Are bioplastics safe? Hazardous effects of polylactic acid (PLA) nanoplastics in Drosophila.

The expanded uses of bioplastics require understanding the potential health risks associated with their exposure. To address this issue, Drosophila melanogaster as a versatile terrestrial in vivo model was employed, and polylactic acid nanoplastics (PLA-NPLs), as a proxy for bioplastics, were tested as a material model. Effects were determined in larvae exposed for 4 days to different concentrations (25, 100, and 400 µg/mL) of 463.9 ± 129.4 nm PLA-NPLs. Transmission electron microscopy (TEM) and scanning electron microscope (SEM) approaches permitted the detection of PLA-NPLs in the midgut lumen of Drosophila larvae, interacting with symbiotic bacteria. Enzymatic vacuoles were observed as carriers, collecting PLA-NPLs and enabling the crossing of the peritrophic membrane, finally internalizing into enterocytes. Although no toxic effects were observed in egg-to-adult survival, cell uptake of PLA-NPLs causes cytological disturbances and the formation of large vacuoles. The translocation across the intestinal barrier was demonstrated by their presence in the hemolymph. PLA-NPL exposure triggered intestinal damage, oxidative stress, DNA damage, and inflammation responses, as evaluated via a wide set of marker genes. Collectively, these structural and molecular interferences caused by PLA-NPLs generated high levels of oxidative stress and DNA damage in the hemocytes of Drosophila larvae. The observed effects point out the need for further studies aiming to deepen the health risks of bioplastics before adopting their uses as a safe plastic alternative.

First Report of the Joint Exposure to Glyphosate and Glufosinate of a Male Population in the Province of Córdoba (Argentina).

Despite potential health implications, data on the presence of Glyphosate (GLY) and other non-GLY herbicides in human matrices remain scarce. This study aimed to develop a simple and cost-effective methodology for detecting and quantifying GLY, its primary biodegradation product; aminomethylphosphonic acid (AMPA); and glufosinate (GLU) in plasma and urine of environmentally and occupationally exposed populations from the province of Córdoba (Argentina). Different alternatives of pre-treatment, derivatization with FMOC-Cl, solid phase extraction, and final sample conditioning steps were evaluated to improve the quantification of the herbicides by a high-performance liquid chromatography system coupled to a triple-quadrupole mass spectrometer. Recoveries ranged from 39 to 84% in both matrices, while limits of quantification were 3, 1, and 0.3 ng/mL and 3.6, 5.1, and 0.3 ng/mL for AMPA, GLY, and GLU in plasma and urine, respectively. In plasma samples, GLY was the most frequently detected analyte (32%), followed by GLU (10%). In urine samples, GLU was the most frequently detected herbicide (13%), followed by GLY (6%). No differences between group or matrix correlations were found. This study is the first report of GLU in human biological matrices and should be used to establish baseline values for future surveillance systems.

Exposure to micro(nano)plastics polymers in water stored in single-use plastic bottles.

Human exposure to micro (nano)plastics (MNPLs) has become a significant concern as a potential health threat. Exposure routes include ingestion, inhalation, and dermal contact, being food and drinking water the primary sources of oral exposure. Here we present the quantification of polymers of MNPLs particles from 700 nm to 20 µm in bottled water commercialised in Spain, including an estimation of the potential risk for daily consumers. We evaluated samples from 20 popular brands in 0.5 and 1.5 L plastic bottles. A double-suspect screening approach developed and validated in our research group for drinking water was adapted for bottled water samples. The identification and quantification of MNPLs-polymers in mass units and the tentative identification of plastic additives (PA) until the second level of confidence was carried out based on high-performance liquid chromatography coupled to high-resolution mass spectrometry (HPLC-HRMS). The results showed the presence of polypropylene (PP), polyethylene (PE) and polypropylene terephthalate (PET) in the samples. Among them, PE was the most frequently detected and quantified polymer (55% of samples) followed by PET which was detected in 33% of the samples and showing the highest concentration (4700 ng L-1). The median value of the sum of polymer concentrations was 359 ng L-1. In addition, 28 plastic additives were detected, where at least one of them was present in 100% of the samples. Stabilizers and plasticisers were the most frequently identified. A prioritisation study was performed using a multi-QSAR modelling software, where bis(2-ethylhexyl) adipate and bis(2-ethylhexyl) phthalate were estimated as the most potentially harmful compounds for human health. Overall, findings suggest that bottled water is a non-negligible route to exposure to MNPLs.

Sublethal effects of bio-plastic microparticles and their components on the behaviour of Daphnia magna.

Bioplastics arise as an alternative to plastic production delinked from fossil resources. However, as their demand is increasing, there is a need to investigate their environmental fingerprint. Here we study the toxicity of microplastics (MPLs) of two widely used materials, the polylactic acid (PLA) and the polyhydroxybutyrate (PHB) on the environmental aquatic model species Daphnia magna. The study was focused on sublethal behavioural and feeding endpoints linked to antipredator scape responses and food intake. The study aimed to test that MPLs from single-use household comercial items and among them bioplastics should be more toxic than those obtained from standard plastic polymers and fossil plastic materials due to the greater amount of plastic additives, and that MPLs should be more toxic than plastic extracts due to the contribution of both particle and plastic additive toxicity. MPLs were obtained by cryogenic grinding and sea-sand erosion to obtain irregular particles. MPL included standard polymers and nine comercial items of PLA and PHB and one fossil-based material of high-density polyethylene (HDPE). The additive content in commercial items was characterised by liquid chromatography coupled with high-resolution mass spectrometry. D. magna juveniles were exposed for 24 h to particles and their plastic extracts. Results indicated that the toxicity of bioplastic particles was five times higher than the effects produced by exposure to the content of the additives alone, that bioplastic particles were more toxic than fossil ones and that particles obtained from commercial items were more toxic than those obtained from PLA, PHB or HDPE polymer standards. Predicted toxicity from the measured plastic additives in the studied commercially available household items, however, was poorly related with the observed behavioural and feeding effects. Further research on unknown chemical components together with physical factors is need it to fully understand the mechanisms of toxicity of bioplastic materials.

Micro(nano)plastics in the atmosphere of the Atlantic Ocean.

The occurrence, long-range atmospheric transport and deposition of micro and nano plastics (MNPLs) remains un-quantified for the oceanic atmosphereopen ocean. Here we show the characterisation of MNPLs and the aerosol composition (PM10) in a north-south Atlantic transect from Vigo (Spain) to Punta Arenas (Chile). The analytical procedure to assess the composition of MNPLs consisted of a double suspect screening approach of the polymers and additives, the two constituents of plastics. Polymers were analysed by size exclusion chromatography coupled with high-resolution mass spectrometry using an atmospheric pressure photoionization source operated in positive and negative conditions (HPLC(SEC)-APPI(+/-)-HRMS). Plastic additives were screened with high-performance liquid chromatography coupled to high-resolution mass spectrometry using an electrospray ionisation source (HPLC-ESI(+/-)-HRMS). The most common polymers were polyethylene (PE), polypropylene (PP), polyisoprene (PI), and polystyrene (PS), with the highest polymer concentration being 51.7 ng·m-3 of PI. The air mass back trajectories showed the variable influence of oceanic and terrestrial air masses. These differences were reflected in the aerosol composition with different contributions of Saharan dust, sea spray aerosol, organic/elemental carbon, and MNPLs. Results showed that samples largely influenced by sea-spray and air masses originating from coastal South America and the north Atlantic subtropical gyre were more contaminated by MNPLs. Moreover, this information was complemented by the characterisation of the largest particles using scanning electron microscopy (SEM) and µ-Fourier Transform Infrared Spectroscopy (µ-FTIR). This work provides the first field evidence of the long-range transport of MNPLs in most of the Atlantic Ocean, as the result of dynamic coupling between the lower atmosphere and the surface ocean. Sea-spray formation arises as a key driver for the aerosolisation of MNPLs, and atmospheric transport followed by dry deposition may modulate the occurrence of MNPLs in large oceanic regions, issues that will require future research efforts.

Per- and Poly-Fluoroalkyl Substances in Portuguese Rivers: Spatial-Temporal Monitoring.

Eighteen per-and polyfluoroalkyl substances (PFASs) were investigated in surface waters of four river basins in Portugal (Ave, Leça, Antuã, and Cértima) during the dry and wet seasons. All sampling sites showed contamination in at least one of the seasons. In the dry season, perfluorooctanoate acid (PFOA) and perfluoro-octane sulfonate (PFOS), were the most frequent PFASs, while during the wet season these were PFOA and perfluobutane-sulfonic acid (PFBS). Compounds detected at higher concentrations were PFOS (22.6 ng L-1) and perfluoro-butanoic acid (PFBA) (22.6 ng L-1) in the dry and wet seasons, respectively. Moreover, the prospective environmental risks of PFASs, detected at higher concentrations, were evaluated based on the Risk Quotient (RQ) classification, which comprises acute and chronic toxicity. The results show that the RQ values of eight out of the nine PFASs were below 0.01, indicating low risk to organisms at different trophic levels in the four rivers in both seasons, wet and dry. Nevertheless, in the specific case of perfluoro-tetradecanoic acid (PFTeA), the RQ values calculated exceeded 1 for fish (96 h) and daphnids (48 h), indicating a high risk for these organisms. Furthermore, the RQ values were higher than 0.1, indicating a medium risk for fish, daphnids and green algae (96 h).

Cytotoxicity assessment and suspected screening of PLASTIC ADDITIVES in bioplastics of single-use household items.

Bioplastics made of renewable sources provide an excellent alternative to fossil-based materials. However, similar or greater quantities of plastic additives than fossil-based plastics are used in the formulations of bioplastics to improve their performance and barrier properties. Nowadays, there is an increasing concern about sources of chemical exposure. However, there is an important knowledge gap regarding complex additive mixtures, particularly in bio-based materials. In this study, we have characterised the presence of plastic additives in single-use materials (collected from retail shops in Spain), which are made of the most common bio-based biodegradable materials, poly(lactic acid) (PLA) and poly(hydroxybutyrate) (PHB), in contrast with a fossil-based plastic material that is extensively made from high-density polyethylene (HDPE). The approach consisted of the pulverization of material in the nano-micro range (100 nm-10 µm), with the materials being extracted using different solvents and ultrasonic-assisted solvent extraction (UASE). 100% of the additives in the material cannot be extracted, but since they were performed in the same condition for all materials can inform about the fingerprint of primary organics and the relative abundances between the different materials. The extracts were analysed by high-performance liquid chromatography coupled with high-resolution mass spectrometry equipped with a heated electrospray ionisation source operated in positive and negative ionisation conditions (HPLC-HESI(+/-)-HRMS), separately, using a suspect screening approach. A total number of 203 additives were tentatively identified (confidence level 2) in the bioplastics items of this study. An average of 123 plastic additives were found in PLA items and 121 in PHB items. Plasticisers were the most abundant additives; the phthalates group was the most commonly found, while 63 plastic additives were confirmed by standards and quantified. In parallel, the cytotoxicity of plastic particles in terms of cell viability and oxidative stress was studied using A549 alveolar basal epithelial cells, and the toxicity of the different extracts was also established using HepG2 adenocarcinoma cells. The main results of this study demonstrate that the plastic particles did not show a significant reduction in cell viability, but oxidative stress was significant, with PLA being the material that showed the highest effect. On the other hand, extracts of plastic particles did not show inhibition of cell viability except for HDPE extract, but the different extracts produced oxidative stress, with PLA showing the highest effect. Although the item showing the highest concentrations of additives was the extract of PLA material while also showing the most elevated oxidative stress, the low migration of toxicants from plastic materials ensures their safe use. However, this also supports the idea that bioplastics can contain many toxic substances in their formulations, some of which are unknown and should be studied in more depth.

Polymers of micro(nano) plastic in household tap water of the Barcelona Metropolitan Area.

Microplastics (MPLs) are emerging persistent pollutants affecting drinking water systems, and different studies have reported their presence in tap water. However, most of the work has a focus on particles in the 100-5 µm range. Here, a workflow to identify and quantify polymers of micro and nanoplastics (MNPLs), with sizes from 0.7 to 20 µm in tap water, is presented. The analytical method consisted of water fractionated filtration followed by toluene ultrasonic-assisted extraction and size-exclusion chromatography, using an advanced polymer chromatography column coupled to high-resolution mass spectrometry with atmospheric pressure photoionization source with negative and positive ionization conditions (HPLC(APC)-APPI(±)-HRMS) and normal phase chromatography HILIC LUNA® column and electrospray ionisation source in positive and negative mode (HPLC(HILIC)-ESI(±)-HRMS). The acquisition was performed in full scan mode, and the subsequent tentative identification of MNPLs polymers has been based on increasing the confirmation level, including the characterisation of monomers by using Kendrick Mass Defect (KMD) analysis, and confirmation and quantification using standards. This approach was applied to assess MNPLs in tap water samples of the Barcelona Metropolitan Area (BMA), that were collected from August to October 2020 from home taps of volunteers distributed in the 42 postal codes of the BMA. Polyethylene (PE), polypropylene (PP), polyisoprene (PI), polybutadiene (PBD), polystyrene (PS), polyamide (PA), and polydimethylsiloxanes (PDMS) were identified. PE, PP, and PA were the most highly detected polymers, and PI and PBD were found at the highest concentrations (9,143 and 1,897 ng/L, respectively). A principal component analysis (PCA) was conducted to assess differences in MNPLs occurrence in drinking water, that was provided from the two drinking water treatment plants (DWTPs) suppliers. Results showed that no significant differences (at 95% confidence level) were established between the drinking water supplies to the different areas of the BMA.

Assessment of Micro- and Nanoplastic Composition (Polymers and Additives) in the Gastrointestinal Tracts of Ebro River Fishes.

One of the main routes of fish exposure to micro- and nanoplastics (MNPLs) is their ingestion. MNPLs can act as reservoirs of organic contaminants that are adsorbed onto their surfaces, or that can leach from their complex formulations, with potential impacts on biota and along the aquatic food chain. While MNPLs have been reported in fishes worldwide, complete information on MNPL compositions, polymers and additives continues to be scarce. In this work, the presence of MNPLs in the gastrointestinal tracts (GIT) of fish from the Ebro River (Spain) was investigated using a double suspected screening approach to assess and quantify polymers and additives. The sample-preparation procedure consisted of sequential alkaline and acidic digestions with KOH and HNO3, followed by ultrasonic-assisted extraction (USAE) with toluene. The analysis of polymers was carried out with size-exclusion chromatography followed by high-resolution mass spectrometry using an atmospheric pressure photoionization source, operating in negative and positive ionisation modes (SEC-(±)-APPI-HRMS) using full-scan acquisition (FS). Plastic additives were assessed using high-performance liquid chromatography with a C18 analytical column coupled to HRMS equipped with an electrospray ionisation source operating under positive and negative conditions (LC-(±ESI)-HRMS). The acquisition was performed in parallel with full-scan (FS) and data-dependent scan (ddMS2) modes, working under positive and negative ionisation modes. The polymers most frequently detected and quantified in fish GITs were polysiloxanes, polyethylene (PE), polypropylene (PP) and polystyrene (PS). PE was detected in 84% of the samples, with a concentration range from 0.55 to 3545 µg/g. On the other hand, plasticisers such as phthalates and stabilisers such as benzotriazoles were the most frequently identified plastic additives.

Analysis of highly polar marine biotoxins in seawater by hydrophilic interaction liquid chromatography coupled to high resolution mass spectrometry.

The monitoring of marine biotoxins (MBTs) in seawater is presented as an alternative strategy to determine their presence and the possible implications in the ecosystem. For this, an analytical method based on hydrophilic interaction liquid chromatography coupled to high resolution mass spectrometry (HILIC-HRMS) has been developed to identify and quantify some hydrophilic MBTs in seawater: saxitoxin (STX), decarbamoyl-saxitoxin (dcSTX), neosaxitoxin (NeoSTX), gonaytoxin-2,3 (GTX-2,3) and tetrodotoxin (TTX), which are responsible of gastrointestinal and central nervous system distress in humans when are consumed via seafood. Particulate and filtrate portion were analyzed separately in order to characterize the extracellular toxins dissolved in the water and those present in the particulate. Ultrasound assisted solid-liquid extraction with methanol was used for the isolation of the MBTs from particulate and solid phase extraction using silica cartridges for the filtrate. Extraction procedure was the most critical step during the analytical method due to the high polarity of the toxins and the absolute recoveries obtained ranged from 15 to 47 % in the filtrate and 26 to 71 % in the particulate portions. Limits of detection of the method ranged from 0.5 to 5 µg/L in the filtrate portion and from 3.1 to 62 µg/L in the particulate portion.•Saxitoxins and tetrodotoxins have been analysed by using HILIC-HRMS.•UAE with methanol and SPE with silica cartridges have been employed for the extractions of the polar MBTs from seawater.

Current Insights into Potential Effects of Micro-Nanoplastics on Human Health by in-vitro Tests.

Humans are exposed to micro and nanoplastics (MNPLs) through inhalation, ingestion and, to a lesser extent, dermal contact. In recent years, new insights indicate the potential of MNPLs to cause damages to human health. Particle toxicity can include oxidative stress, inflammatory lesions, and then increased internalization or translocation through tissues. On the other hand, plastic additives are used in plastic particles, once internalized, can release toxic substances. It is noteworthy that the potential effects of MNPLs encompass a wide range of polymers and chemical additives, showing various physicochemical and toxicological properties, and the size, shape and surface properties are other variables influencing their effects. In spite of the research carried out recently, MNPLs research is in its early stages, and further investigation is required. In this review article, the knowledge of human exposure routes and the recent results on the toxicological effects of MNPLs in human health are presented and discussed. Finally, the current limitations and the main gaps in the body of knowledge are summarised.

Priority and emerging organic microcontaminants in three Mediterranean river basins: Occurrence, spatial distribution, and identification of river basin specific pollutants.

There is a worldwide growing use of chemicals by our developed, industrialized, and technological society. More than 100,000 chemical substances are thus commonly used both by industry and households. Depending on the amount produced, physical-chemical properties, and mode of use, many of them may reach the environment and, notably, the aquatic receiving systems. This may result in undesirable and harmful side-effects on both the human and the ecosystem's health. Mediterranean rivers are largely different from Northern and Central European rivers in terms of hydrological regime, climate conditions (e.g. air temperature, solar irradiation, precipitation), and socio-economics (e.g. land use, tourism, crop types, etc.), with all these factors leading to differences in the relative importance of the environmental stressors, in the classes and levels of the pollutants found and their environmental fate. Furthermore, water scarcity might be critical in affecting water pollution because of the lowered dilution capacity of chemicals. This work provides raw chemical data from different families of microcontaminants identified in three selected Mediterranean rivers (the Sava, Evrotas, and Adige) collected during two sampling campaigns conducted in 2014 and 2015 in three different matrices, namely, water, sediments, and biota (fish). More than 200 organic micropollutants were analyzed, including relevant groups like pharmaceuticals, personal care products, perfluorinated compounds, pesticides, pyrethroid insecticides, flame retardants, and persistent organic pollutants. Data obtained were summarized with some basic statistics for all compound families and matrices analyzed. Observed occurrence and spatial patterns were interpreted both in terms of compound physical-chemical properties and local environmental pressures. Finally, their spatial distribution was examined and their ecotoxicological risk in the water phase was assessed. This allowed locating, at each basin, the most polluted sites ("hot spots") and identifying the respective river basin specific pollutants (RBSPs), prioritizing them in terms of the potential ecotoxicological risk posed to the aquatic ecosystems.

Screening of suspected micro(nano)plastics in the Ebro Delta (Mediterranean Sea).

This is the first work reporting the use of a double suspect-screening to assess most common polymers and additives in micro(nano)plastics (NPLs/MPLs) found in environmental waters. The method consisted of water filtration followed by ultrasonic-assisted extraction with toluene and analysis employing size exclusion chromatography using an advanced polymer chromatography column coupled to high-resolution mass spectrometry with an atmospheric pressure photoionisation source by negative ionisation conditions (LC(APC)-APPI(-)-HRMS). The identification of NPL/MPLs polymers has been based on increasing confirmation level, including the monomers characterisation by the Kendrick Mass Defect and confirmation and quantification when standards were available. In parallel, the identification of main additives in NPL/MPLs composition, as well organic contaminants adsorbed onto the plastic particles were carried out by analysis of the extracts by LC(C18)-APPI (+/-)-HRMS. To assess the impact of plastic pollution it is necessary to assess the composition in terms of polymers but also the additives. This screening approach has been employed to study composition of NPL/MPLs in the Ebro Delta. Two sampling campaigns including freshwater and seawater samples have been investigated to assess plastic composition in the top 5 cm. Polystyrene (PS), polyethylene (PE), polyisoprene (PI), polybutadiene (PBD), polypropylene (PP) and polysiloxanes were the most detected polymers and PP and PE, sizing between < 1000 and 2000 Da, were found at concentrations reaching up to 7000 ng/L in some areas. The pentadecanoic acid, 1,2,3-benzotriazoles, 2-ethylhexanoic acid (2-EHA), and phthalates such as dimethyl phthalate, mono(2-ethylhexyl) phthalate (MEHP) and the phthalimide were more frequently detected plastic additives. Finally, series of organic contaminants were as well detected in the particulate fraction. These organic contaminants cannot be associated to plastic compositions but can be associated to their adsorption to the particulate matter, in particular to NPL/MPLs, due to their non-polar character. Among these organic contaminants, the more frequently detected were pharmaceutical compounds, food additives and pesticides.

Anthropogenic contaminants in freshwater from the northern Antarctic Peninsula region.

This study aimed to evaluate the presence of ultraviolet filters (UV-Fs), benzotriazoles, pyrethroids and per- and polyfluoroalkyl substances (PFASs) in freshwater and wastewater from the northern Antarctic Peninsula region. All water samples analyzed contained UV-Fs residues and high concentrations were detected in anthropogenic impacted sites (< LOD up to 1300 ng/L). Likewise, benzotriazoles were detected in all water samples (< LOQ-920 ng/L). Regarding suspended particulate matter, almost all UV-Fs and all benzotriazoles were measured at concentrations ranging from < LOQ to 33 µg/g dry weight. Pyrethroids were also detected (< LOQ-250 ng/L) and their presence implies the existence of a gateway to the Antarctica Peninsula from other regions. The data confirmed the presence of PFASs (< LOD-7500 ng/L) in this area, in agreement with previous studies. In light of these results, extended monitoring in Antarctica should be carried out to perform a reliable environmental risk assessment leading to propose recommendations to minimize the anthropic impact.

Suspect and Target Screening of Natural Toxins in the Ter River Catchment Area in NE Spain and Prioritisation by Their Toxicity.

This study presents the application of a suspect screening approach to screen a wide range of natural toxins, including mycotoxins, bacterial toxins, and plant toxins, in surface waters. The method is based on a generic solid-phase extraction procedure, using three sorbent phases in two cartridges that are connected in series, hence covering a wide range of polarities, followed by liquid chromatography coupled to high-resolution mass spectrometry. The acquisition was performed in the full-scan and data-dependent modes while working under positive and negative ionisation conditions. This method was applied in order to assess the natural toxins in the Ter River water reservoirs, which are used to produce drinking water for Barcelona city (Spain). The study was carried out during a period of seven months, covering the expected prior, during, and post-peak blooming periods of the natural toxins. Fifty-three (53) compounds were tentatively identified, and nine of these were confirmed and quantified. Phytotoxins were identified as the most frequent group of natural toxins in the water, particularly the alkaloids group. Finally, the toxins identified to levels 2 and 1 were prioritised according to their bioaccumulation factor, biodegradability, frequency of detection, and toxicity. This screening and prioritisation approach resulted in different natural toxins that should be further assessed for their ecotoxicological effects and considered in future studies.

Suspect screening of natural toxins in surface and drinking water by high performance liquid chromatography and high-resolution mass spectrometry.

Besides anthropogenic contamination, freshwater environments can also be affected by the presence of natural toxins. Mycotoxins, plant toxins and cyanotoxins are the most relevant groups that can be found in the aquatic system. However, until now, only cyanotoxins have been more carefully studied. In the present work, single workflow for the assessment of natural toxins in waters, based on suspect screening and target screening of a selected group of toxins is presented. The approach is based on a triple-stage solid-phase extraction (SPE) able to isolate a wide range of natural toxins of different polarities, followed by liquid chromatography coupled to high-resolution mass spectrometry (HPLC-ddHRMS2) using a Q-Exactive Orbitrap analyser. The acquisition was performed in full-scan (FS) and data-dependant acquisition (ddMS2) mode, working under positive and negative mode. For the tentative identification, different on-line databases such as ChemSpider and MzCloud and an in-house natural toxins list with 2384 structures, that includes cyanotoxins, plant toxins and mycotoxins, were used. Also, thanks to the MS2 data, it was possible to achieve a high level of tentative identification confidence, but confirmation was only possible comparing the standards of the suspected compounds. For those, the analytical parameters of the developed method were also validated, and the quantification was possible by external calibration. Validation showed recoveries in the range between 53 and 95%, and method limits of detection (MDL) between 0.02 and 1.22 µg/L. This approach was applied to study natural toxins in 4 sampling sites along the Ter River in Catalonia (NE Spain). In this preliminary study 23 natural toxins were tentatively identified, and 9 of them confirmed (aflatoxin B1, anatoxin-a, nodularin, microcystin-LR, baicalein, kojic acid, cinchonine, B-asarone and atropine). The results of the quantification of these compounds showed concentrations below 1 µg/L in all cases, that is considered safe according to the actual legislation. This suspect screening approach allows a more comprehensive assessment of natural toxins in natural waters.

Adsorption and Desorption Behaviour of Polychlorinated Biphenyls onto Microplastics' Surfaces in Water/Sediment Systems.

The potential of microplastics (MPLs) in marine ecosystems to adsorb and transport other micropollutants to biota, contributing to their entry in the food chain, is a primary cause of concern. However, these interactions remain poorly understood. Here, we have evaluated the adsorption/desorption behaviour of marker polychlorinated biphenyls (PCBs), onto MPL surfaces of three widely used polymers-polystyrene (PS), polyethylene (PE), and polyethylene terephthalate (PET). The range of MPL sizes ranged from 1 to 600 µm. The adsorption/desorption was evaluated in sediment/water systems in marine microcosms emulating realistic environmental conditions for 21 days. The adsorption percentages ranged from 20 to 60%. PCBs with a lower degree of chlorination showed higher adsorption percentages because of conformational impediments of PCBs with high-degree chlorination, and also by their affinity to be adsorbed in sediments. Glassy plastic polymers as PET and PS showed a superior affinity for PCBs than rubbery polymers, such as PE. The polymers that can bond PCBs by π-π interactions, rather than van der Waals forces showed better adsorption percentages, as expected. Finally, the adsorption/desorption behaviour of selected PCBs onto MPLs was fitted to a Freundlich isotherm model, with correlations higher than 0.8 in most of the cases.

A new digestion approach for the extraction of microplastics from gastrointestinal tracts (GITs) of the common dolphinfish (Coryphaena hippurus) from the western Mediterranean Sea.

Plastic ingestion is one of the main impacts of marine litter on organisms. The occurrence of microplastics (MPs < 5 mm) in the stomachs of Mediterranean species was already reported in several studies. In this context, the present study aims to develop a new approach of digestion for the identification of MPs in the gastrointestinal tracts (GITs) of marine organisms. The new approach combines two digestion protocols, including potassium hydroxide (KOH) and nitric acid (HNO3), to remove most organic and inorganic materials. This digestion allows recording small MPs that are difficult to find via routinely stomach content analysis and also to minimize the overestimation of the phenomenon trough the control of airborne contamination. The new approach was tested on a voracious pelagic opportunistic predator, the common dolphinfish, a fishery resource exploited in several Mediterranean areas. The results showed that a large amount of ingested meso- and microplastics, such as fragments or sheets, was recorded in GITs (F = 65.5 %). The FTIR analysis on litter samples allowed to identify polyethylene, polypropylene and polystyrene as dominant constituent polymers of microplastics. These results confirmed that our novel combined digestion protocol represents a reliable approach to detect MPs in opportunistic pelagic predators.

Ultra-Trace Analysis of Cyanotoxins by Liquid Chromatography Coupled to High-Resolution Mass Spectrometry.

The increasing frequency of episodes of harmful algal blooms of cyanobacterial origin is a risk to ecosystems and human health. The main human hazard may arise from drinking water supply and recreational water use. For this reason, efficient multiclass analytical methods are needed to assess the level of cyanotoxins in water reservoirs and tackle these problems. This work describes the development of a fast, sensitive, and robust analytical method for multiclass cyanotoxins determination based on dual solid-phase extraction (SPE) procedure using a polymeric cartridge, Oasis HLB (Waters Corporation, Milford, MA, USA), and a graphitized non-porous carbon cartridge, SupelcleanTM ENVI-CarbTM (Sigma-Aldrich, St. Louis, MO, USA), followed by ultra-high-performance liquid chromatography high-resolution mass spectrometry (SPE-UHPLC-HRMS). This method enabled the analysis of cylindrospermopsin, anatoxin-a, nodularin, and seven microcystins (MC-LR, MC-RR, MC-YR, MC-LA, MC-LY, MC-LW, MC-LF). The method limits of detection (MLOD) of the validated approach were between 4 and 150 pg/L. The analytical method was applied to assess the presence of the selected toxins in 21 samples collected in three natural water reservoirs in the Ter River in Catalonia (NE of Spain) used to produce drinking water for Barcelona city (Spain).

Occurrence of Cerium-, Titanium-, and Silver-Bearing Nanoparticles in the Besòs and Ebro Rivers.

The presence of anthropogenic nanoparticles (NPs) in the aquatic environment has become an emerging concern in terms of environmental and health safety. In the present study, we assessed the presence of Ag-bearing, Ti-bearing, and Ce-bearing NPs in the Barcelona catchment area, including the Besòs River basin and the Barcelona coast, and in the Ebro River Delta, using single particle inductively coupled plasma mass spectrometry (sp-ICP-MS). Ti-NPs and Ce-NPs were ubiquitously detected in surface waters, and their presence was related to a high natural background. Concentrations of Ti-NPs ranged from 23.2 × 106 to 298 × 106 Ti-NPs/L, with high concentrations being detected in areas with little anthropogenic pressure, while the presence of nanosilver (17.9 × 106 to 45.1 × 106 Ag-NPs/L) in the analyzed rivers was limited to certain hotspots close to wastewater treatment plants discharge points. The concentrations of Ce-NPs in the river ranged from 18.1 × 106 to 278 × 106 NPs/L, and they were related to the natural occurrence of the mineral Monazite-(Ce). Overall, the concentrations of these nanomaterials in the Barcelonan coast were significantly attenuated by river-sea environmental dilution. Nevertheless, Ce-NPs were eventually detected in some seawater samples with low levels of lanthanum-NPs, suggesting anthropogenic inputs of nanoCeO2, probably from atmospheric deposition.