Bioconcentration of the antiepileptic drug carbamazepine and its physiological and biochemical effects on Daphnia magna

Elevated temperature increases the susceptibility of D. magna to environmental mixtures of carbamazepine, tramadol and citalopram

The joint risks assessment of thermal stress and rising loads of pharmaceuticals (PhACs) in surface waters is a relevant topic in aquatic ecotoxicology. This study investigated the relevance of increased water temperature to alter the acute toxicity of environmentally relevant carbamazepine (CBZ), citalopram (CIT) and tramadol (TRA) concentrations as mixtures (ECs) and delayed outcomes in Daphnia magna. Responses of detoxification and antioxidant pathways in premature daphnids post an acute 24 h (pulsed) exposure to the PhACs mixtures and delayed responses as the reproductive output over 14 days recovery were investigated under 21- and 26 °C incubation. Biphasic modulation in glutathione S-transferase (GST) activity and significant inhibition of superoxide dismutase (SOD) activity were observed in both thermal regimes with significant shift in effective thresholds from 10-fold ECs at 21 °C to ECs at 26 °C incubation. Significant induction in catalase (CAT) activity and oxidative stress development were recorded at elevated temperatures from the 10-fold ECs dose onward. Pulsed exposures at 26 °C also led to significant decrease in the reproduction of daphnids above the 10-fold ECs of PhACs. The Integrated Biomarker Response scoring (IBRv2) approach outlined a 1.8-fold increase in alterations of daphnids exposed to 100-fold ECs of PhACs at 26 °C.

Bioaccumulation and behavioral response patterns of crucian carp (Carassius carassius) after carbamazepine exposure and elimination

The antiepileptic drug carbamazepine (CBZ) has been widely detected in freshwater, yet its toxic actions in fish at multiple endpoints and the subsequent recovery patterns of the impacted are less discussed. This study investigated the bioaccumulation, physiological and behavioral changes of crucian carp (Carassius carassius) following CBZ exposure (G1 = 6.15 μg/L, G2 = 61.5 μg/L, G3 = 615 μg/L, G4 = 6150 μg/L) and subsequent recovery. Our results showed that CBZ was more likely to accumulate in the liver and brain than in the gills. A concentration-dependent phenomenon was observed; however, the residual CBZ decreased to similar levels after recovery. The behavioral indicators (i.e. feeding, social and spontaneous swimming) were significantly inhibited after 7-days of CBZ exposure, and only recovered at low concentration treatment (G1) after 7-days recovery in CBZ-free water. The acetylcholinesterase (AChE) activity in the brain and superoxide dismutase (SOD) activity in the liver and gills were induced after CBZ exposure and returned to normal levels after 7-days of recovery. In contrast, the inhibition of catalase (CAT) activity caused by CBZ exposure persisted in the high concentration treatment (G4) after recovery. Furthermore, correlation analysis indicated that changes in feeding behavior were closely related to the variation of CBZ concentrations in tissues, and the persistence of abnormal swimming and social behavior was closely related to gill CAT activity. These findings contribute to explore the toxic mechanisms of CBZ and highlight the recovery process and connections between various endpoints.

The responses and tolerance of photosynthetic system in Chlorella vulgaris to the pharmaceutical pollutant carbamazepine

Screening for sensitive toxicological indicators and understanding algal tolerance to pharmaceutical contaminants (PhCs) are essential for assessing PhCs risk and their removal by microalgae. Carbamazepine (CBZ) showed adverse effects on microalgae, but the specific toxicity mechanisms on the most sensitive algal photosynthetic system (PS) remain limited. This study delved into the impact of CBZ exposure on the growth, cell viability, pigment content, and PS of Chlorella vulgaris. The findings revealed a notable inhibition of C. vulgaris growth by CBZ, with an IC50 value of 27.2 mg/L at 96 h. CBZ exposure induced algal membrane damage and cell viability. Intriguingly, CBZ drastically diminished intracellular pigment levels, notably showing "low promotion and high inhibition" of chlorophyll b (Chl b) by 72 h. Moreover, the study identified a decreased number of active reaction centers (RCs) within algal PSII alongside inhibited electron transport from QA to QB on the PSII receptor side, leading to PSII disruption. As an adaptive response to CBZ stress, C. vulgaris stimulated its Chl b synthesis, increased non-photochemical quenching (NPQ), and adapted its tolerance to bright light. Additionally, the alga attempted to compensate for the CBZ-induced reduction in electron transfer efficiency at the PSII receptor side and light energy utilization by increasing its electron transfer from downstream. Principal component analysis (PCA) further verified that the parameters on non-photochemical dissipation, electron transport, and integrative performance were the most sensitive algal toxicological indicators for CBZ exposure, and algal PS has energy protection capability through negative feedback regulation. However, prolonged exposure to high doses of CBZ will eventually result in permanent damage to the algal PS. Hence, attention should be paid to the concentration of CBZ in the effluent and the exposure time, while methods to mitigate algal photodamage should be appropriately sought for algal treatment of dense effluents.

Daphnia magna model for the study of mycotoxins present in food: Gliotoxin, ochratoxin A and its combination

Mycotoxins are low molecular weight compounds present in food and feed. Although their effects on human health have been widely described, their mechanisms of action are still undefined. Gliotoxin (GTX) and ochratoxin A (OTA) are among the most dangerous mycotoxins produced by Aspergillus spp. Therefore, their toxicity was studied in the Daphnia magna model, which has high capacity to predict cytotoxicity and assess ecotoxicity, comparable to mammalian models. The study consisted of a series of tests to evaluate the effects of mycotoxins GTX, OTA and their combinations at different dilutions on Daphnia magna that were conducted according to standardized OECD 202 and 211 guidelines. The following assays were carried out: acute toxicity test, heartbeat, delayed toxicity test, reproduction, growth rate test. Reproducibility was determined by observing the offspring after 21 days of GTX exposure. In acute and delayed toxicity transcript levels of genes involved in xenobiotic metabolism (mox, gst, abcb1, and abcc5), and oxidative stress (vtg-SOD) were analyzed by qPCR. GTX showed acute toxicity and decreased heart rate in D. magna compared to OTA. On the other hand, OTA showed a delayed effect as evidenced by the immobility test. Both mycotoxins showed to increase genes involved in xenobiotic metabolism, while only the mycotoxin mixture increased oxidative stress. These results suggest that the mycotoxins tested could have negative impact on the environment and human health.

Environmentally Relevant Levels of Antiepileptic Carbamazepine Altered Intestinal Microbial Composition and Metabolites in Amphibian Larvae

There is growing concern about the potential ecological risks posed by pharmaceutical residues in the aquatic environment. However, our understanding of the toxic effects of antiepileptic pharmaceuticals, such as carbamazepine (CBZ), on aquatic animal larvae is still limited. In this study, the tadpoles of the black-spotted pond frog (Pelophylax nigromaculatus) were exposed to environmentally relevant concentrations of CBZ (0.3 and 3.0 μg/L) for 30 days, and their growth, intestinal microbial composition, and metabolites were investigated to assess the potential toxic effects of CBZ in non-targeted aquatic organisms. Some tadpoles died during exposure, but there was no significant among-group difference in the survival and growth rates. CBZ exposure significantly altered the composition of tadpole intestinal microbiota. Relative abundances of some bacterial genera (e.g., Blautia, Prevotella, Bacillus, Microbacterium, etc.) decreased, while others (e.g., Paucibacter, etc.) increased in CBZ-exposed tadpoles. Interestingly, CBZ-induced alterations in some bacteria might not necessarily lead to adverse outcomes for animals. Meanwhile, small molecular intestinal metabolites related to energy metabolism, and antioxidant and anti-inflammatory activities were also altered after exposure. Taken together, environmentally relevant levels of CBZ might alter the metabolic and immune performances of amphibian larvae by modifying the abundance of some specific bacteria and the level of metabolites in their intestines, thereby potentially causing a long-term effect on their fitness.

Fate of contaminants of emerging concern in two wastewater treatment plants after retrofitting tertiary treatment for reduction of nitrogen discharge

More and more previously designed wastewater treatment plants (WWTPs) are upgraded to tertiary treatment to meet the higher effluent discharge standards of conventional pollutants. Contaminants of emerging concern (CECs) can cause adverse effects on organisms and usually flow into WWTPs along with urban sewage. How the retrofitted WWTPs targeting conventional pollutants will influence the treatment efficiency of CECs is seldom discussed. This study investigates the removal of CECs in two full-scale newly retrofitted WWTPs (CD and JM WWTPs), containing high-efficiency sedimentation tank and denitrification deep bed filter for enhancing total nitrogen removal. The overall CEC removal efficiencies in the CD and JM WWTPs were 73.79 % and 93.63 %, respectively. Mass balance results indicated that CD WWTP and JM WWTP release a total of 36.89 and 88.58 g/d of CECs into the environment through effluent and excess sludge, respectively. Analysis of the concentration of CECs along the treatment process revealed most CECs were removed in the biological treatment units. The incorporation of newly constructed tertiary treatment proved beneficial for CEC removal and removed 2.93 % and 2.36 % CECs, corresponding to CEC removal of 2.92 and 27.49 g/d in the CD and JM WWTPs, respectively. The data of this study were further used to evaluate the suitability of the SimpleTreat model for simulating the fate of CECs in WWTPs. The predicted fraction of CECs discharged through the biological treatment effluent were generally within ten-fold difference from the measured results, highlighting its potential for estimating CEC removal in WWTPs.

Toxic effects of environmentally relevant concentrations of naproxen exposure on Daphnia magna including antioxidant system, development, and reproduction

Naproxen (NPX) is one of common non-prescription non-steroidal anti-inflammatory drugs (NSAIDs) which is widely detected in aquatic environments worldwide due to its high usage and low degradation. NPX exerts anti-inflammatory and analgesic pharmacological effects through the inhibition of prostaglandin-endoperoxide synthase (PTGS), also known as cyclooxygenase (COX). Given its evolutionarily relatively conserved biological functions, the potential toxic effects of NPX on non-target aquatic organisms deserve more attention. However, the ecotoxicological studies of NPX mainly focused on its acute toxic effects under higher concentrations while the chronic toxic effects under realistic concentrations exposure, especially for the underlying molecular mechanisms still remain unclear. In the present study, Daphnia magna, being widely distributed in freshwater aquatic environments, was selected to investigate the toxic effects of environmentally relevant concentrations of NPX via determining the response of the Nrf2/Keap1 signaling pathway-mediated antioxidant system in acute exposure, as well as the changes in life-history traits, such as growth, reproduction, and behavior in chronic exposure. The results showed that the short-term exposure to NPX (24 h and 48 h) suppressed ptgs2 expression while activating Nrf2/Keap1 signaling pathway and its downstream antioxidant genes (ho-1, sod, cat and trxr). However, with prolonged exposure to 96 h, the opposite performance was observed, the accumulation of malondialdehyde (MDA) indicated that D. magna suffered from severe oxidative stress. To maintain homeostasis, the exposed organism may trigger ferroptosis and apoptosis processes with the help of Silent mating type information regulation 2 homologs (SIRTs). The long-term chronic exposure to NPX (21 days) caused toxic effects on D. magna at the individual and population levels, including growth, reproduction and behavior, which may be closely related to the oxidative stress induced by the drug. The present study suggested that more attention should be paid to the ecological risk assessment of NSAIDs including NPX on aquatic non-target organisms.

The occurrence of typical psychotropic drugs in the aquatic environments and their potential toxicity to aquatic organisms - A review

Psychotropic drugs (PDs) and their bioactive metabolites often persist in aquatic environments due to their typical physical properties, which made them resistant to removal by traditional wastewater treatment plants (WWTPs). Consequently, such drugs and/or their metabolites are frequently detected in both aquatic environments and organisms. Even at low concentrations, these drugs can exhibit toxic effects on non-target organisms including bony fish (zebrafish (Danio rerio) and fathead minnows) and bivalves (freshwater mussels and clams). This narrative review focuses on the quintessential representatives of three different categories of PDs-antiepileptics, antidepressants, and antipsychotics. The data regarding their concentrations occurring in the environment, patterns of distribution, the degree of enrichment in various tissues of aquatic organisms, and the toxicological effects on them are summarized. The toxicological assessments of these drugs included the evaluation of their effects on the reproductive, embryonic development, oxidative stress-related, neurobehavioral, and genetic functions in various experimental models. However, the mechanisms underlying the toxicity of PDs to aquatic organisms and their potential health risks to humans remain unclear. Most studies have focused on the effects caused by acute short-term exposure due to limitations in the experimental conditions, thus making it necessary to investigate the chronic toxic effects at concentrations that are in coherence with those occurring in the environment. Additionally, this review aims to raise awareness and stimulate further research efforts by highlighting the gaps in the understanding of the mechanisms behind PD-induced toxicity and potential health risks. Ultimately, the study underscores the importance of developing advanced remediation methods for the removal of PDs in WWTPs and encourages a broader discussion on mitigating their environmental impacts.

Research progress of plant-derived natural alkaloids in central nervous system diseases

Central nervous system (CNS) disease is one of the most important causes of human death. Because of their complex pathogenesis, more and more attention has been paid to them. At present, drug treatment of the CNS is the main means; however, most drugs only relieve symptoms, and some have certain toxicity and side effects. Natural compounds derived from plants can provide safer and more effective alternatives. Alkaloids are common nitrogenous basic organic compounds found in nature, which exist widely in many kinds of plants and have unique application value in modern medicine. For example, Galantamine and Huperzine A from medicinal plants are widely used drugs on the market to treat Alzheimer's disease. Therefore, the main purpose of this review is to provide the available information on natural alkaloids with the activity of treating central nervous system diseases in order to explore the trends and perspectives for the further study of central nervous system drugs. In this paper, 120 alkaloids with the potential effect of treating central nervous system diseases are summarized from the aspects of sources, structure types, mechanism of action and structure-activity relationship.

Omics techniques reveal the toxicity mechanisms of three antiepileptic drugs to juvenile zebrafish (Danio rerio) brain and liver

Epilepsy, a neurological disorder, is characterized by seizures that are an appearance of excessive brain activity and is symptomatically treated with antiepileptic drugs (AEDs). Oxcarbazepine (OCBZ), lamotrigine (LTG), and carbamazepine (CBZ) are widely used AEDs in clinics and are very often detected in aquatic environments. However, neither the sub-lethal effects nor the specific mechanisms of these AEDs' action on the fish are well understood. In this study, juvenile zebrafish were exposed to a sub-lethal concentration (100 μg/L) of OCBZ, LTG, and CBZ for 28 d, after which indicators of oxidative stress (i.e. superoxide dismutase (SOD) activity, catalase (CAT) activity, and malondialdehyde (MDA) level) and neurotoxicity (i.e. acetylcholinesterase (AChE) activity, γ-aminobutyric acid (GABA) level, and glutamic acid (Glu) level) were measured. Brain SOD activity was significantly increased by three AEDs, while brain CAT activity was significantly inhibited by LTG and CBZ. Liver SOD activity was significantly enhanced by CBZ, and liver CAT activity was significantly induced by OCBZ and LTG. Liver MDA level was significantly increased by three AEDs. Brain AChE activity was significantly increased by LTG and CBZ, and brain GABA level was significantly enhanced by three AEDs. However, there were no significant alterations in the levels of MDA and Glu in zebrafish brain. To ascertain mechanisms of AEDs-induced toxicity, brain transcriptomics and liver metabolomics were conducted in zebrafish. The brain transcriptomics results showed that lots of differentially expressed genes (DEGs) were enriched in the sensory system, the immune system, the digestive system, the metabolic processes, and others in three AEDs treated groups. The metabolomics data indicated dysregulation of glycerophospholipid signaling and lipid homeostasis in zebrafish liver after three AEDs exposure. The overall results of this study improve understanding of the sub-lethal effects and potential molecular mechanisms of action of AEDs in fish.

A review of hybrid enzymatic-chemical treatment for wastewater containing antiepileptic drugs

Epilepsy is one of the most common neurological diseases worldwide and requires treatment with antiepileptic drugs for many years or for life. This fact leads to the need for constant production and use of these compounds, placing them among the four pharmaceutical classes most found in wastewater. Even at low concentrations, antiepileptics pose risks to human and environmental health and are considered organic contaminants of emerging concern. Conventional treatments have shown low removal of these drugs, requiring advanced and innovative approaches. In this context, this review covers the results and perspectives on (1) consumption and occurrence of antiepileptics in water, (2) toxicological effects in aquatic ecosystems, (3) enzymatic and advanced oxidation processes for degrading antiepileptics drugs from a molecular point of view (biochemical and chemical phenomena), (4) improvements in treatment efficiency by hybridization, and (5) technical aspects of the enzymatic-AOP reactors.

Bioconcentration of pharmaceuticals in benthic marine organisms (Holothuria tubulosa, Anemonia sulcata and Actinia equina) exposed to environmental contamination by atenolol and carbamazepine

The present work assess the bioconcentration kinetics of atenolol (ATN) and carbamazepine (CBZ) in common marine organisms including Holothuria tubulosa, Anemonia sulcata and Actinia equina under controlled laboratory conditions. CBZ exhibited higher uptake and excretion rates resulting higher bioconcentration factor (BCF) (41-537L/kg for CBZ vs 7-50L/kg for ATN) although both are below the limits established by the European Union (EU). The measured BCF using kinetic data showed some differences with those predicted using the concentrations measured at the steady-state, probably explained because the steady state was not ready reached. The animal-specific BCF followed the order of Holothuria tubulosa >Actinia equina >Anemonia sulcata for ATN while was the opposite for CBZ. The study highlighted between-tissues differences in the digestive tract and the body wall of the Holothuria tubulosa. The work presented is the first to model bioconcentration of ATN and CBZ in holothurian and anemone animal models.

Updated knowledge, partitioning and ecological risk of pharmaceuticals and personal care products in global aquatic environments

Over the last few decades, the occurrence of pharmaceuticals and personal care products (PPCPs) in aquatic environments has generated increasing public concern. In this review, data on the presence of PPCPs in environmental compartments from the past few years (2014-2022) are summarized by carrying out a critical survey of the partitioning among water, sediment, and aquatic organisms. From the available articles on PPCP occurrence in the environment, in Web of Science and Scopus databases, 185 articles were evaluated. Diclofenac, carbamazepine, caffeine, ibuprofen, ciprofloxacin, and sulfamethoxazole were reported to occur in 85% of the studies in at least one of the mentioned matrices. Risk assessment showed a moderate to high environmental risk for these compounds worldwide. Moreover, bioconcentration factors showed that sulfamethoxazole and trimethoprim can bioaccumulate in aquatic organisms, while ciprofloxacin and triclosan present bioaccumulation potential. Regarding spatial distribution, the Asian and European continents presented most studies on the occurrence and effects of PPCPs on the environment, while Africa and Asia are the most contaminated continents. In addition, the impact of COVID-19 on environmental contamination by PPCPs is discussed.

Literature Review: Evaluation of Drug Removal Techniques in Municipal and Hospital Wastewater

There are several techniques for the removal of pharmaceuticals (drugs) from wastewater; however, strengths and weaknesses have been observed in their elimination processes that limit their applicability. Therefore, we aimed to evaluate the best techniques for the removal of pharmaceuticals from municipal and hospital wastewater. For this, a non-experimental, descriptive, qualitative-quantitative design was used, corresponding to a systematic review without meta-analysis. Based on established inclusion and exclusion criteria, 31 open-access articles were selected from the Scopus, ProQuest, EBSCOhost, and ScienceDirect databases. The results showed that high concentrations of analgesics such as naproxen (1.37 mg/L) and antibiotics such as norfloxacin (0.561 mg/L) are frequently found in wastewater and that techniques such as reverse osmosis, ozonation, and activated sludge have the best removal efficiency, achieving values of 99%. It was concluded that reverse osmosis is one of the most efficient techniques for eliminating ofloxacin, sulfamethoxazole, carbamazepine, and diclofenac from municipal wastewater, with removal rates ranging from 96 to 99.9%, while for hospital wastewater the activated sludge technique proved to be efficient, eliminating analgesics and antibiotics in the range of 41-99%.

Endocrine-disrupting potential and toxicological effect of para-phenylphenol on Daphnia magna

Several phenol derivatives are suspected endocrine disruptors and have received attention in risk assessment studies for several decades owing to the structural similarity between estrogens and phenolic compounds. We assessed the endocrine disrupting effect of the phenolic compound para-phenylphenol (PPP) through acute tests and evaluating chronic endpoints in an invertebrate model, Daphnia magna. Exposure of D. magna to PPP induced substantial adverse effects, namely, reduced fecundity, slowed growth rate, delayed first brood, and a reduction in neonate size. Furthermore, we investigated the mRNA expression of relevant genes to elucidate the mechanism of endocrine disruption by PPP. Exposure of D. magna to PPP induced the substantial downregulation of genes and markers related to reproduction and development, such as EcR-A, EcR-B, Jhe, and Vtg. Consequently, we demonstrated that PPP has an endocrine disrupting effect on reproduction and development in D. magna.

Chronic toxicity of diclofenac, carbamazepine and their mixture to Daphnia magna: a comparative two-generational study

The chronic toxicity of diclofenac (DCF) and carbamazepine (CBZ) as separate substances and in conjunction with their mixture on Daphnia magna was assessed in the parental (F0) and first filial (F1) generations. The second (F1-B2) and fifth (F1-B5) broods of F1 offspring were investigated and compared. Both drugs and their mixture were exposed to each generation of Daphnia magna for 21 days with life history, behavioural and gene expressions as measured endpoints. After the parental exposure, offspring from these two broods were transferred to a clean medium for a 21-day recovery. Exposure to diclofenac, carbamazepine and their mixture significantly inhibited growth, reproduction, swimming activities, heart rate, thoracic limb activities, reproductive and antioxidant-related genes in the parental as well as the first filial generations. These effects were relatively greater in the F1 generation. This indicates that Daphnia magna's sensitivity improved while its fitness declined over the two generations, which is an indicator of greater energy requirements for maintenance. Besides, the significant inhibition in the antioxidant-related genes implies that oxidative stress occurred in Daphnia magna under the exposure to these drugs. The significant reduction in the reproductive output, moulting frequency and cyp314 gene expression as a result of exposure to CBZ simultaneously obtained herein may indicate that this drug could act as an endocrine disruptor. Most of these significant effects were not recoverable after the 21-day recovery period. The findings reported herein highlight the necessity to include maternal effects in environmental risk assessment processes, considering that pollutant effects are underestimated during single-generational exposure.

A multi-biomarker approach for the early assessment of the toxicity of hospital wastewater using the freshwater organism Daphnia magna

Hospital wastewater (HWW) contains different hazardous substances resulting from a combination of medical and non-medical activities of hospitals, including pharmaceutical residues. These substances may represent a threat to the aquatic environment if they do not follow specific treatment processes. Therefore, we aimed to investigate the effects of the untreated effluent collected from a general hospital in Mahdia City (Tunisia) on neonatal stages of the freshwater crustacean Daphnia magna. Test organisms were exposed to three proportions (3.12%, 6.25%, and 12.5% v/v) of HWW. After 48 h of exposure, a battery of biomarkers was measured, including the quantification of antioxidant enzymes [catalase (CAT) and total and selenium-dependent glutathione peroxidase (total GPx; Se-GPx)], phase II biotransformation isoenzymes glutathione-S-transferases (GSTs), cyclooxygenases (COX) involved in the regulation of the inflammatory process, and total cholinesterases (ChEs) activities. Lipid peroxidation (LPO) was measured to estimate oxidative damage. The here-obtained results showed significant decreases of CAT and GSTs activities and also on LPO content in daphnids, whereas Se-GPx activity was significantly increased in a dose-dependent manner. Impairment of cholinesterasic and COX activities were also observed, with a significant decrease of ChEs and an increase of COX enzymatic activities. Considering these findings, HWW was capable of inducing an imbalance of the antioxidant defense system, but without resulting in oxidative damage in test organisms, suggesting that peroxidases and alternative detoxifying pathways were able to prevent the oxidant potential of several drugs, which were found in the tested effluents. In general, this study demonstrated the toxicity of hospital effluents, measured in terms of the potential impairment of key pathways, namely neurotransmission, antioxidant defense, and inflammatory homeostasis of crustaceans.

Effects of carbamazepine in aquatic biota

Carbamazepine (CBZ) is one of the most common pharmaceuticals found in the aquatic environment. Here, we reviewed studies in aquatic animals highlighting that CBZ affected ROS homeostasis but also the neuroendocrine system, cell viability, immunity, reproduction, feeding behavior and growth. Notably, the acetylcholinesterase activity was modified by concentrations of the order of ng L^-1 CBZ. At ≥10 μg L^-1, data pointed that CBZ triggered the production of ROS, modifying the activity of antioxidant enzymes and produced a significant cellular stress at concentrations ≥100 μg L^-1. However, the response appeared species-, organ- and time-dependent, and was impacted by different experimental conditions and the origin of animals. In this context, this review discusses the available data and proposes future research priorities.

Occurrence, source apportionment and potential risks of selected PPCPs in groundwater used as a source of drinking water from key urban-rural settings of Pakistan

BACKGROUND

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants that have been extensively used in present time to improve the living standards. Their persistence in water resources due to various anthropogenic sources such as wastewater treatment plants, pharmaceutical industries, and runoff from agricultural and livestock farms has not only threaten aquatic life but their occurrence in groundwater has also raised concerns related to humans' wellbeing.

METHODS

Considering this as a neglected area of research in Pakistan, a systematic monitoring study was designed to investigate their occurrence, sources, and potential environmental and human health risks in groundwater from urban-rural areas of six cities. Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS) was used to analyze the collected samples preceded by solid-phase extraction.

RESULTS

Overall, 8 out of 11 selected PPCPs were detected in groundwater samples with detection frequency ranging from 5.5-65%. Their concentrations ranged from below limit of detection (<LOD) to 1961 ng/L. The overall mean concentrations of detected PPCPs were found below 100 ng/L. The highest mean concentration was reported for Ibuprofen (154 ng/L) in Rawalpindi/Islamabad. Results of PCA-MLR revealed that domestic wastewater discharge (76.4%) was the dominant source contributing to PPCPs contamination in groundwater. Followed by mixed source (pharmaceutical & hospital waste) 17.8%, and rural discharge/animal husbandry 5.8%. No appreciable risk to human health upon exposure to detected PPCPs via drinking water was anticipated. However, environmental risk assessment indicated moderate risk posed to P. subcapitata (RQ = 0.98) and D. magna (RQ = 0.2) by ibuprofen.

CONCLUSION

The current study reports the first evidence of PPCPs occurrence in groundwater in Pakistan. Reporting their occurrence in groundwater is a fundamental initial step to inform public-health decisions concerning sewage systems and drinking water quality. Hence, comprehensive monitoring programs are required to further investigate contamination of emerging contaminants in groundwater and their associated risks.

Insights into the wavelength-dependent photolysis of chlorite: Elimination of carbamazepine and formation of chlorate

Simultaneous removal of chlorite (ClO₂^-) and organic micro-pollutants (OMPs) by the irradiation of UV is a novel process. In this study we used UV light emitting diode (UV-LED) as a new UV source to systematically investigate the effect of UV wavelength (255, 285, 365 nm) on the simultaneous removal of carbamazepine (CBZ) and ClO₂^-. Removal of both CBZ and ClO₂^- followed the order of 255, 285, and 365 nm. Formation of hydroxyl radical and reactive chlorine species (RCS) were confirmed during the photolysis of ClO₂^- using probe compounds. RCS were always the predominant contributor to the degradation of CBZ in UV-LED/ClO₂^- system. The impacts of ClO₂^- dosage, pH, bicarbonate/carbonate (HCO₃^-/CO₃^2-), and the effect of natural organic matter (NOM) on CBZ degradation were also evaluated. This study identified the products produced by CBZ through possible degradation pathways during the transformation process. Further, the amount of ClO₂^- may affect the amount of chlorate produced in UV/ClO₂^- system. Overall, our research provides an in-depth analysis of the effects of UV wavelength on the simultaneous removal of ClO₂^- and OMPs in water.

Carbamazepine degradation by visible-light-driven photocatalyst Ag3PO4/GO: Mechanism and pathway

Carbamazepine (CBZ), as one of the most frequently detected pharmaceuticals, is of great concern due to its potential impact on the ecosystem and human health. This study provides an effective approach to remove CBZ by using photocatalyst silver phosphate combined with graphene oxide (Ag3PO4/GO) under visible irradiation. The morphology, composition, and optical properties of Ag3PO4/GO were characterized employing SEM, XRD, and DRS. Graphene oxide could improve the visible-light utilization and promote electron's charge to enhance the photocatalytic performance of Ag3PO4/GO. With the optimal reaction condition of 5.86 mW/cm2 light intensity, 15-25 °C temperature, 5-7 pH, and 0.5 mg/L catalytic dosages, 5 mg/L CBZ could be completely degraded in 30 min, and the apparent rate constant could reach 0.12 min-1. Additionally, the radical trapping experiments indicated •OH and O2-• were the main reactive oxygen species employed to eliminate CBZ. The decay pathways of CBZ had been proposed accordingly, and the main product was the low-molecular products.

Human health risk assessment of selected pharmaceuticals in the five major river basins, China

Pharmaceuticals in aquatic environment have raised wide attention in recent years due to their potential adverse effects and bioaccumulation in biota. China has been a major producer and consumer of pharmaceuticals, however, the potential human health risk of these chemicals is yet to be determined in China. In this study, we evaluated available exposure data for twenty pharmaceuticals in surface waters from Chinese five major river basins (the Yangtze, Haihe, Pearl, Songliao, and Yellow River Basins), and human health risk assessment was performed. Based on the concentration data and risk data, we conducted research on the source, cause, and control measures of the pharmaceuticals. The twenty pharmaceuticals were found to be ubiquitous in China with median concentrations between 0.09 and 304 ng/L. The estimated daily intake of pharmaceuticals from drinking water and eating fish was calculated. The intake via drinking water was significantly lower than that via eating fish. The risk quotients via water intake and fish consumption ranged from 0 to 17.2, with estrogen and sulfapyridine highest among the twenty pharmaceuticals. High risks of exposure were mainly in North China, including the Haihe and Songliao River Basins. This is the first analysis in Chinese major river basins that has filled the gaps in the research on the human health risks of pharmaceuticals. The results of the study provide basic information of pharmaceutical intake from drinking water and eating fish in China and provide insights into the risk management guidance of pharmaceuticals, and will facilitate the optimization of health advisories and policy making.

Role of benzophenone-3 additive in chronic toxicity of polyethylene microplastic fragments to Daphnia magna

Plastic additives may accelerate adverse effects of microplastics (MPs). This study aimed to identify the role of benzophenone-3 (BP-3) additive (10.82 ± 1.20% w/w) in chronic toxicity of polyethylene MP fragments to Daphnia magna (D. magna). MP fragments with and without BP-3 (48.37 ± 6.26 and 44.39 ± 11.16 μm, respectively) were synthesized and 4 d-old D. magna were exposed for 17 d. Daphnids exposed to MP/BP-3 fragments (98%) showed higher survival than those exposed to MP fragments (62%), which can be explained by a significantly low (p < 0.0001) bioconcentration of MP/BP-3 fragments. BP-3 leachate induced significantly low (p < 0.05) phototactic behavior of D. magna, likely leading to the low bioconcentration of MP/BP-3 fragments. Unlike MP fragments, both MP/BP-3 fragments and BP-3 additive inhibited embryonic development and offspring growth in a similar manner. Additionally, only BP-3 additive significantly induced (p < 0.05) higher lipid peroxidation in D. magna. This study suggests the critical role of plastic additives in MPs chronic toxicity to aquatic organisms, which should be further identified for other environmentally relevant plastic additives.

Pharmaceutical Products and Pesticides Toxicity Associated with Microplastics (Polyvinyl Chloride) in Artemia salina

Pharmaceutical products, as well as insecticides and antimicrobials, have been extensively studied, but knowledge of their effects-especially those caused by their mixtures with microplastics-on aquatic organisms remains limited. However, it should be borne in mind that the state of knowledge on acute and chronic effects in aquatic organisms for pharmaceuticals and pesticides is not similar. In response, this investigation analyzed the presence of microplastics (polyvinyl chloride) and their impacts on the toxicity of chlorpyrifos (an insecticide) and triclosan (an antibacterial) when they coincide in the environment, alongside the two most consumed drugs of their type (hypolipemic and anticonvulsant, respectively), namely simvastatin and carbamazepine, in Artemia salina. LC₅₀ and cholinesterase enzyme activity were calculated to determine the possible neurotoxicity associated with emergent contaminants in the treatments. The LC₅₀ values obtained were 0.006 mg/dm³ for chlorpyrifos, 0.012 mg/dm³ for chlorpyrifos associated with microplastics, 4.979 mg/dm³ for triclosan, 4.957 mg/dm³ for triclosan associated with microplastics, 9.35 mg/dm³ for simvastatin, 10.29 mg/dm³ for simvastatin associated with microplastics, 43.25 mg/dm³ for carbamazepine and 46.50 mg/dm³ for carbamazepine associated with microplastics in acute exposure. These results indicate that the presence of microplastics in the medium reduces toxicity, considering the LC₅₀ values. However, exposure to chlorpyrifos and carbamazepine, both alone and associated with microplastics, showed a decline in cholinesterase activity, confirming their neurotoxic effect. Nevertheless, no significant differences were observed with the biomarker cholinesterase between the toxicant and the toxicant with microplastics.

A green solar photo-Fenton process for the degradation of carbamazepine using natural pyrite and organic acid with in-situ generated H2O2

Pyrite is widely used in Fenton reaction for degradation of pollutants and exhibits great potential for environmental remediation, however, its efficiency is greatly compromised by extra H₂O₂ and pH adjustment. Herein, a pyrite based green solar photo-Fenton system for carbamazepine (CBZ) treatment is constructed, involving the use of simulated sunlight and natural organic acids with in situ-generated H₂O₂ and without extra pH adjustment. The addition of organic acids including tartaric acid (TA), citric acid (CA), and ascorbic acid (AA) can form complex with iron in pyrite, which promotes the Fe(II) dissolution. Upon irradiation, pyrite could be excited to produce photoelectrons, which would reduce oxygen to produce H₂O₂ through a two-step route assisted by organic acids. The simulated sunlight and organic acids promoted the in-situ production of H₂O₂ and Fe(II) species, sustaining an efficient Fenton reaction. This produced massive hydroxyl radical (OH), as demonstrated by the active species capture experiment. Compared with no degradation of CBZ under pure pyrite, the degradation efficiency of CBZ reached to 70%, 60%, and 53% in pyrite/TA, pyrite/CA, pyrite/AA within 30 min under simulated solar light irradiation, respectively. This work reports the first use of natural pyrite, a typical Fe-mineral semiconductor, to produce OH for CBZ degradation through natural additive assisted Fenton reaction excluding the adding extra H₂O₂ and pH adjustment.

Bioaccessibility evaluation of pharmaceuticals in market fish with in vitro simulated digestion

The consumption of pharmaceuticals-contaminated aquatic products could pose risks to human health, and risk assessments considering bioaccessibility can provide better dietary recommendations. In this study, the bioaccessibility of 6 pharmaceuticals (sulfadiazine (SD), sulfapyridine (SPD), roxithromycin (ROX), tylosin (TYL), diclofenac (DIC) and carbamazepine (CMZP)) in several fish species collected from Shanghai markets was evaluated using in vitro simulated digestion. The total mixed pharmaceuticals concentration in freshwater fish were lower than those in marine fish, and statistics showed that the total concentrations of SD, SPD and CMZP in freshwater fish were significantly lower than those of marine fish (p < 0.05). The bioaccessible concentration of each pharmaceutical accounted for 26.3% (TYL) to 101.5% (CMZP) of the total concentration in market fish (n = 70). The bioaccessibility of 6 pharmaceuticals in species of fish was 18.8% (cutlassfish) to 99.6% (bream), which may be related to the physical-chemical properties of the pharmaceutical and the characteristics of the matrix (e.g. lipid content). According to health risk assessments, the consumption of market fish in Shanghai posed no remarkable risk to human health (hazard quotient < 0.099). Ignoring the bioaccessibility of pharmaceuticals in aquatic products might overestimate the human health risks by dietary exposure.

Behavioral and physiological responses of Daphnia magna to salicylic acid

Salicylic acid (SA), a metabolite of acetylsalicylic acid is a monohydroxybenzoic acid a common non-steroidal analgesic and anti-inflammatory drug (NSAID) frequently detected in various aquatic ecosystems at concentrations up to 19.50 μg L^-1 in surface waters near livestock farms and 59.6 μg L^-1 in wastewaters. Little is known on the effects of short-term exposure of freshwater crustaceans to salicylic acid. Therefore, the aim of our study was to determine the effects of SA at concentrations of 5 μg L^-1, 500 μg L^-1, 5 mg L^-1, 50 mg L^-1 and 500 mg L^-1 on the behavior (swimming speed, swimming height, distance travelled) and physiological endpoints (heart rate, mandible movement) of Daphnia magna exposed for 24 h, 48 h and 72 h. The results showed that SA inhibited the swimming speed, swimming height and distance travelled, heart rate and mandible movement at 5 mg L^-1, 50 mg L^-1 and 500 mg L^-1 when compared to the control. On the other hand, SA at 5 μg L^-1 and 500 μg L^-1 transiently increased swimming speed and distance travelled after 24 h of the exposure, except for swimming height. Behavioral and physiological disturbances were observed much earlier than lethality. Our study showed SA at environmental levels may be an ecotoxicological agent imparing behavior and physiology of freshwater crustaceans.

Toxicological outcome of exposure to psychoactive drugs carbamazepine and diazepam on non-target insect Nauphoeta cinerea

The continuous detection of human pharmaceuticals during environmental biomonitoring is a global concern because of the menaces they may exert on non-target organisms. Carbamazepine (CBZ) and diazepam (DZP) are commonly prescribed psychotropic drugs which have been reported to coexist in the environment globally. Nauphoeta cinerea is a common insect with high ecological impact. This study elucidated the influence of co-exposure to DZP (0.5 and 1.0 μg kg^-1 diet) and CBZ (1.5 and 3.0 μg kg^-1 diet) for 42 days on the behavior and biochemical responses in Nauphoeta cinerea. Results showed that DZP alone did not induce adverse effect on the behavior and antioxidant status in the exposed insects. However, exposure to CBZ alone and binary mixtures of DZP and CBZ significantly decreased locomotor and exploratory accomplishments evidenced by decreased mobile episodes, total mobile time, maximum speed, total distance traveled, absolute turn angle, body rotation and path efficiency in comparison with control. The decline observed in the exploratory activities of insects fed with CBZ alone and the mixtures was confirmed by track plots and heat maps. Further, acetylcholinesterase and antioxidant enzyme activities decreased significantly whereas reactive oxygen and nitrogen species, nitric oxide and lipid peroxidation levels increased significantly in the hemolymph, head and midgut of insects exposed to CBZ alone and the mixtures. Collectively, CBZ alone and binary mixtures of CBZ and DZP caused neurotoxicity via induction of inflammatory and oxidative stress in insects. Nauphoeta cinerea may be a potential non-target insect model for monitoring ecotoxicological hazard of pharmaceuticals.

Carbamazepine exposure in the sea anemones Anemonia sulcata and Actinia equina: Metabolite identification and physiological responses

Pharmaceuticals and other emerging contaminants (EC) have been increasingly detected and measured in coastal waters and large effort has been devoted to knowing the effects these substances have in coastal ecosystems. Anthozoa class is underrepresented in ecotoxicology studies despite some of their species being endangered. Anemonia sulcata and Actinia equina are species widely distributed in the Mediterranean Sea. The objectives of this work have been to evaluate the ability of these species to accumulate carbamazepine (CBZ) from water, to determine the effects of this pharmaceutical on some physiological and biochemical endpoints and to characterize the degradation routes followed by this compound in Anthozoa tissues (biotransformation) and water. Sea anemones were exposed to 1 μg L^-1 and 100 μg L^-1 of CBZ in artificial sea water in a semi-static system for 8 days. At several times small portions of the tentacles and whole organisms were taken. Ion transport (measured as NKATPase activity), energetic metabolism (measured as glucose and lactate levels) and nitrogen excretion (measured as ammonia concentration in tissues) were determined. CBZ-exposed individuals of A. sulcata and A. equina were analyzed by ultra-high-performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS) on a quadrupole-time-of-flight (QqTOF). The structures of nine metabolites have been tentatively identified using HRMS and HRMS/MS data with the aid of the free available Medline database. The current work constitutes the first study on the identification of Cnidarian metabolites of CBZ in species of the Anthozoa class.

Chronic exposure of Brown (Hydra oligactis) and green Hydra (Hydra viridissima) to environmentally relevant concentrations of pharmaceuticals

Low concentrations of pharmaceuticals in the environment (ng/L to μg/L) are an environmental concern. We used the invertebrates, Hydra oligactis and Hydra viridissima, as freshwater models for primary toxicity testing to study effects of chronic low concentrations of pharmaceuticals in the environment. H. oligactis were exposed to three concentrations (0.1, 1.0 and 10 μg/L) of either fluoxetine, carbamazepine, or triclosan; H. viridissima were exposed to three concentrations (0.1, 1.0 and 10 μg/L) of triclosan. Ecologically relevant endpoints including morphology, budding rate, feeding behaviour, and regenerative capacity were examined during the 14 days exposure period. The interstitial:epithelial stem cell ratios was also examined in H. oligactis. There were no significant effects on the morphology, budding rate and feeding behaviour of the H. oligactis across all concentrations of fluoxetine, carbamazepine, and triclosan. However, regenerative capacity significantly decreased in comparison to the controls when H. oligactis was exposed to 10 μg/L of triclosan and fluoxetine, although there was no significant difference when exposed to carbamazepine. Neither fluoxetine nor carbamazepine treatment altered stem cell ratios. Exposure to triclosan at any concentration did not impact H. viridissima morphology, budding rate, regeneration or feeding behaviour. These results show there are limited effects in Hydra after exposure to chronic, low concentrations of fluoxetine, carbamazepine, and triclosan, except for regeneration in H. oligactis. These endpoints can be used effectively (and cost effectively) to study the effects of environmentally relevant concentrations of pharmaceuticals in Hydra species.

Tunable Synthesis of Ultrathin BiOCl 2D Nanosheets for Efficient Photocatalytic Degradation of Carbamazepine upon Visible-Light Irradiation

A series of ultrathin BiOCl 2D nanosheet photocatalysts were prepared by the TBAOH-assisted hydrolysis method in water. The effects of tetrabutylammonium hydroxide (TBAOH) dosages, chlorine source, preparation pH value, ultrasonic treatment, and magnetic stirring on the photocatalytic degradation dynamics of carbamazepine were examined under visible-light irradiation to optimize the preparation parameters. It was found that ultrathin BiOCl prepared with TBAOH dosages of 1 mmol and chlorine source of NaCl in the pH of 2 upon magnetic stirring of 6 h displayed the highest photocatalytic degradation rate constant (0.0038 min−1) of carbamazepine, which is 7.6 times higher than that with the ordinary BiOCl (without TBAOH). To clarify the mechanism on the outstanding photocatalytic activity of ultrathin BiOCl, the elemental composition/state, micromorphology, and separation efficiency of photogenerated electron-hole pairs were investigated by X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and photoluminescence (PL). Results showed that the presence of oxygen vacancy, ultrathin nanosheet structure, and improved separation efficiency of photogenerated electron-hole pairs contributed to the excellent photocatalytic degradation activity of ultrathin BiOCl. The obtained result provides a novel method to fabricate ultrathin BiOCl with excellent photocatalytic degradation activity of carbamazepine under visible-light irradiation.

Improving ozonation to remove carbamazepine through ozone-assisted catalysis using different NiO concentrations

The carbamazepine (CBZ) abatement is herein evaluated using catalytic ozonation at different NiO concentrations as catalyst: 100, 300, and 500 mg L^-1, revealing its total destruction after 5 min of reaction either by conventional or catalytic ozonation. The NiO incorporation in the reactor does not increase the destruction rate, but the catalyst presence enhances the partial mineralization of the contaminant by conversion into oxalic and formic acids and the removal of total organic carbon (TOC) associated with the formation of oxidant species such as hydroxyl radical. Evidence for this behavior is the accumulation rate of the above acids which rise proportionally to the NiO concentration. The highest NiO concentration (500 mg L^-1) reached a maximum TOC removal of 79.2%, which exceeds by 50% the outcome of the conventional treatment. The accumulation-decomposition profiles of oxalic and formic acids suggest the occurrence of simultaneous reaction mechanisms (hydroxyl radicals and complex formations) on the catalyst during CBZ ozonation. According to XPS analysis, the presence of nitrogen species in the NiO-ozonated was attributable to byproducts of CBZ decomposition. The toxicity bioassay based on Lactuca sativa seeds demonstrate that ozonated samples attained similar plant germination than the reference substance (water) after 120 min of treatment. This result is comparable with or without the catalyst presence, indicating the formation of non-toxic accumulated byproducts at the end of the ozonation reaction.

Inhibition effects of isoproterenol, chlorpromazine, carbamazepine, tamoxifen drugs on glutathione S-transferase, cholinesterases enzymes and molecular docking studies

Nowadays, inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and glutathione S-transferases (GSTs) have been a very crucial issue for pharmacological treatments of several disasters. Herein, we investigated inhibition effects of Tamoxifen (TAM), Isoprenaline (ISO), Chlorpromazines (CPZ) and Carbamazepine (CBZ) on GST, AChE, BChE and then molecular structures and active sides of the tested drugs by molecular docking process. The enzyme activity results showed that nearly the whole tested drugs inhibited GST, BChE, AChE efficiently. Chlorpromazine was found to be the best inhibitor for the GST enzyme and the Ki value of this drug was found to be 42.83 ± 8.52 nM. Besides, Isoproterenol drug with the Ki value of 51.80 ± 9.44 nM was found to be the most effective inhibitor on the AChE enzyme. Molecular docking studies showed that the receptor-binding sites of GST, AChE, and BChE were found to 1.069, 1.090, and 1.15 of Sitecore and 0.992, 1.113, and 1.217 of Dscore, respectively. The method was validated by doing validation studies and these validations revealed that re-docked ligands located a very closed position with co-crystallized ligand into the active site for all receptors. Calculation studies for determining the possible enzyme inhibition mechanism with the used drugs revealed that amino and aromatic ring in the structure of the drugs used are effective in inhibition reactions.Communicated by Ramaswamy H. Sarma.

Physical, chemical, and biological impact (hazard) of hospital wastewater on environment: presence of pharmaceuticals, pathogens, and antibiotic-resistance genes

Hospital wastewater contains various pharmaceuticals and pathogens. Improper management of the wastewater has caused the leakage of these harmful materials to the environment. The presence of pathogens, pharmaceuticals, and their derivatives such as antibiotic resistance genes as the most typical one in the environment leads to physical, chemical, and biological harmful impact. This chapter has reviewed the pharmaceuticals and pathogens in the hospital; discussed the development of antibiotic resistance genes; and revealed the possible impact of these harmful materials in microorganisms, organism, and human being. In addition, the measures that can be taken to prevent the transportation of pharmaceuticals and pathogens into environment have been stated in this chapter.

Chronic Toxicological Effects of Carbamazepine on Daphnia magna Straus: Effects on Reproduction Traits, Body Length, and Intrinsic Growth

In recent years, pharmaceuticals and personal care products (PPCPs) that remain in the environment have become increasingly important. Carbamazepine (CBZ) is a widely used antiepileptic drug that has a potential impact on the environment due to its Physico-chemical properties, which are rarely eliminated in conventional water treatment. Daphnia magna Straus (DMS) is a fundamental link of aquatic ecosystem chain. The influence of CBZ toxicity on DMS can effectively reflect the effects of CBZ toxicity on the aquatic environment. In this study, DMS was used as a subject to assess the chronic effects of CBZ exposure. It was found that after 21 days of CBZ exposure, the breeding frequency, the total number of eggs laid, body length, and intrinsic growth rate of DMS decreased with increasing CBZ concentrations. Maximum reductions of 69% in fecundity and 60% in fertility were observed at 0.5 mg/L CBZ, while a maximum reduction of 60% in body length was observed at 0.001 mg/L CBZ concentration. The integrated biomarker response version 2 (IBRv2) analysis suggests that with the increase in CBZ concentration, the overall negative effect of CBZ on DMS was enhanced.