Effects of non-steroidal anti-inflammatory drug (NSAID) diclofenac exposure in mussel Mytilus galloprovincialis

A mechanistic study on the interaction effects between legacy and pollutants of emerging concern: A case study with B[a]P and diclofenac

To study the intricate toxicological mechanisms triggered by exposure to mixed pollutants, we exposed zebrafish embryos to legacy and emerging pollutants through binary mixtures of benzo[a]pyrene (B[a]P) and diclofenac (DFC). The combination of next-generation transcriptomics and toxicopathology disclosed instances where exposure to mixtures did not attain the expected sum of acute effects of individual toxicants, indicating potential antagonism. Despite overall higher mortality in DFC treatments, the same antagonistic trend was noted in genotoxicity and molecular pathways related to RNA turnover, cell proliferation, apoptosis and cell-cycle control. The formation of oedemas in the heart cavity and yolk sac can be an adverse outcome (AO) resulting from exposure to DFC isolated or combined, whose potential key events (KEs) may involve cell cycle arrest and apoptosis via p53 and MAPK pathways. From the findings it can be hypothesised that, rather than genotoxicity, the molecular initiating event (MIE) maybe inflammation triggered by oxidative stress. Nonetheless, the exact role of ROS in the process needs further clarification. Impaired eye function by action of DFC and B[a]P combined may be another AO, in the case caused by ocular degeneration following the suppression of biologic processes and molecular functions involved in eye development and its functionalities, possibly linked to hindered regulation of the expression of hsf4 and cryaa. Altogether, toxicopathology suggests predominance of antagonistic effects, but its integration with mechanism suggests that interactions between DFC and B[a]P in environmentally-relevant concentrations that may lead to hindrance of key functions such as the control of inflammation and cell cycle. These outcomes suggest potentially severe implications for health and survival, in case of prolonged chronic exposure to combined toxicants.

Cellular pathway disturbances elicited by realistic dexamethasone concentrations in gills of mussel Mytilus galloprovincialis as assessed by a multi-biomarker approach

The growing usage of glucocorticoids for a variety of diseases raises concerns since these drugs, including the anti-inflammatory dexamethasone (DEX), are frequently found in the environment. The impact of DEX was evaluated on mussels Mytilus galloprovincialis (Lamarck, 1819) by exposure to environmental concentrations (C1: 4 ng/L; C2: 40 ng/L; C3: 400 ng/L; C4: 2000 ng/L), and sampling at 3 (T3), 6 (T6), and 12 (T12) days. A multi-biomarker approach was applied on gills, involved in gas exchange, feed filtering, and osmoregulation. A dose- and time-dependent uptake of DEX was recorded, besides haemocyte infiltration, increased neutral and acid mucopolysaccharides, and a general pro-oxidant effect witnessed by lipid peroxidation and altered antioxidant system. Metabolomics revealed rise in protein turnover and energy demand by fluctuations in free amino acids (alanine, glycine) and energy-related metabolites (succinate, ATP/ADP). It is necessary to reduce DEX dosage from the environment by recovery strategies and effective eco-pharmacovigilance programs.

Transformation products of diclofenac: Formation, occurrence, and toxicity implication in the aquatic environment

Diclofenac (DCF) is the first drug on the EU Watch List of Priority Substances due to its extensive uses, incomplete removal in wastewater treatment plants (WWTPs), and toxic effects. Once in the environment, DCF undergoes processes that yield various transformation products (TPs) or metabolites, whichcan be more toxic than DCF. While these TPs or metabolites often dominate the majority of the drug load in municipal wastewater, they have been largely ignored. This review critically examines recent data on the formation, occurrence, fate, and toxicology of DCF TPs in the aquatic environment. This review reveals some important findings. First, DCF TPs may constitute >57 % of DCF in wastewater influent, ∼60 % in effluent, and ∼30 % in surface waters. Second, TPs persistently retain the core structure of DCF and may pose greater environmental risks than the parent drug. Third, some metabolites may revert back to the parent drug. Fourth, WWTPs serve as a consistent source that release DCF and its by-products into the environment. Fifth, mixtures of DCF and its metabolites, along with other contaminants, may pose elevated and synergistic environmental risks than individual compounds. These findings suggest that current risk assessment practices, which ignore the impacts of the metabolites and the chemical interactions/synergies, may seriously underestimate the overall toxicity of DCF and likely other pharmaceuticals. Further studies are needed to monitor the long-term fate and toxicity of the metabolites, as well as new analytical methods and standards to unveil the hidden metabolites and the associated environmental risks.

Mytilus galloprovincialis: A valuable bioindicator species for understanding the effects of diclofenac under warming conditions

Drugs are chemical compounds used to treat and improve organic dysfunctions caused by diseases. These include analgesics, antibiotics, antidepressants, and antineoplastics. They can enter aquatic environments through wastewater streams, where their physico-chemical properties allow metabolites to distribute and accumulate. Current climate change and associated extreme weather events may significantly impact these substances' toxicity and aquatic organisms' sensitivity. Among the chemicals present in aquatic environments is the non-steroidal anti-inflammatory drug diclofenac (DIC), which the EU monitors due to its concentration levels. This study investigated the influence of temperature (control at 17 °C vs. 21 °C) on the effects of DIC (0 μg/L vs. 1 μg/L) in the mussel species Mytilus galloprovincialis. Significant results were observed between 17 and 21 °C. Organisms exposed to the higher temperature showed a decrease in several parameters, including metabolic capacity and detoxification, particularly with prolonged exposure. However, in some parameters, after 21 days, the M. galloprovincialis showed no differences from the control, indicating adaptation to the stress. The results of this study confirm that DIC concentrations in the environment, particularly when combined with increased temperatures, can produce oxidative stress and adversely affect M. galloprovincialis biochemical and physiological performance. This study also validates this species as a bioindicator for assessing environmental contamination with DIC. Beyond its direct impact on aquatic organisms, the presence of pharmaceuticals like DIC in the environment highlights the interconnectedness of human, animal, and ecosystem health, underscoring the One Health approach to understanding and mitigating environmental pollution.

Looking beyond the obvious: The ecotoxicological impact of the leachate from fishing nets and cables in the marine mussel Mytilus galloprovincialis

Once in the marine environment, fishing nets and cables undergo weathering, breaking down into micro and nano-size particles and leaching plastic additives, which negatively affect marine biota. This study aims to unravel the ecotoxicological impact of different concentrations of leachate obtained from abandoned or lost fishing nets and cables in the mussel Mytilus galloprovincialis under long-term exposure (28 days). Biochemical biomarkers linked to antioxidant defense system, xenobiotic biotransformation, oxidative damage, genotoxicity, and neurotoxicity were evaluated in different mussel tissues. The chemical nature of the fishing nets and cables and the chemical composition of the leachate were assessed and metals, plasticizers, UV stabilizers, flame retardants, antioxidants, dyes, flavoring agents, preservatives, intermediates and photo initiators were detected. The leachate severely affected the antioxidant and biotransformation systems in mussels' tissues. Following exposure to 1 mg·L-1 of leachate, mussels' defense system was enhanced to prevent oxidative damage. In contrast, in mussels exposed to 10 and 100 mg·L-1 of leachate, defenses failed to overcome pro-oxidant molecules, resulting in genotoxicity and oxidative damage. Principal component analysis (PCA) and Weight of Evidence (WOE) evaluation confirmed that mussels were significantly affected by the leachate being the hazard of the leachate concentrations of 10 mg·L-1 ranked as major, while 1 and 100 mg·L-1 was moderate. These results highlighted that the leachate from fishing nets and cables can be a threat to the heath of the mussel M. galloprovincialis.

Exposure to environmental pharmaceuticals affects the macromolecular composition of mussels digestive glands

Human pharmaceuticals represent a major challenge in natural environment. A better knowledge on their mechanisms of action and adverse effects on cellular pathways is fundamental to predict long-term consequences for marine wildlife. The FTIRI Imaging (FTIRI) spectroscopy represents a vibrational technique allowing to map specific areas of non-homogeneous biological samples, providing a unique biochemical and ultrastructural fingerprint of the tissue. In this study, FTIRI technique has been applied, for the first time, to characterize (i) the chemical building blocks of digestive glands of Mytilus galloprovincialis, (ii) alterations and (iii) resilience of macromolecular composition, after a 14-days exposure to 0.5 µg/L of carbamazepine (CBZ), valsartan (VAL) and their mixture, followed by a 14-days recovery period. Spectral features of mussels digestive glands provided insights on composition and topographical distribution of main groups of biological macromolecules, such as proteins, lipids, and glycosylated compounds. Pharmaceuticals caused an increase in the total amount of protein and a significant decrease of lipids levels. Changes in macromolecular features reflected the modulation of specific molecular and biochemical pathways thus supporting our knowledge on mechanisms of action of such emerging pollutants. Overall, the applied approach could represent an added value within integrated strategies for the effects-based evaluation of environmental contaminants.

Nabumetone and flufenamic acid pose a serious risk to aquatic plants: A study with Chlamydomonas reinhardtii as a model organism

The aquatic environment is constantly under threat due to the release of numerous pollutants. Among them, pharmaceuticals constitute a huge and diverse group. Non-steroidal anti-inflammatory drugs (NSAIDs) are increasingly found in water bodies, but knowledge about their potential toxicity is still low. In particular, there is a lack of information about their influences on aquatic plants and algae. We estimated the susceptibility of the microalgae Chlamydomonas reinhardtii to nabumetone (NBT) and flufenamic acid (FFA), focusing on photosynthesis. Due to the differences in the structures of these compounds, it was assumed that these drugs would have different toxicities to the tested green algae. The hypothesis was confirmed by determining the effective concentration values, the intensity of photosynthesis, the intensity of dark respiration, the contents of photosynthetic pigments, the fluorescence of chlorophyll a in vivo (OJIP test), and cell ultrastructure analysis. Assessment of the toxicity of the NSAIDs was extended by the calculation of an integrated biomarker response index (IBR), which is a valuable tool in ecotoxicological studies. The obtained results indicate an over six times higher toxicity of NBT compared to FFA. After analysis of the chlorophyll a fluorescence in vivo, it was found that NBT inhibited electron transport beyond the PS II. FFA, unlike NBT, lowered the intensity of photosynthesis, probably transforming some reaction centers into "silent centers", which dissipate energy as heat. The IBR estimated based on photosynthetic parameters suggests that the toxic effect of FFA results mainly from photosynthesis disruption, whereas NBT significantly affects other cellular processes. No significant alteration in the ultrastructure of treated cells could be seen, except for changes in starch grain number and autophagic vacuoles that appeared in FFA-treated cells. To the best of our knowledge, this is the first work reporting the toxic effects of NBT and FFA on unicellular green algae.

Toxicological effects of diclofenac on signal crayfish (Pacifastacus leniusculus) as related to weakly acidic and basic water pH

The widespread use and continuous discharge of pharmaceuticals to environmental waters can lead to potential toxicity to aquatic biota. Pharmaceuticals and their metabolites are often complex organic and environmentally persistent compounds that are bioactive at low doses. This study aimed to investigate the effects of diclofenac (DCF) on the antioxidant defence system and neurotoxicity biomarkers in signal crayfish (Pacifastacus leniusculus) under weakly acidic and basic conditions. Crayfish were exposed to 200 µg/L of DCF at pH 6 and 8 for 96 h and subsequently underwent the depuration phase for 96 h. Gills, hepatopancreas, and muscle were sampled after the exposure and depuration phases to assess the toxicological biomarker responses of DCF in crayfish by evaluating lipid peroxidation (LPO) levels, activities of antioxidant enzymes and acetylcholinesterase. After the exposure phase, the hemolymph DCF concentration was detected one order higher at pH 6 than at pH 8. The DCF was subsequently fully eliminated from the hemolymph during the depuration phase. Our results showed that DCF caused alteration in the activities of six of the seven tested biomarkers in at least one crayfish tissue. Although exposure to DCF caused imbalances in the detoxification system on multiple tissue levels, it was regenerated to a balanced state after the depuration phase. Integrated biomarker response (IBRv2) showed that the highest toxicological response to DCF exposure was elicited in the gills, whereas the hepatopancreas was the highest-responding tissue after the depuration phase. Exposure to DCF at pH 6 caused higher toxicological effects than at pH 8; however, crayfish antioxidant mechanisms recovered more quickly at pH 6 than at pH 8 after the depuration phase. Our results showed that water pH influenced the toxicological effects of DCF, an ionisable compound in crayfish.

Pharmaceutically active compounds in aqueous environment: recent developments in their fate, occurrence and elimination for efficient water purification

The existence of pharmaceutically active compounds (PhACs) in the water is a major concern for environmentalists due to their deleterious effects on living organisms even at minuscule concentrations. This review focuses on PhACs such as analgesics and anti-inflammatory compounds, which are massively excreted in urine and account for the majority of pharmaceutical pollution. Furthermore, other PhACs such as anti-epileptics, beta-blockers and antibiotics are discussed because they also contribute significantly to pharmaceutical pollution in the aquatic environment. This review is divided into two parts. In the first part, different classes of PhACs and their fate in the wastewater environment are presented. In the second part, recent advances in the removal of PhACs by conventional wastewater treatment plants, including membrane bioreactors (MBRs), activated carbon adsorption and bench-scale studies concerning a broad range of advanced oxidation processes (AOPs) that render practical and appropriate strategies for the complete mineralization and degradation of pharmaceutical drugs, are reviewed. This review indicates that drugs like diclofenac, naproxen, paracetamol and aspirin are removed efficiently by conventional systems. Activated carbon adsorption is suitable for the removal of diclofenac and carbamazepine, whereas AOPs are leading water treatment strategies for the effective removal of reviewed PhACs.

A multibiomarker approach to assess the ecotoxicological effects of diclofenac on Asian clam Corbicula fluminea (O. F. Müller, 1774)

Diclofenac (DCF), one of the most current and widely used nonsteroidal anti-inflammatory drugs (NSAIDs), has been frequently detected in aquatic environments worldwide. However, the ecotoxicological effects of DCF on freshwater invertebrates remain largely unknown. In the present study, Corbicula fluminea were exposed to environmentally relevant concentrations of DCF (0, 2, 20, and 200 μg/L) for 28 days, and the potential adverse effects of DCF on siphoning behavior, antioxidant responses, and apoptosis were investigated. Our results showed that the siphon efficiencies of clams were significantly suppressed under DCF stress. DCF exerted neurotoxicity via reducing the activity of acetylcholinesterase (AChE) in gills and digestive gland of C. fluminea. Exposure to DCF induced antioxidant stress and increased malondialdehyde (MDA) levels in both gills and digestive gland of C. fluminea. Transcriptional alterations of apoptosis-related genes indicated that DCF might induce apoptosis by triggering mitochondrial apoptotic pathway. These findings can improve our understanding of the ecological risk of DCF in freshwater ecosystems.

The occurrence of emerging compounds in real urban wastewater before and after the COVID-19 pandemic in Cali, Colombia

The COVID-19 pandemic is considered one of the most significant global disasters in the last years. The rapid increase in infections, deaths, treatment, and the vaccination process has resulted in the excessive use of pharmaceuticals that have entered the environment as micropollutants. Considering the prior information about the presence of pharmaceuticals found in the wastewater of Cali, Colombia, which was collected from 2015 to 2022. The data monitored after the COVID-19 pandemic showed an increase in the concentration of analgesics and anti-inflammatory drugs of up to 91%. This increase was associated with the consumption of pharmaceuticals for mild symptoms, such as fever and pain. Moreover, the increase in concentration of pharmaceuticals poses a highly ecological threat, which was up to 14 times higher than that reported before of COVID-19 pandemic. These results showed that the COVID-19 had not only impacted human health but also had an effect on environmental health.

Selective enrichment, identification, and isolation of diclofenac, ibuprofen, and carbamazepine degrading bacteria from a groundwater biofilm

Diclofenac, ibuprofen, and carbamazepine are three of the most widely detected and most concerning pharmaceutical residues in aquatic ecosystems. The aim of this study was to identify bacteria that may be involved in their degradation from a bacterial biofilm. Selective enrichment cultures in mineral salt solution containing pharmaceutical compounds as sole source of carbon and energy were set up, and population dynamics were monitored using shotgun metagenome sequencing. Bacterial genomes were reconstructed using genome-resolved metagenomics. Thirty bacterial isolates were obtained, identified at species level, and tested regarding pharmaceutical biodegradation at an initial concentration of 1.5 mg l-1. The results indicated that most probably diclofenac biodegrading cultures consisted of members of genera Ferrovibrio, Hydrocarboniphaga, Zavarzinia, and Sphingopyxis, while in ibuprofen biodegradation Nocardioides and Starkeya, and in carbamazepine biodegradation Nocardioides, Pseudonocardia, and Sphingopyxis might be involved. During the enrichments, compared to the initial state the percentage relative abundance of these genera increased up to three orders of magnitude. Except Starkeya, the genomes of these bacteria were reconstructed and annotated. Metabolic analyses of the annotated genomes indicated that these bacteria harbored genes associated with pharmaceutical biodegradation. Stenotrophomonas humi DIC_5 and Rhizobium daejeonense IBU_18 isolates eliminated diclofenac and ibuprofen during the tests in the presence of either glucose (3 g l-1) or in R2A broth. Higher than 90% concentration reduction was observed in the case of both compounds.

Mixtures of environmental pharmaceuticals in marine organisms: Mechanistic evidence of carbamazepine and valsartan effects on Mytilus galloprovincialis

Unravelling the adverse outcomes of pharmaceuticals mixture represents a research priority to characterize the risk for marine ecosystems. The present study investigated, for the first time, the interactions between two of the most largely detected pharmaceuticals in marine species: carbamazepine (CBZ) and valsartan (VAL), elucidating mechanisms that can modulate bioaccumulation, excretion and the onset of toxicity. Mytilus galloprovincialis were exposed to environmental levels of CBZ and VAL dosed alone or in combination: measurement of drug bioaccumulation was integrated with changes in the whole transcriptome and responsiveness of various biochemical and cellular biomarkers. Interactive and competing mechanisms between tested drugs were revealed by the much higher CBZ accumulation in mussels exposed to this compound alone, while an opposite trend was observed for VAL. A complex network of responses was observed as variations of gene expression, functional effects on neurotransmission, cell cycle, immune responses and redox homeostasis. The elaboration of results through a quantitative Weight of Evidence model summarized a greater biological reactivity of CBZ compared to VAL and antagonistic interactions between these compounds, resulting in a reduced effect of the antiepileptic when combined with valsartan. Overall, new perspectives are highlighted for a more comprehensive risk assessment of environmental mixtures of pharmaceuticals.

Molecular Responses of Daphnids to Chronic Exposures to Pharmaceuticals

Pharmaceutical compounds are among several classes of contaminants of emerging concern, such as pesticides, heavy metals and personal care products, all of which are a major concern for aquatic ecosystems. The hazards posed by the presence of pharmaceutical is one which affects both freshwater organisms and human health-via non-target effects and by the contamination of drinking water sources. The molecular and phenotypic alterations of five pharmaceuticals which are commonly present in the aquatic environment were explored in daphnids under chronic exposures. Markers of physiology such as enzyme activities were combined with metabolic perturbations to assess the impact of metformin, diclofenac, gabapentin, carbamazepine and gemfibrozil on daphnids. Enzyme activity of markers of physiology included phosphatases, lipase, peptidase, β-galactosidase, lactate dehydrogenase, glutathione-S-transferase and glutathione reductase activities. Furthermore, targeted LC-MS/MS analysis focusing on glycolysis, the pentose phosphate pathway and the TCA cycle intermediates was performed to assess metabolic alterations. Exposure to pharmaceuticals resulted in the changes in activity for several enzymes of metabolism and the detoxification enzyme glutathione-S-transferase. Metabolic perturbations on key pathways revealed distinct groups and metabolic fingerprints for the different exposures and their mixtures. Chronic exposure to pharmaceuticals at low concentrations revealed significant alterations of metabolic and physiological endpoints.

Physiological Impairment and Biochemical Modifications Induced by Triclosan in Mediterranean Mussels

The effects of pharmaceutical under aquatic biota are still not well established. In this investigation, we assessed the results of a common pharmaceutical's, triclosan (TCS), treatment on physiological and biochemical status of the Mediterranean mussels. Filtration and respiration rates were statistically reduced after treatment with highest considered concentration TCS2 = 100 µg·L^-1. However, no modification (p > 0.05) was detected after treatment with TCS1 = 50 µg·L^-1. For biochemical responses, oxidative stress parameters including H₂O₂ level and antioxidant enzymes were enhanced following concentration in considered organs. In parallel, Malondialdheyde content was measured in mussels after TCS treatment and lipid peroxidation occurred at high TCS concentration. Neurotoxicity evaluated by acetylcholinesterase (AChE) activity was induced in gills and digestive glands after exposure to TCS2. Overall, physiological impairment, oxidative stress, lipid peroxidation and neurotoxicity could be induced by triclosan in mussels. The association of physiological and biochemical biomarkers constitute a useful tool to measure the impact of pharmaceuticals in marine organism.

Chronic Diclofenac Exposure Increases Mitochondrial Oxidative Stress, Inflammatory Mediators, and Cardiac Dysfunction

PURPOSE

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among one of the most commonly prescribed medications for pain and inflammation. Diclofenac (DIC) is a commonly prescribed NSAID that is known to increase the risk of cardiovascular diseases. However, the mechanisms underlying its cardiotoxic effects remain largely unknown. In this study, we tested the hypothesis that chronic exposure to DIC increases oxidative stress, which ultimately impairs cardiovascular function.

METHODS AND RESULTS

Mice were treated with DIC for 4 weeks and subsequently subjected to in vivo and in vitro functional assessments. Chronic DIC exposure resulted in not only systolic but also diastolic dysfunction. DIC treatment, however, did not alter blood pressure or electrocardiographic recordings. Importantly, treatment with DIC significantly increased inflammatory cytokines and chemokines as well as cardiac fibroblast activation and proliferation. There was increased reactive oxygen species (ROS) production in cardiomyocytes from DIC-treated mice, which may contribute to the more depolarized mitochondrial membrane potential and reduced energy production, leading to a significant decrease in sarcoplasmic reticulum (SR) Ca2+ load, Ca2+ transients, and sarcomere shortening. Using unbiased metabolomic analyses, we demonstrated significant alterations in oxylipin profiles towards inflammatory features in chronic DIC treatment.

CONCLUSIONS

Together, chronic treatment with DIC resulted in severe cardiotoxicity, which was mediated, in part, by an increase in mitochondrial oxidative stress.

A multi-biomarker approach to assess toxicity of diclofenac and 4-OH diclofenac in Mytilus trossulus mussels - First evidence of diclofenac metabolite impact on molluscs

Although the presence of pharmaceuticals in the environment is an issue widely addressed in research over the past two decades, still little is known about their transformation products. However, there are indications that some of these chemicals may be equally or even more harmful than parent compounds. Diclofenac (DCF) is among the most commonly detected pharmaceuticals in the aquatic environment, but the potential effects of its metabolites on organisms are poorly understood. Therefore, the present study aimed to evaluate and compare the toxicity of DCF and its metabolite, 4-hydroxy diclofenac (4-OH DCF), in mussels using a multi-biomarker approach. Mytilus trossulus mussels were exposed to DCF and 4-OH DCF at 68.22 and 20.85 μg/L (measured concentrations at day 0), respectively, for 7 days. In our work, we showed that both tested compounds have no effect on most of the enzymatic biomarkers tested. However, it has been shown that their action can affect the protein content in gills and also be reflected through histological markers. ENVIRONMENTAL IMPLICATION: Studies in recent years clearly prove that pharmaceuticals can negatively affect aquatic organisms. In addition to parent compounds, metabolites of pharmaceuticals can also be a significant environmental problem. In the present work, the effects of diclofenac and its main metabolite, 4-hydroxy diclofenac, on marine mussels were evaluated. Both compounds showed negative effects on mussels, which was primarily observed through histological changes. The present study therefore confirms that not only diclofenac, but also its main metabolite can have negative effects on aquatic organisms.

Time- and dose-dependent biological effects of a sub-chronic exposure to realistic doses of salicylic acid in the gills of mussel Mytilus galloprovincialis

Among nonsteroidal anti-inflammatory drugs (NSAIDs) commonly found in seawater and wastewater, salicylic acid (SA) represents one of the most persistent and hazardous compounds for aquatic organisms. This study was therefore designed to elucidate the biological effects of SA in mussel Mytilus galloprovincialis. During a sub-chronic exposure (12 days), mussels were exposed to five realistic concentrations of SA (C1: 0.05 μg/L; C2: 0.5 μg/L; C3: 5 μg/L; C4: 50 μg/L; C5: 100 μg/L) and gills, selected as the target organ, were collected at different time points (T3: 3 days; T5: 5 days; T12: 12 days). Exposure to SA induced no histological alterations in mussel gills, despite a relevant hemocyte infiltration was observed throughout the exposure as a defensive response to SA. Temporal modulation of glutathione S-transferase (GST), catalase (CAT), and superoxide dismutase (SOD) activities suggested the occurrence of antioxidant and detoxifying responses against SA exposure, while lipid peroxidation (LPO), except for a partial increase at T3, was prevented. Inhibition of the cholinergic system was also reported by reduced acetylcholinesterase (AChE) activity, mainly at T12. Overall, findings from this study contribute to enlarge the current knowledge on the cytotoxicity of SA, on non-target aquatic organisms, and might for the enhancement of new ecopharmacovigilance programs and optimization of the efficacy of wastewater treatment plants for mitigation of pharmaceutical pollution in coastal areas.

Removal of organic micropollutans by adsorptive membrane

Various emerging organic micropollutants, such as pharmaceuticals, have attracted the interest of the water industry during the last two decades due to their insufficient removal during conventional water and wastewater treatment methods and increasing demand for pharmaceuticals projected to climate change-related impacts and COVID-19, nanosorbents such as carbon nanotubes (CNTs), graphene oxides (GOs), and metallic organic frameworks (MOFs) have recently been extensively explored regarding their potential environmental applications. Due to their unique physicochemical features, the use of these nanoadsorbents for organic micropollutans in water and wastewater treatment processes has been a rapidly growing topic of research in recent literature. Adsorptive membranes, which include these nanosorbents, combine the benefits of adsorption with membrane separation, allowing for high flow rates and faster adsorption/desorption rates, and have received a lot of publicity in recent years. The most recent advances in the fabrication of adsorptive membranes (including homogeneous membranes, mixed matrix membranes, and composite membranes), as well as their basic principles and applications in water and wastewater treatment, are discussed in this review. This paper covers ten years, from 2011 to 2021, and examines over 100 published studies, highlighting that micropollutans can pose a serious threat to surface water environments and that adsorptive membranes are promising, particularly in the adsorption of trace substances with fast kinetics. Membrane fouling, on the other hand, should be given more attention in future studies due to the high costs and restricted reusability.

Method optimisation and application based on solid phase extraction of non steroidal anti-inflammatory drugs, antiretroviral drugs, and a lipid regulator from coastal areas of Durban, South Africa

This study presents an optimized method that is applicable in monitoring the occurrence of pharmaceuticals in a wide range of aquatic environments. The optimised Solid Phase Extraction method is based on Bond Elut Plexa cartridges for the identification and quantification of three non-steroidal anti-inflammatory drugs, three antiretroviral drugs and a lipid regulator in the coastal area of Durban city, South Africa covering four seasons. The extracted compounds are qualitatively and quantitatively detected by a high-performance liquid phase chromatographic instrument coupled to a photodiode array detector. The recoveries range from 62 to 110% with a Relative Standard Deviation of 0.56−4.68%, respectively, for the determination of emtricitabine, tenofovir, naproxen, diclofenac, ibuprofen, efavirenz, and gemfibrozil. The analytical method is validated by spiking estuarine water samples with 5 µg L− 1 of a mixture containing the target pharmaceuticals and the matrix detection limit is established to be 0.62–1.78 µg L− 1 for the target compounds. The optimized method is applied to seasonal monitoring of pharmaceuticals at chosen study sites from winter and spring of 2019 and summer and autumn of 2020. The results indicate the concentration of the pharmaceuticals studied varies with the type of aquatic environment and season.

Toxicological Evaluation of Acetylsalicylic Acid in Non-Target Organisms: Chronic Exposure on Mytilus galloprovincialis (Lamarck, 1819)

Pharmaceuticals are now considered to be established contaminants, and their presence in water poses a real risk not only to the marine ecosystem, as they may adversely affect non-target organisms that are exposed to them, but also indirectly to humans. This is particularly true for the model organism considered in this work, Mytilus galloprovincialis (Lamarck, 1819), a suspensivore and bioaccumulating organism that enters the human food chain. Among the most commonly used over-the-counter medicines, anti-inflammatory drugs certainly feature prominently, with acetylsalicylic acid (ASA) at the top. In this work, M. galloprovincialis specimens were exposed to two concentrations of ASA (10 and 100 μg/L) for 10 and 20 days to evaluate possible alterations in the decrease in regulatory volume (RVD) in digestive gland cells and cell viability of both these cells and hemocytes. In addition, the histopathological condition index of the gills and digestive gland was evaluated. The data obtained showed that chronic exposure to ASA did not alter the cell viability of hemocytes and digestive gland cells but alters the physiological mechanisms of volume regulation in the digestive gland and, in addition, a time-dose reaction to ASA in the gills and digestive gland showing numerous alterations such as lipofuscin deposits and hemocyte infiltration was found. These results confirm the potential toxicity to the marine biota, highlighting the necessity to deepen the knowledge regarding the link between over-the-counter pharmaceuticals and non-target organisms.

Exposure to diclofenac alters thyroid hormone levels and transcription of genes involved in the hypothalamic-pituitary-thyroid axis in zebrafish embryos/larvae

Diclofenac (DCF), one of typical non-steroidal anti-inflammatory drugs (NSAIDs), has been frequently detected in various environmental media. Nevertheless，the potential endocrine disrupting effects of DCF on fish were poorly understood. In the present study, zebrafish embryos/larvae were used as a model to evaluate the adverse effects of DCF on development and thyroid system. The results demonstrated that DCF only significantly decreased the heart rate at 72 h post-fertilization (hpf), exhibiting limited influence on the embryonic development of zebrafish. Treatment with DCF significantly reduced whole-body thyroxine (T4) levels, and changed transcriptional levels of several genes related to the hypothalamic-pituitary-thyroid (HPT) axis. These findings provide important information regarding to the mechanisms of DCF-induced developmental toxicity and thyroid disruption in fish.

Comparison of cellular mechanisms induced by pharmaceutical exposure to caffeine and its combination with salicylic acid in mussel Mytilus galloprovincialis

Urban and hospital-sourced pharmaceuticals are continuously discharged into aquatic environments, threatening biota. To date, their impact as single compounds has been widely investigated, whereas few information exists on their effects as mixtures. We assessed the time-dependent biological impact induced by environmental concentrations of caffeine alone (CAF; 5 ng/L to 10 µg/L) and its combination with salicylic acid (CAF+SA; 5 ng/L+0.05 µg/L to 10 µg/L+100 µg/L) on gills of mussel Mytilus galloprovincialis during a 12-day exposure. Although no histological alteration was observed in mussel gills, haemocyte infiltration was noticed at T12 following CAF+SA exposure, as confirmed by flow cytometry with increased hyalinocytes. Both the treatments induced lipid peroxidation and cholinergic neurotoxicity, which the antioxidant system was unable to counteract. We have highlighted the biological risks posed by pharmaceuticals on biota under environmental scenarios, contributing to the enhancement of ecopharmacovigilance programmes and amelioration of the efficacy of wastewater treatment plants.

Nocardioides carbamazepini sp. nov., an ibuprofen degrader isolated from a biofilm bacterial community enriched on carbamazepine

From the metagenome of a carbamazepine amended selective enrichment culture the genome of a new to science bacterial species affiliating with the genus Nocardioides was reconstructed. From the same enrichment an aerobic actinobacterium, strain CBZ_1^T, sharing 99.4% whole-genome sequence similarity with the reconstructed Nocardioides sp. bin genome was isolated. On the basis of 16S rRNA gene sequence similarity the novel isolate affiliated to the genus Nocardioides, with the closest relatives Nocardioides kongjuensis DSM19082^T (98.4%), Nocardioides daeguensis JCM17460^T (98.4%) and Nocardioides nitrophenolicus DSM15529^T (98.2%). Using a polyphasic approach it was confirmed that the isolate CBZ_1^T represents a new phyletic lineage within the genus Nocardioides. According to metagenomic, metatranscriptomic studies and metabolic analyses strain CZB_1^T was abundant in both carbamazepine and ibuprofen enrichments, and harbors biodegradative genes involved in the biodegradation of pharmaceutical compounds. Biodegradation studies supported that the new species was capable of ibuprofen biodegradation. After 7 weeks of incubation, in mineral salts solution supplemented with glucose (3 g l^-1) as co-substrate, 70% of ibuprofen was eliminated by strain CBZ_1^T at an initial conc. of 1.5 mg l^-1. The phylogenetic, phenotypic and chemotaxonomic data supported the classification of strain CBZ_1^T to the genus Nocardioides, for which the name Nocardioides carbamazepini sp. nov. (CBZ_1^T = NCAIM B.0.2663 = LMG 32395) is proposed. To the best of our knowledge, this is the first study that reports simultaneous genome reconstruction of a new to science bacterial species using metagenome binning and at the same time the isolation of the same novel bacterial species.

Pharmaceutical Pollution in Aquatic Environments: A Concise Review of Environmental Impacts and Bioremediation Systems

The presence of emerging contaminants in the environment, such as pharmaceuticals, is a growing global concern. The excessive use of medication globally, together with the recalcitrance of pharmaceuticals in traditional wastewater treatment systems, has caused these compounds to present a severe environmental problem. In recent years, the increase in their availability, access and use of drugs has caused concentrations in water bodies to rise substantially. Considered as emerging contaminants, pharmaceuticals represent a challenge in the field of environmental remediation; therefore, alternative add-on systems for traditional wastewater treatment plants are continuously being developed to mitigate their impact and reduce their effects on the environment and human health. In this review, we describe the current status and impact of pharmaceutical compounds as emerging contaminants, focusing on their presence in water bodies, and analyzing the development of bioremediation systems, especially mycoremediation, for the removal of these pharmaceutical compounds with a special focus on fungal technologies.

The influence of salinity on the toxicity of remediated seawater

Mercury (Hg) is one of the most hazardous pollutants, due to its toxicity, biological magnification and worldwide persistence in aquatic systems. Thus, new efficient nanotechnologies (e.g. graphene oxide functionalized with polyethyleneimine (GO-PEI)) have been developed to remove this metal from the water. Aquatic environments, in particular transitional systems, are also subjected to disturbances resulting from climate change, such as salinity shifts. Salinity is one of the most relevant factors that influences the distribution and survival of aquatic species such as mussels. To our knowledge, no studies assessed the ecotoxicological impairments induced in marine organisms exposed to remediate seawater (RSW) under different salinity levels. For this, the focus of the present study was to evaluate the effects of seawater previously contaminated with Hg and remediated with GO-PEI, using the species Mytilus galloprovincialis, maintained at three different salinities (30, 20 and 40). The results obtained demonstrated similar histopathological and metabolic alterations, oxidative stress and neurotoxicity in mussels under RSW treatment at stressful salinity conditions (20 and 40) in comparison to control salinity (30). On the other hand, the present findings revealed toxicological effects including cellular damage and histopathological impairments in mussels exposed to Hg contaminated seawater in comparison to non-contaminated ones, at each salinity level. Overall, these results confirm the high efficiency of GO-PEI to sorb Hg from water with no noticeable toxic effects even under different salinities, leading to consider it a promising eco-friendly approach to remediate contaminated water.

Histological endpoints and oxidative stress transcriptional responses in the Mediterranean mussel Mytilus galloprovincialis exposed to realistic doses of salicylic acid

Despite the availability of analytic data, little is known about the toxicity of salicylic acid (SA) on aquatic non-target organisms. The present study aimed at evaluating the impact of SA through a short-term exposure of the Mediterranean mussel Mytilus galloprovincialis to five environmentally relevant concentrations of SA. A set of suitable biomarkers was applied at selected time-points on mussel digestive glands, including histological observations and expression of oxidative stress related genes. The obtained results showed a conspicuous hemocytic infiltration among mussel digestive tubules, as confirmed also by a flow cytometric approach that revealed an increase of halinocytes and granulocytes. Interestingly, a significant dose and time dependent decrease in the expression levels of oxidative stress related genes was found in mussels exposed to SA except for the glutathione S-transferase gene that was significantly up-regulated in a time-dependent manner confirming its important role against oxidant species and in the metabolism of pharmaceuticals.

Efficiency of the bank filtration technique for diclofenac removal: A review

Bank filtration (BF) has been employed for more than a century for the production of water with a better quality, and it has been showing satisfactory results in diclofenac attenuation. Considered the most administered analgesic in the world, diclofenac has been frequently detected in water bodies. Besides being persistent in the environment, this compound is not completely removed by the conventional water treatments, drinking water treatment plants (DWTPs) and wastewater treatment plant (WWTPs). BF has a high complexity, whose efficiency depends on the characteristics of the observed pollutant and on the environment where the system in installed, which is why this is a topic that has been constantly studied. Nevertheless, studies present the behavior of diclofenac during the BF process. In this context, this research performed the evaluation of the factors and the biogeochemical processes that influence the efficiency of the BF technique in diclofenac removal. The aerobic conditions, higher temperatures, microbial biomass density, hydrogen potential close to neutrality and sediments with heterogeneous fractions are considered the ideal conditions in the aquifer for diclofenac removal. Nonetheless, there is no consensus on which of these factors has the greatest contribution on the mechanism of attenuation during BF. Studies with columns in laboratory and modeling affirm that the highest degradation rates occur in the first centimeters (5-50 cm) of the passage of water through the porous medium, in the environment known as hyporheic zone, where intense biogeochemical activities occur. Research has shown 100% removal efficiency for diclofenac persistent to compounds not removed during the BF process. However, half of the studies had removal efficiency that ranged between 80 and 100%. Therefore, the performance of more in-depth studies on the degradation and mobility of this compound becomes necessary for a better understanding of the conditions and biogeochemical processes which act in its attenuation.

Evaluating the effect of diclofenac on hydrogen production by anaerobic fermentation of waste activated sludge

Hydrogen production from waste-activated sludge (WAS) anaerobic fermentation is considered to be an effective method of resource recovery. However, the presence of a large number of complex organic compounds in sludge will affect the biological hydrogen production process. As an extensively applied prevalent anti-inflammatory drug, diclofenac (DCF) is inevitably released into the environment. However, the effect of diclofenac on hydrogen production from WAS anaerobic fermentation has not been fully investigated. This work therefore aims to comprehensively investigate the removal efficiency of DCF in mesophilic anaerobic fermentation of WAS and its effect on hydrogen yield. Experiment results showed that 32.5%-38.3% of DCF was degraded in the fermentation process when DCF concentration was ranged from 6 to 100 mg/kg TSS (total suspended solids). DCF at environmental level inhibited hydrogen production, the maximal hydrogen yield decreased from 24.2 to 15.3 mL/g VSS (volatile suspended solids) with an increase of DCF addition from 6 to 100 mg/kg TSS. This is because the presence of DCF caused inhibitions to acetogenesis and acidogenesis, the processes responsible for hydrogen production, probably due to that the polar groups of DCF (i.e., carboxyl group) could readily bind to active sites of [FeFe]- Hydrogenase. Besides, the microbial analysis revealed that DCF increased the microbial diversity but had few influences on the microbial structure.

Assessment of Paracetamol Toxic Effects under Varying Seawater pH Conditions on the Marine Polychaete Hediste diversicolor Using Biochemical Endpoints

Simple Summary

Context of climate change is being widely studied, nevertheless its effects in the toxicity of other contaminants have been poorly study. Particularly, the effects of ocean acidification on the modulation of pharmaceutical absorption and consequent effects, have not been extensively addressed before. In this study, we aimed to assess the effects of ocean acidification (specifically pH values of 8.2, 7.9, and 7.6) combined with paracetamol exposure (0, 30, 60, and 120 µg/L) on the polychaeta Hediste diversicolor. To do so, specific biomarkers were measured namely (CAT), glutathione S-transferases (GSTs), acetylcholinesterase (AChE), and cyclooxygenase (COX) activities, as well as thiobarbituric acid reactive substance (TBARS), were quantified to serve as ecotoxicological endpoints. Alterations of CAT, and GSTs activities, and TBARS levels indicate an alteration in redox balances. Differences in exposed pH levels indicate the possible modulation of the absorption of this pharmaceutical in ocean acidifications scenarios. Alterations in AChE were only observed following paracetamol exposure, not being altered by media pH. Hereby obtained results suggest that seawater acidification is detrimental to marine wildlife, since it may enhance toxic effects caused by environmental realistic concentrations of pharmaceuticals. This work is crucial to understand the potential effects of pharmaceuticals in a climate change scenario.

Abstract

Increasing atmospheric carbon dioxide (CO₂) levels are likely to lower ocean pH values, after its dissolution in seawater. Additionally, pharmaceuticals drugs are environmental stressors due to their intrinsic properties and worldwide occurrence. It is thus of the utmost importance to assess the combined effects of pH decreases and pharmaceutical contamination, considering that their absorption (and effects) are likely to be strongly affected by changes in oceanic pH. To attain this goal, individuals of the marine polychaete Hediste diversicolor were exposed to distinct pH levels (8.2, 7.9, and 7.6) and environmentally relevant concentrations of the acidic drug paracetamol (PAR: 0, 30, 60, and 120 µg/L). Biomarkers such as catalase (CAT), glutathione S-transferases (GSTs), acetylcholinesterase (AChE), and cyclooxygenase (COX) activities, as well as peroxidative damage (through thiobarbituric acid reactive substance (TBARS) quantification), were quantified to serve as ecotoxicological endpoints. Data showed a general increase in CAT and a decrease in GST activities (with significant fluctuations according to the tested conditions of PAR and pH). These changes are likely to be associated with alterations of the redox cycle driven by PAR exposure. In addition, pH levels seemed to condition the toxicity caused by PAR, suggesting that the toxic effects of this drug were in some cases enhanced by more acidic conditions. An inhibition of AChE was observed in animals exposed to the highest concentration of PAR, regardless of the pH value. Moreover, no lipid peroxidation was observed in most individuals, although a significant increase in TBARS levels was observed for polychaetes exposed to the lowest pH. Finally, no alterations of COX activities were recorded on polychaetes exposed to PAR, regardless of the pH level. The obtained results suggest that seawater acidification is detrimental to marine wildlife, since it may enhance toxic effects caused by environmental realistic concentrations of acidic drugs, such as PAR. This work was crucial to evidence that ocean acidification, in the context of a global change scenario of increased levels of both atmospheric and oceanic CO₂, is a key factor in understanding the putative enhanced toxicity of most pharmaceutical drugs that are of an acidic nature.

When pharmaceutical drugs become environmental pollutants: Potential neural effects and underlying mechanisms

Pharmaceutical drugs have become consumer products, with a daily use for some of them. The volume of production and consumption of drugs is such that they have become environmental pollutants. Their transfer to wastewater through urine, feces or rinsing in case of skin use, associated with partial elimination by wastewater treatment plants generalize pollution in the hydrosphere, including drinking water, sediments, soils, the food chain and plants. Here, we review the potential effects of environmental exposure to three classes of pharmaceutical drugs, i.e. antibiotics, antidepressants and non-steroidal anti-inflammatory drugs, on neurodevelopment. Experimental studies analyzing their underlying modes of action including those related to endocrine disruption, and molecular mechanisms including epigenetic modifications are presented. In addition, the contribution of brain imaging to the assessment of adverse effects of these three classes of pharmaceuticals is approached.

Long-term exposure to environmental diclofenac concentrations impairs growth and induces molecular changes in Lymnaea stagnalis freshwater snails

As pharmaceutical substances are highly used in human and veterinary medicine and subsequently released in the environment, they represent emerging contaminants in the aquatic compartment. Diclofenac (DCF) is one of the most commonly detected pharmaceuticals in water and little research has been focused on its long-term effects on freshwater invertebrates. In this study, we assessed the chronic impacts of DCF on the freshwater gastropod Lymnaea stagnalis using life history, behavioral and molecular approaches. These organisms were exposed from the embryo to the adult stage to three environmentally relevant DCF concentrations (0.1, 2 and 10 μg/L). The results indicated that DCF impaired shell growth and feeding behavior at the juvenile stage, yet no impacts on hatching, locomotion and response to light stress were noted. The molecular findings (metabolomics and transcriptomic) suggested that DCF may disturb the immune system, energy metabolism, osmoregulation and redox balance. In addition, prostaglandin synthesis could potentially be inhibited by DCF exposure. The molecular findings revealed signs of reproduction impairment but this trend was not confirmed by the physiological tests. Combined omics tools provided complementary information and enabled us to gain further insight into DCF effects in freshwater organisms.

Salinity-dependent impacts on the effects of antiepileptic and antihistaminic drugs in Ruditapes philippinarum

In coastal systems, pollutants as pharmaceutical drugs exert changes from the molecular to the organism level in marine bivalves. Besides pollutants, coastal systems are prone to changes in environmental parameters, as the alteration of salinity values because of Climate Change. Together, these stressors (pharmaceutical drugs and salinity changes) can exert different threats than each stressor acting individually; for example, salinity can change the physical-chemical properties of the drugs and/or the sensitivity of the organisms to them. However, limited information is available on this subject, with variable results, and for this reason, this study aimed to evaluate the impacts of salinity changes (15, 25 and 35) on the effects of the antiepileptic carbamazepine (CBZ, 1 μg/L) and the antihistamine cetirizine (CTZ, 0.6 μg/L), when acting individually and combined (CBZ + CTZ), in the edible clam Ruditapes philippinarum. After 28 days of exposure, drugs concentrations, bioconcentration factors and biochemical parameters, related to clam's metabolic capacity and oxidative stress were evaluated. The results showed that clams under low salinity suffered more changes in metabolic, antioxidant and biotransformation activities, in comparison with the remaining salinities under study. However, limited impacts were observed when comparing drug effects at low salinity. Indeed, it seemed that CTZ and CBZ + CTZ, under high salinity (salinity 35) were the worst exposure conditions for the clams, since they caused higher levels of cellular damage. It stands out that salinity changes altered the impact of pharmaceutical drugs on marine bivalves.

Biochemical and respiratory parameters in a gastropod Radix balthica exposed to diclofenac

Diclofenac, an anti-inflammatory drug, is often detected in natural waters in the ng/L to μg/L range, posing a threat to aquatic organisms. The study focused on the effects of diclofenac in a gastropod mollusk Radix balthica. A 72-h exposure to environmentally relevant concentrations of diclofenac caused deviations from the baseline activities of the studied enzymes in the digestive gland of snails. Acetylcholinesterase activity was induced by the end of exposure, with the most pronounced increase at 3 μg/L. Results on glutathione-S-transferase activity were nonuniform, and no significant variations were observed in thiobarbituric acid reactive substances concentrations, indicating that diclofenac did not cause oxidative stress in the digestive gland of R. balthica at 0.04-4 μg/L range. Diclofenac lowered the oxygen consumption rate in snails in a concentration-dependent manner. At concentrations ≥0.9 μg/L, animals attempted to switch aquatic respiration to breathing air to regulate their metabolic needs. The study showed that diclofenac at environmentally relevant concentrations affected the fitness of R. balthica.

First transcriptome of the copepod Gladioferens pectinatus subjected to chronic contaminant exposures

Contaminants are often at low concentrations in ecosystems and their effects on exposed organisms can occur over long periods of time and across multiple generations. Alterations to subcellular mechanistic pathways in response to exposure to contaminants can provide insights into mechanisms of toxicity that methods measuring higher levels of biological may miss. Analysis of the whole transcriptome can identify novel mechanisms of action leading to impacts in exposed biota. The aim of this study was to characterise how exposures to copper, benzophenone and diclofenac across multiple generations altered molecular expression pathways in the marine copepod Gladioferens pectinatus. Results of the study demonstrated differential gene expression was observed in cultures exposure to diclofenac (569), copper (449) and benzophenone (59). Pathways linked to stress, growth, cellular and metabolic processes were altered by exposure to all three contaminants with genes associated with oxidative stress and xenobiotic regulation also impacted. Protein kinase functioning, cytochrome P450, transcription, skeletal muscle contraction/relaxation, mitochondrial phosphate translocator, protein synthesis and mitochondrial methylation were all differentially expressed with all three chemicals. The results of the study also suggested that using dimethyl sulfoxide as a dispersant influenced the transcriptome and future research may want to investigate it's use in molecular studies. Data generated in this study provides a first look at transcriptomic response of G. pectinatus exposed to contaminants across multiple generations, future research is needed to validate the identified biomarkers and link these results to apical responses such as population growth to demonstrate the predictive capacity of molecular tools.

Effects of diclofenac on the swimming behavior and antioxidant enzyme activities of the freshwater interstitial crustacean Bryocamptus pygmaeus (Crustacea, Harpacticoida)

Diclofenac (DCF) is one of the most widespread pharmaceutical compounds found in freshwaters as a pseudo-persistent pollutant due to its continuous release from point and diffuse sources, being its removal in Wastewater Treatment Plants incomplete. Moreover, DCF is particularly persistent in interstitial habitats and potentially toxic for the species that spend their whole life cycle among the same sediment grains. This study is aimed at offering a first contribution to the assessment of DCF effects on freshwater invertebrate species living in the interstitial habitats of springs, rivers, lakes and groundwaters. The Crustacea Copepoda are one of the main components of the freshwater interstitial communities, with the primacy taken by the worm-like and small-sized harpacticoids. A sub-lethal concentration of 50 μg L^-1 DCF significantly affected six out of the eight behavior parameters of the burrower/interstitial crustacean harpacticoid Bryocamptus pygmaeus recorded by video tracking analysis. DCF exposure reduced swimming speed, swimming activity, exploration ability and thigmotaxis, and increased swimming path tortuosity. The biochemical approach revealed a reduced level of the mitochondrial superoxide dismutase 2 in individuals exposed to DCF. It could be explained by a decline in mitochondrial performance or by a reduced number of functional mitochondria. Since mitochondrial dysfunction may determine ATP reduction, it comes that less energy is produced for maintaining the cell functions of the DCF-exposed individuals. In addition, the increasing energy demand for the detoxification process further contributes to decrease the total energetic budget allocated for other physiological activities. These observations can explain the changes we have observed in the swimming behavior of the copepod B. pygmaeus.

Self-supported 3D reduced graphene oxide for solid-phase extraction: An efficient and low-cost sorbent for environmental contaminants in aqueous solution

A 3D reduced graphene oxide (3D-rGO), a self-supported, efficient, and low-cost sorbent, was synthesised and employed in a solid-phase extraction (SPE) cartridge. As a proof of concept, it was applied to remove diclofenac from aqueous solution. After applying statistical methods to systematically investigate key parameters for optimizing the 3D-rGO cartridge performance, it reached removal and elution efficiencies of 100 % and 90 %, respectively. This SPE cartridge presented advantages compared to traditional ones as the smaller amount of material into the cartridge (mass twenty times smaller), in addition to the ability of eliminating sorbent preconditioning, reducing the use of solvents, and making the process environmentally friendly with a faster operation. Also, it presented improved reproducibility after several cycles of reuse, and finally a lower cost of production unveiled by a cost-benefit analysis. Analysis with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectrometry, Raman, and Fourier transform infrared spectroscopy in attenuated total reflectance mode suggested that the 3D framework morphology with a high content of carbon at the surface and some residual oxygen-containing groups are the protagonists in this performance. Therefore, 3D-rGO has the potential to be a highly efficient sorbent in analytical procedures using SPE for environmental contaminants in water and effluent samples.

Effects of the antineoplastic drug cyclophosphamide on the biochemical responses of the mussel Mytilus galloprovincialis under different temperatures

Cyclophosphamide (CP) is an antineoplastic drug widely used in chemotherapy treatments with high consumption rates and that has been detected in the aquatic environment. After being released into the aquatic environment, CP may cause adverse effects on aquatic organisms since antineoplastics are well-known cytotoxic, genotoxic, mutagenic and teratogenic drugs. Moreover, predicted environmental changes, such as the temperature rising, may alter the impacts caused by CP on organisms. Thus, the present study aimed to assess the effects caused by CP chronic exposure in the mussel Mytilus galloprovincialis, under actual and predicted warming scenarios. Organisms were exposed for 28 days to different concentrations of CP (10, 100, 500 and 1000 ng/L) at control (17 ± 1.0 °C) and increased (21 ± 1.0 °C) temperatures. Biochemical responses related to metabolic capacity, energy reserves, oxidative stress and neurotoxicity were assessed. The results showed that the organisms were able to maintain their metabolic capacity under all exposure conditions. However, their antioxidant defense mechanisms were activated mostly at higher CP concentrations being able to prevent cellular damage, even under the warming scenario. Overall, the present findings suggest that temperature rise may not alter the impacts of CP towards M. galloprovincialis.

Metabolism of non-steroidal anti-inflammatory drugs by non-target wild-living organisms

The presence of the non-steroidal anti-inflammatory drugs (NSAIDs) in the environment is a fact, and aquatic and soil organisms are chronically exposed to trace levels of these emerging pollutants. This review presents the current state of knowledge on the metabolic pathways of NSAIDs in organisms at various levels of biological organisation. More than 150 publications dealing with target or non-target analysis of selected NSAIDs (mainly diclofenac, ibuprofen, and naproxen) were collected. The metabolites of phase I and phase II are presented. The similarity of NSAIDs metabolism to that in mammals was observed in bacteria, microalgae, fungi, higher plants, invertebrates, and vertebrates. The differences, such as newly detected metabolites, the extracellular metabolism observed in bacteria and fungi, or phase III metabolism in plants, are highlighted. Metabolites detected in plants (conjugates with sugars and amino acids) but not found in any other organisms are described. Selected, in-depth studies with isolated bacterial strains showed the possibility of transforming NSAIDs into assimilable carbon sources. It has been found that some of the metabolites show higher toxicity than their parent forms. The presence of metabolites of NSAIDs in the environment is the cumulative effect of their introduction with wastewaters, their formation in wastewater treatment plants, and their transformation by non-target wild-living organisms.

A review of ecotoxicity reduction in contaminated waters by heterogeneous photocatalytic ozonation

The widespread deterioration of our water systems requires new wastewater treatment technologies to ensure environmental protection. Conventional wastewater treatments were not designed for, and are therefore ineffective, at removing contaminants of emerging concern (CECs) such as pharmaceuticals, personal care products, pesticides, and industrial chemicals. Furthermore, treatment processes capable of breaking down CECs may produce toxic transformation products more harmful than the parent chemicals. Heterogeneous photocatalytic ozonation provides a promising option with high degradation and mineralization of organic compounds. The aim of the present paper is to review ecotoxicity reduction in water treated by heterogeneous photocatalytic ozonation as a measure of process viability. The discussion investigates changes in toxicity based on a variety of toxicity tests performed to evaluate potential effects on ecosystems, the types of catalysts and radiation sources used, the nature of the target contaminants, and the type of water matrix treated. Acute toxicity testing, TiO₂ catalysts, and mercury-vapour lamps including blacklights were dominant in the reviewed studies, investigated in 86%, 84% and 79% of the papers, respectively. Pharmaceuticals were the main group of chemicals treated and the water matrices used were predominantly pure water and secondary effluent. Overall, the findings of these studies provide evidence that photocatalytic ozonation is an efficient process to remove persistent organic compounds while, most of the time, not increasing the toxicity of the effluent (as reported by 86% of the studies). Due to the wide variation in experimental set-ups, no clear correlation between reaction conditions and toxicity was determined, however, V. fischeri acute toxicity assays and chronic/sublethal tests appeared most sensitive to transformation products. Future studies need to a) incorporate multiple toxicity tests to produce a more reliable and inclusive ecotoxicity assessment of treated effluent and b) investigate immobilized catalysts and energy efficient radiation sources (i.e. solar and LEDs) for industrial applications.

Characterization of a fatty acid-binding protein from the Pacific oyster (Crassostrea gigas): pharmaceutical and toxicological implications

Pharmaceuticals and their metabolites constitute a class of xenobiotics commonly found in aquatic environments which may cause toxic effects in aquatic organisms. Several different lipophilic molecules, including some pharmaceuticals, can bind to fatty acid-binding proteins (FABPs), a group of evolutionarily related cytoplasmic proteins that belong to the intracellular lipid-binding protein (iLBP) family. An oyster FABP genome-wide investigation was not available until a recent study on gene organization, protein structure, and phylogeny of Crassostrea gigas iLBPs. Higher transcript levels of the C. gigas FABP2 gene were found after exposure to sewage and pharmaceuticals. Because of its relevance as a potential biomarker of aquatic contamination, in this study, recombinant FABP2 from C. gigas (CgFABP2) was successfully cloned, expressed, and purified, and in vitro and in silico assays were performed using lipids and pharmaceuticals. This is the first characterization of a protein from the iLBP family in C. gigas. Homology modeling and molecular docking were used to evaluate the binding affinities of natural ligands (palmitic, oleic, and arachidonic acids) and pharmaceuticals (ibuprofen, sodium diclofenac, and acetaminophen). Among the tested fatty acids, CgFABP2 showed preference for palmitic acid. The selected pharmaceuticals presented a biphasic-binding mode, suggesting a different binding affinity with a preference for diclofenac. Therefore, the approach using circular dichroism and in silico data might be useful for ligand-binding screening in an invertebrate model organism.

Effects of Carbamazepine in Bivalves: A Review

Carbamazepine (CBZ) is among the ten most frequent pharmaceuticals that occur in the aquatic systems, with known effects on inhabiting organisms, including bivalves. Bivalves are important species in coastal ecosystems, often exhibiting a dominant biomass within invertebrate communities. These organisms play a major role in the functioning of the ecosystem and particularly in food webs (as suspension-feeders) and represent a significant fraction of the fisheries resource. They also have strong interactions with the environment, water and sediment and are considered good bioindicator species. The present paper reviews the known literature on the impacts of CBZ in biological endpoints of marine bivalves exposed to environmentally and non-environmentally relevant concentrations, highlighting differences in terms of biological responses, associated with exposure period, concentrations tested, and species used. Overall, the literature available showed that CBZ induces individual and sub-individual effects in marine bivalves (adults and life stages) and the most common effect reported was the induction of oxidative stress.

Endocrine-disruptive chemicals as contaminants of emerging concern in wastewater and surface water: A review

Population growth followed by rapid development of industrialisation has caused serious environmental pollution with contaminants of emerging concern found in wastewater and surface water. As one of the most important resources for human survival, water is daily polluted by endocrine-disruptive chemicals (EDCs) including pharmaceuticals and personal care products, organic pollutants and heavy metals. Even at low concentrations in water bodies, chronic exposure to EDCs can cause adverse effects on human and environment health. The main concern with EDCs is the diseases they can generate in humans or wildlife by affecting the function of hormones in the body. Problems in the reproductive system, thyroid problems, Alzheimer's, cancer and obesity are some of the major effects of EDCs in humans. In wildlife, the reproductive system may be affected, including its levels of hatchability and vitellogenin. The efforts of the present review are on emphasising on the environmental concern on the occurrence and risk assessment of EDCs, their harmful effects in the ecosystem, human life, and wildlife, as a result of their incomplete removal from wastewater treatment plants. The review focuses on studies conducted in South Africa highlights the use of fungal bioreactors as a low-cost and eco-effective environmentally friendly wastewater treatment processes.

Biomarker Responses of the Clam Ruditapes decussatus Exposed to a Complex Mixture of Environmental Stressors under the Influence of an Urban Wastewater-Treatment Plant

To evaluate the potential impact of an urban wastewater-treatment plant on Ria Formosa coastal lagoon, a sentinel species, the clam Ruditapes decussatus, was exposed along a gradient of the effluent's dispersal for 1 mo. Three exposure sites were selected to study the responses of 3 biomarkers: electron transport system, acetylcholinesterase, and lipid peroxidation. As complementary data, morphometric measurements, condition index, and lipid and protein content were considered together with in situ physicochemical characterization of the sites (temperature, salinity, pH, and dissolved oxygen). Electron transport system activity levels were between 35.7 and 50.5 nmol O₂ /min g protein, acetylcholinesterase activity levels ranged from 2.6 to 3.8 nmol/min g protein, and lipid peroxidation ranged from 174.7 to 246.4 nmol malondialdehyde/g protein. The exposure sites shaped the response not only of biomarkers but also of "health" parameters (protein, lipids, and condition index). Lipid peroxidation was the most responsive biomarker also associated with electron transport system, especially at the closest site to the urban wastewater-treatment plant. Because of the presence of complex mixtures of contaminants in urban effluents, biomarker responses can provide valuable information in environmental assessment. However, it is vital to identify all biological and ecological factors induced by the natural life cycle of clams. Abiotic factors can mask or overlap the response of biomarkers and should be considered in a multibiomarker approach. Environ Toxicol Chem 2021;40:272-283. © 2020 SETAC.

Diclofenac and atrazine restrict the growth of a synchronous Chlamydomonas reinhardtii population via various mechanisms

Non-steroidal anti-inflammatory drug diclofenac (DCF) is commonly found in freshwater bodies and can have adverse effects on non-target organisms. Among the studies on DCF toxicity, several ones have reported its harmful effects on plants and algae. To gain a better understanding of the mechanisms of DCF toxicity towards green algae, we used a synchronous Chlamydomonas reinhardtii cc-1690 culture and compared DCF (135 mg/L) effects with effects caused by atrazine (ATR; 77.6 μg/L), an herbicide with a well-known mechanism of toxic action. To achieve our goal, cell number and size, photosynthetic oxygen consumption/evolution, chlorophyll a fluorescence in vivo, H₂O₂ production by the cells, antioxidative enzymes encoding genes expression were analyzed during light phase of the cell cycle. We have found, that DCF and ATR affect C. reinhardtii through different mechanisms. ATR inhibited the photosynthetic electron transport chain and induced oxidative stress in chloroplast. Such chloroplastic energetics disruption indirectly influenced respiration, the intensification of which could partially mitigate low efficiency of photosynthetic energy production. As a result, ATR inhibited the growth of single cell leading to limitation in C. reinhardtii population development. In contrast to ATR-treated algae, in DCF-treated cells the fraction of active PSII reaction centers was diminished without drastic changes in electron transport or oxidative stress symptoms in chloroplast. However, significant increase in transcript level of gene encoding for mitochondria-located catalase indicates respiratory processes as a source of H₂O₂ overproduced in the DCF-treated cells. Because the single cell growth was not strongly affected by DCF, its adverse effect on progeny cell number seemed to be related rather to arresting of cell divisions. Concluding, although the DCF phytotoxic action appeared to be different from the action of the typical herbicide ATR, it can act as algal growth-inhibiting factor in the environment.

Biological uptake, depuration and biochemical effects of diclofenac and carbamazepine in Carassius carassius

The uptake and depuration kinetics of diclofenac and carbamazepine alone at an environmentally relevant nominal concentration of 2 μg/L and in combination at a concentration ratio of 1:1 with total concentration of 4 μg/L were evaluated in Carassius carassius after 7 d uptake and depuration. Also, the biochemical effects of both drugs alone at nominal concentrations of 2 and 10 μg/L as well as in combination with total concentrations of 4 and 20 μg/L were investigated in Carassius carassius after 7 d exposure followed by 10 d recovery. In the single treatments, steady-state BCFs measured after the 7 d exposure were 73.05, 49.71, 38.01 and 24.93 L/kg for diclofenac and 9.25, 8.99, 5.29 and 4.11 L/kg for carbamazepine in the liver, brain, gill and muscle of Carassius carassius, respectively. Comparatively lower BCFs were measured in the tissues of Carassius carassius for both drugs in the combined treatments. Acetylcholinesterase activity in the brain was significantly induced by diclofenac while carbamazepine and the mixtures significantly inhibited it during all the exposure days as well as after the 10 d recovery in all treatments. This indicates that Carassius carassius could not recover from the neurotoxic effects caused by carbamazepine unlike the inductive effect caused by diclofenac which was recoverable after 10 days. A significant increase in the activities of 7-ethoxyresorufin O-deethylase and glutathione s-transferase for individual and mixed pharmaceuticals suggest that metabolism and detoxification of both drugs took place in the liver of Carassius carassius. Also, a significant increase in the activities of superoxide dismutase, catalase, glutathione reductase and malondialdehyde contents in the individual and mixture treatments mean that the antioxidant defence system of Carassius carassius was triggered to fight against oxidative stress but lipid peroxidation still occurred. However, Carassius carassius recovered from all these increases (superoxide dismutase, catalase, glutathione reductase and malondialdehyde) after the 10 d recovery, suggesting that oxidative damage is reversible. Our results indicate that both drugs at environmentally relevant concentrations might cause adverse effects in Carassius carassius and other fish species.

Cytotoxic responses of the anticancer drug cyclophosphamide in the mussel Mytilus galloprovincialis and comparative sensitivity with human cells lines

The rise of cancer cases worldwide led to an increase in production and consumption of anticancer drugs, that ultimately end up in the marine environment and are accumulated in aquatic organisms. Cyclophosphamide (CP) is a cytotoxic alkylating agent frequently prescribed in cancer treatments. This study assess ecotoxicological effects of CP on mussels Mytilus galloprovincialis, through in vivo and ex vivo approaches and compares the sensitivity of mussel haemocytes with well-established human cell lines (RPE and HeLa). Mussels were exposed in vivo to CP (1000 ng L^-1) and several biomarkers analysed in gills and digestive glands namely neurotoxicity (AChE activity), oxidative stress (GPx activity), biotransformation (GST activity), lipid peroxidation (LPO) and apoptosis (caspase activity), whereas genotoxicity was determined in mussels' haemocytes. Cytotoxicity was also assessed in haemocytes (in vivo and ex vivo) and human cell lines (in vitro) exposed to a range of CP concentrations (50, 100, 250, 500 and 1000 ng L^-1) over 24 h, via neutral red assay. In in vivo exposure, detoxification of CP did not efficiently occur in the gills while in digestive glands GPx and GST activities were induced, jointly with a decrease in lipid peroxidation, indicating a potential outcome of the protective antioxidant mechanisms, whereas no apoptosis was noted. Moreover, cytotoxicity and DNA damage were detected in haemocytes. The ex vivo exposure haemocytes to CP caused cytotoxicity (from 100 ng L^-1), whereas no effects occurred in human cell lines. This suggests that, at relevant environmental concentrations, CP cause subtle and irreversible impacts on M. galloprovincialis.

EAT BREATHE EXCRETE REPEAT: Physiological Responses of the Mussel Mytilus galloprovincialis to Diclofenac and Ocean Acidification

Combined effects of the nonsteroidal anti-inflammatory drug diclofenac and lowered seawater pH were assessed on the physiological responses of the mussel Mytilus galloprovincialis. Bivalves were exposed for 1 week to natural pH (8.1) and two reduced pH values (pH −0.4 units and pH −0.7 units), as predicted under a climate change scenario. After the first week, exposure continued for additional 2 weeks, both in the absence and in the presence of environmentally relevant concentrations of diclofenac (0.05 and 0.5 µg/L). Clearance rate, respiration rate, and excretion rate were measured after 7 days of exposure to pH only and after 14 (T1) and 21 (T2) days of exposure to the various pH*diclofenac combinations. At all sampling times, pH significantly affected all the biological parameters considered, whereas diclofenac generally exhibited a significant influence only at T2. Overall, results demonstrated that the physiological performance of M. galloprovincialis was strongly influenced by the experimental conditions tested, in particular by the interaction between the two stressors after 21 days of exposure. Further studies are needed to assess the combined effects of climate changes and emerging contaminants on bivalve physiology during different life stages, especially reproduction.

Organic micropollutants in water and sediment from Lake Mälaren, Sweden

The occurrence and distribution of 111 organic micropollutants (OMPs) were evaluated in water and sediment samples from Lake Mälaren, Sweden, using a liquid chromatography-tandem mass spectrometry method. The partitioning of contaminants between lake compartments was estimated using solid water distribution coefficients (K_d) and organic carbon-water partitioning coefficients (K_OC). In total, 30 and 24 OMPs were detected in lake water and sediment, respectively. Concentrations ranged from low ng/L to 89 ng/L (lamotrigine) in lake water and from low ng/g dry weight (dw) to 28 ng/g dw (citalopram) in sediment. Carbamazepine, lamotrigine, caffeine, and tolyltriazole were the dominant compounds in Lake Mälaren samples (both water and sediment). Seventeen OMPs were detected in both water and sediment samples, including carbamazepine, DEET, tolyltriazole, bicalutamide, caffeine, lamotrigine, and cetirizine. Log K_d values varied between 0.84 for lamotrigine and 4.4 for citalopram, while log K_OC values varied between 2.1 for lamotrigine and 5.9 for citalopram. These results indicate that sorption to sediment plays a minor role in removal of all OMPs analyzed in the aqueous phase except for citalopram and cetirizine, which showed high sorption potential. The environmental risks of OMPs were assessed based on the RQ values. The worst-case scenario for environmental risk assessment was conducted using the maximum measured environment concentration. For most of the target OMPs, including tolyltriazole, bicalutamide, fexofenadine, oxazepam, cetirizine, and diclofenac, the RQ values were below 0.01, indicating low or no risk to lake ecosystems.

Can salicylic acid modulate biochemical, physiological and population alterations in a macrophyte species under chemical stress by diclofenac?

Salicylic acid (SA) is a pharmaceutical drug that may exert toxic effects by its own; however, simultaneous exposure of plants to SA and to other substances, often results in the significant changes in the patterns of toxic response/resistance to these other sources of chemical stress. Thus, the aim of this work was to investigate the capacity of SA of modulating Lemna minor responses co-exposed to the pharmaceutical drug, diclofenac - DCF. To attain this objective, L. minor was exposed for 7 days, to DCF alone, and to combinations of DCF with SA. After exposure, biochemical, physiological and population endpoints were analyzed as follows: catalase (CAT) and glutathione S-transferases (GSTs) activities, pigments content (chlorophyll a (Chl a), b (Chl b) and total (TChl), carotenoids (Car) and [Chl a]/[Chl b] and [TChl]/[Car] ratios), and growth specific rate, fresh weight and root length. Single exposures to DCF were capable of causing effects in all analyzed endpoints. However, co-exposure of DCF with SA partially reverted these effects. Finally, we may suggest that SA is capable to prevent the toxicity of DCF in macrophytes, by modulating the toxic response of exposed plants.