Long-term ecotoxicological effects of ciprofloxacin in combination with caffeine on the microalga Raphidocelis subcapitata

Evaluation of contaminants of emerging concern in surface waters (rivers and lake) from Peru: Occurrence and environmental risk assessment

This study represents one of the first efforts to investigate the presence and environmental risk of contaminants of emerging concern (CECs) in surface water of the main watersheds of the Department of Lima (Rímac River, Chillón River, and Lurin River), Department of Arequipa (Chili-Quilca-Vítor River, Cámana-Majes River, and Tambo River), and Department of Puno (Lake Titicaca) from Peru. Water samples were collected during two sampling campaigns (June and September-October 2023) in Lima and Arequipa, and one sampling campaign (April-May 2023) in Puno. A strategy combining qualitative and quantitative analysis of CECs was applied, based on liquid chromatography coupled to ion mobility-high resolution mass spectrometry (LC-IMS-HRMS) and tandem mass spectrometry (LC-MS/MS), respectively. A total of 16 pharmaceutically active compounds (PhACs) and other compounds (sweeteners, stimulants, UV filters, and preservatives) and 16 metabolites were identified by LC-IMS-HRMS with a high level of confidence, in addition to the 39 target PhACs quantified by LC-MS/MS. The watersheds of Lima showed the highest pollution in terms of the number of pharmaceuticals and concentration levels compared to the watersheds of Arequipa and Lake Titicaca (Puno), with antibiotics persisting from the upper watersheds to the lower watersheds in the rivers and the lake. For the environmental risk assessment, five different scenarios were considered depending on the water uses/destinations, and the multicriteria scoring method allowed to identification of relevant/concerning PhACs. Azithromycin, clarithromycin, erythromycin, ciprofloxacin, flumequine, trimethoprim, diclofenac, acetaminophen, losartan, valsartan, atorvastatin and metabolite O-desmethyl venlafaxine posed a high level of risk/concern. This information will facilitate the design of a Watch List for CECs, with future monitoring programs and environment risk assessments to protect vulnerable areas most affected by anthropogenic pollution.

Individual and mixture effect of selected high-hazard pharmaceuticals on aquatic primary producers

The extensive use of pharmaceuticals has led to their occurrence in surface waters due to insufficient treatment processes for their removal. Their environmental impact remains largely unexplored for certain trophic levels, particularly plants and algae. Pharmaceuticals often occur in mixtures with other pollutants, highlighting the need for comprehensive toxicological assessments that evaluate their combined interactions. This study evaluated the acute toxicity of four high-hazard pharmaceuticals -diphenhydramine, fluoxetine, ketoprofen, and trimethoprim- and their binary mixtures, on the green microalgae Raphidocelis subcapitata and the aquatic macrophyte Lemna gibba. For individual compounds, R. subcapitata growth rate was inhibited in all cases, with fluoxetine, ketoprofen and diphenhydramine exhibiting moderate toxicity (EC50 = 0.34, 0.14, and 4.88 mg/L, respectively), while trimethoprim showed low toxicity (EC50 = 332.35 mg/L). Similar trends were observed in L. gibba, except for diphenhydramine, which also showed low toxicity (EC50 = 26.57 mg/L). Binary mixtures demonstrated a synergistic interaction towards the microalgae in the presence of ketoprofen, except ketoprofen-trimethoprim combination (antagonism, p < 0.0001). In contrast, most interactions in L. gibba exhibited antagonism, except ketoprofen-fluoxetine (synergism, p = 0.0042). Differences were observed between the two model organisms for individual compounds and mixtures. No correlation was found between L. gibba experimental data and QSAR predictions derived from R. subcapitata. Our results highlight the need for: i. further studies including mixtures of relevant pharmaceuticals; ii. caution in the use of predictive models or extrapolation between taxa; and iii. the inclusion of fluoxetine and ketoprofen as priority compounds in future risk assessments.

The Potential Role of Ecotoxicological Data in National Essential Medicine Lists: A Cross-Sectional Analysis

BACKGROUND

Medicines affect the environment throughout their lifecycle, from production and distribution to use and disposal. They contribute to the pollution of air, water, and soil, impacting ecosystems and human health. Recognizing these risks, regulatory bodies and organizations have highlighted pharmaceutical pollution as a global concern, emphasizing the need for environmental risk assessments and sustainable practices.

METHODS

This study reviewed the essential medicines lists (EMLs) from 158 countries and examined the available ecotoxicological data. Medicines with high bioaccumulation, persistence, and toxicity were identified and cross-referenced with their inclusion in EMLs. Additionally, we analyzed the presence of alternative medicines with similar therapeutic effects but potentially lower environmental risks.

RESULTS

Five medicines-ciprofloxacin, ethinylestradiol, levonorgestrel, ibuprofen, and sertraline-were selected as illustrative examples due to their high environmental persistence and toxicity. All were listed in the 2023 WHO model list, with ciprofloxacin appearing in 94.3% of national EMLs.

CONCLUSIONS

This study underscores the limited availability of ecotoxicological data, which hinders environmental risk assessment for medicines. EMLs could serve as a tool to enhance the awareness and data mobilization of pharmaceutical pollution. Incorporating environmental criteria into EMLs could support more sustainable medicine selection and regulatory practices.

Cashew gum-assisted synthesis of Zn0.98Nd0.02O photocatalyst: pH-dependent green approach and photocatalytic degradation of ciprofloxacin and ibuprofen pharmaceutical pollutants

The presence of pharmaceutical residues in aquatic environments represents a serious environmental problem, with negative impacts on ecosystems and public health. The removal of these contaminants from wastewater is a challenge that requires innovative and sustainable strategies. In this study, a green synthesis approach, assisted by cashew gum, was employed to synthesize the Zn0.98Nd0.02O photocatalysts at varying pH levels (5, 7, 9, 11, and 13) via the sol-gel method. The effects of synthesis pH on structural, optical, and photocatalytic properties were systematically investigated. The structural analysis revealed a hexagonal wurtzite structure, with crystallite sizes ranging from 69 nm (pH 5) to 235 nm (pH 9). Micrography images showed that pH significantly influenced morphology, with particles ranging from agglomerates to more dispersed spherical shapes. Porosity analysis indicated mesoporous structures with surface areas varying between 2.2 and 5.2 m2/g, depending on pH. Photoluminescence (PL) spectra highlighted the presence of oxygen-related defects, with emission peaks shifting due to structural disorder induced by doping and pH variation. Optical studies also indicated a tunable bandgap (3.284-3.218 eV) and Urbach energy (50.96-75.30 meV), signifying increased structural disorder at higher pH. Photocatalytic performance was evaluated against Ciprofloxacin (CIP) and Ibuprofen (IBU), achieving degradation efficiencies of 97.5 % (CIP at pH 7) and 74.1 % (IBU at pH 13) under UV light. Kinetic studies confirmed pseudo-first-order behavior with rate constants of 2.14 × 10-2 min-1 for CIP and 8.99 × 10-3 min-1 for IBU. Reactive species analysis identified hydroxyl radicals (•OH) as dominant contributors to pollutant degradation. Reusability tests demonstrated >96 % CIP removal over four cycles and consistent structural stability, validated via XRD. This study highlights the potential of the Zn0.98Nd0.02O photocatalysts synthesized under eco-friendly conditions for addressing pharmaceutical pollutants in wastewater treatment.

Recent Advances on Starch-Based Adsorbents for Heavy Metal and Emerging Pollutant Remediation

Starch is one of the most abundant polysaccharides in nature and has a high potential for application in several fields, including effluent treatment as an adsorbent. Starch has a unique structure, with zones of different crystallinity and a glycosidic structure containing hydroxyl groups. This configuration allows a wide range of interactions with pollutants of different degrees of hydrophilicity, which includes from hydrogen bonding to hydrophobic interactions. This review article aims to survey the use of starch in the synthesis of diverse adsorbents, in forms from nanoparticles to blends, and evaluates their performance in terms of amount of pollutant adsorbed and removal efficiency. A critical analysis of the materials developed, and the results obtained is also presented. Finally, the review provides an outlook on how this polysaccharide can be used more effectively and efficiently in remediation efforts in the near future.

A review on emerging pharmaceutical residues in Ethiopia: occurrence, ecotoxicological aspects, and regulatory concerns

Background

Pharmaceuticals are expected to improve human and animal health, but improper management and regulation have led to adverse effects such as reproductive disorders, antibiotic resistance, and biodiversity loss in ecosystems. Their presence in the environment poses significant risks, including a reduction in biodiversity, reproductive issues, and the development of antimicrobial resistance. This review aims to examine the occurrence and sources of pharmaceuticals in the environment and their ecotoxicological and regulatory aspects, with a focus on Ethiopia.

Methods

A narrative review of relevant studies conducted in Ethiopia was undertaken. The review included findings on the occurrence, sources, contributing factors, ecotoxicological impacts, and regulatory concerns related to pharmaceutical residues in the environment. Literature was sourced from Google Scholar, Scopus, PubMed, and institutional repositories.

Result

The findings revealed the detection of pharmaceutical residues in wastewater treatment facilities, aquatic environments (e.g., lakes and rivers), and commercially available animal products. Aquatic samples also showed significant concentrations, with sulfamethoxazole and fluconazole detected at 0.15 μg/L and 0.012 μg/L, respectively. Antimicrobial resistance genes were identified in wastewater and treatment plant samples, which correlate with the presence of pharmaceutical residues. An ecological risk assessment based on the risk quotient (RQ) revealed ciprofloxacin as a major concern, with an RQ of 8.58, indicating high ecological risk. Sulfonamides exhibited moderate risk, with RQ values ranging from 0.1 to 1.

Conclusion

The study highlights the significant presence of pharmaceutical residues in the environment and underscores the inadequacy of regulatory enforcement in addressing this public health issue. Urgent measures are required to prevent environmental contamination and mitigate public health risks, including antimicrobial resistance. Strengthened regulatory measures and proactive interventions by relevant organizations are essential to control and prevent pharmaceutical residues in the environment, offering a critical solution for the country.

Pharmaceutical Removal with Photocatalytically Active Nanocomposite Membranes

The advancement of pharmaceutical science has resulted in the development of numerous tailor-made compounds, i.e., pharmaceuticals, tuned for specific drug targets. These compounds are often characterized by their low biodegradability and are commonly excreted to a certain extent unchanged from the human body. Due to their low biodegradability, these compounds represent a significant challenge to wastewater treatment plants. Often, these compounds end up in effluents in the environment. With the advancement of membrane technologies and advanced oxidation processes, photocatalysis in particular, a synergistic approach between the two was recognized and embraced. These hybrid advanced water treatment processes are the focus of this review, specifically the removal of pharmaceuticals from water using a combination of a photocatalyst and pressure membrane process, such as reverse osmosis or nanofiltration employing photocatalytic nanocomposite membranes.

A comprehensive review on the application of semiconducting materials in the degradation of effluents and water splitting

In this comprehensive review article, we delve into the critical intersection of environmental science and materials science. The introduction sets the stage by emphasizing the global water shortage crisis and the dire consequences of untreated effluents on ecosystems and human health. As we progress into the second section, we embark on an intricate exploration of piezoelectric and photocatalytic principles, illuminating their significance in wastewater treatment and sustainable energy production. The heart of our review is dedicated to a detailed analysis of the detrimental impacts of effluents on human health, underscoring the urgency of effective treatment methods. We dissected three key materials in the realm of piezo-photocatalysis: ZnO-based materials, BaTiO3-based materials, and bismuth-doped materials. Each material is scrutinized for its unique properties and applications in the removal of pollutants from wastewater, offering a comprehensive understanding of their potential to address this critical issue. Furthermore, our exploration extends to the realm of hydrogen production, where we discuss various types of hydrogen and the role of piezo-photocatalysis in generating clean and sustainable hydrogen. By illuminating the synergistic potential of these advanced materials and technologies, we pave the way for innovative solutions to the pressing challenges of water pollution and renewable energy production. This review article not only serves as a valuable resource for researchers and scholars in the fields of material science and environmental engineering but also underscores the pivotal role of interdisciplinary approaches in addressing complex global issues.

Degradation of the antibiotic ciprofloxacin in urine by electrochemical oxidation with a DSA anode

Ciprofloxacin (CIP) is a commonly prescribed fluoroquinolone antibiotic that, even after uptake, remains unmetabolized to a significant extent-over 70%. Unmetabolized CIP is excreted through both urine and feces. This persistent compound manages to evade removal in municipal wastewater facilities, leading to its substantial accumulation in aquatic environments. This accumulation raises concerns about potential risks to the health of various living organisms. Herein, we present a study on the remediation of CIP in synthetic urine by electrochemical oxidation in an undivided cell with a DSA (Ti/IrO2) anode and a stainless-steel cathode. Physisorbed hydroxyl radical formed at the anode surface from water discharge and free chlorine generated from Cl- oxidation were the main oxidizing agents. The effect of pH and current density (j) on CIP degradation was examined, and its total removal was easily achieved at pH ≥ 7.0 and j ≥ 60 mA cm-2 due to the action of free chlorine. The CIP decay always followed a pseudo-first-order kinetics. The components of the synthetic urine were also oxidized. The main nitrogenated species released was NH3. A very small concentration of free chlorine was quantified at the end of the treatment, thus demonstrating the good performance of electrochemical oxidation and its effectiveness to destroy all the organic pollutants. The present study demonstrates the simultaneous oxidation of the organic components of urine during CIP degradation, thus showing a unique perspective for its electrochemical oxidation that enhances the environmental remediation strategies.

Ecotoxicity of Caffeine as a Bio-Protective Component of Flax-Fiber-Reinforced Epoxy-Composite Building Material

Caffeine is a verified bio-protective substance in the fight against the biodegradation of cellulose materials, but its ecotoxicity in this context has not yet been studied. For this reason, the ecotoxicity of flax-fiber-reinforced epoxy composite with or without caffeine was tested in the present study. Prepared samples of the composite material were tested on freshwater green algal species (Hematococcus pluvialis), yeasts (Saccharomyces cerevisae), and crustacean species (Daphnia magna). Aqueous eluates were prepared from the studied material (with caffeine addition (12%) and without caffeine and pure flax fibers), which were subjected to chemical analysis for the residues of caffeine or metals. The results indicate the presence of caffeine up to 0.001 mg/L. The eluate of the studied material was fully toxic for daphnids and partially for algae and yeasts, but the presence of caffeine did not increase its toxicity statistically significantly, in all cases. The final negative biological effects were probably caused by the mix of heavy metal residues and organic substances based on epoxy resins released directly from the tested composite material.

Do microplastics influence the long-term effects of ciprofloxacin on the polychaete Hediste diversicolor? An integrated behavioral and biochemical approach

Ciprofloxacin (CPX), the most commonly used fluoroquinolone antibiotic, and microplastics (MPs) are two classes of emerging contaminants with severe adverse impacts on aquatic organisms. Previous studies suggest that both CPX and MPs induce deleterious changes in exposed aquatic biota, but the characterization of a chronic and combined ecotoxicological response is not well known, especially in organisms from estuarine ecosystems. Thus, in this study, we investigated the behavioral and biochemical effects of environmentally relevant levels of CPX alone and in combination with polyethylene terephthalate (PET) microplastics over 28 days of exposure, using the polychaete Hediste diversicolor as a model. In addition to behavioral parameters, different biochemical endpoints were also evaluated, namely the levels of metabolic enzymes of phase I (7-ethoxy-resorufin-O-deethylase, EROD), and phase II (glutathione-S-transferase, GSTs), antioxidant defense (catalase, CAT; glutathione peroxidase, GPx; superoxide dismutase, SOD), oxidative damage (lipid peroxidation, by means of levels of thiobarbituric acid reactive substances [TBARS]) and acetylcholinesterase (AChE). Chronic exposure to ciprofloxacin caused a decrease in burrowing time and a significant increase in SOD activity. In animals exposed to the combination of CPX and PET MPs, effects on behavioral traits were also observed, with higher concentrations of MPs leading to a marked delay in the animals' burrowing time. In addition, these animals showed changes in their antioxidant defenses, namely, a significant increase in SOD activity, while GPx activity was severely compromised. For none of the experimental groups, significant alterations were observed in the metabolic enzymes, TBARS or AChE. These findings provide the first insights into the responses of H. diversicolor when exposed to the combination of CPX and PET MPs, highlighting that, although the here studied conditions, there was no evidence of oxidative damage or neurotoxicity, these organisms are not risk-free in co-exposure scenarios, even at low environmental relevant concentrations.

Adsorption of recalcitrant contaminants of emerging concern onto activated carbon: A laboratory and pilot-scale study

According to the World Health Organization (WHO), the definition of water quality indicators, including contaminants of emerging concern (CECs), associated with the development of multi-barrier approaches for wastewater treatment, are crucial steps towards direct potable reuse of water. The aims of this study were 1) quantifying twelve CECs (including pharmaceutical, stimulant, and artificial sweetener compounds) in both untreated and treated wastewater samples in a Brazilian wastewater treatment plant (WWTP) using bidimensional liquid chromatography coupled with tandem mass spectrometry, allowing the selection of five marker (i.e., priority) CECs; 2) evaluating the adsorption potential of such selected CECs [caffeine, hydrochlorothiazide, saccharin, sucralose (SUC), and sulfamethoxazole (SMX)] onto coconut-shell granular activated carbon (GAC); and 3) investigating the removal of the same CECs by a multi-barrier system (pilot-scale, 350 L h^-1) treating the effluent of the WWTP and composed of reverse osmosis (RO), photoperoxidation (UV/H₂O₂), and filtration with GAC. Such technologies were tested separately and in binary or ternary combinations. Eleven and eight CECs were detected and quantified on the untreated and treated wastewater samples of the Brazilian WWTP, respectively. For the treated wastewater, the concentrations ranged from 499 ng L^-1 (SMX) to 87,831 ng L^-1 (SUC). The adsorption onto AC data fitted the Sips isotherm model, indicating monolayer chemisorption, which was also suggested by the mean adsorption energy values (>16 kJ mol^-1). SMX and SUC were the most and the least adsorbed CECs (4.33 and 1.21 mg g^-1, respectively). Concerning the pilot-scale treatment plant, the ternary combination (RO + UV/H₂O₂+GAC) removed >99% of the five marker CECs and promoted reductions on water color, turbidity, as well as on nitrogen and phosphorus concentrations. Further studies on water reuse could prioritize the selected marker CECs as quality indicators. While the removal of marker CECs is one of the WHO performance requirements, the RO + UV/H₂O₂+GAC system showed promising results as a first approach to direct potable reuse of water.

Growth and physiological responses in a submerged clonal aquatic plant and multiple-endpoint assessment under prolonged exposure to ciprofloxacin

Ciprofloxacin is ubiquitous and poses a potential threat to aquatic ecosystems. However, the comprehensive effect of prolonged ciprofloxacin exposure on the submerged clonal plant Vallisneria natans (Lour.) Hara remains unknown. Growth and physiological responses in V. natans exposed to ciprofloxacin at concentrations of 0, 0.05, 0.25, 1.25, 2.5, 5 and 10 mg/L were repeatedly evaluated on Days 7, 14, 28, 42 and 56. V. natans maintained good growth properties under 0.05-0.25 mg/L ciprofloxacin treatments, while the inhibition effect on plant growth induced by higher-concentration treatments increased over time. The IC50 values of ciprofloxacin for growth endpoints ranged from 1.6 mg/L to 5.3 mg/L and displayed time-dependent decreases. Pigment contents were significantly stimulated by ciprofloxacin on Day 7 but decreased to varying degrees as the exposure time was extended. Soluble protein and hydrogen peroxide content rose significantly over the first 14 days of treatment with 0.25-10 mg/L ciprofloxacin but decreased under 1.25-10 mg/L ciprofloxacin treatments since Day 28. Antioxidants including superoxide dismutase, catalase, guaiacol peroxidase, ascorbate peroxidase and proline functioned well in mitigating oxidative stress under different ciprofloxacin concentrations, lowering the comprehensive toxic effects of ciprofloxacin on V. natans during the period from Day 14 to Day 42, as evidenced by decreased IBR (integrated biomarker response) values. However, the toxic pressure of ciprofloxacin on V. natans peaked on Day 56. These findings suggest that exposure time can influence the responses of V. natans exposed to ciprofloxacin and that IBR can be employed to evaluate the integrated impacts of prolonged ciprofloxacin contamination in aquatic settings.