PFAS-free superhydrophobic chitosan coating for fabrics

In view of health and environmental concerns, together with the upcoming restrictive regulations on per- and polyfluoroalkyl substances (PFAS), less impactful materials must be explored for the hydrophobization of surfaces. Polysaccharides, and especially chitosan, are being explored for their desirable properties of film formation and ease of modification. We present a PFAS-free chitosan superhydrophobic coating for textiles deposited through a solvent-free method. By contact angle analysis and drop impact, we observe that the coating imparts hydrophobicity to the fabrics, reaching superhydrophobicty (θA = 151°, θR = 136°) with increased amount of coating (from 1.6 g/cm2). This effect is obtained by the combination of chemical water repellency of the modified chitosan and the nano- and micro-roughness, assessed by SEM analysis. We perform a comprehensive study on the durability of the coatings, showing good results especially for acidic soaking where the hydrophobicity is maintained until the 8th cycle of washing. We assess the degradation of the coating by a TGA-IR investigation to define the compounds released with thermal degradation, and we confirm the coating's biodegradability by biochemical oxygen consumption. Finally, we demonstrate its biocompatibility on keratinocytes (HaCaT cell line) and fibroblasts (HFF-1 cell line), confirming that the coating is safe for human skin cells.

Indigo-dyed cellulose fibers and synthetic polymers in surface-feeding seabird chick regurgitates from the Gulf of Alaska

We provide evidence of anthropogenic materials ingestion in seabirds from a remote oceanic area, using regurgitates obtained from black-legged kittiwake (Rissa tridactyla) chicks from Middleton Island (Gulf of Alaska, USA). By means of GPS tracking of breeding adults, we identified foraging grounds where anthropogenic materials were most likely ingested. They were mainly located within the continental shelf of the Gulf of Alaska and near the Alaskan coastline. Anthropogenic cellulose fibers showed a high prevalence (85 % occurrence), whereas synthetic polymers (in the micro- and mesoplastics dimensional range) were less frequent (20 %). Most fibers (60 %) were blue and we confirmed the presence of indigo-dyed cellulosic fibers, characteristic of denim fabrics. In terms of mass, contamination levels were 0.077 μg g-1 wet weight and 0.009 μg g-1 wet weight for anthropogenic microfibers and synthetic polymers, respectively. These results represent the only recent report of contamination by anthropogenic fibers in seabirds from the Gulf of Alaska.

Application of non-lethal bioSPME-LC-MS/MS for the detection of human pharmaceuticals in soft corals: A survey at the North Nilandhe atoll (Maldives)

At present the information regarding the occurrence of human pharmaceuticals (PhaCs) in coral reefs and their potential impacts on the associated fauna is limited. To optimize the collection of data in these delicate environments, we employed a solid-phase microextraction (bioSPME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) procedure that enabled in vivo determinations in soft corals. Specifically, we researched the antibiotics Ofloxacin Sulfamethoxazole and Clarithromycin, the anti-inflammatory Diclofenac Propyphenazone Ketoprofen and Amisulpride, the neuroactive compounds Gabapentin-lactam, the beta-blocker Metoprolol and the antiepileptic Carbamazepine. Reproducibility was between 2.1% and 9.9% and method detection limits LODs) were between 0.2 and 1.6 ng/g and LOQs between 0.8 and 5.4 mg/g. The method was then applied to establish a baseline for the occurrence of these compounds in the Maldivian archipelago. Colonies of Sarcophyton sp. and Sinularia sp. were sampled along an inner-outer reef transect. Five of the ten targeted PhaCs were identified, and 40% of the surveyed coral colonies showed the occurrence of at least one of the selected compounds. The highest concentrations were found inside the atoll rim. Oxoflacin (9.5 ± 3.9 ng/g) and Ketoprofen (4.5 ± 2.3 ng/g) were the compounds with the highest average concentrations. Outside the atoll rim, only one sample showed contamination levels above the detection limit. No significant differences were highlighted among the two surveyed soft coral species, both in terms of average concentrations and bioconcentration factors (BCFs).

Phthalate levels in common sea anemone Actinia equina and Anemonia viridis: A proxy of short-term microplastic interaction?

Phthalates are widely employed plasticizers blended to plastic polymers that, during plastic aging and weathering are prone to leach in the surrounding environment. Thus, phthalates were proposed to indirectly evaluate MPs contamination in marine environments, with still uncertain and scarce data, particularly for wildlife. This study investigates simultaneously microplastics (MPs) and phthalates (PAEs) occurrence in wild Actinia equina and Anemonia viridis, two common and edible sea anemone species. Both species had a 100 % frequency of MPs occurrence, with similar average concentrations. PAEs were detected in 70 % of samples, with concentrations up to 150 ng/g in A. equina and 144.3 ng/g for A. viridis. MPs and PAEs present in sea anemone tissues appear to reflect seawater plastic contamination conditions in the study area. Given the rapid biodegradation of PAEs, occurrence and concentrations of both these additives and their metabolites could be useful tracers of short-term plastic debris-biota interactions.

Occurrence of phthalic acid esters (PAEs) and active pharmaceutical ingredients (APIs) in key species of anthozoans in Mediterranean Sea

The Mediterranean Sea's biodiversity is declining due to climate change and human activities, with plastics and emerging contaminants (ECs) posing significant threats. This study assessed phthalic acid esters (PAEs) and active pharmaceutical ingredients (APIs) occurrence in four anthozoan species (Cladocora caespitosa, Eunicella cavolini, Madracis pharensis, Parazoanthus axinellae) using solid phase microextraction (SPME) and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). All specimens were contaminated with at least one contaminant, reaching maximum values of 57.3 ng/g for the ∑PAEs and 64.2 ng/g (wet weight) for ∑APIs, with dibutyl phthalate and Ketoprofen being the most abundant. P. axinellae was the most contaminated species, indicating higher susceptibility to bioaccumulation, while the other three species showed two-fold lower concentrations. Moreover, the potential adverse effects of these contaminants on anthozoans have been discussed. Investigating the impact of PAEs and APIs on these species is crucial, given their key role in the Mediterranean benthic communities.

Sublethal effects induced by different plastic nano-sized particles in Daphnia magna at environmentally relevant concentrations

A growing number of studies have reported the toxic effects of nanoplastics (NPs) on organisms. However, the focus of these studies has almost exclusively been on the use of polystyrene (PS) nanospheres. Herein, we aim to evaluate the sublethal effects on Daphnia magna juveniles of three different NP polymers: PS-NPs with an average size of 200 nm, polyethylene [PE] NPs and polyvinyl chloride [PVC] NPs with a size distribution between 50 and 350 nm and a comparable mean size. For each polymer, five environmentally relevant concentrations were tested (from 2.5 to 250 μg/L) for an exposure time of 48 h. NP effects were assessed at the biochemical level by investigating the amount of reactive oxygen species (ROS) and the activity of the antioxidant enzyme catalase (CAT) and at the behavioral level by evaluating the swimming behavior (distance moved). Our results highlight that exposure to PVC-NPs can have sublethal effects on Daphnia magna at the biochemical and behavioral levels. The potential role of particle size on the measured effects cannot be excluded as PVC and PE showed a wider size range distribution than PS, with particles displaying sizes from 50 to 350 nm. However, we infer that the chemical structure of PVC, which differs from that of PE of the same range size, concurs to explain the observed effects. Consequently, as PS seems not to be the most hazardous polymer, we suggest that the use of data on PS toxicity alone can lead to an underestimation of NP hazards.

The interactions of plastic with tar and other petroleum derivatives in the marine environment: A general perspective

Plastic and oil pollution are closely linked to our dependence on petroleum derivatives. Their excessive use and inefficiencies in their management, have led to negative impacts on marine ecosystems since their very introduction. Agglomerates of tar, plastic, paraffins, and other petrochemicals and oil derivatives with naturally occurring materials, are increasingly widespread in coastal environments, stalling as an iconic and readable sign of environmental degradation. Starting from a historical review of the available reports on the occurrence of similar aggregates dating back to 1971, we highlight how most of these observations are based on the morphological description of the petroleum residues with no chemical fingerprinting and are mainly related to materials stranded on the coastline, with few and unclear indications for the open sea. We discuss here a list of scientific questions and knowledge gaps, that need to be examined by future studies.

Plastitar in the Mediterranean Sea: New records and the first geochemical characterization of these novel formations

A new geological formation consisting of plastic debris admixed to petroleum oil residue, termed "plastitar", has been recently described in the Canary Islands. Here, we report its widespread occurrence across the Mediterranean coast and new insights into its biogeochemical composition. Specifically, we found marked differences in the diagenetic stable indicator profiles, suggesting a heterogeneous seeps provenance. Moreover, the 801 plastic particles found in the 1372 g of tar surveyed, with a maximum concentration of 2.0 items/g, showed interesting patterns in the tar mat, with nurdles predominantly layered in the external of the tar mat and lines in the inner core. Overall, the collected observation suggests that tar entraps plastics through a stepwise process and is a sink for them.

Hotspots of microplastic accumulation at the land-sea transition and their spatial heterogeneity: The Po River prodelta (Adriatic Sea)

Deltas are the locus of river-borne sediment accumulation, however, their role in sequestering plastic pollutants is still overlooked. By combining geomorphological, sedimentological, and geochemical analyses, which include time-lapse multibeam bathymetry, sediment provenance, and μFT-IR analyses, we investigate the fate of plastic particles after a river flood event providing an unprecedented documentation of the spatial distribution of sediment as well as of microplastics (MPs), including particles fibers, and phthalates (PAEs) abundances in the subaqueous delta. Overall sediments are characterized by an average of 139.7 ± 80 MPs/kg d.w., but display spatial heterogeneity of sediment and MPs accumulation: MPs are absent within the active sandy delta lobe, reflecting dilution by clastic sediment (ca. 1.3 Mm3) and sediment bypass. The highest MP concentration (625 MPs/kg d.w.) occurs in the distal reaches of the active lobe where flow energy dissipates. In addition to MPs, cellulosic fibers are relevant (of up to 3800 fibers/kg d.w.) in all the analyzed sediment samples, and dominate (94 %) with respect to synthetic polymers. Statistically significant differences in the relative concentration of fiber fragments ≤0.5 mm in size were highlighted between the active delta lobe and the migrating bedforms in the prodelta. Fibers were found to slightly follow a power law size distribution coherent with a one-dimensional fragmentation model and thus indicating the absence of a size dependent selection mechanism during burial. Multivariate statistical analysis suggests traveling distance and bottom-transport regime as the most relevant factors controlling particle distribution. Our findings suggest that subaqueous prodelta should be considered hot spots for the accumulation of MPs and associated pollutants, albeit the strong lateral heterogeneity in their abundances reflects changes in the relative influence of fluvial and marine processes.

On fine particulate matter and COVID-19 spread and severity: An in vitro toxicological plausible mechanism

COVID-19 pandemic had a significant impact on global public health. The spread of the disease was related to the high transmissibility of SARS-CoV-2 virus but incidence and mortality rate suggested a possible relationship with environmental factors. Air pollution has been hypothesized to play a role in the transmission of the virus and the resulting severity of the disease. Here we report a plausible in vitro toxicological mode of action by which fine particulate matter (PM2.5) could promote a higher infection rate of SARS-CoV-2 and severity of COVID-19 disease. PM2.5 promotes a 1.5 fold over-expression of the angiotensin 2 converting enzyme (ACE2) which is exploited by viral particles to enter human lung alveolar cells (1.5 fold increase in RAB5 protein) and increases their inflammatory state (IL-8 and NF-kB protein expression). Our results provide a basis for further exploring the possible synergy between biological threats and air pollutants and ask for a deeper understanding of how air quality could influence new pandemics in the future.

Effects of polypropylene nanofibers on soft corals

Current information regarding the effects of both micro- and nano-plastic debris on coral reefs is limited; especially the toxicity onto corals from nano-plastics originating from secondary sources such as fibers from synthetic fabrics. Within this study, we exposed the alcyonacean coral Pinnigorgia flava to different concentrations of polypropylene secondary nanofibers (0.001, 0.1, 1.0 and 10 mg/L) and then assayed mortality, mucus production, polyps retraction, coral tissue bleaching, and swelling. The assay materials were obtained by artificially weathering non-woven fabrics retrieved from commercially available personal protective equipment. Specifically, polypropylene (PP) nanofibers displaying a hydrodynamic size of 114.7 ± 8.1 nm and a polydispersity index (PDI) of 0.431 were obtained after 180 h exposition in a UV light aging chamber (340 nm at 0.76 Wˑm^-2ˑnm^-1). After 72 h of PP exposure no mortality was observed but there were evident stress responses from the corals tested. Specifically, the application of nanofibers at different concentrations caused significant differences in mucus production, polyps retraction and coral tissue swelling (ANOVA, p < 0.001, p = 0.015 and p = 0.015, respectively). NOEC (No Observed Effect Concentration) and LOEC (Lowest Observed Effect concentration) at 72 h resulted 0.1 mg/L and 1 mg/L, respectively. Overall, the study indicates that PP secondary nanofibers can cause adverse effects on corals and could potentially act as a stress factor in coral reefs. The generality of the method of producing and assaying the toxicity of secondary nanofibers from synthetic textiles is also discussed.

A baseline assessment of the relationship between microplastics and plasticizers in sediment samples collected from the Barcelona continental shelf

It has been suggested that the seafloor may be a sink for the plastic debris that enters the ocean. Therefore, the collection of data in the seafloor sediments regarding the co-presence of microplastics (MPs) and contaminants associated to plastic is considered a relevant topic. However, the number of studies addressing their possible correlation in this environment is still limited, and very little is known about the mechanisms that determine the release of plastic additives from plastic items. Starting from this basis, we investigated the presence of MPs and eleven phthalic acid esters (PAEs) in the continental shelf offshore Barcelona. Following a shelf-slope continuum approach, we sampled sediments from five stations, and we performed analysis by means of infrared micro spectroscopy (µFTIR) and liquid chromatography tandem mass spectrometry (LC-MS/MS). MPs were found to range from 62.0 to 931.1 items/kg d.w. with maximum concentration in the submarine canyon Besòs and at the highest depth. Moreover, different trends in the size distribution of fibers and non-fibers were observed, indicating the occurrence of a size dependent selection mechanism during transport and accumulation. PAEs resulted comprised between 1.35 to 2.41 mg/kg with Di(2-ethylhexyl)phthalate (DEHP) the most abundant congeners (1.04 mg/kg). Statistical analysis revealed no correlation between the Σ₁₁PAEs and the total MPs concentration, but correlation between DEHP and fibers (σ = 0.667, p = 0,037), that resulted both correlated to the distance to the coast (ρ = 0.941 with p = 0,008 and ρ = 0.673 with p = 0.035, respectively).

Microplastics in the first-year sea ice of the Novik Bay, Sea of Japan

Sea ice is heavily contaminated with microplastics particles (MPs, <5 mm). First-year sea ice cores (38-41 cm thick) were taken in the beginning of spring in a narrow populated bay of the Sea of Japan. Two ice cores were examined (layer-by-layer, excluding surface) for MPs content: one using μ-FTIR for 25-300 μm (SMPs), and another one - with visual+Raman identification for 300-5000 μm particles (LMPs). The integral (25-5000 μm) bulk mean abundance of MPs was found to be 428 items/L of meltwater, with fibers making 19 % in SMPs size range and 59 % in LMPs. Integral mean mass of MPs was estimated in 34.6 mg/L, with 99.6 % contribution from fragments of LMPs. Comparison with simple fragmentation models confirms deficit of SMPs (especially of fibers in size range 150-300 μm), suggested to result from their leakage with brine. Multivariate statistical analysis indicates strong positive correlation of large fiber (>300 μm) counts and ice salinity.

Detection of microplastics and phthalic acid esters in sea urchins from Sardinia (Western Mediterranean Sea)

The occurrence of microplastics (MPs) and phthalic acid esters (PAEs) in wild purple sea urchins (Paracentrotus lividus) of Sardinia (Italy, Western Mediterranean Sea) was surveyed. Specifically, MPs were analyzed in the digestive tract by μFTIR and PAEs in the gonads by SPME-LC-MS/MS. 9 out of 22 specimens resulted contaminated with MPs and 20 displayed levels of PAEs over the quantification limit. A total of 23 MPs were detected with a maximum concentration of 4 microplastics/individual in the commercially undersized specimens. PAEs displayed average concentration of 32 ng/g, σ = 5.3 with maximum value of 77 ng/g. The most abundant congeners were DEHP (17 ng/g, σ = 4.3) and DBP (10 ng/g, σ = 2.5). Statistical analysis showed correlation between DEHP and fiber concentrations and among the concentration of MEP, DEP, DBP and BBzP. Due to local use of sea urchin gonads as gourmet delicacy, the potential human exposition to MPs and PAEs by consumption is also discussed.

Microplastic contamination in terrestrial ecosystems: A study using barn owl (Tyto alba) pellets

Microplastics (MPs) are recognised as an emerging environmental problem that needs to be carefully monitored. So far, MPs have been widely recorded in marine and freshwater ecosystems. Still, few studies have focused on MP occurrence in terrestrial ecosystems, although soils are suspected to be one of the main MP reservoirs. To test a non-invasive method for assessing MP contamination in terrestrial ecosystems, we analysed the pellets of a top terrestrial predator, the barn owl (Tyto alba). Sixty pellets were collected from three agricultural areas (20 pellets each) and analysed to assess both barn owl diet and MP content. Thirty-four MPs were confirmed by micro-Fourier Transform Infrared Spectroscopy (μ-FTIR) analysis in 33% of the pellets (min-max 1-5 MPs per pellet). Most of the detected items were microfibres (88.2%). Polyethylene terephthalate, polyacrylonitrile and polyamide were the most abundant polymers. One of the three sites was significantly less contaminated. In the two sites with the highest MP occurrences, barn owl diet was characterised by predation on synanthropic rodents, particularly brown rats (Rattus norvegicus), which may indicate habitat degradation and increased exposure to MPs. Analyses also suggest that Savi's pine vole (Microtus savii) is the prey least at risk of MP contamination, probably due to its strictly herbivorous diet. We argue that the analysis of barn owl pellets may represent a cost-effective method for monitoring MP contamination in terrestrial ecosystems.

First detection of microplastics in reef-building corals from a Maldivian atoll

The presence of microplastics in the world's oceans and their effects on marine habitats are highly concerning. As suspension-feeders, corals are very exposed to microplastics, compromising the health of coral reef ecosystems. In this study we surveyed for the first time the presence of microplastics in Maldivian reef-building corals. Aiming to determine the influence of exposure and depth on microplastic distribution, analyses were carried out on 38 individuals belonging to three different species. 58% of the investigated colonies resulted contaminated with particles within the 25-150 μm size range. The maximum concentration was encountered in a Pocillopora verrucosa colony sampled from a shallow inner reef (8.9 particles/g of coral). No significant differences in microplastic concentration were observed between different depths, exposures, sites and species. Overall, this study confirmed microplastic presence in coral reefs of the Maldivian archipelago including foundation species.

Airborne and marine microplastics from an oceanographic survey at the Baltic Sea: An emerging role of air-sea interaction?

Microplastics (MPs) pollution is one of the most important problems of the Earth. They have been found in all the natural environments, including oceans and the atmosphere. In this study, the concentrations of both atmospheric and marine MPs were measured over the Baltic along a research cruise that started in the Gdansk harbour, till the Gotland island, and the way back. A deposition box (based on a combination of active/passive sampling) was used to collect airborne MPs while, marine MPs concentrations were investigated during the cruise using a dedicated net. Ancillary data were obtained using a combination of particle counters (OPC, LAS and CPC), Aethalometer (AE33 Magee Scientific), spectrofluorometer (sea surface samples, Varian Cary Eclipse), and meteorological sensors. Results showed airborne microplastics average concentrations higher in the Gdansk harbour (161 ± 75 m^-3) compared to the open Baltic Sea and to the Gotland island (24 ± 9 and 45 ± 20 m^-3). These latter values are closer to the ones measured in the sea (79 ± 18 m^-3). The MPs composition was investigated using μ-Raman (for the airborne ones) and FTIR (for marine ones); similar results (e.g. polyethylene, polyethylene terephthalates, polyurethane) were found in the two environmental compartments. The concentrations and similar composition in air and sea suggested a linkage between the two compartments. For this purpose, the atmospheric MPs' equivalent aerodynamic diameter was calculated (28 ± 3 μm) first showing the capability of atmospheric MPs to remain suspended in the air. At the same time, the computed turnover times (0.3-90 h; depending on MPs size) limited the transport distance range. The estimated MPs sea emission fluxes (4-18 ∗ 10⁶ μm³ m^-2 s^-1 range) finally showed the contemporary presence of atmospheric transport together with a continuous emission from the sea surface enabling a grasshopper long-range transport of microplastics across the sea.

Phthalates bioconcentration in the soft corals: Inter- and intra- species differences and ecological aspects

The bioconcentration of dimethyl phthalate (DMP) diethyl phthalate (DEP) dibutyl phthalate (DBP) butyl benzyl phthalate (BBzP), di-(2-ethy hexyl) phthalates (DEHP), mono-butyl phthalate (MBP), mono-benzyl phthalate (MBzP), mono-(2-ethy hexyl) phthalate (MEHP) in the soft corals Coelogorgia palmosa, Sinularia sp., Sarcophyton glaucum, and Lobophytum sp. was investigated. Specimens were cultured in a microcosm environment built-up at the Genova Aquarium and analyses were carried out by in vivo SPME-LC-MS/MS. The distributions of the phthalates among the four surveyed species resulted significantly different. Calculated bioconcentration factors (BCFs) showed values spanning over two orders of magnitude, from a minimum of log10 BCF_DEP = 1.0 in Sarcophyton glaucum to a maximum of log10 BCF_DBP = 3,9 calculated for Coelogorgia palmosa. Moreover, the calculated BCFs of the long chain phthalates resulted up to three orders of magnitude lower than theoretically predicted (from logK_ow), whereas BCF of short chain phthalates resulted higher. This, together with the detection of phthalic acid monoesters, suggests the presence of species-specific different metabolic transformation among the surveyed soft coral species that involve DEHP.

Detection of plastic particles in marine sponges by a combined infrared micro-spectroscopy and pyrolysis-gas chromatography-mass spectrometry approach

Plastic pollution threatens the marine environment, especially due to the adverse effects caused by micro and nano particles interacting with the marine biota. In order to provide reliable data regarding micro and nanoplastic contamination and the related impacts, efficient analytical solutions are needed. We developed a new analysis workflow that uses marine sponges to monitor plastic pollution by characterizing the plastic particles accumulated in their tissue. Specimens of cf. Haliclona (Haplosclerida) were sampled in the Maldivian archipelago. The aim was to optimize the method and to carry out a pilot study of the contamination of the related reef habitat. Particles were isolated, size fractioned, counted and submitted to morphological and chemical characterization. The constituting polymer was identified by infrared microspectroscopy for particles >25 μm, and by pyrolysis coupled with gas chromatography mass spectrometry for those <25 μm. Method recoveries were between 87 and 83% and limits of quantitation (LOQs) were between 6.6 and 30.2 ng/g. Analyses showed that 70% of the sponges presented plastic contamination, with an average of 1.2 particles/g tissue for the 25-150 μm size range, and a total plastic concentration of up to 4.8 μg/g in the 0.2-25 μm size range, with polyolefin being the most represented polymer in both size ranges. Overall, the study demonstrated the reliability of the proposed analytical workflow and of the use of sponges as biosamplers for plastic particles.

Cytotoxic Compounds from Alcyoniidae. An Overview of the Last 30 Years

The octocoral family Alcyoniidae represents a rich source of bioactive substances with intriguing and unique structural features. This review aims to provide an updated overview of the compounds isolated from Alcyoniidae and displaying potential cytotoxic activity. In order to allow a better comparison among the bioactive compounds, we focused on molecules evaluated in vitro by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, by far the most widely used method to analyze cell proliferation and viability. Specifically, we surveyed the last thirty years of research, finding 153 papers reporting on 344 compounds with proven cytotoxicity. The data were organized in tables to provide a ranking of the most active compounds, to be exploited for the selection of the most promising candidates for further screening and pre-clinical evaluation as anti-cancer agents. Specifically, we found that (22S,24S)-24-methyl-22,25-epoxyfurost-5-ene-3β,20β-diol (16), 3β,11-dihydroxy-24-methylene-9,11-secocholestan-5-en-9-one (23), (24S)-ergostane-3β,5α,6β,25 tetraol (146), sinulerectadione (227), sinulerectol C (229), and cladieunicellin I (277) exhibited stronger cytotoxicity than their respective positive control and that their mechanism of action has not yet been further investigated.

An annual study on plastic accumulation in surface water and sediment cores from the coastline of Tenerife (Canary Island, Spain)

Sediment core samples from high tide lines and in submerged zones as well as surface water samples from eight beaches of Tenerife were analysed. Sampling was conducted over a period of one year in intervals of 5 weeks. The majority of particles were found in the high tide sediment (66%), followed by water samples (23%) and finally in sediment from submerged zones (11%). Regarding the particle amount per volume (items/L), accumulation in sediment samples was statistically higher compared to water samples. Mean values of items/L were higher in high tide sediments. In high tide and water samples, mostly white and transparent particles >1 mm were found. More than 70% were represented by fragments. In sediments from submerged zones, yellow and blue microparticles (<1 mm) were predominant and 61.9% consisted of fibres. Larger particles were mainly identified as PP, PE, PS, PTFE and PVC, while polymer types of smaller particles were more variable.

Microplastics from miscellaneous plastic wastes: Physico-chemical characterization and impact on fish and amphibian development

Microplastic pollution represents a global problem with negative impacts on aquatic environment and organisms' health. To date, most of the laboratory toxicological studies on microplastics (MPs) have made use of single commercial micro and nano-polymers, which do not reflect the heterogeneity of environmental MPs. To improve the relevance of the hazard assessment, micrometer-sized plastic particles of miscellaneous non-reusable waste plastics, with size <100 µm and <50 µm (waste microplastics, wMPs), were characterized by microscopic and spectroscopic techniques and tested on developing zebrafish and Xenopus laevis by FET and FETAX assays respectively. Moreover, the modalities of wMP interaction with the embryonic structures, as well as the histological lesions, were explored by light and electron microscopy. We have shown that wMPs had very heterogeneous shapes and sizes, were mainly composed of polyethylene and polypropylene and contained metal and organic impurities, as well as submicrometric particle fractions, features that resemble those of environmental occurring MPs. wMPs (0.1-100 mg/L) caused low rate of mortality and altered phenotypes in embryos, but established species-specific biointeractions. In zebrafish, wMPs by adhering to chorion were able to delay hatching in a size and concentration dependent manner. In Xenopus embryos, which open stomodeum earlier than zebrafish, wMPs were accumulated in intestinal tract, where produced mechanical stress and stimulated mucus overproduction, attesting an irritation response. Although wMP biointeractions did not interfere with morphogenesis processes, further studies are needed to understand the underlying mechanisms and long-term impact of these, or even smaller, wMPs.

Extraction of microplastic from marine sediments: A comparison between pressurized solvent extraction and density separation

Due to the ecotoxicological effects, microplastics are considered a threat for the marine environment. Recent reports indicate their presence not only in subsurface water and in coastal beach sediments, but also in the deep-sea. Notwithstanding, there is still not a scientific consensus about the analytical procedure to be applied for their determination. In this work we compared the performance of two extraction methods: pressurized solvent extraction (PSE) and density separation. Sea sand and seafloor sediments were spiked with known amounts of polystyrene (PS), polyethylene (PE) and polypropylene (PP) microplastics and submitted to both the extraction procedures. Results showed that the PSE ensured higher recoveries for the smaller size particle fractions (89,2 ± 1.1% in the 50-150 μm range) whereas the density separation enabled precise recoveries for the larger size particles (SD = 1,5%). No significant differences in terms of blanks control were highlighted.

Evidence of microplastic ingestion by cultured European sea bass (Dicentrarchus labrax)

The presence of microplastics (MPs) in the marine environment is a concerning topic due to the ecotoxicological effects and possible seafood contamination. Data is needed to evaluate human exposure and assess risks, in the context of a healthy and beneficial seafood consumption. While microplastic ingestion by wild fish has been reported since the early 70's, farmed fish are rarely investigated. Here, for the first time the presence of microplastics in fish cultivated in the coastal water of Tenerife (Canary Island, Spain) was evaluated. From 83 examined individuals, 65% displayed microplastics in their gastrointestinal tracts, with averages between 0.6 ± 0.8 (SD) and 2.7 ± 1.85 (SD) particles per fish. The total number of microplastics detected was 119. Fibres (81%) and fragments (12%) were the predominant shapes. FTIR analysis showed that fibres were mostly composed by Cellulose (55%) and Nylon (27%), whereas fragments by PE (25%) and PP (25%).

Evaluation of chitosan aggregates as pickering emulsifier for the remediation of marine sediments

To restore the marine environments contaminated by oil spills to an acceptable state, sediments are commonly washed with seawater, and surfactants added into the aqueous solution to increase the oil recovery. However, the resulting mixture may release toxic break-down products, and the surfactants may themselves pose an environmental risk to marine species. In this work we investigated for the first time the addition of chitosan nanoparticles to the washing solution as an alternative and greener method to ensure the cleanup of contaminated sediments. Results showed 65.1 ± 6.4% of average removal from sand and seafloor sediments artificially contaminated at 4 wt % with crude oils displaying different specific gravity. These results were comparable to those obtained with commercial surfactant mixtures containing non-ionic and anionic surfactant (67.8 ± 5.2% removal). Moreover it was possible to recover the crude oil from the washing solution thanks to the reversible demulsification induced by the addition of CO₂.

Determination of phthalates in fish fillets by liquid chromatography tandem mass spectrometry (LC-MS/MS): A comparison of direct immersion solid phase microextraction (SPME) versus ultrasonic assisted solvent extraction (UASE)

Due to the increasing presence of plastic and plastic associated contaminants in the aquatic environments, the monitoring of this contamination in fish products and the understanding of possible human health implications is considered urgent. However, data are still relatively scarce, mostly due to the methodological challenges in the chemical analysis: these contaminants are ubiquitous and procedural contamination from the laboratory is frequent. In this work, we compared solid-phase microextraction (SPME) to ultrasonic assisted solvent extraction (UASE) as sample preparation methods for the liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) determination of phthalates in fish fillets. UASE was carried out with an acetone-hexane (1:1) solution and according to a reference procedure aimed to obtain the exhaustive extraction of the target analytes. SPME was carried out by applying C18 fibers in direct immersion mode and by using water/methanol 20:80 mixture to desorb the aliquot required for the analysis. Overall, SPME displayed an improved control of the background contamination and enabled lower LOQs. Precision, calculated as relative standard deviation (RSD) on replicates of a reference sample, was below 24% for both the method. Analysis of real samples purchased from Italian supermarkets showed that SPME might be an efficient tool for estimating the risk associated with fish consumption.

Omega-3 rich oils from microalgae: A chitosan mediated in situ transesterification method

Microalgae are a precious source of polyunsaturated fatty acids (PUFA), however extraction is difficult due to the peculiar microalgae cell structure. Here we describe a new method based on the application of chitosan nanoaggregates as CO₂ responsive emulsifier, used to promote the swelling of algae cell wall and the formation of a large oil - ethanol interphase area during the ethanolysis. Tests were carried out with Pseudokirchneriella subcapitata and Nannochloropsis sp. at different biomass/ethanol/chitosan ratios. CO₂ was added to trigger demulsification to promote an easy recovery of the lipid fraction. The highest yields in PUFA were obtained with Nannochloropsis sp. (207.9 mg/g of oil) using 0.4% wt of chitosan and 1:10 biomass:ethanol ratio; 43.6 mg/g of linolenic acid were obtained from Pseudokirchneriella subcapitata. Overall, because the method employs ethanol, a generally recognized as safe (GRAS) solvent, and food grade additives, it is suited for the preparation of PUFA supplements.

Spatial variability of phthalates contamination in the reef-building corals Porites lutea, Pocillopora verrucosa and Pavona varians

Microplastic pollution represents a serious hazard for the marine environment, including coral reefs. Scleractinian corals can easily mistake microplastics with their natural preys, and ingest them and all the annexed plasticizer additives. Here we selectively searched on field for five phthalates esters (PAEs) namely dibutyl-phthalate (DBP), benzylbutyl-phthalate (BBzP), diethyl-phthalate (DEP), Bis(2-ethylhexyl)-phthalate (DEHP), and dimethyl-phthalate (DMP) in the coral species Pocillopora verrucosa, Porites lutea and Pavona varians. Our data reveal that >95% of corals sampled were contaminated, with a maximum of 172.4 ng/g, a value 7 time-fold higher than those found in a previous study. The Σ₅ PAEs showed an average of about 30 ng/g per coral, but no differences in PAEs contamination was detected between species, depth or reef exposure. Despite their effects on coral physiology are not yet known, PAEs should be now considered as a novel, and ubiquitous, form of contamination in corals.

Spatial variability of phthalates contamination in the reef-building corals Porites lutea, Pocillopora verrucosa and Pavona varians

Microplastic pollution represents a serious hazard for the marine environment, including coral reefs. Scleractinian corals can easily mistake microplastics with their natural preys, and ingest them and all the annexed plasticizer additives. Here we selectively searched on field for five phthalates esters (PAEs) namely dibutyl-phthalate (DBP), benzylbutyl-phthalate (BBzP), diethyl-phthalate (DEP), Bis(2-ethylhexyl)-phthalate (DEHP), and dimethyl-phthalate (DMP) in the coral species Pocillopora verrucosa, Porites lutea and Pavona varians. Our data reveal that >95% of corals sampled were contaminated, with a maximum of 172.4 ng/g, a value 7 time-fold higher than those found in a previous study. The Σ₅ PAEs showed an average of about 30 ng/g per coral, but no differences in PAEs contamination was detected between species, depth or reef exposure. Despite their effects on coral physiology are not yet known, PAEs should be now considered as a novel, and ubiquitous, form of contamination in corals.

Multi-analytical characterization of perigonadal fat in bluefin tuna: from waste to marine lipid source

BACKGROUND

Marine lipids are widely recognized as supplements beneficial to health in the human diet. Bluefin tuna, as most migrating fish, may have high and variable marine lipid contents in their tissues. The viscera of the specimens caught in the Mediterranean Sea are generally discarded. Only ovaries are (locally) used for artisanal seafood preparations.

RESULTS

A multi-analytical approach carried out using infrared (IR), nuclear magnetic resonance (NMR) and mass spectrometry (MS) revealed that the perigonadal fats usually discarded during bluefin tuna evisceration are characterized by a high relative abundance of polyunsaturated triacylglycerols (76.2% of dry mass), with docosahexaenoic (DHA, 22:6) and eicosapentaenoic (EPA, 20:5) acids preferentially located at the sn-2 position of the glycerol backbone. By contrast, in fats from the ovarian tissues, no wax esters and phospholipids were evidenced. Cholesterol was found in very low amounts (84 mg/100 g ovarian tissue). In vitro assays showed that this fatty material is rapidly hydrolyzed by lipase and is prone to auto-oxidation, especially if compared to the stable wax esters contained in the ovary.

CONCLUSION

The results show that the perigonadal fats of bluefin tuna, traditionally wasted after evisceration, may be an interesting source for the preparation of marine lipid supplements that do not require complex fractionation processes. © 2019 Society of Chemical Industry.

Microplastic and charred microplastic in the Faafu Atoll, Maldives

Microplastics are recognized as a growing threat for the marine environment that may even affect areas generally considered pristine. In this work we surveyed the microplastic contamination in the Faafu Atoll (Maldives, Indian Ocean) across twelve sampling station, located either inside or outside the reef rim. Sediments and seawater samples were collected. Despite the remoteness of the atoll, the scarce local population and low touristic annual afflux, the detected average abundance were 0.32 ± 0.15 particles/m³ in the surface water and 22.8 ± 10.5 particles/m² in the beach sediments. Polymers identified through Fourier-Transform Infrared spectroscopy were mostly polyethylene, polypropylene, polystyrene, polyvinylchloride, polyethyleneterephtalate, and polyamide. Elastomeric residues and charred microparticles were also found. In particular, the charred microparticles were prevalently located nearby the inhabited island and they might be considered a peculiarity of the area, related to local practice of burning plastic waste at the shoreline.

N-aryl lactams by regioselective ozonation of N-aryl cyclic amines

Ozonation of N-aryl-cyclic amines in organic solvents gave N-aryl-lactams regioselectively. In particular, 4-(4-aminophenyl)-morpolin-3-one, a key intermediate in the preparation of factor Xa inhibitors, was obtained in fair yields. The method represents an alternative approach for the lactamization of tertiary N-arylic substrates and is based on a “metal-free” introduction of the carbonyl function into the heterocyclic ring.

Field trial for evaluating the effects on honeybees of corn sown using Cruiser and Celest xl treated seeds

A first field study was conducted to investigate the possible adverse effects that seeds dressed with neonicotinoid insecticides pose to honeybees during sowing. It was observed that in the exposure hives bee mortality increased on the day of sowing and that the number of foraging bees decreased the days after the sowing. The corn sowing posed a significant threat to honeybees, with thiamethoxam being the most probable toxic agent. A theoretical contact exposure was calculated for a bee when flying over the sown fields, revealing a dose of 9.2 ng bee(-1) close to the contact LD(50) of thiamethoxam.