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.

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).

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.

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.

Bioconcentration and bioaccumulation of C60 fullerene and C60 epoxide in biofilms and freshwater snails (Radix sp.).

Fullerenes are carbon nanomaterials that have awaken a strong interest due to their adsorption properties and potential applications in many fields. However, there are some gaps of information about their effects and bioconcentration potential in the aquatic biota. In the present work, freshwater biofilms and snails (Radix sp.) were exposed to fullerene C60 aggregates, at concentrations in the low µg/L order, in mesocosms specifically designed to mimic the conditions of a natural stream. The bioconcentration factors of C60 fullerene and its main transformation product, [6,6]C60O epoxide, were studied to the mentioned organisms employing analyses by liquid chromatography coupled to high-resolution mass spectrometry. Our results show that C60 fullerene and its [6,6]C60O present a low bioconcentration factor (BCF) to biofilms: BCFC60 = 1.34 ±â€¯0.95 L/kgdw and BCFC60O = 1.43 ±â€¯0.72 L/kgdw. This suggests that the sorption of these aggregates to biota may be less favoured than it would be suggested by its hydrophobic character. According to our model, the surface of fullerene aggregates is saturated with [6,6]C60O molecules, which exposes the polar epoxide moieties in the surface of the aggregates and decreases their affinity to biofilms. In contrast, freshwater snails showed a moderate capacity to actively retain C60 fullerenes in their organism (BAFC60 = 2670 ±â€¯3070 L/kgdw; BAFC60O = 1330 ±â€¯1680 L/kgdw), probably through ingestion. Our results indicate that the bioaccumulation of these carbon nanomaterials can be hardly estimated using their respective octanol-water partition coefficients, and that their colloidal properties, as well as the feeding strategies of the tested organism, play fundamental roles.

Development and validation of a multianalyte immunoassay for the quantification of environmental pollutants in seawater samples from the Catalonia coastal area.

Five different enzyme-linked immunosorbent assays (ELISAs) have been developed and applied for the detection of five representatives of important families of chemical pollutants in seawater: Irgarol 1051® (triazine biocide), sulfapyridine and chloramphenicol (antibiotics), 17ß-estradiol (hormone), and domoic acid (algae toxin). The assays were validated by high-performance liquid chromatography (HPLC) coupled with high-resolution mass spectrometry (HRMS) showing good correlation between both immunochemical and chemical techniques. A process of extraction and clean-up was added prior to the analysis based on solid-phase extraction (SPE). The multianalyte platform presented good specificity for each compound and adequate sensitivity, with limits of detection (LOD) after the SPE treatment of 0.124 ± 0.006, 0.969 ± 0.09, 0.20 ± 0.05, 1.11 ± 0.012, and 1.39 ± 0.09 ng L-1 for Irgarol 1051®, sulfapyridine, chloramphenicol, 17ß-estradiol, and domoic acid, respectively. No matrix effects were noticed in working with the seawater extracts. Afterward, seawater samples from the Mediterranean Sea (coastal area of Catalonia) were analyzed by both techniques and only one sample presented one contaminant, 17ß-estradiol, in the concentration of 0.011 ± 0.04 µg L-1.

Impact of fullerenes in the bioaccumulation and biotransformation of venlafaxine, diuron and triclosan in river biofilms.

A huge variety of organic microcontaminants are presently detected in freshwater ecosystems, but there is still a lack of knowledge about their interactions, either with living organisms or with other contaminants. Actually, carbon nanomaterials like fullerenes (C60) can act as carriers of organic microcontaminants, but their relevance in processes like bioaccumulation and biotransformation of organic microcontaminants by organisms is unknown. In this study, mesocosm experiments were used to assess the bioaccumulation and biotransformation of three organic microcontaminants (venlafaxine, diuron and triclosan) in river biofilms, and to understand how much the concomitant presence of C60 at environmental relevant concentrations could impact these processes. Results indicated that venlafaxine exhibited the highest bioaccumulation (13% of the initial concentration of venlafaxine in water), while biotransformation was more evident for triclosan (5% of the initial concentration of triclosan in water). Furthermore, biotransformation products such as methyl-triclosan were also present in the biofilm, with levels up to 42% of the concentration of accumulated triclosan. The presence of C60 did not involve relevant changes in the bioaccumulation and biotransformation of microcontaminants in biofilms, which showed similar patterns. Nevertheless, the study shows that a detailed evaluation of the partition of the organic microcontaminants and their transformation products in freshwater systems are important to better understand the impact of the co-existence of others microcontaminants, like carbon nanomaterials, in their possible routes of bioaccumulation and biotransformation.

Metabolic Responses of Mytilus galloprovincialis to Fullerenes in Mesocosm Exposure Experiments.

In this study, Mediterranean mussels (Mytilus galloprovincialis) were exposed through the diet to fullerene soot at three concentrations in parallel to a control group. Their metabolomics response was assessed by high-performance liquid chromatography coupled to high-resolution mass spectrometry (HPLC-HRMS). The experiments were conducted in marine mesocosms, during 35 days (7 days of acclimatization, 21 days of exposure, and 7 days of depuration). Real conditions were emulated in terms of physicochemical conditions of the habitat. Results confirmed the bioaccumulation of fullerenes, and the metabolome of the exposed organisms revealed significant differences in the concentrations of seven free amino acids in comparison to the control group. An increase in small nonpolar amino acids (e.g., alanine) and branched chain amino acids (leucine and isoleucine) were observed. Also, glutamine concentrations decreased significantly, suggesting the activation of facultative anaerobic energy metabolism. Branched chain amino acids, such as leucine and isoleucine, followed the opposite trend after the highest level of exposure, which can imply hormesis effects. Other significant differences were observed on lipids content, such as the general increase of free fatty acids, i.e., long-chain fatty acids (lauric, myristic, and palmitic acids) when the concentration of exposure was increased. These results were consistent with hypoxia and oxidative stress.

Analysis of lipophilic marine biotoxins by liquid chromatography coupled with high-resolution mass spectrometry in seawater from the Catalan Coast.

Marine biotoxins regularly occur along the coast, with several consequences for the environment as well as the food industry. Monitoring of these compounds in seawater is required to assure the safety of marine resources for human consumption, providing a means for forecasting shellfish contamination events. In this study, an analytical method was developed for the detection of ten lipophilic marine biotoxins in seawater: azaspiracids 1, 2, 3, 4 and 5, classified as azaspiracid shellfish poisoning toxins, and pectenotoxin 2, okadaic acid and the related dinophysistoxin 1, yessotoxin and homoyessotoxin, classified as diarrheic shellfish poisoning toxins. The method is based on the application of solid-liquid ultrasound-assisted extraction and solid-phase extraction, followed by high-performance liquid chromatography coupled with high-resolution mass spectrometry. The limits of detection of this method are in the range of nanograms per litre and picograms per litre for most of the compounds, and recoveries range from 20.5% to 97.2%. To validate the effectiveness of this method, 36 samples of surface water from open coastal areas and marinas located along the Catalan coast on the Mediterranean Sea were collected and analysed. Eighty-eight per cent of these samples exhibited okadaic acid in particulate and aqueous phases in concentrations ranging from 0.11 to 560 µg/g and from 2.1 to 1780 ng/L respectively. Samples from open coastal areas exhibited higher concentrations of okadaic acid in particulate material, whereas in samples collected in sportive ports, the particulate material exhibited lower levels than the aqueous phase. Graphical Abstract Biotoxins investigated in seawater of the Catalan coast.

Cytotoxic effects of commonly used nanomaterials and microplastics on cerebral and epithelial human cells.

Plastic wastes are among the major inputs of detritus into aquatic ecosystems. Also, during recent years the increasing use of new materials such as nanomaterials (NMs) in industrial and household applications has contributed to the complexity of waste mixtures in aquatic systems. The current effects and the synergism and antagonisms of mixtures of microplastics (MPLs), NMs and organic compounds on the environment and in human health have, to date, not been well understood but instead they are a cause for general concern. The aim of this work is to contribute to a better understanding of the cytotoxicity of NMs and microplastics/nanoplastics (MPLs/NPLs), at cell level in terms of oxidative stress (evaluating Reactive Oxygen Species effect) and cell viability. Firstly, the individual cytotoxicity of metal nanoparticles (NPs) (AgNPs and AuNPs), of metal oxide NPs (ZrO2NPs, CeO2NPs, TiO2NPs, and Al2O3NPs), carbon nanomaterials (C60fullerene, graphene), and MPLs of polyethylene (PE) and polystyrene (PS) has been evaluated in vitro. Two different cellular lines T98G and HeLa, cerebral and epithelial human cells, respectively, were employed. The cells were exposed during 24-48h to different levels of contaminants, from 10ng/mL to 10µg/mL, under the same conditions. Secondly, the synergistic and antagonistic relationships between fullerenes and other organic contaminants, including an organophosphate insecticide (malathion), a surfactant (sodium dodecylbenzenesulfonate) and a plasticiser (diethyl phthalate) were assessed. The obtained results confirm that oxidative stress is one of the mechanisms of cytotoxicity at cell level, as has been observed for both cell lines and contributes to the current knowledge of the effects of NMs and MPLs-NPLs.

New Insights on the Influence of Organic Co-Contaminants on the Aquatic Toxicology of Carbon Nanomaterials.

At present, there is a lack of understanding of the combined ecotoxicity of carbon-based nanomaterials and co-contaminants. In this paper, we report on the toxicity of three carbon nanomaterials (fullerene-soot, multiwall carbon nanotubes, and graphene). Two standardized toxicity bioassays, the immobilization of the invertebrate Daphnia magna and the bioluminescence inhibition of the marine bacteria Vibrio fischeri, have been used. Synergistic and antagonistic effects of binary mixtures composed of fullerene soot and organic co-contaminants as malathion, glyphosate, diuron, triclosan, and nonylphenol were assessed. The isobologram method was used to evaluate the concentrations producing an effect, in comparison to those effects expected by a simple additive approach. In this study, antagonism was the predominant effect. However, synergism was also observed as in the case of D. magna exposed to mixtures of malathion and fullerene soot. D. magna was shown to be the most sensitive assay when carbon nanomaterials were present. Toxicity to D. magna was as follows: fullerene soot > multiwall carbon nanotubes > graphene. These results were proportional to the size of aggregates, smaller aggregates being the most toxic. The vector function of nanomaterials aggregates and the unexpected release inside living organisms was proven for malathion. These results highlight new insights on the risks associated with the release of carbon nanomaterials into the environment.

Unexpected occurrence of volatile dimethylsiloxanes in Antarctic soils, vegetation, phytoplankton, and krill.

Volatile methyl siloxanes (VMS) are high-production synthetic compounds, ubiquitously found in the environment of source regions. Here, we show for the first time the occurrence of VMS in soils, vegetation, phytoplankton, and krill samples from the Antarctic Peninsula region, which questions previous claims that these compounds are "flyers" and do not significantly reach remote ecosystems. Cyclic VMS are the predominant compounds, with concentrations ranging from the limits of detection to 110 ng/g in soils. Concentrations of cyclic VMS in phytoplankton are negatively correlated with sea surface salinity, indicating a source from ice and snow melting and consistent with snow depositional inputs. After the summer snow melting, VMS accumulate in the Southern Ocean and Antarctic biota. Therefore, once introduced into the marine environment, VMS are eventually trapped by the biological pump and, thus, behave as "single hoppers". Conversely, VMS in soils and vegetation behave as "multiple hoppers" due to their high volatility.

Quantitative profiling of perfluoroalkyl substances by ultrahigh-performance liquid chromatography and hybrid quadrupole time-of-flight mass spectrometry.

The accurate determination of perfluoroalkyl substances (PFSAs) in water, sediment, fish, meat, and human milk was achieved by ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QqTOF-MS) with an ABSciex Triple TOF®. A group of 21 PFSAs was selected as target to evaluate the quantitative possibilities. Full scan MS acquisition data allows quantification at relevant low levels (0.1-50 ng L(-1) in water, 0.05-2 ng g(-1) in sediments, 0.01-5 ng g(-1) in fish and meat, and 0.005-2 ng g(-1) in human milk depending on the compound). Automatic information dependent acquisition product ion mass spectrometry (IDA-MS/MS) confirms the identity even for those compounds that presented only one product ion. The preparation of a homemade database using the extracted ion chromatogram (XIC) Manager of the software based upon retention time, accurate mass, isotopic pattern, and MS/MS library searching achieves not only the successful identification of PFSAs but also of some pharmaceuticals, such as acetaminophen, ibuprofen, salicylic acid, and gemfibrozid. Mean recoveries and relative standard deviation (RSD) were 67-99% (9-16% RSD) for water, 62-103% (8-18% RSD) for sediment, 60-95% (8-17% RSD) for fish, 64-95% (8-15% RSD) for meat, and 63-95% (8-16%) for human milk. The quantitative data obtained for 60 samples by UHPLC-QqTOF-MS agree with those obtained by LC-MS/MS with a triple quadrupole (QqQ).

Nanoparticle tracking analysis characterisation and parts-per-quadrillion determination of fullerenes in river samples from Barcelona catchment area.

In the present work, the analysis of seven fullerenes (C60 and C70 fullerenes and five functionalised fullerenes) has been performed in river samples collected in the vicinities of Barcelona (Catalonia, NE of Spain). The results of 48 samples (25 river waters, 12 river sediments and 11 wastewater effluents) are presented. Extracts of river water, river sediments and wastewater effluents were analysed by liquid chromatography (LC), using a pyrenylpropyl group bonded silica based column, coupled to a high-resolution mass spectrometer (HRMS), using a dual ion source, atmospheric pressure photoionisation/atmospheric pressure chemical ionisation source (APPI/APCI). The novel methodology presents good chromatographic separation, excellent selectivity and instrumental limits of quantification (ILOQ) in the femtogram order. Method limits of quantification (MLOQ) ranged from 2.9 to 17 pg/l and from 3.2 to 31 pg/l in surface waters and wastewaters, respectively. In wastewater effluents, the sums of C60 and C70 ranged from 0.5 to 9.3 ng/l. In surface waters, C60 fullerene was the most ubiquitous compound, being detected in 100% of the samples in concentrations from 31 pg/l to 4.5 ng/l, while C70 concentrations ranged from less than the method limits of detection (MLOD) to 1.5 ng/l. The presence of fullerenes in both the large particulate (diameter Ø > 450 nm) and the colloidal (Ø < 450 nm) fractions of surface waters should be noticed. In sediments, the concentrations of fullerenes were between the MLOD and 34.4 pg/g. In addition, nanoparticle tracking analysis (NTA) was used for the characterisation of water samples in terms of nanoparticle number concentration and size distribution. As far as our knowledge is concerned, this is the first time that NTA has been used for the characterisation of complex river waters with an environmental focus.

Assessment of perfluoroalkyl substances in food items at global scale.

This study assessed the levels of 21 perfluoroalkyl substances (PFASs) in 283 food items (38 from Brazil, 35 from Saudi Arabia, 174 from Spain and 36 from Serbia) among the most widely consumed foodstuffs in these geographical areas. These countries were chosen as representatives of the diet in South America, Western Asia, Mediterranean countries and South-Eastern Europe. The analysis of foodstuffs was carried out by turbulent flow chromatography (TFC) combined with liquid chromatography with triple quadrupole mass spectrometry (LC-QqQ-MS) using electrospray ionization (ESI) in negative mode. The analytical method was validated for the analysis of different foodstuff classes (cereals, fish, fruit, milk, ready-to-eat foods, oil and meat). The analytical parameters of the method fulfill the requirements specified in the Commission Recommendation 2010/161/EU. Recovery rates were in the range between 70% and 120%. For all the selected matrices, the method limits of detection (MLOD) and the method limits of quantification (MLOQ) were in the range of 5 to 650 pg/g and 17 to 2000 pg/g, respectively. In general trends, the concentrations of PFASs were in the pg/g or pg/mL levels. The more frequently detected compounds were perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA). The prevalence of the eight-carbon chain compounds in biota indicates the high stability and bioaccumulation potential of these compounds. But, at the same time, the high frequency of the shorter chain compounds is also an indication of the use of replacement compounds in the new fluorinated materials. When comparing the compounds profile and their relative abundances in the samples from diverse origin, differences were identified. However, in absolute amounts of total PFASs no large differences were found between the studied countries. Fish and seafood were identified as the major PFASs contributors to the diet in all the countries. The total sum of PFASs in fresh fish and seafood was in the range from the MLOQ to 28ng/g ww. According to the FAO-WHO diets composition, the daily intake (DI) of PFASs was calculated for various age and gender groups in the different diets. The total PFASs food intake was estimated to be between 2300 and 3800 ng /person per day for the different diets. Finally, the risk intake (RI) was calculated for selected relevant compounds. The results have indicated that by far in no case the tolerable daily intake (TDI) (150, 1500, 50,000, 1,000,000, 150, 1500 ng/kg body weight, for perfluorohexanesulfonate (PFHxS), fluorotelomer alcohol (FTOH), perfluorobutanesulfonic acid (PFBS), perfluorobutanoic acid (PFBA), PFOS and PFOA, respectively) was exceeded.

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.

Occurrence and fate of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in an urban aquifer located at the Besòs River Delta (Spain).

Urban aquifers are at risk of contamination from persistent and mobile organic compounds (PMOCs), especially per- and polyfluoroalkyl substances (PFAS), which are artificial organic substances widely used across various industrial sectors. PFAS are considered toxic, mobile and persistent, and have therefore gained significant attention in environmental chemistry. Moreover, precursors could transform into more recalcitrant products under natural conditions. However, there is limited information about the processes which affect their behaviour in groundwater at the field-scale. In this context, the aim of this study is to assess the presence of PFAS in an urban aquifer in Barcelona, and identify processes that control their evolution along the groundwater flow. 21 groundwater and 6 river samples were collected revealing the presence of 16 PFAS products and 3 novel PFAS. Short and ultra-short chain PFAS were found to be ubiquitous, with the highest concentrations detected for perfluorobutanesulfonic acid (PFBS), trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TFSA). Long chain PFAS and novel PFAS were found to be present in very low concentrations (<50 ng/L). It was observed that redox conditions influence the behaviour of a number of PFAS controlling their attenuation or recalcitrant behaviour. Most substances showed accumulation, possibly explained by sorption/desorption processes or transformation processes, highlighting the challenges associated with PFAS remediation. In addition, the removal processes of different intensities for three PFAS were revealed. Our results help to establish the principles of the evolution of PFAS along the groundwater flow, which are important for the development of conceptual models used to plan and adopt site specific groundwater management activities (e.g., Managed Aquifer Recharge).

Direct peel monitoring of xenobiotics in fruit by direct analysis in real time coupled to a linear quadrupole ion trap-orbitrap mass spectrometer.

Study of xenobiotics present in fruit peel by exposing it (without any pretreatment) to direct analysis in real time coupled to a high-resolution orbitrap mass spectrometer (DART-HRMS) is reported for the first time. Variables such as DART gas heater temperature and pressure, source-to-MS distance, and sample velocity are investigated. The analysis of one sample by DART-MS lasts ca. 1 min, and the benefits of both high-resolution and tandem mass spectrometry to elucidate nontarget or unknown compounds are combined. Identification of postharvest fungicides, antioxidants, and sugars in fruit peel is performed in the positive ion mode. A possible elemental formula is suggested for marker components. The lowest imazalil concentration that could be detected by this system is 1 ng (equivalent to a concentration of ca. 300 µg kg(-1)), which is well below the maximum residue limit. For oranges and apples, direct peel exposition demonstrated good interday precision (within 20% for any concentration) and proper linearity (R(2) ≥ 0.99), with a dynamic range from 1 to 2500 ng for apple. A comparison of the results obtained using the direct peel screening DART-based method is made with those obtained by DART analysis of solvent extracts, as well as those obtained analyzing these extracts by ultrahigh-performance liquid chromatography orbitrap mass spectrometry (UHPLC-Orbitrap). The results are in good agreement. Thus, the proposed method proves to be quantitatively accurate with indisputable identification specificity. As an independent method, the approach of direct scanning of peel is of high interest and of potential future within food analysis to guarantee safety, quality, and authenticity.

Quantitative trace analysis of fullerenes in river sediment from Spain and soils from Saudi Arabia.

A quantitative method based on ultrasound-assisted toluene extraction followed by liquid chromatography-electrospray ionization-tandem mass spectrometry for the analysis of C60 and C70 fullerenes, N-methylfulleropyrrolidine, [6, 6]-phenyl C61 butyric acid methyl ester and [6, 6]-thienyl C61 butyric acid methyl ester has been developed. The method was validated using fortified blank river sediments according to the criteria of Commission Decision 2002/657/EC. The method limits of detection ranged from 14 to 290 pg/g, making it suitable for its application in environmental analysis. The method has been applied to investigate fullerene content in 58 soil samples collected from different urban and industrial areas in Saudi Arabia and in river sediment from six different sites in the Llobregat River Basin. In addition, in the case of the Llobregat River, superficial water samples from the same sites of the sediments were collected and analysed using a previous method. In soils from Saudi Arabia, C60-fullerene was the only compound that was detected and quantified in 19% of samples. In the sediments of the Llobregat River, C60-fullerene was also the only one detected (33% of the samples), while in river water, C70-fullerene was the most frequent compound, and it was quantified in 67% of the samples. However, C60-fullerene was present in two of the six samples, but at higher concentrations than C70-fullerene, ranging from 0.9 to 7.8 ng/L.

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.