Accumulation of polyethylene microplastics in river biofilms and effect on the uptake, biotransformation and toxicity of the antimicrobial triclosan.

The interaction of multiple stressors in freshwater ecosystems may lead to adverse effects on aquatic communities and their ecological functions. Microplastics (MPs) are a class of contaminants of emerging concern that can exert both direct and indirect ecotoxicological effects. A growing number of studies have investigated MPs-attached microbial communities, but the interaction between MPs and substrate-associated biofilm (i.e., on natural river substrates, such as stones and sediments) remains poorly studied. In this work, the combined effects of polyethylene MPs (PE-MPs) with a particle size of 10-45 µm (2 mg/L) and the antimicrobial triclosan (TCS) (20 µg/L) were investigated on river biofilms through a short-term exposure experiment (72 h). To the best of authors' knowledge, this is the first time that the combined effects of MPs and chemical contaminants in substrate-associated river biofilms were assessed. Different response parameters were evaluated, including (i) exposure assessment and ii) contaminants effects at different levels: bacterial community composition, antibiotic resistance, extracellular polymeric substances (EPS), photosynthetic efficiency (Yeff), and leucine aminopeptidase activity (LAPA). Triclosan was accumulated in river biofilms (1189-1513 ng/g dw) alongside its biotransformation product methyl-triclosan (20-29 ng/g dw). Also, PE-MPs were detected on biofilms (168-292 MP/cm2), but they had no significant influence on the bioaccumulation and biotransformation of TCS. A moderate shift in bacterial community composition was driven by TCS, regardless of PE-MPs co-exposure (e.g., increased relative abundance of Sphingomonadaceae family). Additionally, Yeff and EPS content were significantly disrupted in TCS-exposed biofilms. Therefore, the most remarkable effects on river biofilms were related to the antimicrobial TCS, whereas single PE-MPs exposure did not alter any of the evaluated parameters. These results demonstrate that biofilms might act as environmental sink of MPs. Although no interaction between PE-MPs and TCS was observed, the possible indirect impact of other MPs-adsorbed contaminants on biofilms should be further assessed.

Combined exposure of the bivalve Mytilus galloprovincialis to polyethylene microplastics and two pharmaceuticals (citalopram and bezafibrate): Bioaccumulation and metabolomic studies.

Pharmaceuticals and microplastics constitute potential hazards in aquatic systems, but their combined effects and underlying toxicity mechanisms remain largely unknown. In this study, a simultaneous characterization of bioaccumulation, associated metabolomic alterations and potential recovery mechanisms was performed. Specifically, a bioassay on Mediterranean mussels (Mytilus galloprovincialis) was carried out with polyethylene microplastics (PE-MPLs, 1 mg/L) and citalopram or bezafibrate (500 ng/L). Single and co-exposure scenarios lasted 21 days, followed by a 7-day depuration period to assess their potential recovery. PE-MPLs delayed the bioaccumulation of citalopram (lower mean at 10 d: 447 compared to 770 ng/g dw under single exposure), although reaching similar tissue concentrations after 21 d. A more limited accumulation of bezafibrate was observed overall, regardless of PE-MPLs co-exposure (

Bioaccumulation and fate of pharmaceuticals in a Mediterranean coastal lagoon: Temporal variation and impact of a flash flood event.

Coastal ecosystems are particularly vulnerable to terrestrial inputs from human-impacted areas. The prevalence of wastewater treatment plants, unable to remove contaminants such as pharmaceuticals (PhACs), leads to their continuous input into the marine environment. In this paper, the seasonal occurrence of PhACs in a semi-confined coastal lagoon (the Mar Menor, south-eastern Spain) was studied during 2018 and 2019 by evaluating their presence in seawater and sediments, and their bioaccumulation in aquatic organisms. Temporal variation in the contamination levels was evaluated by comparison to a previous study carried out between 2010 and 2011 before the cessation of permanent discharges of treated wastewater into the lagoon. The impact of a flash flood event (September 2019) on PhACs pollution was also assessed. A total of seven compounds (out of 69 PhACs analysed) were found in seawater during 2018-2019, with a limited detection frequency (<33%) and concentrations (up to 11 ng/L of clarithromycin). Only carbamazepine was found in sediments (ND-1.2 ng/g dw), suggesting an improved environmental quality in comparison to 2010-2011 (when 24 and 13 compounds were detected in seawater and sediments, respectively). However, the biomonitoring of fish and molluscs showed a still remarkable accumulation of analgesic/anti-inflammatory drugs, lipid regulators, psychiatric drugs and ß-blocking agents, albeit not higher than in 2010. The flash flood event from 2019 increased the prevalence of PhACs in the lagoon, compared to the 2018-2019 sampling campaigns, especially in the upper water layer. After the flash flood the antibiotics clarithromycin and sulfapyridine yielded the highest concentrations ever reported in the lagoon (297 and 145 ng/L, respectively), alongside azithromycin in 2011 (155 ng/L). Flash flood events associated with sewer overflows and soil mobilisation, which are expected to increase under climate change scenarios, should be considered when assessing the risks posed by pharmaceuticals to vulnerable aquatic ecosystems in the coastal areas.

Frameworks for mapping lake ecosystem services. An example from Lithuania.

Lake ecosystems are essential for human well-being. Due to its transboundary nature, connecting terrestrial and aquatic habitats, its environmental processes and functions support a wide array of ecosystem services (ES). Hence, despite its importance in supporting socio-ecologic systems, these freshwater ecosystems are highly impacted due to anthropogenic influence. ES may shed light on the importance of maintaining and restoring lake ecosystems. Hence, despite the increased effort in the last decades to provide robust spatial information, most scientific studies still follow a qualitative approach that carries a great deal of uncertainty and is not uptake by decision-makers. It is necessary to develop quantitative and robust methodologies for mapping ES, especially in the aquatic realm. This study develops several frameworks to map ES in lake ecosystems. Important to highlight is that this study.•develops a quantitative multi-method (biophysical and statistical) toolbox for lake ES multi-temporal mapping.•covers five ES from Provisioning, Regulating & Maintenance, and Cultural sections, namely: (1) Fibres and other materials for construction; (2) Water used for non-drinking purposes; (3) Maintenance of nursery populations; (4) nutrient regulation; and (5) recreation.•addresses three dimensions of ES: supply, flow; and demand.

A holistic assessment of the sources, prevalence, and distribution of bisphenol A and analogues in water, sediments, biota and plastic litter of the Ebro Delta (Spain).

Bisphenol A (BPA) is one of the main ubiquitous compounds released from plastics in the environment. This compound, considered an endocrine disruptor, poses a risk to aquatic wildlife and human population, being included in multiple environmental monitoring programmes. Following the regulations restricting BPA use in the last years, BPA-like chemicals have been produced and used as BPA substitutes. However, they are not commonly included in monitoring programs yet and their presence is thus misrepresented, despite showing similar endocrine disrupting potential. In this work, an analytical method for analysing bisphenol A and five of its analogues (Bisphenol S, B, F, AF and Tetrabromobisphenol A) is described, validated for water (riverine, sea and wastewater), sediment, and biota (fish and biofilm) and applied to monitor their presence in the Ebro River Delta (NE Spain). In addition, plastic litter was also collected to evaluate their role as potential source of bisphenols. All compounds except BPF were detected in the analysed samples. Wastewater treatment plants (WWTPs) were discarded as major sources of BPs into the natural aquatic environment, as no BPs were detected in treated effluents. Indeed, the high levels of BPs in the natural environment could be related with direct discharge of raw wastewater from small rural population nucleus. The analysis of riverine plastic leachates yielded 4 out of the 6 BPs analysed, strengthening the hypothesis that plastic debris are also a source of BPs in the natural environment. Whereas Bisphenol S and BPA were detected in water and, to a limited extent, in biota, less polar analogues (mainly BPAF and TBBPA) were not found in any of the water samples. Instead, these hydrophobic BPs were found in fish tissues and biofilm, pointing out plastics and microplastics as their possible vectors. Finally, biofilm demonstrated its potential as sentinel of chemical contamination in freshwater environment.

Occurrence and accumulation of pharmaceutical products in water and biota of urban lowland rivers.

We evaluated the distribution of eleven groups of pharmaceutically active compounds (PhACs) in surface waters and biota of different trophic levels, in five sites of two lowland urban rivers in Argentine. Twenty-nine out of 39 PhACs and two metabolites were detected in at least one water sample (2-9622 ng/L), eleven detected in biofilms (1-179 ng/g d.w.) and eight in the macrophyte Lemna gibba (4-112 ng/g d.w). The two more polluted sites had a similar distribution of the main groups of compounds. In surface waters, the largest concentrations were for the analgesic acetaminophen (9622 ng/L), the antibiotic sulfamethoxazole (326 ng/L), the antihypertensive valsartan (963 ng/L), the ß-blocking agent atenolol (427 ng/L), the diuretic hydrochlorothiazide (445 ng/L) and the psychiatric drug carbamazepine (99 ng/L). The antibiotic ciprofloxacin exhibited the highest concentration in the biofilm (179 ng/g d.w.) and in the macrophyte L. gibba (112 ng/g d.w.) Several compounds were detected in the water but not in the biota (e.g., codeine and bezafibrate), and others (e.g., azithromycin and citalopram) were found in the biota but not in the surface water. Significant bioaccumulation factors (>1000 L/kg d.w.) were obtained for venlafaxine and ciprofloxacin in biofilm. Our results show that PhACs may accumulate in several biological compartments. Within an environmental compartment, similar PhACs profile and concentrations were found in different sites receiving urban pollution. Among different compartments, biofilms may be the most suitable biota matrix to monitor the immediate reception of PhACs in the biota. Our results indicate that the presence of PhACs in urban rivers and their accumulation in the biota could be incorporated as symptoms of the urban stream syndrome.

Fate, modeling, and human health risk of organic contaminants present in tomato plants irrigated with reclaimed water under real-world field conditions.

Using reclaimed water to irrigate crops can be an important route for organic contaminants of emerging concern (CECs) to be introduced into agricultural production and thus find their way into the food chain. This work aims to establish accumulation models for the different parts of a crop (fruit/leaves/roots) and the soil of some of the most commonly detected CECs in reclaimed water, through field trials in greenhouses. For this, tomato plants were permanently irrigated under realistic agricultural conditions with a mixture of the selected compounds at approx. 1 µg/L. A total of 30 contaminants were analyzed belonging to different compound categories. A modified QuEChERS extraction method followed by liquid chromatography coupled to tandem mass spectrometry was the procedure used. The study revealed the presence of 21 target contaminants in the tomatoes, and 18 CECs in the leaves, roots, and soil. The average total concentration of pesticides detected in the tomatoes was 3 µg/kg f.w., whereas the average total load of pharmaceuticals was 5.8 µg/kg f.w. after three months, at the time of crop harvesting. The levels of pharmaceutical products and pesticides in the non-edible tissues were up to 3.5 and 2.1 µg/kg f.w., respectively, in the leaves and up to 89.3 and 31.3 µg/kg f.w., respectively, in the roots. In the case of the soil samples, the pesticide concentration found after crop harvesting was below 11.4 µg/kg d.w., and less than 3.0 µg/kg d.w. for pharmaceuticals. Overall, the concentration levels of CECs detected in the tomatoes, which were permanently irrigated with contaminated reclaimed water, do not pose a risk to human health via dietary intake.

Antipsychotics as environmental pollutants: An underrated threat?

The heterogeneous class of what we nowadays call antipsychotics was born almost 70 years ago with the serendipitous discovery of chlorpromazine. Their utilization is constantly growing because they are used to treat a diverse group of diseases and patients across all age groups: schizophrenia, bipolar disease, depression, autism, attention deficit hyperactivity disorder, behavioural and psychological symptoms in dementia, among others. They possess a complex pharmacological profile, acting on multiple receptors: dopaminergic, serotoninergic, histaminergic, adrenergic, and cholinergic, leading scientists to call them "agents with rich pharmacology" or "dirty drugs". Serotonin, dopamine, acetylcholine, noradrenaline, histamine and their respective receptors are evolutionary ancient compounds, and as such, are found in many different living beings in the environment. Antipsychotics do not disappear once excreted by patient's urine or faeces and are transported to wastewater treatment plants. But as these plant's technology is not designed to eliminate drugs and their metabolites, a variable proportion of the administered dose ends up in the environment, where they have been found in almost every matrix: municipal wastewater, hospital sewage, rivers, lakes, sea and even drinking water. We believe that reported concentrations found in the environment might be high enough to exert significant effect to aquatic wildlife. Besides, recent studies suggest antipsychotics, among others, are very likely bioaccumulating through the web food. Crucially, psychotropics may provoke behavioural changes affecting populations' dynamics at lower concentrations. We believe that so far, antipsychotics have not received the attention they deserve with regards to drug pollution, and that their role as environmental pollutants has been underrated.

Removal and toxicity evaluation of a diverse group of drugs from water by a cyclodextrin polymer/pulsed light system.

The presence of pharmaceutical compounds (PhCs) in the effluents of wastewater treatment plants (WWTPs) is an ecological concern. The issue could be alleviated by trapping those substances by cyclodextrin (CD) polymers or photolyzing them by pulsed light (PL). Consequently, a sequential CD polymer/PL system was tested for the removal of PhCs. Firstly, a survey detected the presence of recurrent PhCs in the effluents of local WWTPs. Then, pure water was spiked with 21 PhCs, 100 µg/L each one. The three-dimensional network provides amphiphilic features to the CD polymer that reduced the pollutant concentration by 77 %. Sorption involves a plead of physical and chemical mechanisms hindering the establishment of a general removal model for all compounds. The performed simulations hint that the retention capacity mainly correlates with the computed binding energies, so that theoretical models are revealed as valuable tools for further improvements. The complementary action of PL rose the elimination to 91 %. The polymer can be reused at least 10 times for ibuprofen (model compound) removal, and was able to eliminate the ecotoxicity of an ibuprofen solution. Therefore, this novel sequential CD polymer/PL process seems to be an efficient alternative to eliminate PhCs from wastewater.

A sustainable approach by using microalgae to minimize the eutrophication process of Mar Menor lagoon.

The present study evaluates the removal capacity of microalgae photobioreactors of environmental pollutants present in wastewater from the dry riverbed El Albujón, as a way to minimize the eutrophication process of the Mar Menor. Particularly, the capacity of four autochthonous microalgae consortia collected from different locations of the salty lagoon to remove emerging contaminants (simazine, atrazine, terbuthylazine, adenosine and ibuprofen), nitrates, and phosphates, was evaluated. Among the four microalgae consortia, consortium 1 was the best in terms of biomass productivity (0.11 g L-1 d-1) and specific growth rate (0.14 d-1), providing 100% removal of emerging contaminants (simazine, atrazine, terbuthylazine, adenosine and ibuprofen), and a maximal reduction and consumption of macronutrients, especially nitrates and phosphates, reaching levels below 28 mg L-1, that is, a decrease of 89.90 and 99.70% of nitrates and phosphates, respectively. Therefore, this consortium (Monoraphidium sp., Desmodesmus subspicatus, Nannochloris sp.) could be selected as a green filter for successful large-scale applications. This study is the first one that combines the successful removal of herbicides, ibuprofen and adenosine as emerging contaminants, and nitrate removal.

Analysis of pharmaceuticals in fish using ultrasound extraction and dispersive spe clean-up on que Z-Sep/C18 followed by LC-QToF-MS detection.

The presence of pharmaceutically active compounds (PhACs) in aquatic biota has been received much less attention than their presence in surface or waste water, and it was not until the mid-2000s, this gap started to be addressed. Here, we present SQUEEZe (Solid-liQuid Ultrasound Extraction with QuE Z-Sep/C18 as dispersive clean-up): a fast method for analysis of the trace 47 PhACs in fish muscle. Compared to our previously reported method [1], it offers alternatives with improvements in recoveries, number of analytes, sample volume and solvent used. The key aspects of this method are:•The ultrasound extraction was performed with acetonitrile/isopropanol 0.1% V/V formic acid. A clean-up step using QuE Z-Sep/C18 sorbents was employed to reduce lipid content of the extracts and further matrix effects in the detection of the analytes.•A HPLC separation with a Kinetex EVO C18 packed column in 11 min was optimized. MS and MS/MS data were collected using SWATH acquisition on the SCIEX X500R QTOF in (+)-ESI mode.•The method validated at 3 different concentrations levels: 5, 25 and 50 ng/g fish. It presented good intraday/interday reproducibility and absolute recoveries ≥ 60% for majority of analytes in composite homogenate muscle matrix of Squalius cephalus.•10 out 47 compounds were detected in fish samples.

Discovery of large molecules as new biomarkers in wastewater using environmental proteomics and suitable polymer probes.

The capability of monitoring large molecules as possible biomarkers in wastewater will be an important contribution to the new field of sewage epidemiology. Here, we explore the use of polymer probes together with untargeted proteomics for large scale protein analysis in sewage and treated water. Polymeric probes were immersed in the influent, anoxic reactor and effluent waters of a Spanish WWTP during 11 days. Proteins sorbed were extracted and identified by mass spectrometry. A total of 690 proteins from bacteria, plants and animals, including human, were identified showing different proteome profiles in the different sites. Bacterial proteins (510) pointed at 175 genera distributed in 22 bacterial classes. The most abundant were EF-Tu, GroEL and ATP synthase which were contributed by a high number of species. Human was the species contributing the greatest number of identified proteins (57), some in high abundance like keratins. Human proteins dominated in the influent water and were efficiently removed at the effluent. Several of the proteins identified (S100A8, uromodulin, defensins) are known disease biomarkers. This study provides the first insight into the proteome profiles present in real wastewater.

Management actions to mitigate the occurrence of pharmaceuticals in river networks in a global change context.

Human consumption of pharmaceuticals leads to high concentrations of pharmaceuticals in wastewater, which is usually not or insufficiently collected and treated before release into freshwater ecosystems. There, pharmaceuticals may pose a threat to aquatic biota. Unfortunately, occurrence data of pharmaceuticals in freshwaters at the global scale is scarce and unevenly distributed, thus preventing the identification of hotspots, the prediction of the impact of Global Change (particularly streamflow and population changes) on their occurrence, and the design of appropriate mitigation actions. Here, we use diclofenac (DCL) as a typical pharmaceutical contaminant, and a global model of DCL chemical fate based on wastewater sanitation, population density and hydrology to estimate current concentrations in the river network, the impact of future changes in runoff and population, and potential mitigation actions in line with the Sustainable Development Goals. Our model is calibrated against measurements available in the literature. We estimate that 2.74 ± 0.63% of global river network length has DCL concentrations exceeding the proposed EU Watch list limit (100 ng L-1). Furthermore, many rivers downstream from highly populated areas show values beyond 1000 ng L-1, particularly those associated to megacities in Asia lacking sufficient wastewater treatment. This situation will worsen with Global Change, as streamflow changes and human population growth will increase the proportion of the river network above 100 ng L-1 up to 3.10 ± 0.72%. Given this background, we assessed feasible source and end-of-pipe mitigation actions, including per capita consumption reduction through eco-directed sustainable prescribing (EDSP), the implementation of the United Nations Sustainable Development Goal (SDG) 6 of halving the proportion of population without access to safely managed sanitation services, and improvement of wastewater treatment plants up to the Swiss standards. Among the considered end-of-pipe mitigation actions, implementation of SDG 6 was the most effective, reducing the proportion of the river network above 100 ng L-1 down to 2.95 ± 0.68%. However, EDSP brought this proportion down to 2.80 ± 0.64%. Overall, our findings indicate that the sole implementation of technological improvements will be insufficient to prevent the expected increase in pharmaceuticals concentration, and that technological solution need to be combined with source mitigation actions.

Diet quality and NSAIDs promote changes in formation of prostaglandins by an aquatic invertebrate.

We used the freshwater insect Hydropsyche sp. to investigate the impact of diets lacking arachidonic acid (ARA) and an environmentally relevant mixture of NSAIDs (Ibuprofen, Ketoprofen, Diclofenac and Naproxen at a nominal concentration of all compounds together 16.75 µg L-1) on their metabolism of ARA and prostaglandins (PGs). The organisms were exposed for 16 days to four different treatments: a reference (FF), a diet lacking ARA (O), to NSAIDs in water (FFN) and to the combination of the two factors (ON). Mortality, biomass and bioconcentration of pharmaceuticals were investigated. The ARA and PGs levels in the organisms were monitored by utilising a targeted metabolomics approach. NSAIDs or dietary constraints did not produce significant differences in biomass or mortality of Hydropsyche sp. among treatments. In organisms exposed to NSAIDs, all pharmaceuticals were detected, except for Ketoprofen. Metabolomic approach determined the presence of PGH2, PGE1 and PGD1. Levels of ARA diminished significantly in those organisms in treatment ON. The levels of PGs responded negatively to the absence of ARA in diet: PGH2 diminished significantly with respect to the reference in treatment O while PGE1 diminished significantly in treatment ON. Regarding the effects of NSAIDs on ARA metabolism, our results suggest that it was sensitive to NSAIDs, but effects were weak and did not imply a general decrease in the PGs. We confirmed that ARA was the main substrate for the synthesis of PGs in Hydropsyche sp, their absence or poor levels of ARA in diet, produced changes in the PG levels.

Combining quantitative and qualitative approaches using Sequential Window Acquisition of All Theoretical Fragment-Ion methodology for the detection of pharmaceuticals and related compounds in river fish extracted using a sample miniaturized method.

A fast method for analysis of 47 pharmaceuticals active compounds (PhACs) in fish muscle has been developed and validated addressing the parameters accuracy, precision (intraday and interday), matrix effect at three spiking levels: 5, 25 and 50 ng PhAC g-1 in fish as well as linearity, limit of detection (LOD), limit of quantification (LOQ). Sixteen protocols were performed varying extraction techniques, solvents, sample filtration and clean-up step. The selected method was based on an ultrasound extraction with acidified mixture of acetonitrile and isopropyl alcohol followed by a clean-up step using Z-Sep/C18 sorbents. Quantitative analysis of the PhACs in the extracts was accomplished by UPLC- QTOF-MS using Sequential Window Acquisition of All Theoretical Fragment-Ion, SWATHTM acquisition technology. 90% Of the compounds presented extraction recoveries between 60 and 130% with LOQ between 0.2 and 11 ng g-1. The validated method was applied to the analysis of 32 muscle samples from thirteen different species of fish collected in four European river basins (Adige, Evrotas, Llobregat and Sava). A total of ten compounds were found in fish samples with diltiazem as the most frequently detected one followed by carbamazepine and caffeine. Additionally, by taking advantage of the information-rich mass spectral data from the SWATH mode acquisition, the raw data were reprocessed for the presence of the most prescribed 250 pharmaceuticals, metabolites, and drugs of abuse previously reported to occur in the aquatic environment. By considering the mass errors of the molecular ion (˂± 3 ppm) and one characteristic fragment ion (˂±10 ppm) as well as the Library score and the Formula Finder score of the data processing software six compounds were retrieved, and eventually four of them confirmed with authentic standards: cocaine and its metabolite benzoylecgonine, the stimulant nicotine, and the antibiotic ofloxacin. Two lipid regulators, lovastatin and simvastatin, were determined as a false positive.

Fast analysis of relevant contaminants mixture in commercial shellfish.

One of the major challenges currently faced is to develop systematic ways of addressing chemical mixtures in environmental assessment. With this purpose, a simple, rapid, and sensitive method for the detection and quantification of a mixture of relevant contaminants in molluscs has been developed. The method is based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and Ultra-High Performance Liquid Chromatography-High Resolution Mass Spectrometry (UHPLC-HRMS). It includes a mixture of 23 compounds formed by pesticides, endocrine disruptors and pharmaceuticals (metolachlor, simazine, desethylatrazine, atrazine, thiabendazole, diazinon, malathion, bentazone, MCPA, propanil, acetamiprid, imidacloprid, caffeine, bisphenol A, triclosan, triclocarban, methylparaben, ethylparaben, propylparaben, 1H-benzotriazole, sulfamethoxazole, venlafaxine and carbamazepine). The method was developed and validated in 4 different types of shellfish of high commercial interest such as mussel (Mytilus galloprovincialis), oyster (Crassostrea gigas), cockle (Cerastoderma edule) and razor shell (Solen marginatus). The mean percentage of recoveries obtained for all the compounds in each mollusc type (intra-specie) ranged from 96% to 107% showing the good performance of the method developed. The relative standard deviation was under 10% for the intra-day and 17% inter-day analyses. Method detection limits and method quantification limits were below 10 ng/g dry weight for all the species and compounds targeted. Finally, the method was applied to aquaculture samples, oysters and cockles, from Ebro Delta (Spain), after some episodes of mortality occurred in 2017. A high level of bisphenol A was detected in C. edule which may explain the mortality suffered by this organism. C. gigas presented low levels of metolachlor, bentazone, acetamiprid, and methylparaben.

Exposure to single and binary mixtures of fullerenes and triclosan: Reproductive and behavioral effects in the freshwater snail Radix balthica.

Emerging pollutants occur in complex mixtures in rivers and have the potential to interact with freshwater organisms. The chronic effects of nominal exposure to 3 µg/L of fullerenes (C60) and 1 µg/L of triclosan (TCS) alone and in a binary mixture, were evaluated using the freshwater snail Radix balthica. Pollutants accumulation, reproductive output and feeding behavior were selected as sublethal endpoints. After 21 days of exposure, we did not observe interactive effects between TCS and C60 on the studied endpoints, except for the accumulation of C60 in R. balthica in TCS + C60 treatment, which was lower than when the fullerenes were alone. Neither TCS nor C60 caused significant effects on reproduction, expressed as number of eggs per individual, but an increase in the clutch size was observed in treatments with TCS at the third week of exposure, independently of the presence of C60 (16.15 ± 1.67 and 18.9 ± 4.01 eggs/egg mass in TCS and TCS + C60 treatments, respectively, vs. 13.17 ±â€¯4.01 in control). The presence of C60 significantly enhanced the grazing activity of R. balthica during the first seven days (4.95 ±â€¯1.35 and 3.91 ±â€¯0.59% of the area grazed per individual in C60 and TCS + C60 treatments, respectively, vs 2.6 ±â€¯0.39% in control). The accumulation of TCS was quite similar in treatments where this pollutant was present (BAF ≈ 1007 L/kg d.w.); however, the accumulation of C60 was higher when the nanoparticles were alone (BAF = 254.88 L/kg d.w.) than when it was in the binary mixture (BAF = 7.79 L/kg d.w). Overall, although TCS has been listed as an endocrine disrupter compound, no significant effects on reproduction were observed in the assayed conditions. Regarding C60, the limited effects on feeding activity and the low BAF obtained in this experiment indicate that fullerenes do not have ecological consequences of relevance at the studied environmental concentrations in freshwater snails.

Polluted water from an urban reservoir (Madín dam, México) induces toxicity and oxidative stress in Cyprinus carpio embryos.

The Madín Dam is a reservoir located in the municipalities of Naucalpan and Atizapán, in the metropolitan area adjacent to Mexico City. The reservoir supplies drinking water to nearby communities and provides an area for various recreational activities, including kayaking, sailing and carp fishing. Over time, the number of specimens of common carp has notably diminished in the reservoir, which receives direct domestic drainage from two towns as well as numerous neighborhoods along the Tlalnepantla River. Diverse studies have demonstrated that the pollutants in the water of the reservoir produce oxidative stress, genotoxicity and cytotoxicity in juvenile Cyprinus carpio, possibly explaining the reduction in the population of this species; however, it is necessary to assess whether these effects may also be occurring directly in the embryos. Hence, surface water samples were taken at five sites and pharmaceutical drugs, personal care products (especially sunscreens), organophosphate and organochlorine pesticides, and other persistent organic pollutants (e.g., polychlorinated biphenyls and polycyclic aromatic hydrocarbons) were identified. Embryos of C. carpio were exposed to the water samples to evaluate embryolethality, modifications in embryonic development, lipoperoxidation, the quantity of hydroperoxide and oxidized proteins, and antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase). It was found that the polluted water of the Madín Dam gave rise to embryolethality, embryotoxicity, congenital abnormalities, and oxidative stress on the common carp embryos.

Contaminants of emerging concern in freshwater fish from four Spanish Rivers.

This study investigated the occurrence of 135 contaminants of emerging concern (CECs) - pharmaceuticals, pesticides, a set of endocrine disrupting compounds (EDCs) (parabens, bisphenols, hormones, triazoles, organophosphorus flame retardants and triclosan), UV-filters, perfluoroalkyl substances (PFASs) and halogenated flame retardants (HFRs) - in 59 fish samples, collected in 2010 in 4 Spanish Rivers (Guadalquivir, Júcar, Ebro and Llobregat). Of the 135 CECs, 76 including 8 pharmaceuticals, 25 pesticides, 10 EDCs, 5 UV-filters, 15 PFASs and 13 HFRs were detected. Pharmaceuticals were the less frequently found and at lower concentrations. Pesticides, EDCs, UV-filters, PFASs and HFRs were detected more frequently (>50% of the samples). The maximum concentrations were 15 ng/g dry weight (dw) for pharmaceuticals (diclofenac), 840 ng/g dw for pesticides (chlorpyrifos), 224 ng/g dw for EDCs (bisphenol A), 242 ng/g dw for UV-filters (EHMC), 1738 ng/g dw for PFASs (PFHxA) and 64 ng/g dw for HFRs (Dec 602). The contaminants detected in fish are commonly detected also in sediments. In light of current knowledge, the risk assessment revealed that there was no risk for humans related to the exposure to CECs via freshwater fish consumption. However, results provide detailed information on the mixtures of CECs accumulated that would be very useful to identify their effects on aquatic biota.