastics (MP), the potential effects at organ and tissue level remain unclear, especially considering exposure to different microplastic sizes and concentrations. The present study aimed at investigating potential pathophysiological effects of the ingestion of MP by marine filter-feeders. For the purpose, Mediterranean mussel (Mytilus galloprovincialis) was exposed to spherical polystyrene MP (2 and 10 µm Ø) over short- and medium-term exposure periods, under single and combined concentrations that represent high, yet realistic doses (10 and 1000 MP mL-1). Overall, results suggest rapid MP' clearance from water column by filtering, regardless of MP size. Ingestion occurred, identified by MP in the lumen of the gut (mostly in midgut region), followed by excretion through faeces. However, no MP were found in gills or digestive gland diverticula. Biochemical indicators for oxidative stress were generally irresponsive regardless of organ and time of exposure. Small foci of haemocytic infiltration in gastric epithelia were found, albeit not clearly related to MP ingestion. Globally, no evident histopathological damage was recorded in whole-body sections of exposed animals. The present findings highlight the adaptative ability of filter-feeding bivalves to cope with filtration of suspended MP, resulting in rapid elimination and reduced internal damage following ingestion of spherical MP. Nevertheless, the fact that the animals are able to translocate MP to the gut reveals that filter feeding organisms may indeed became a target of concern for fragmented materials with smaller, mixed sizes and sharper edges.

Plastic ingestion and trophic transfer between Easter Island flying fish (Cheilopogon rapanouiensis) and yellowfin tuna (Thunnus albacares) from Rapa Nui (Easter Island).

Millimetre-sized fragments have been documented in many fish species, but their transfer through food webs is still poorly understood. Here we quantified and described plastic fragments in the digestive tracts of 43 Easter Island flying fish (Cheilopogon rapanouiensis) and 50 yellowfin tunas (Thunnus albacares) from coastal waters around Rapa Nui (Easter Island) in the South Pacific subtropical gyre, and of fish preyed upon by T. albacares. Overall, seven C. rapanouiensis (16%) individuals had ingested microplastics, most of which resembled the common planktonic prey of the fish. One microplastic was found in the gut of a fish ingested by a tuna, which indicates that trophic transfer may occur between tuna and prey. A single T. albacares (2%) had ingested five mesoplastics (15.2-26.3 mm) that were probably not mistaken for prey items, but rather accidentally ingested during foraging on fish prey. The absence of microplastics in T. albacares suggests that such small particles, if transferred from the prey, do not accumulate in the relatively large digestive tract of large predators. On the other hand, larger plastic items may accumulate in the gut of tunas, to which they may induce deleterious effects that still need to be examined. However, only a small portion of the fish had ingested mesoplastics. The results of this study suggest that microplastic contamination is not an immediate threat to large predatory fish, such as T. albacares, along the coast of Easter Island within the South Pacific subtropical gyre.

Longitudinal Melanonychia Biopsy: What Not to Do.

The nail matrix biopsy is an important technique in confirming or excluding a diagnosis of melanoma in a patient with longitudinal melanonychia. Dermatologists are the first-line diagnosticians for these pigmented lesions of the nail unit, however, for different reasons, some are reluctant to perform a nail biopsy. This case demonstrates how a poor biopsy technique resulted in a misdiagnosis in a patient with melanoma in situ. J Drugs Dermatol. 2018;17(5):587-588.

Occurrence of microplastics in commercial fish from a natural estuarine environment.

Microplastic ingestion has been reported for several marine species, but the level of contamination in transitional systems and associated biota is less known. The aim of this study was to assess the occurrence of microplastic ingestion in three commercial fish species: the sea bass (Dicentrarchus labrax), the seabream (Diplodus vulgaris) and the flounder (Platichthys flesus) from the Mondego estuary (Portugal). Microplastics were extracted from the gastrointestinal tract of 120 individuals by visual inspection and digestion solution. A total of 157 particles were extracted from 38% of total fish (96% fibers), with 1.67 ±â€¯0.27 (SD) microplastics per fish. Significantly higher amount of ingested microplastics was recorded for D. vulgaris (73%). The dominant polymers identified by µ-FTIR were polyester, polypropylene and rayon (semi-synthetic fiber). It is reported for the first time the presence of this pollutant in fish populations from the Mondego estuary raising concerns on their potential negative effects.

A workflow for improving estimates of microplastic contamination in marine waters: A case study from North-Western Australia.

Plastic pollution is ubiquitous throughout the marine environment, with microplastic (i.e. <5 mm) contamination a global issue of emerging concern. The lack of universally accepted methods for quantifying microplastic contamination, including consistent application of microscopy, photography, an spectroscopy and photography, may result in unrealistic contamination estimates. Here, we present and apply an analysis workflow tailored to quantifying microplastic contamination in marine waters, incorporating stereomicroscopic visual sorting, microscopic photography and attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy. The workflow outlines step-by-step processing and associated decision making, thereby reducing bias in plastic identification and improving confidence in contamination estimates. Specific processing steps include (i) the use of a commercial algorithm-based comparison of particle spectra against an extensive commercially curated spectral library, followed by spectral interpretation to establish the chemical composition, (ii) a comparison against a customised contaminant spectral library to eliminate procedural contaminants, and (iii) final assignment of particles as either natural- or anthropogenic-derived materials, based on chemical type, a compare analysis of each particle against other particle spectra, and physical characteristics of particles. Applying this workflow to 54 tow samples collected in marine waters of North-Western Australia visually identified 248 potential anthropogenic particles. Subsequent ATR-FTIR spectroscopy, chemical assignment and visual re-inspection of photographs established 144 (58%) particles to be of anthropogenic origin. Of the original 248 particles, 97 (39%) were ultimately confirmed to be plastics, with 85 of these (34%) classified as microplastics, demonstrating that over 60% of particles may be misidentified as plastics if visual identification is not complemented by spectroscopy. Combined, this tailored analysis workflow outlines a consistent and sequential process to quantify contamination by microplastics and other anthropogenic microparticles in marine waters. Importantly, its application will contribute to more realistic estimates of microplastic contamination in marine waters, informing both ecological risk assessments and experimental concentrations in effect studies.

Low prevalence of microplastic contamination in planktivorous fish species from the southeast Pacific Ocean.

The gut contents of 292 planktivorous fish, from four families (Atherinopsidae, Clupeidae, Engraulidae and Scombridae) and seven species, captured along the coast of the southeast Pacific, were examined for microplastic contamination. Only a small fraction of all studied fish (2.1%; 6 individuals) contained microplastic particles in their digestive tract. Microplastics found were degraded hard fragments and threads, ranging from 1.1 to 4.9 (3.8±SD 2.4) mm in length, and of various colours, which suggests that the planktivorous fish species examined herein did not capture microplastics on the basis of their colour. The low prevalence of microplastic contamination in planktivorous fishes found in this study suggests that the risk of accidental ingestion by these species might be limited in the coastal upwelled waters of the southeast Pacific, perhaps due to small human population and highly dynamic oceanographic processes.

Amberstripe scad Decapterus muroadsi (Carangidae) fish ingest blue microplastics resembling their copepod prey along the coast of Rapa Nui (Easter Island) in the South Pacific subtropical gyre.

An increasing number of studies have described the presence of microplastics (≤5mm) in many different fish species, raising ecological concerns. The factors influencing the ingestion of microplastics by fish remain unclear despite their importance to a better understanding of the routes of microplastics through marine food webs. Here, we compare microplastics and planktonic organisms in surface waters and as food items of 20 Amberstripe scads (Decapterus muroadsi) captured along the coast of Rapa Nui (Easter Island) to assess the hypothesis that fish ingest microplastics resembling their natural prey. Sixteen (80%) of the scad had ingested one to five microplastics, mainly blue polyethylene fragments that were similar in colour and size to blue copepod species consumed by the same fish. These results suggest that planktivorous fish, as a consequence of their feeding behaviour as visual predators, are directly exposed to floating microplastics. This threat may be exacerbated in the clear oceanic waters of the subtropical gyres, where anthropogenic litter accumulates in great quantity. Our study highlights the menace of microplastic contamination on the integrity of fragile remote ecosystems and the urgent need for efficient plastic waste management.