An assessment of the concentration of pharmaceuticals adsorbed on microplastics

Micro- and nanoplastics interact with conventional pollutants on microalgae: Synthesis through meta-analysis

Micro- and nanoplastics (MNPs) have been found to occur intensively in aquatic environments, along with other conventional pollutants (Po) such as heavy metals, pesticides, pharmaceuticals, etc. However, our understanding of how MNPs and Po interact on aquatic primary producers is fragmented. We performed a quantitative meta-analysis based on 933 published experimental assessments from 44 studies to examine the coupled effects of MNPs and Po on microalgae. Although the results based on interaction type frequency (the proportion of each interaction type in all results) revealed dominantly additive interactions (56%) for overall physiological performance, an overall antagonistic effect was observed based on the mean interaction effect sizes. A higher proportion of antagonistic interaction type frequency was found in marine species compared to fresh species. The antagonistic effects were particularly significant for growth, oxidative responses, and photosynthesis, which could be attributed to the adsorption effect of MNPs on Po and thus the decreasing concentrations of pollutants in the medium. Larger-sized, negatively charged or uncharged and aged MNPs had higher proportions of antagonistic effects compared to smaller-sized, positively charged and virgin MNPs, due to their stronger adsorption capacity to Po. This study provides a comprehensive insight into the interactive effects of MNPs and Po on microalgae.

Floating plastics as integrative samplers of organic contaminants of legacy and emerging concern from Western Mediterranean coastal areas

This study investigates the role of floating plastics as integrative samplers of organic contaminants. To this end, plastics items were collected in two Western Mediterranean coastal areas: the Mar Menor lagoon, and the last transect of Ebro river. Floating plastics were identified and characterized by attenuated total reflection Fourier-transform infrared spectrometry. Then, organic contaminants were extracted from plastic items by ultrasonic extraction with methanol, and the concentrations of 168 regulated and emerging contaminants were analysed. These compounds were analysed by stir bar sorptive extraction coupled to gas chromatography-mass spectrometry (GC-MS), except for bisphenol analogues, which were analysed with a ultraperformance liquid chromatography pump coupled to a triple quadrupole mass spectrometer (UHPLC-MS/MS), and pharmaceutical compounds, determined by UPLC coupled to hybrid triple quadrupole-linear ion trap mass spectrometer (UPLC-MS/MS). All the contaminants groups considered were detected in the samples, being particularly relevant the contribution of plastic additives. The most frequently detected contaminants were UV-filters, PAHs, pharmaceuticals and synthetic musks. Apart from plasticizers, the individual contaminants octocrylene, homosalate, galaxolide, salycilic acid and ketoprofen were frequently detected in plastics items. The results pointed out to urban and touristic activities as the main sources of pollution in the coastal areas investigated. The utility of floating plastics as integrative samplers for the detection of organic contaminants in aquatic ecosystems has been demonstrated.

Immunotoxicological effects of perfluorooctanesulfonic acid on European seabass are reduced by polyethylene microplastics

Marine environments receive plastic waste, where it suffers a transformation process into smaller particles. Among them, microplastics (MPs; <5 mm) are ingested by aquatic organisms leading to negative effects on animal welfare. The interactions between MPs, contaminants and organisms are poorly understood. To clarify this issue, European seabass (Dicentrarchus labrax L.) were fed with diets supplemented with 0 (control), polyethylene (PE) MPs (100 mg/kg diet), perfluorooctanesulfonic acid (PFOS, 4.83 μg/kg diet) or PFOS adsorbed to MPs (MPs-PFOS; final concentrations of 4.83 μg and 100 mg of PFOS and MP per kg of feed, respectively). Samples of skin mucus, serum, head-kidney (HK), liver, muscle, brain and intestine were obtained. PFOS levels were high in the liver of fish fed with the PFOS-diet, and markedly reduced when adsorbed to MPs. Compared to the control groups, liver EROD activity did not show any significant changes, whereas brain and muscle cholinesterase activities were decreased in all the groups. The histological and morphometrical study on liver and intestine showed significant alterations in fish fed with the experimental diets. At functional level, all the experimental diets affected the humoral (peroxidase, IgM, protease and bactericidal activities) as well as cellular (phagocytosis, respiratory burst and peroxidase) activities of HK leukocytes, being more marked those effects caused by the PFOS diet. Besides, treatments produced inflammation and oxidative stress as evidenced at gene level. Principal component analysis demonstrated that seabass fed with MPs-PFOS showed more similar effects to MPs alone than to PFOS. Overall, seabass fed with MPs-PFOS diet showed similar or lower toxicological alterations than those fed with MPs or PFOS alone demonstrating the lack of additive effects or even protection against PFOS toxicity.

Transcriptome sequencing and metabolite analysis reveal the single and combined effects of microplastics and di-(2-ethylhexyl) phthalate on Peneaus vannamei

Due to the rising usage of plastics, plastic debris are present throughout marine ecosystems and detrimentally affects marine biota. Additionally, plastics likely result in elusive toxicity effects due to addition of plasticizers. The aim of the present study was to reveal the potential effects and mechanism of microplastics (MPs), di-(2-ethylhexyl) phthalate (DEHP) and copollution of MPs and DEHP (MPs-DEHP) on Peneaus vannamei (P. vannamei) juveniles regarding oxidative stress, transcriptomics and metabolomics. MPs, DEHP and MPs-DEHP significantly induced the activities of superoxide dismutase (SOD) and catalase (CAT); MPs and DEHP have an antagonistic effect for malondialdehyde (MDA); suggesting that disorders of the antioxidant defence systems. 13, 133 and 58 differentially expressed genes and 21, 82 and 39 differentially expressed metabolites were responsible for the distinction of MPs, DEHP and MPs-DEHP groups, respectively. The combination of transcriptomic and metabolomic analyses showed that MPs, DEHP and MPs-DEHP exposure disturbed amino acid and lipid metabolism, and further induced inflammatory responses and dysfunction of purine metabolism. Furthermore, the presence of MPs might alleviate the biotoxicity of DEHP in P. vannamei. These findings provide new insights into the single and combined toxicological effects of MPs and additives for marine biota.

Assessing the effects of the cytostatic drug 5-Fluorouracil alone and in a mixture of emerging contaminants on the mussel Mytilus galloprovincialis

The assessment of contaminants of emerging concern, alone and in mixtures, and their effects on marine biota requires attention. 5-Fluorouracil is a cytostatic category 3 anti-cancer medication (IARC) that is used to treat a variety of cancers, including colon, pancreatic, and breast cancer. In the presence of other pollutants, this pharmaceutical can interact and form mixtures of contaminants, such as adhering to plastics and interaction with metal nanoparticles. This study aimed to comprehend the effects of 5-Fluorouracil (5FU; 10 ng/L) and a mixture of emerging contaminants (Mix): silver nanoparticles (nAg; 20 nm; 10 μg/L), polystyrene nanoparticles (nPS; 50 nm; 10 μg/L) and 5FU (10 ng/L), in an in vivo (21 days) exposure of the mussel Mytilus galloprovincialis. A multibiomarker approach namely genotoxicity, the antioxidant defence system (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx), glutathione - S - transferases (GST) activities), and oxidative damage (LPO) was used to assess the effects in gills and digestive gland of mussels. Both treatments cause genotoxicity in mussel's haemolymph, and antagonism between contaminants was observed in the Mix. Genotoxicity observed confirms 5FU's mode of action (MoA) by DNA damage. The antioxidant defence system of mussels exposed to 5FU kicked in and counter balanced ROS generated during the exposure, though the same was not seen in Mix-exposed mussels. Mussels were able to withstand the effects of the single compound but not the effects of the Mix. For oxidative stress and damage, the interactions of the components of the mixture have a synergistic effect.

The ecotoxicological consequences of microplastics and co-contaminants in aquatic organisms: a mini-review

Microplastics (MPs, <5 mm in size) are a grave environmental concern. They are a ubiquitous persistent pollutant group that has reached into all parts of the environment - from the highest mountain tops to the depths of the ocean. During their production, plastics have added to them numerous chemicals in the form of plasticizers, colorants, fillers and stabilizers, some of which have known toxicity to biota. When released into the environments, MPs are also likely to encounter chemical contaminants, including hydrophobic organic contaminants, trace metals and pharmaceuticals, which can sorb to plastic surfaces. Additionally, MPs have been shown to be ingested by a wide range of organisms and it is this combination of ingestion and chemical association that gives weight to the notion that MPs may impact the bioavailability and toxicity of both endogenous and exogenous co-contaminants. In this mini-review, we set the recent literature within what has been previously published about MPs as chemical carriers to biota, with particular focus on aquatic invertebrates and fish. We then present a critical viewpoint on the validity of laboratory-to-field extrapolations in this area. Lastly, we highlight the expanding 'microplastic universe' with the addition of anthropogenic particles that have gained recent attention, namely, tire wear particles, nanoplastics and, bio-based or biodegradable MPs, and highlight the need for future research in their potential roles as vehicles of co-contaminant transfer.

Co-occurence of antibiotics and micro(nano)plastics: a systematic review between 2016-2021

Pollution by plastics and antibiotics are emerging issues in the areas of the environment and human health. In recent years, several studies have documented the widespread occurrence of plastic particles in various environmental, as well as human, systems, and much research has focused on possible interactions of contaminants with microplastics. Thus, the co-occurrence of plastics and antibiotics has caused another global problem for the environment and human health. Therefore, we focused on the current knowledge in the field of the co-occurrence of plastics and antibiotics to summarize the available studies. In this review, categorization of the topics, contaminants details, such as polymer type, size and source, antibiotic type, and other experimental parameters were summarized and discussed. This study indicated that the sorption of antibiotics on plastics, antibiotic susceptibility in the presence of plastics, and antibiotic resistance gene onto plastics were the most frequently examined categories in this field. Moreover, the variability in the procedures and the processes, and the heterogeneity data of reporting between different studies on similar topic make it difficult to bring all results together and produce a comprehensive picture of the current knowledge. Therefore, it is suggested that further research should be done using this systematic study.

Polyamide microplastics in wastewater as vectors of cationic pharmaceutical drugs

Reported here is the first study to investigate the adsorption of pharmaceutical drugs to microplastics in wastewater. Wastewater is an environmental source of microplastics and pharmaceuticals, which is discharged as treated effluent or combined sewer overflows. In this study, adsorption of cationic pharmaceuticals, with a range of octanol-water distribution coefficients, to polyamide (Nylon 12) microplastics was investigated in real wastewater samples. Significant adsorption was observed for the more hydrophobic pharmaceuticals studied, propranolol, amitriptyline, and fluoxetine, with equilibrium reached within 24 h. Microplastic-wastewater distribution coefficients for these three pharmaceuticals were 191, 749 and 1020 L kg^-1, respectively. Favourable wastewater conditions for adsorption of pharmaceuticals to polyamide were at pH > 7, summer temperatures (20 °C), and no stormwater dilution. Adsorption of the more hydrophilic pharmaceuticals atenolol, pseudoephedrine, metoprolol, and tramadol was ≤7% under all conditions and considered insignificant. Limited desorption (7-17%) of propranolol, amitriptyline, and fluoxetine was observed in river water over 24 h. This suggests that microplastics may be able to transport adsorbed pharmaceuticals for considerable distances after discharge. In simulated gastric fluids their desorption increased to 24-27% and 40-58% in cold- and warm-blooded temperatures respectively. The findings demonstrate that wastewater microplastics could act as a vector of pharmaceutical drugs, from wastewater treatment plants to aquatic organisms. However, further research is needed to better appreciate the risks posed by pharmaceuticals adsorbed to microplastics in comparison to other organic particulates found in wastewater.

Determination of the pharmaceuticals-nano/microplastics in aquatic systems by analytical and instrumental methods

Pharmaceutical residues and nanoplastic and microplastic particles as emerging pollutants in the aquatic environment are a subject of increasing concern in terms of the effect on water sources and marine organisms. There is lack of information about pharmaceutical-nanoplastic and pharmaceutical-microplastic mixtures. The present study aimed to investigate the fate and effect of pharmaceutical residues and nanoplastic and microplastic particles, the results of combinations of pharmaceutical residues with nanoplastic and microplastic particles, and toxic effects of pharmaceutical residues and nanoplastic and microplastic particles. Moreover, the objective was also to introduce analytical methods for pharmaceuticals, along with instrumental techniques for nanoplastic and microplastic particles in aquatic environments and organisms. PhAC alone can affect marine environments and aquatic organisms. When pharmaceutical residues combine with nanoplastic and microplastic particles, the rate of toxicity increases, and the result of this phenomenon constitutes this kind of pollutant in wastewater. Hence, the rate of mortality in organisms enhances. This study aimed to investigate the effect of pharmaceuticals residues and nanoplastic and microplastic particles, and a mixture of pharmaceutical residues and nanoplastic and microplastic particles in aquatic biota. Another object was survey methods for recognizing pharmaceutical residues and nanoplastic and microplastic particles. The findings show that pharmaceutical residues in organisms caused cell structure damage, inflammatory response, and nerve cell apoptosis. This study aimed to investigate the effect of microplastic particles in the human food chain and their impact on human health. Moreover, this review aims to present an innovative methodology based on comprehensive analytical techniques used to determine and identify pharmaceuticals adsorbed on nano- and microplastics in aquatic ecosystems. Finally, this review addresses the knowledge gaps and provides insights into future research strategies to better understand their interactions.

Bioaccumulation of emerging contaminants in mussel (Mytilus galloprovincialis): Influence of microplastics

Coastal environments are heavily influenced by human activities. Chemical substances considered as emerging contaminants (ECs) are one of the most important indicators of the anthropic influence on the environment, and they have recently shown to interact with microplastics (MPs). Mussels are suitable for in-lab bioacumulation studies providing insight about the occurrence and fate of contaminants in the organisms. In this study, bioacummulation of 20 chemical substances catalogued as ECs, including pharmaceuticals and personal care products (PPCPs), pesticides, and perfluoroalkyl substances (PFASs) in Mytilus galloprovincialis was assessed, with or without the influence of the presence of MPs. Mussels were distributed in three groups: control (B), exposed to ECs (C) and exposed to ECs and polyethylene MPs (C+M). The study was carried out for 58 days separated in two stages (i) exposure during days 0-28, and (ii) depuration during days 29-58. Visceral mass and haemolymph of the mussels were extracted separately, using QuEChERS and solid phase extraction (SPE), respectively. Then, extracts were analysed via UHPLC-MS/MS. Results showed that 3 PPCPs, 4 pesticides and 3 PFASs accumulated in visceral mass with bioconcentration factors (BCFs) ranging 6.7-15000 L/kg/d. In addition, 2 PPCPs, 2 pesticides and PFPeA were detected in haemolymph showing BCFs ranging 0.9-3.3 L/kg/d. When comparing C and C+M, MPs worked as a vector for the accumulation of the PFASs: PFOA, PFOS, PFDA and PFPeA; showing higher BCFs in the presence of MPs. Furthermore, the elimination of PFDA and PFOS was slower in the mussels exposed to MPs. On the other hand, the pesticides terbuthylazine and chlorpyrifos showed lower BCFs and more rapid elimination in the mussels exposed to MPs.

Functionalized Nanoplastics (NPs) Increase the Toxicity of Metals in Fish Cell Lines

Nanoplastics (NPs) are one of the most abundant environment-threatening nanomaterials on the market. The objective of this study was to determine in vitro if functionalized NPs are cytotoxic by themselves or increase the toxicity of metals. For that, we used 50 nm polystyrene nanoparticles with distinct surface functionalization (pristine, PS-Plain; carboxylic, PS-COOH; and amino PS-NH₂) alone or combined with the metals arsenic (As) and methylmercury (MeHg), which possess an environmental risk to marine life. As test model, we chose a brain-derived cell line (SaB-1) from gilthead seabream (Sparus aurata), one of the most commercial fish species in the Mediterranean. First, only the PS-NH₂ NPs were toxic to SaB-1 cells. NPs seem to be internalized into the cells but they showed little alteration in the transcription of genes related to oxidative stress (nrf2, cat, gr, gsta), cellular protection against metals (mta) or apoptosis (bcl2, bax). However, NPs, mainly PS-COOH and PS-NH₂, significantly increased the toxicity of both metals. Since the coexistence of NPs and other pollutants in the aquatic environment is inevitable, our results reveal that the combined effect of NPs with the rest of pollutants deserves more attention.