Predicted concentrations of antineoplastic drugs in the aquatic environment: The case of Ría de Vigo (NW, Spain).

The European Medicines Agency (EMA) mandates Environmental Risk Assessments (ERAs) since 2006 to determine potential risks of new marketed medicines. Drugs with a Predicted Environmental Concentration (PEC) in inland surface waters exceeding 0.01 µg L-1 require further environmental risk assessment. PEC may be refined based on prevalence data and/or based on the treatment regimen. In this study, based on EMA regulations, refined PEC of 108 antineoplastic drugs in coastal waters were determined based on the consumption in a coastal health area during 2021, identifying six drugs with potential environmental risk in surface waters (hydroxyurea, capecitabine, abiraterone, ibrutinib, imatinib and 5-fluorouracil) and two in marine ecosystem (hydroxyurea and capecitabine). Comparison of these refined PECs with data from marketing laboratories revealed significant disparities, suggesting the need for regular updates, especially with changes in drug indications or financing. Notably, the identified drugs are not yet on the main reference lists of emerging contaminants.

A green approach for the automatic quantitative analysis of additives in plastic samples using in-tube extraction dynamic headspace sampling technique coupled to GC-MS/MS.

BACKGROUND: Many of the chemicals frequently used as additives have been recognised as hazardous substances, and therefore their analysis is necessary to evaluate plastic contamination risk. Additives analysis in plastic samples is usually performed by methods involving high volumes of toxic solvents or having high detection limits. In this work, a novel, fast, solventless and reliable green method was developed for the automated analysis of plastic additives from plastic samples. The proposed method consists of in-tube extraction dynamic headspace sampling (ITEX-DHS) combined with gas chromatography (GC) and mass spectrometry (MS/MS) determination. RESULTS: Several parameters affecting the ITEX-DHS extraction of 47 additives in plastic samples (including phthalates, bisphenols, adipates, citrates, benzophenones, organophosphorus compounds, among others) were optimised. The use of matrix-matched calibration, together with labelled surrogate standards, minimises matrix effects, resulting in recoveries between 70 and 128%, with good quantitation limits (below 0.1 µg g-1 for most compounds) and precision (<20%). The method proposed can be applied to any type of polymer, but due to the existence of the matrix effect, calibrates with the adequate matrix should be performed for each polymer. SIGNIFICANCE: This method represents an effective improvement compared to previous methods because it is fast, solvent-free, fully automated, and provides reliable quantification of additives in plastic samples.

Comparison of microplastic type, size, and composition in atmospheric and foliage samples in an urban scenario.

The rising trend of plastic production in last years and the inadequate disposal of related waste has raised concerns regarding microplastic-related environmental issues. Microplastic particles disperse by means of transport and deposition processes to different ecosystems and enter food chains. In this paper, atmospheric deposition and foliage samples of two species (i.e., Hedera helix and Photinia glabra) were collected and analysed for the quantity and identity of microplastics (MPs). A preliminary methodology to treat foliage samples and subsequently identify MPs using a quantum cascade laser IR spectrophotometer is presented. The treatment of airborne samples involved filtration, mild digestion, concentration, and transfer onto reflective slides whereas that for foliage involved washing, concentration, and transference of putative MPs onto reflective slides. Fibers and fragments were differentiated according to their physical features (size, width, height, etc.) and calculating derived characteristics (namely, circularity and solidity). The preliminary results obtained suggest a good agreement between atmospheric-deposited and foliage-retained MPs, showing the capability of leaves to act as passive samplers for environmental monitoring.

Oxidative potential of the inhalation bioaccessible fraction of PM10 and bioaccessible concentrations of polycyclic aromatic hydrocarbons and metal(oid)s in PM10.

Atmospheric particulate matter (PM) has been related to numerous adverse health effects in humans. Nowadays, it is believed that one of the possible mechanisms of toxicity could be the oxidative stress, which involves the development of reactive oxygen species (ROS). Different assays have been proposed to characterize oxidative stress, such as dithiothreitol (DTT) and ascorbic acid (AA) acellular assays (OPDTT and OPAA), as a metric more relevant than PM mass measurement for PM toxicity. This study evaluates the OP of the bioaccessible fraction of 65 PM10 samples collected at an Atlantic Coastal European urban site using DTT and AA assays. A physiologically based extraction (PBET) using Gamble's solution (GS) as a simulated lung fluid (SLF) was used for the assessment of the bioaccessible fraction of PM10. The use of the bioaccessible fraction, instead of the fraction assessed using conventional phosphate buffer and ultrasounds assisted extraction (UAE), was compared for OP assessment. Correlations between OPDTT and OPAA, as well as total and bioaccessible concentrations of polycyclic aromatic hydrocarbons (PAHs) and metal(oid)s, were investigated to explore the association between those compounds and OP. A correlation was found between both OP (OPDTT and OPAA) and total and bioaccessible concentrations of PAHs and several metal(oid)s such as As, Bi, Cd, Cu, Ni, and V. Additionally, OPDTT was found to be related to the level of K+.

Bioaccumulation of trace metals in the plastisphere: Awareness of environmental risk from a European perspective.

The term "Plastisphere" refers to the biofilm layer naturally formed by microorganisms attaching to plastic surfaces. This layer possesses the capability to adsorb persistent organic and inorganic pollutants, particularly trace metals, which are the focus of this research study. Immersion experiments were concurrently conducted in five locations spanning four European countries (France, Ireland, Spain, and Italy) utilising eight distinct polymers. These immersions, repeated every three months over a one-year period, aimed to evaluate the baseline bioaccumulation of 12 trace metals. The study underscores the intricate nature of metal bioaccumulation, influenced by both micro-scale factors (such as polymer composition) and macro-scale factors (including geographical site and seasonal variations). Villefranche Bay in France exhibited the lowest metals bioaccumulation, whereas Naples in Italy emerged as the site where bioaccumulation was often the highest for the considered metals. Environmental risk assessment was also conducted in the study. The lightweight nature of certain plastics allows them to be transported across significant distances in the ocean. Consequently, evaluating trace metal concentrations in the plastisphere is imperative for assessing potential environmental repercussions that plastics, along with their associated biota, may exert even in locations distant from their point of emission.

Development of a dispersive liquid-liquid microextraction method for the determination of plastic additives in seawater.

A method using dispersive liquid-liquid microextraction (DLLME) prior to high performance liquid chromatography-diode array detection (HPLC-DAD) was developed to determine seven additives from the plastics industry (butylated hydroxytoluene, diisodecyl phthalate, irgafos 168, lawsone, quercetin, triclosan and vitamin E) in seawater samples. These compounds can reach seawater due to direct discharge from wastewater treatment plants and leaching from plastics and microplastics. The extraction was performed using 25 mL of seawater, 500 µL of 1-octanol (extraction solvent) and a stirring step instead of dispersive solvent. Additive concentrations were determined by LC-DAD on a C18 column with a mobile phase of acetonitrile and phosphoric acid aqueous solution (pH 3.5) by gradient elution. The analytical recoveries ranged from 82 to 93% for all compounds, except for lawsone (60%). Repeatability and intermediate precision were adequate with RSD < calculated values following the Horwitz equation at the concentration levels evaluated (0.06 and 0.24 mg L-1). All additives exhibited linear matrix calibration curves (R2 > 0.99). Detection limits ranged from 0.009 to 0.028 mg L-1 and quantification limits ranged from 0.027 to 0.084 mg L-1. Finally, the application of the method to real samples verified the method as accurate and applicable to seawater.

A reliable method to determine airborne microplastics using quantum cascade laser infrared spectrometry.

The number of studies dealing with airborne microplastics (MPs) is increasing but sampling and sample treatment are not standardized, yet. Here, a fast and reliable method to characterize MPs is presented. It involves the study of two passive sampling devices to collect atmospheric bulk deposition (wet and dry deposition) and three digestion methods (two alkaline-oxidative and an oxidative) to treat the samples. The alkaline-oxidative method based on KOH and NaClO was selected for a mild organic matrix digestion. In addition, some operational parameters of a high-throughput quantum cascade laser-based infrared device (LDIR) were optimized: an effective automatic tiered approach to differentiate fibres from particles (>90 % success in validation) and a criterion to establish positive matches when comparing an unknown spectrum against the spectral database (proposed match index > 0.85). The procedural analytical recoveries were very good for particles (82-90 %) and slightly lower for fibres (62-73 %). Finally, the amount and type of MPs deposited at a sub-urban area NW Spain were evaluated. Most common polymers were Polyethylene (PE), Polypropylene (PP) and Polyethylene terephthalate (PET). The deposition rates ranged 98-1220 MP/m2/day, ca. 1.7 % of the total collected particles. More than 50 % of the total MPs deposited were in the 20-50 µm size range, whereas fibres were mostly in the 50-500 µm size range.

A multi-residue method for the analysis of organic pollutants released from atmospheric PM2.5 in simulated biological fluids: Inhalation bioaccessibility and bioavailability estimation.

BACKGROUND: In recent decades, there has been a growing interest within the scientific community regarding the study of the fraction that could be released in simulated biological fluids to estimate in vitro bioaccessibility and bioavailability of compounds. Concerning particulate matter (PM), studies were essentially focused on metal (oid)s probably due to more complex methodologies needed for organic compounds, requiring extraction and pre-concentration steps from simulated fluids, followed by chromatographic analysis. Thus, the development of a simple and sensitive methodology for the analysis of multi-class organic compounds released in different inhalation simulated fluids would represent a great contribution to the field. RESULTS: In this work, a methodology for the analysis of 49 organic pollutants, including 18 polycyclic aromatic hydrocarbons (PAHs), 12 phthalate esters (PAEs), 11 organophosphorus flame retardants (OPFRs), 6 synthetic musk compounds (SMCs) and 2 bisphenols released in simulated fluids from PM2.5 samples was developed. After a physiologically based extraction test (PBET) by using artificial lysosomal fluid (ALF) and a simulated body fluid (SBF, filling a dialysis membrane) to obtain in vitro inhalation bioaccessible and bioavailable fractions, respectively; compounds were determined by a vortex-assisted liquid-liquid extraction (VALLE) and a subsequent analysis by programmed temperature vaporization-gas chromatography-tandem mass spectrometry (PTV-GC-MS/MS). Experimental conditions concerning VALLE extraction (extraction time and amount of NaCl (g)) were optimized by using a central composite design (CCD), best MS/MS transitions were selected and matrix-matched calibration combined with use of labelled subrogate standards provided high sensitivity, minimization of matrix effects and recovering losses compensation. SIGNIFICANCE: The successful validation results obtained for most of the compounds demonstrated the effectiveness of the proposed methodology for the analysis of multi-class organic pollutants released in ALF and SBF for inhalation bioaccessibility and bioavailability assessment, respectively. Furthermore, applicability of the method was proved by analysing 20 p.m.2.5 samples, being the proposed in vitro PBET dialyzability approach for assessing organic pollutant's inhalation bioavailability applied to PM2.5 samples for the first time.

A nationwide monitoring of atmospheric microplastic deposition.

Plastic production continues to increase every year, yet it is widely acknowledged that a significant portion of this material ends up in ecosystems as microplastics (MPs). Among all the environmental compartments affected by MPs, the atmosphere remains the least well-known. Here, we conducted a one-year simultaneous monitoring of atmospheric MPs deposition in ten urban areas, each with different population sizes, economic activities, and climates. The objective was to assess the role of the atmosphere in the fate of MPs by conducting a nationwide quantification of atmospheric MP deposition. To achieve this, we deployed collectors in ten different urban areas across continental Spain and the Canary Islands. We implemented a systematic sampling methodology with rigorous quality control/quality assurance, along with particle-oriented identification and quantification of anthropogenic particle deposition, which included MPs and industrially processed natural fibres. Among the sampled MPs, polyester fibres were the most abundant, followed by acrylic polymers, polypropylene, and alkyd resins. Their equivalent sizes ranged from 22 µm to 398 µm, with a median value of 71 µm. The particle size distribution of MPs showed fewer large particles than expected from a three-dimensional fractal fragmentation pattern, which was attributed to the higher mobility of small particles, especially fibres. The atmospheric deposition rate of MPs ranged from 5.6 to 78.6 MPs m-2 day-1, with the higher values observed in densely populated areas such as Barcelona and Madrid. Additionally, we detected natural polymers, mostly cellulosic fibres with evidence of industrial processing, with a deposition rate ranging from 6.4 to 58.6 particles m-2 day-1. There was a positive correlation was found between the population of the study area and the median of atmospheric MP deposition, supporting the hypothesis that urban areas act as sources of atmospheric MPs. Our study presents a systematic methodology for monitoring atmospheric MP deposition.

Organotin compounds in seafood by ultrasonic assisted extraction and gas chromatography-triple quadrupole tandem mass spectrometry.

Although restricting environmental quality values for organotin compounds (OTs) are set by Directive 2013/39/EU of the European Parliament, marine environment remains being affected due to maritime circulation at global scale. Fish and seafood accumulate OTs, making fish and seafood consumption the main source of OTs in humans. Because of the fish and seafood matrices complexity and the required low limits of detection, a robust and fast procedure for the quantification of OTs in fish and seafood, using ultrasound-assisted extraction and gas chromatography-tandem mass spectrometry, was validated and applied. Detection (2.7 µg Sn kg-1) and quantification (8.0 µg Sn kg-1) limits, repeatability and intermediate precision (<10%), accuracy by analysing ERM®-CE477 Mussel Tissue and analytical recoveries (65-122%) were assessed. Multivariate analysis shown that the matrix effect for some OTs displayed good negative correlation with the fat and protein content. Health risk assessment of OTs intake revealed no serious risk for human consumption.

Microplastics in surface water of the Bay of Asunción, Paraguay.

This study identified and quantified microplastics in the Bay of Asunción, Paraguay, and its main tributaries. Surface water samples were sieved in duplicate at six locations using stainless-steel sieves (0.3-4.75 mm range), digested employing the Fenton's reaction (Fe-catalysed H2O2 digestion), and floated using NaCl and NaI. Particles were inspected using a microscope and characterized by IR spectrometry. Microplastics were found in all samples; more abundant (p < 0.05) in water from the bay (13.2 ± 13.4 items·m-3) than from the tributaries (1.0 ± 0.5 items·m-3). Most microplastics were common polymers and their abundance was in the order polypropylene > high-density polyethylene > low-density polyethylene, transparent and white. The results were similar to other regional studies and suggested that their main source was single-use packaging, disposed inadequately due to poor garbage collection.

Occurrence and size distribution study of microplastics in household water from different cities in continental Spain and the Canary Islands.

The purpose of this study was to investigate the occurrence of microplastics (MPs) in drinking water in Spain by comparing tap water from different locations using common sampling and identification procedures. We sampled tap water from 24 points in 8 different locations from continental Spain and the Canary Islands by means of 25 µm opening size steel filters coupled to household connections. All particles were measured and spectroscopically characterized including not only MPs but also particles consisting of natural materials with evidence of industrial processing, such as dyed natural fibres, referred insofar as artificial particles (APs). The average concentration of MPs was 12.5 ± 4.9 MPs/m3 and that of anthropogenic particles 32.2 ± 12.5 APs/m3. The main synthetic polymers detected were polyamide, polyester, and polypropylene, with lower counts of other polymers including the biopolymer poly(lactic acid). Particle size and mass distributions were parameterized by means of power law distributions, which allowed performing estimations of the concentration of smaller particles provided the same scaling parameter of the power law applies. The calculated total mass concentration of the identified MPs was 45.5 ng/L. The observed size distribution of MPs allowed an estimation for the concentration of nanoplastics (< 1 µm) well below the ng/L range; higher concentrations are not consistent with scale invariant fractal fragmentation. Our findings showed that MPs in the drinking water sampled in this work do not represent a significant way of exposure to MPs and would probably pose a negligible risk for human health.

Source apportionment of PM10 and health risk assessment related in a narrow tropical valley. Study case: Metropolitan area of Aburrá Valley (Colombia).

This study investigates spatio-temporal variations of PM10 mass concentrations and associated metal(oid)s, δ13C carbon isotope ratios, polycyclic aromatic hydrocarbons (PAHs), total organic carbon (TOC) and equivalent black carbon (eBC) concentrations over a half year period (from March 2017 to October 2017) in two residential areas of Medellín (MED-1 and MED-2) and Itagüí municipality (ITA-1 and ITA-2) at a tropical narrow valley (Aburrá Valley, Colombia), where few data are available. A total of 104 samples were analysed by using validated analytical methodologies, providing valuable data for PM10 chemical characterisation. Metal(oid)s concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion, and PAHs concentrations were measured by Gas Chromatography-Mass Spectrometry (GC-MS) after Pressurised Hot Water Extraction (PHWE) and Membrane Assisted Solvent Extraction (MASE). Mean PM10 mass concentration ranged from 37.0 µg m-3 to 45.7 µg m-3 in ITA-2 and MED-2 sites, respectively. Al, Ca, Mg and Na (from 6249 ng m-3 for Mg at MED-1 site to 10,506 ng m-3 for Ca at MED-2 site) were the major elements in PM10 samples, whilst As, Be, Bi, Co, Cs, Li, Ni, Sb, Se, Tl and V were found at trace levels (< 5.4 ng m-3). Benzo[g,h,i] perylene (BghiP), benzo[b + j]fluoranthene (BbjF) and indene(1,2,3-c,d)pyrene (IcdP) were the most profuse PAHs in PM10 samples, with average concentrations of 0.82-0.86, 0.60-0.78 and 0.47-0.58 ng m-3, respectively. Results observed in the four sampling sites showed a similar dispersion pattern of pollutants, with temporal fluctuations which seems to be associated to the meteorology of the valley. A PM source apportionment study were carried out by using the positive matrix factorization (PMF) model, pointing to re-suspended dust, combustion processes, quarry activity and secondary aerosols as PM10 sources in the study area. Among them, combustion was the major PM10 contribution (accounting from 32.1 to 32.9% in ITA-1 and ITA-2, respectively), followed by secondary aerosols (accounting for 13.2% and 23.3% ITA-1 and MED-1, respectively). Finally, a moderate carcinogenic risk was observed for PM10-bound PAHs exposure via inhalation, whereas significant carcinogenic risk was estimated for carcinogenic metal(oid)s exposure in the area during the sampling period.

Filtration of biopolymer PHB particles loaded with synthetic musks does not cause significant bioaccumulation in marine mussels.

The role of the biopolymer polyhydroxybutyrate (PHB, <250 µm) as a vehicle of a synthetic musks mixture (celestolide, galaxolide, tonalide, musk xylene, musk moskene and musk ketone) to Mytilus galloprovincialis was investigated. For 30 days, virgin PHB, virgin PHB+musks (6.82 µg g-1) and weathered PHB+musks, were daily spiked into tanks containing mussels, followed by a 10-day depuration period. Water and tissues samples were collected to measure exposure concentrations and accumulation in tissues. Mussels were able to actively filter microplastics in suspension but the concentration of the musks found in tissues (celestolide, galaxolide, tonalide) were markedly lower than the spiked concentration. Estimated Trophic Transfer Factors suggest that PHB will only play a minor role on musks accumulation in marine mussels, even if our results suggest a slightly extended persistence in tissues of musks loaded to weathered PHB.

Mixed-mode chromatography of mixed functionalized analytes as the homologues of benzalkonium chloride. Application to pharmaceutical formulations.

In this work, a retention behavior based on mixed-mode reversed-phase (RP)/hydrophilic interaction liquid chromatography (HILIC) was observed for benzalkonium chloride (BAK) using a core-shell column functionalized with biphenyl groups. Although in the literature, the U-shaped retention was reported for polar compounds in mixed functionalized phases, in the present work, the behavior was dependent upon the chemical structure of the analyte with mixed functionality (ammonium group, a benzyl group and an alkyl chain) and on the high selectivity of the chromatographic column. The bimodal retention was observed for the four BAK homologues using a content of acetonitrile from 65 to 95% in the mobile phase. The data were adjusted to polynomial equations which allow for modeling and predicting the U-shaped retention. The salt concentration (50 and 100 mM), anion (formate and acetate) and cation (ammonium and triethylammonium) of the salt, pH (4 and 5) in the mobile phase were studied in order to understand their influence on the two retention modes. Significant electrostatic interactions were involved in the two retention modes, especially with a content of acetonitrile higher that 90%. Linear relationships between the retention factors of the four homologues were found in a wide range of %acetonitrile when the salt and triethylamine concentration, pH and nature of salt were changed. The differences found on the retention of the homologues, when increasing the alkyl chain length, were more significant in the RP mode due to predominant hydrophobic interactions. A pH decrease and a salt concentration increase caused a retention decrease for both modes. A decrease on of the retention was observed when acetate anion was replaced by formate anion. The different order of the polynomial equations according to the used mobile phase confirmed its relevant role in the interactions with the analytes and stationary phase. A mobile phase was selected (85% acetonitrile, pH 4 and 100 mM ammonium formate) for the BAK determination in cutaneous, otic and ophthalmic formulations with different active pharmaceutical ingredients and excipients. Low sample volume (500 µL) and short analysis time (<5 min) were some of the advantages of the proposed method. In addition, good analytical performance (R2 > 0.999, % RSD <4.5% for intra-day precision and <5.8% for inter-day precision, and recoveries in the 92-105% range) was obtained.

In-vitro inhalation bioavailability estimation of Metal(oid)s in atmospheric particulate matter (PM2.5) using simulated alveolar lysosomal fluid: A dialyzability approach.

A novel in-vitro method, by using synthetic body fluids, human physiological conditions and a simulated air-blood barrier (by using a dialysis membrane) has been developed and applied to assess in-vitro inhalation bioavailability of metal(oid)s associated to particulate matter (PM2,5) samples collected from an industrial site of the Northwest of Spain. A validated analytical methodology based on inductively coupled plasma mass spectrometry (ICP-MS) was used to analyse metal(oid)s concentrations in bioavailable fractions. This approach would be a more realistic human health risk assessment since considering processes that occur in human body in contrast the overestimation derived from current models (which consider environmental concentrations). Metal(oid)s such as Cu and Mo seemed to be the most bioavailable (mean in-vitro bioavailability ratios higher than 70%); Ba, Cd, Mn, Pb, Rb, Sb, Sn, V and Zn shown mean ratios between 20 and 60%, while low in-vitro bioavailability ratios (less than 20%) were observed for metal(oid)s such as Al, Co, Cr, Fe, Ni, Ti, and Tl. Health risk assessment via inhalation based on hazard carcinogenic and non-carcinogenic indexes (HIc and HInc, respectively) were performed considering three exposure scenarios using both inhalation bioavailable and total metal(oid)s concentrations in PM2.5 samples, suggesting no risk to human health. The influence of chemical composition on in-vitro bioavailability ratios was obtained, pointing out that inhalation ratios of Al, Ba, Cr, Cu, Fe, Ni, Pb and V seem to be affected by sea salt and/or crustal and/or biogenic and/or anthropogenic content of PM2.5.

Development of an analytical procedure to analyze microplastics in edible macroalgae using an enzymatic-oxidative digestion.

Besides being food and a refuge to marine species, macroalgae are a powerful and renewable economic resource. However, they may introduce microplastics (MPs) in the trophic chain. We developed a reliable analytical method to characterize and quantify MPs in common and edible macroalgae. Several digestion methods and filters, along with various measurement options, were studied. A new enzymatic-oxidative protocol with a unique final filtration was selected and validated with a mixture of 5 commercial macroalgae (Undaria pinnatifida spp, Porphyra spp, Ulva spp, Laminaria ochroleuca and Himanthalia elongate). Further, it was shown that washing the macroalgae to release MPs is suboptimal and the potential adhesion of MPs to macroalgae was evaluated. A filter subsampling strategy that scans 33.64 % of its surface reduced the time required to characterize <70 µm particles and fibres directly on the 47 mm diameter filter using an IR microscope (1 sample/day).

Multi-class organic pollutants in atmospheric particulate matter (PM2.5) from a Southwestern Europe industrial area: Levels, sources and human health risk.

The occurrence of 50 multi-class pollutants comprising 18 polycyclic aromatic hydrocarbons (PAHs), 12 phthalate esters (PAEs), 12 organophosphorus flame retardants (OPFRs), 6 synthetic musk compounds (SMCs) and 2 bisphenols was studied in atmospheric particulate matter (PM2.5) samples collected at an industrial area focused on automotive manufacturing located at the Southwestern Atlantic European region (Vigo city, Spain) during 1-year period. Among all quantitated pollutants in PM2.5 samples, bisphenol A (BPA) was the most predominant with an average concentration of 6180 pg m-3, followed by PAHs comprising benzo(b+j)fluoranthene (BbF + BjF) and benzo(g,h,i)perylene (BghiP), accounting for 546 pg m-3 and 413 pg m-3 respectively. In addition, two OPFRs concerning tris(chloropropyl) phosphate (TCPP) and triphenyl phosphine oxide (TPPO) were the next following the concentration order, accounting for 411 pg m-3 and 367 pg m-3 respectively; being butyl benzyl phthalate (BBP) the most profuse PAE (56.1 pg m-3 by average). High relative standard deviations (RSDs) were observed during the whole sampling period, while statistically significant differences were only observed for PAHs concentrations during cold and warm seasons. Furthermore, some water-soluble ions and metal(oid)s were analysed in PM2.5 samples to be used as PM source tracers, whose concentrations were quite below the target levels set in the current legislation. Data obtained from principal component analysis (PCA) and PAHs molecular indices suggested a pyrogenic and petrogenic origin for PAHs, whereas occurrence of the remaining compounds seems to be attributed to resources used in the automotive industrial activity settled in the sampling area. Moreover, although a substantial anthropogenic source to PM2.5 in the area was observed, marine and soil resuspension contributions were also accounted. Finally, carcinogenic and non-carcinogenic risks posed by PM2.5-bound pollutants inhalation were assessed, being both averages within the safe level considering the whole period.

Improved methodology for microplastic extraction from gastrointestinal tracts of fat fish species.

Potassium hydroxide (KOH) digestion protocols are currently applied to separate microplastics from biological samples, allowing efficient digestion with minor degradation of polymers in a time- and cost-effective way. For biota samples with high-fat content, KOH reacts with triglycerides generating an overlying soap layer, making difficult the digestion and solubilization and subsequent microplastics extraction. Here we studied the addition of Tween-20 in different concentrations to evaluate the effect on the soap layer of post-digested samples. Addition of 10 % of Tween-20 presented higher flow rate during filtration, being set as optimal value. Incorporation of Tween-20 in the extraction procedure increased recovery rates of LDPE, PC and PET and appears to have a protective effect on PC and PET degradation. Tween-20 did not interfere in FTIR spectrum of polymers available in the marine environment. Being low-toxic, makes addition of Tween-20 a simple and economical way to optimize KOH digestion protocols for microplastics extraction.

Adsorption of pesticides and personal care products on pristine and weathered microplastics in the marine environment. Comparison between bio-based and conventional plastics.

The hydrophobicity of persistent organic pollutants (POPs) makes them adsorb on microplastics in the marine environment, affecting their distribution, persistence, or their transfer to the trophic chain. Fragrances and non-polar pesticides can be adsorbed by microplastics in the marine environment because of their physico-chemical characteristics. In this work, the adsorption of two pesticides (α-endosulfan and chlorpyrifos) and 6 musk fragrances (musk xylene, musk ketone, musk moskene, galaxolide, tonalide, and celestolide) on polyamide (PA6) (a petroleum based polymer) and on polyhydroxybutyrate (PHB) (biopolymer) in seawater was studied, considering also the effect of water temperature and plastic weathering. Results show higher adsorption of the selected pollutants for PHB than PA, being PA more affected by the water temperature and the plastic weathering. The highest percentage of adsorption was achieved in most cases at 24 h. In addition, this process was irreversible, as it showed the leaching assays. Besides, this work revealed that plastics mitigate the degradation of α-endosulfan in aquatic media (hydrolysis), showing that plastics can act as inhibitors of degradation of POPs, increasing its persistence in the environment.