Residues, bioaccumulation, and trophic transfer of pharmaceuticals and personal care products in highly urbanized rivers affected by water diversion

Screening and risk assessment of priority organic micropollutants for control in reclaimed water in China

Organic micropollutants (OMPs) in reclaimed water have been frequently detected over the past decades, posing significant risks to ecosystems and human health. Given the complexity of these pollutants and the differences in their risk and toxicity, current assessments remain incomplete. This study conducted a large-scale investigation of OMPs in reclaimed water across China and developed a comprehensive multi-criteria integrated scoring method based on OMP toxicity and exposure potential. This method aims to protect aquatic organisms and human health by screening and prioritizing OMPs in reclaimed water, classifying their priority levels, and creating a prioritized control list. The study quantified OMP exposure potential, environmental persistence, bioaccumulation, and impacts on ecology and human health. The survey detected 369 OMPs from 11 chemical classes, with 325 compounds passing pre-selection. According to the prioritization scheme, 29 OMPs were identified as high priority, 171 as medium priority, and 125 as low priority. The BPs and Other Industrial Chemicals categories had the highest average maximum concentrations, followed by HPCCs and PAEs. High-priority pollutants were dominated by PAHs and PCBs, each comprising 31.03 %. Medium- and low-priority groups were mainly composed of Pesticides. PAHs and PCBs showed higher risk quotients, indicating significant ecological risks, while PCB 126, BaP, and PFOA exhibited high toxicity and potential health risks. This study provides valuable information for controlling priority pollutants in Chinese reclaimed water and establishes a foundation for OMP risk management. Future research should intensify monitoring to ensure the safe and sustainable use of water resources.

Exploring the mechanism of PPCPs on human metabolic diseases based on network toxicology and molecular docking

This research endeavor seeks to delve into the potential mechanisms by which pharmaceutical and personal care products (PPCPs), recognized as emerging pollutants, could contribute to the human metabolic disorders and then trigger metabolic diseases. Therefore, we have selected lipid and atherosclerosis, Alzheimer's disease, and type Ⅱ diabetes mellitus as representative metabolic diseases, aiming to systematically explore the critical molecular pathways that may be disrupted by PPCPs for the metabolic disease development. By employing advanced network toxicology and molecular docking techniques, we have successfully elucidated the molecular mechanisms that trigger the three diseases. We pinpointed the potential targets associated with the disease by leveraging databases including PubChem, ADEMTlab2.0, SwissADME, and GeneCards. We further employed STRING analysis and Cytoscape software to pinpoint the core targets that were most significantly associated with these metabolic diseases. In addition, enrichment analysis of these core targets was conducted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways within the David database. To obtain the structural aspects of the target proteins, we also employed AlphaFold 3 for protein structure prediction. Finally, we validated the binding affinity of PPCPs to these target proteins using molecular docking with AutoDock Vina. Our findings suggested that PPCPs could potentially trigger metabolic diseases by modulating the expression of microRNAs, influencing cellular apoptosis and proliferation, and affecting signal transduction pathways. Interestingly, we also found the correlations among lipid and atherosclerosis, Alzheimer's disease, and type Ⅱ diabetes mellitus. Taken together, our study provides innovative insights into both the mechanisms of how environmental pollutants trigger human diseases and revealing the correlations among different diseases, thereby laying a theoretical foundation for disease prevention and treatment.

2-Ethylhexyl-4-methoxycinnamate on marine and coastal environments: A comprehensive review of its environmental significance and biological impact

Marine and coastal environments are constantly subjected to increasing pressures associated with population growth, industrialization development, pollution and higher demand feeding society's consumerism. Among these pressures, there has been an increasing concern towards UV filters occurrence in aquatic ecosystems due to a greater use of personal care products (PCPs). 2-ethylhexyl-4-methoxycinnamate (EHMC) is one of the most used UV filters in sunscreen formulations, yet few reports address its effects in biota. This literature review intends to collect the available information concerning the environmental presence of EHMC in marine and coastal ecosystems and their effects in biota. The EHMC effects have been reported for the taxonomic groups: Actinomycetes, Alphaproteobacteria, Bacilli, Cytophagia, Flavobacteriia, Gammaproteobacteria, Actinopterygii, Anthozoa, Bacillariophyceae, Bivalvia, Branchiopoda, Coccolithophyceae, Echinoidea, Gastropoda, Malacostraca, Annelida and Thecostraca. The reported literature evaluated endpoints mainly related to development, viability, mortality, estrogenicity, gene transcription disruptions, biochemical alterations and morphophysiological changes. Based on the available information, there is still a clear need for further investigations related to EHMC and its toxicological effects on marine and coastal organisms.

A review of ultraviolet filters and their impact on aquatic environments

Numerous anthropogenic ultraviolet filters (UVF) have been detected in aquatic environments and concerns have arisen regarding their potential impacts on aquatic organisms. This manuscript reviews the environmental concentrations and potential toxicity of various UVF. The highest concentrations of UVF are typically observed near frequently visited recreational areas and during peak water-activity periods, which suggests that sunscreen application correlates with noticeable alterations in UVF concentrations. Aquatic concentrations of certain filters have sporadically exceeded 10 μg/L, although most measurements remain below 1 µg/L, which is below commonly reported toxicity levels. UVF have also been detected in aquatic organisms, typically ranging from nondetectable levels to a few hundred ng/g, depending on the species. The toxic effects from UVF, such as coral bleaching and diminished growth, have been observed in laboratory settings, however, toxicity tends to manifest only at significantly higher levels than what is typically detected in aquatic environments. Further research is imperative to provide consumers with improved guidance on selecting sunscreen containing UVF that poses the least environmental risk.

Mass load and source apportionment of pharmaceutical and personal care product in the Wuhan section of the Yangtze River, China

Given the limited research on pharmaceuticals and personal care products (PPCPs) in the Wuhan section of the Yangtze River (WYR), this work investigated the distribution of 15 PPCPs in this region, assessed their ecological risks and annual fluxes. It was further to analyze the levels of indicator sucralose in the WYR to understand the sources of PPCPs. The results showed the average concentrations were 143.9 ± 76.77 ng/L, 3.98 ± 3.89 ng/g, and 8.14 ± 18.91 ng/g for 15 PPCPs in surface water, sediment, and soil, respectively. Among those PPCPs, bisphenol-A was the dominant compound found across the three environmental media. Significant amounts of ibuprofen and caffeine were detected in surface water, which may be linked to the increased demand for these compounds during the COVID-19 pandemic. Besides, the concentrations of synthetic estrogens (bisphenol-A and 4-nonylphenol) were higher than those of natural estrogens (estrone, 17β-estradiol, and estriol). Due to runoff dilution, climatic factors (rainfall and sunlight), and prevalence of disease, PPCPs in water showed significant seasonal variation, with higher total concentrations in dry season than those in wet and normal seasons. Spatially, higher concentrations of PPCPs were found in the middle reaches of the WYR due to the population density.Our study estimated the annual flux of 15 PPCPs in the WYR to be 71.17 tons. Source analysis revealed that untreated domestic wastewater might be discharged into the WYR during the wet season. The ecological risk of PPCPs in the WYR were generally low, with only E2 and E3 categorized as posing moderate to high risks. These findings provided valuable support for the management and control of PPCPs in the WYR.

Biotransformation of carbamazepine and nicotine in juvenile American alligator (Alligator mississippiensis) in vitro hepatic S9 vs. in situ perfused liver

American alligators (Alligator mississippiensis) are apex predators and sentinel species in the coastal wetland ecosystem along the Gulf of Mexico. There is concern for alligator exposure and susceptibility to chemical contaminants due to their high trophic level and lower metabolic capability. At present, their hepatic biotransformation capacity to metabolize or detoxify contaminants has not been comprehensively determined. In this study, the hepatic biotransformation capability of juvenile American alligators to metabolize two commonly found environmental pharmaceuticals: carbamazepine (CBZ) or nicotine (NCT) was evaluated. The formation of their respective primary metabolites, i.e., carbamazepine-10,11-epoxide (CBZ-E) and cotinine (CTN), was evaluated at 10 μM (within the human therapeutic range). The in vitro S9 and a novel in situ liver perfusion assays were used to characterize and compare metabolic ability in isolated hepatic enzymes vs. whole organ (liver). For CBZ, the perfused livers exhibited only 30% of intrinsic formation clearance (CLf,int) relative to the S9 assay. The metabolism of NCT was not detectable in the S9 assay and was only observed in the perfused liver assay. Compared to the corresponding rat models (S9 or perfused livers),alligators' CLf,int was 2060% for CBZ and 50% for NCT of rats. Additionally, NCT exposure increased lactate levels in perfused livers indicating metabolic stress. This study provides insight into the hepatic capability of alligators to metabolize CBZ and NCT using an established in vitro (S9) system and a newly developed in situ liver perfusion system.

Microbes as Resources to Remove PPCPs and Improve Water Quality

The inadequate removal of pharmaceuticals and personal care products (PPCPs) by traditional wastewater treatment plants (WWTPs) poses a significant environmental and public health challenge. Residual PPCPs find their way into aquatic ecosystems, leading to bioaccumulation in aquatic biota, the dissemination of antibiotic resistance genes (ARGs), and contamination of both water sources and vegetables. These persistent pollutants can have negative effects on human health, ranging from antibiotic resistance development to endocrine disruption. To mitigate these risks, there is a growing interest in exploiting microorganisms and their enzymes for bioremediation purposes. By harnessing the metabolic capabilities of microbial communities, PPCPs can be efficiently degraded, transformed, or sequestered in water systems. Additionally, microbial communities exhibit remarkable adaptability and resilience to diverse PPCP contaminants, further underscoring their potential as sustainable and cost-effective solutions for water treatment. This review explores the promise of microbial bioremediation as an approach to addressing the complex challenges posed by persistent PPCP contamination, emphasising its potential to safeguard both environmental integrity and human well-being.

Maternal Daphnia magna exposure to the antidepressant sertraline causes molting disorder, multi-generational reproductive and serotonergic dysfunction

Sertraline, one of the most commonly used antidepressants, has exhibited a progressively escalating trend in usage over the course of the last decades years, which have been exacerbated by the COVID-19 pandemic. Here, this study assessed the transgenerational effects of sertraline on the aquatic microcrustacean Daphnia magna, a parthenogenetic model species. The parental D. magna (G0) were exposed to environmentally relevant concentrations of sertraline (0.1 and 10 μg/L) for 21 days at individual and population level, and observed exposure triggered specific increased fecundity and desynchronized molting. These alterations were partially inherited through three subsequent non-exposed generations (G1, G2, and G3), as evidenced by increased fecundity and disordered molting in G1, reduced fecundity in G2, and reduced body size of G3-offspring. The molt-related genes neverland 1 and hormone receptor 3 were significantly different to the control group simultaneously only in the exposed generation, which may well be responsible for the molting asynchrony. Vitellogenin plays an important role in reproduction, and our results indicate that its abnormal expression persists up to G3, which was highly correlated with the expression of serotonin transporter, the drug target of sertraline. This finding suggested that sertraline possesses a sustained reproductive toxicity and disrupting potential and may be associated with serotonin dysregulation caused by compensatory feedback of serotonin transporter. In combination with male birth and upregulation of doublesex and vitellogenin, sertraline was deemed to trigger a self-defense response of D. magna, known as "abandon-ship" by increasing reproductive inputs. However, no males was found in individual reproduction test in each generation, which may suggest some interaction between sertraline and population density. Our findings emphasize that the toxic effects of sertraline can be transferred to unexposed generations, even with different adverse consequences, implying that future studies need to focus on transgenerational delayed effects and the underlying mechanisms.

Sorption of tetracycline antibiotics by microplastics, associated mechanisms, and risk assessments

In this study, we selected polyvinyl chloride (PVC), polyethylene (PE), and polystyrene (PS) as representative microplastics (MPs) to systematically investigate the sorption behavior of tetracycline (TC) antibiotics by MPs. Scanning electron microscopy, X-ray diffraction, Fourier transform-infrared spectroscopy, and adsorption experiments were applied to assess the sorption behavior of MPs. The results demonstrated that the sorption of TC by MPs was most favorable under neutral conditions, where a modest increase in the salt ion concentration enhanced the adsorption of TC by MPs. The saturation adsorption capacities for PVC, PE, and PS for TC were determined as 121.95 μg/g, 81.301 μg/g, and 178.57 μg/g, respectively. The strength of TC sorption by MPs followed the order of: PS > PVC > PE. Analysis of the sorption behavior of TC by MPs showed that the adsorption of TC by PE was weak and it readily desorbed, and thus their interaction will not lead to excessive compound pollution. By contrast, the adsorption of TC was high by PVC and PS, and they were not readily desorbed.

Environmental fate of organic UV filters: Global occurrence, transformation, and mitigation via advanced oxidation processes

Organic UV filters are used in personal care products, plastics, paints, and textiles to protect against UV radiation. Despite regulatory limits, these compounds still enter the environment through direct wash-off during swimming, evaporation, leaching from products, and incomplete removal in wastewater treatment plants. They have been detected in various environmental matrices worldwide. Once in the environment, organic UV filters can undergo phototransformation and biotransformation, forming transformation products that, together with parent substances, pose health risks to humans and wildlife and harm marine ecosystems, especially coral reefs. The increasing concern over water scarcity and the environmental impact of pollutants underscores the importance of eliminating these contaminants from aquatic environments. This review primarily focuses on organic UV filters approved for use in sunscreens, many of which are also utilized in other materials, with a few exceptions including UV stabilizer UV-328. It includes an in-depth analysis of 155 peer-reviewed articles published from 2015 to 2024, assessing the concentrations of these filters in various environmental matrices, including water and solid matrices, air and biota. Moreover, this review explores the environmental transformation of these chemicals and assesses the effectiveness of advanced oxidation processes (AOPs) in removing these pollutants. The findings highlight the pervasive presence of organic UV filters in the environment and the promising potential of AOPs to mitigate the associated environmental challenges.

In vitro study of the UV-filter homosalate effects on rat and human thyroid cells

Homosalate is a UV-B filter, commonly used in sunscreens and personal-care products. Homosalate was shown to exert estrogenic and anti-androgenic effects in animal models, while few data are available on the effects of Homosalate on thyroid cells. The aim of this study was to evaluate if Homosalate exposure could exert adverse effect on thyroid cells in vitro. FRTL-5 and NHT were treated with increasing concentration of Homosalate for 24-48-72 h. Cell viability was assessed by WST-1. Cell proliferation was evaluated by cristal violet. Micronucleus staining was performed to assess genotoxicity. mRNA levels of thyroid-related genes (TSHR, TPO, TG, NIS, and PAX8) were evaluated by RT-PCR. Changes in ROS production by FRTL-5 and NHT were assessed with H2DCFDA. Homosalate significantly reduced cell viability after 72 h in FRTL-5 starting from the concentration 250 μM, while in NHT, Homosalate exposure significantly reduced cell viability after 48 and 72 h only at highest concentration (2000 μM). Cell proliferation was not modified by Homosalate at any concentration and time-point. Homosalate significantly up-regulated mRNA expression levels of TPO and Tg genes in FRTL-5, while a significant increase only in Tg mRNA expression was observed in NHT. No changes in ROS production was found in both cell types. The present study suggest that the effects of Homosalate exposure may differ according to the type of cell tested. The in vitro exposure of thyroid cells to Homosalate produces: i) cytotoxicity at high concentrations or after long time of incubation, ii) genotoxicity only in rat thyroid cells at the highest concentration, iii) upregulation of Tg mRNA in both thyroid cell types and of TPO mRNA in rat thyroid cells, iv) no changes in cell proliferation or oxidative stress. Further studies on the effects of Homosalate on thyroid cells should be encouraged.

Ultraviolet absorbents and industrial antioxidants in seabirds, mammals, and fish from the Canadian Arctic

Ultraviolet (UV) absorbents and industrial antioxidants are two groups of plastic-derived contaminants of emerging environmental concern. However, their distribution and fate are poorly understood in Arctic wildlife. In the present study, 16 UV absorbents (10 benzotriazole UV stabilizers (BZT-UVs) and 6 organic UV filters (UVFs)) and 7 industrial antioxidants (6 aromatic secondary amines (Ar-SAs) and 2,6-di-tert-butylphenol (26DTBP)) were analyzed in the livers of thick-billed murre (Uria lomvia; n = 28), northern fulmar (Fulmarus glacialis; n = 4), black guillemot (Cepphus grylle; n = 11), polar bear (Ursus maritimus; n = 18), beluga whale (Delphinapterus leucas; n = 10), landlocked (n = 25) and sea-run (n = 10) Arctic char (Salvelinus alpinus) from the Canadian Arctic collected between 2017 and 2021. Compared to industrial antioxidants (median range: ΣAr-SAs: not calculated due to detection frequency < 30 % (NA)-4.06 ng/g, wet weight (ww); 26DTBP: NA-1.91 ng/g ww), UV absorbents (median range: ΣBZT-UVs: NA-8.71 ng/g ww; ΣUVFs: NA-48.3 ng/g ww) generally showed greater concentrations in the liver of these species. Seabirds accumulated higher levels of these contaminants (median range: ΣBZT-UVs: 3.38-8.71 ng/g ww; ΣUVFs: NA-48.3 ng/g ww; ΣAr-SAs: 0.07-4.06 ng/g ww; 26DTBP: NA-1.14 ng/g ww)) than the other groups (median range: ΣBZT-UVs: NA-1.31 ng/g ww; ΣUVFs: NA-4.22 ng/g ww; ΣAr-SAs: NA; 26DTBP: NA-1.91 ng/g ww), suggesting that seabirds may be useful indicator species for future long-term monitoring. The livers of Arctic char in the Canadian Arctic generally contain lower levels of these contaminants than those of freshwater fish in temperate regions. Spatial variations were found in the liver of black guillemots, Hudson Bay polar bears, and landlocked char for some target contaminants, indicating differences in the levels of these contaminants in their surrounding environment or diet. Consumption of liver tissues from these species may expose humans to varying levels of UV absorbents and industrial antioxidants. This study establishes a baseline for future research of the spatial and temporal trends of these contaminants in Arctic species. It provides the basis for elucidating the fate of these contaminants and assessing their adverse effects at environmental-relevant concentrations in the Arctic. Factors influencing the accumulation patterns of these contaminants in Arctic biota and their potential health risks require further investigation.

Developing an Approach for Integrating Chemical Analysis and Transcriptional Changes to Assess Contaminants in Water, Sediment, and Fish

Pharmaceuticals in aquatic environments pose threats to aquatic organisms because of their continuous release and potential accumulation. Monitoring methods for these contaminants are inadequate, with targeted analyses falling short in assessing water quality's impact on biota. The present study advocates for integrated strategies combining suspect and targeted chemical analyses with molecular biomarker approaches to better understand the risks posed by complex chemical mixtures to nontarget organisms. The research aimed to integrate chemical analysis and transcriptome changes in fathead minnows to prioritize contaminants, assess their effects, and apply this strategy in Wascana Creek, Canada. Analysis revealed higher pharmaceutical concentrations downstream of a wastewater-treatment plant, with clozapine being the most abundant in fathead minnows, showing notable bioavailability from water and sediment sources. Considering the importance of bioaccumulation factor and biota-sediment accumulation factor in risk assessment, these coefficients were calculated based on field data collected during spring, summer, and fall seasons in 2021. Bioaccumulation was classified as very bioaccumulative with values >5000 L kg-1, suggesting the ability of pharmaceuticals to accumulate in aquatic organisms. The study highlighted the intricate relationship between nutrient availability, water quality, and key pathways affected by pharmaceuticals, personal care products, and rubber components. Prioritization of these chemicals was done through suspect analysis, supported by identifying perturbed pathways (specifically signaling and cellular processes) using transcriptomic analysis in exposed fish. This strategy not only aids in environmental risk assessment but also serves as a practical model for other watersheds, streamlining risk-assessment processes to identify environmental hazards and work toward reducing risks from contaminants of emerging concern. Environ Toxicol Chem 2024;43:2252-2273. © 2024 SETAC.

Identification of a Novel Ibuprofen Biotransformation Pathway in Streptomyces sp. D218 and Detoxification as Indicated by the Green Algae Scenedesmus obliquus

Ibuprofen, a widely used nonsteroidal anti-inflammatory drug, contaminates agricultural products and potentially threatens human health due to its frequent detection and poor biodegradability. Microbial metabolism dominates the elimination of residual ibuprofen in the environment. In mineral salt medium at pH 6 with 5 mM glucose, Streptomyces sp. D218 transformed ibuprofen concentrations ranging from 0.05 to 0.40 mM in 24 h. The optimal temperature, pH, and initial OD600 nm for ibuprofen transformation by strain D218 were 25-37 °C, 5.0-6.0, and 1.0-1.5, respectively. Strain D218 could simultaneously transform ibuprofen into the intermediates 2-hydroxyibuprofen and ibuprofen amide (IBUA). The two intermediates were further metabolized to 2-hydroxyibuprofen amide (2HIBUA), thus relieving the growth inhibition of ibuprofen in Scenedesmus obliquus. This is the first complete pathway reported for the detoxification of ibuprofen transformation by a Gram-positive strain. These findings further our understanding of the microbial catabolism of the IBU.

Identifying pathways of pharmaceutical exposure in a mesoconsumer marine fish

Pharmaceutical uptake involves processes that vary across aquatic systems and biota. However, single studies examining multiple environmental compartments, microhabitats, biota, and exposure pathways in mesoconsumer fish are sparse. We investigated the pharmaceutical burden in bonefish (Albula vulpes), pathways of exposure, and estimated exposure to a human daily dose. To evaluate exposure pathways, the number and composition of pharmaceuticals across compartments and the bioconcentration in prey and bonefish were assessed. To evaluate bioaccumulation, we proposed the use of a field-derived bioaccumulation factor (fBAF), due to variability inherent to natural systems. Exposure to a human daily dose was based on bonefish daily energetic requirements and consumption rates using pharmaceutical concentrations in prey. Pharmaceutical number and concentration were highest in prey, followed by bonefish, water and sediment. Fifteen pharmaceuticals were detected in common among bonefish, prey, and water; all of which bioconcentrated in prey and bonefish, and four bioaccumulated in bonefish. The composition of detected pharmaceuticals was compartment specific, and prey were most similar to bonefish. Bonefish were exposed to a maximum of 1.2 % of a human daily dose via prey consumption. Results highlight the need for multicompartment assessments of exposure and consideration of prey along with water as a pathway of exposure.

Construction of an antidepressant priority list based on functional, environmental, and health risks using an interpretable mixup-transformer deep learning model

As emerging pollutants, antidepressants (AD) must be urgently investigated for risk identification and assessment. This study constructed a comprehensive-effect risk-priority screening system (ADRank) for ADs by characterizing AD functionality, occurrence, persistence, bioaccumulation and toxicity based on the integrated assignment method. A classification model for ADs was constructed using an improved mixup-transformer deep learning method, and its classification accuracy was compared with those of other models. The accuracy of the proposed model improved by up to 23.25 % compared with the random forest model, and the reliability was 80 % more than that of the TOPSIS method. A priority screening candidate list was proposed to screen 33 high-priority ADs. Finally, SHapley Additive explanation (SHAP) visualization, molecular dynamics, and amino acid analysis were performed to analyze the correlation between AD structure and toxic receptor binding characteristics and reveal the differences in AD risk priority. ADs with more intramolecular hydrogen bonds, higher hydrophobicity, and electronegativity had a more significant risk. Van der Waals and electrostatic interactions were the primary influencing factors, and significant differences in the types and proportions of the main amino acids in the interaction between ADs and receptors were observed. The results of the study provide constructive schemes and insights for AD priority screening and risk management.

Multidimensional occurrence and diet risk of emerging contaminants in freshwater with urban agglomerations

Freshwater systems near highly urbanized areas are extremely susceptible to emerging contaminants (ECs), yet their stereoscopic persistence in aquatic ecosystems and related risks remain largely unknown. Herein, we characterized the multi-mediums distribution of 63 ECs in Baiyangdian Lake, the biggest urban lake in the North of China. We identified variations in the seasonal patterns of aquatic EC levels, which decreased in water and increased in sediment from wet to dry seasons. Surprisingly, higher concentrations and a greater variety of ECs were detected in reeds than in aquatic animals, indicating that plants may contribute to the transferring of ECs. Source analysis indicated that human activity considerably affected the distribution and risk of ECs. The dietary risk of ECs is most pronounced among children following the intake of aquatic products, especially with a relatively higher risk associated with fish consumption. Besides, a comprehensive scoring ranking method was proposed, and 9 ECs, including BPS and macrolide antibiotics, are identified as prioritized control pollutants. These findings highlight the risks associated with aquatic ECs and can facilitate the development of effective management strategies.

Modelling lethality and teratogenicity of zebrafish (Danio rerio) due to β-lactam antibiotics employing the QSTR approach

Nowadays, β-lactam antibiotics are one of the most consumed OTC (over-the-counter) medicines in the world. Its frequent use against several infectious diseases leads to the development of antibiotic resistance. Another unavoidable risk factor of β-lactam antibiotics is environmental toxicity. Numerous terrestrial as well as aquatic species have suffered due to the excessive use of these pharmaceuticals. In this present study, we have performed a toxicity assessment employing a novel in silico technique like quantitative structure-toxicity relationships (QSTRs) to explore toxicity against zebrafish (Danio rerio). We have developed single as well as inter-endpoint QSTR models for the β-lactam compounds to explore important structural attributes responsible for their toxicity, employing median lethal (LC50) and median teratogenic concentration (TC50) as the endpoints. We have shown how an inter-endpoint model can extrapolate unavailable endpoint values with the help of other available endpoint values. To verify the models' robustness, predictivity, and goodness-of-fit, several universally popular metrics for both internal and external validation were extensively employed in model validation (single endpoint models: r2 = 0.631 - 0.75, Q2F1 = 0.607 - 0.684; inter-endpoint models: r2 = 0.768 - 0.84, Q2F1 = 0.678 - 0.76). Again, these models were engaged in the prediction of these two responses for a true external set of β-lactam molecules without response values to prove the reproducibility of these models.

Dynamics of antibiotic resistance genes in the sediments of a water-diversion lake and its human exposure risk behaviour

The dynamics and exposure risk behaviours of antibiotic resistance genes (ARGs) in the sediments of water-diversion lakes remain poorly understood. In this study, spatiotemporal investigations of ARG profiles in sediments targeting non-water (NWDP) and water diversion periods (WDP) were conducted in Luoma Lake, a typical water-diversion lake, and an innovative dynamics-based risk assessment framework was constructed to evaluate ARG exposure risks to local residents. ARGs in sediments were significantly more abundant in the WDP than in the NWDP, but there was no significant variation in their spatial distribution in either period. Moreover, the pattern of ARG dissemination in sediments was unchanged between the WDP and NWDP, with horizontal gene transfer (HGT) and vertical gene transfer (VGT) contributing to ARG dissemination in both periods. However, water diversion altered the pattern in lake water, with HGT and VGT in the NWDP but only HGT in the WDP, which were critical pathways for the dissemination of ARGs. The significantly lower ARG sediment-water partition coefficient in the WDP indicated that water diversion could shift the fate of ARGs and facilitate their aqueous partitioning. Risk assessment showed that all age groups faced a higher human exposure risk of ARGs (HERA) in the WDP than in the NWDP, with the 45-59 age group having the highest risk. Furthermore, HERA increased overall with the bacterial carrying capacity in the local environment and peaked when the carrying capacity reached three (NWDP) or four (WDP) orders of magnitude higher than the observed bacterial population. HGT and VGT promoted, whereas ODF covering gene mutation and loss mainly reduced HERA in the lake. As the carrying capacity increased, the relative contribution of ODF to HERA remained relatively stable, whereas the dominant mechanism of HERA development shifted from HGT to VGT.

Polystyrene microplastics alter the trophic transfer and biotoxicity of fluoxetine in an aquatic food chain

Microplastics (MPs) and fluoxetine are ubiquitous emerging pollutants in aquatic environments that may interact with each other due to the carrier effects of MPs, posing unpredictable risks to non-target organisms. However, limited studies have focused on the carrier effects of MPs in the aquatic food chain. This study evaluated the influences of polystyrene MPs on the trophic transfer and biotoxicity of fluoxetine in a simple food chain composed of brine shrimp (Artemia nauplii) and zebrafish (Danio rerio). The finding reveals that carrier effects of MPs enhanced the accumulation of waterborne fluoxetine in brine shrimp, but suppressed that in zebrafish due to the distinct retention times. The accumulated fluoxetine in shrimp was further transferred to fish through the food chain, which was alleviated by MPs due to their cleaning effects. In addition, the specific neurotransmission biotoxicity in fish induced by fluoxetine was mitigated by MPs, whilst the oxidative damage, apoptosis, and immune responses in zebrafish were reversely enhanced by MPs due to the stimulating effect. These findings highlight the alleviating effects of MPs on the trophic transfer and specific biotoxicity of fluoxetine in the food chain, providing new insights into the carrier effects of MPs in aquatic environments in the context of increasing global MP pollution.

The effect of warming and seasonality on bioaccumulation of selected pharmaceuticals in freshwater invertebrates

Multiple human-induced environmental stressors significantly threaten global biodiversity and ecosystem functioning. Climate warming and chemical pollution are two widespread stressors whose impact on freshwaters is likely to increase. However, little is known about the combined effects of warming on the bioaccumulation of environmentally relevant mixtures of emerging contaminants, such as pharmaceutically active compounds (PhACs) in freshwater biota. This study investigated the bioaccumulation of a mixture of 15 selected PhACs at environmentally relevant concentrations in common freshwater macroinvertebrate taxa, exposed to ambient temperatures and warming (+4 °C) during the warm and cold seasons in two outdoor mesocosm experiments. Nine PhACs (carbamazepine, cetirizine, clarithromycin, clindamycin, fexofenadine, telmisartan, trimethoprim, valsartan and venlafaxine) were dissipated faster in the warm season experiment than in the cold season experiment, while lamotrigine showed the opposite trend. The most bioaccumulated PhACs in macroinvertebrates were tramadol, carbamazepine, telmisartan, venlafaxine, citalopram and cetirizine. The bioaccumulation was taxon, season and temperature dependent, but differences could not be fully explained by the different water stability of the PhACs and their partitioning between water and leaf litter. The highest water-based bioaccumulation factors were found in Asellus and Planorbarius. Moreover, the bioaccumulation of some PhACs increased with warming in Planorbarius, suggesting that it could be used as a sentinel taxon in environmental studies of the effects of climate warming on PhAC bioaccumulation.

Occurrence, bioaccumulation, fate, and risk assessment of emerging pollutants in aquatic environments: A review

Significant concerns on a global scale have been raised in response to the potential adverse impacts of emerging pollutants (EPs) on aquatic creatures. We have carefully reviewed relevant research over the past 10 years. The study focuses on five typical EPs: pharmaceuticals and personal care products (PPCPs), per- and polyfluoroalkyl substances (PFASs), drinking water disinfection byproducts (DBPs), brominated flame retardants (BFRs), and microplastics (MPs). The presence of EPs in the global aquatic environment is source-dependent, with wastewater treatment plants being the main source of EPs. Multiple studies have consistently shown that the final destination of most EPs in the water environment is sludge and sediment. Simultaneously, a number of EPs, such as PFASs, MPs, and BFRs, have long-term environmental transport potential. Some EPs exhibit notable tendencies towards bioaccumulation and biomagnification, while others pose challenges in terms of their degradation within both biological and abiotic treatment processes. The results showed that, in most cases, the ecological risk of EPs in aquatic environments was low, possibly due to potential dilution and degradation. Future research topics should include adding EPs detection items for the aquatic environment, combining pollution, and updating prediction models.

Spatiotemporal distribution, source apportionment, and ecological risk of bisphenol analogues in a highly urbanized river basin

Bisphenol analogues (BPs), as one of the endocrine disruptors, have received wide attention due to their adverse impacts on ecosystems. However, the seasonal spatiotemporal distribution, source apportionment, and ecological risk of BPs in natural basins are poorly understood. Especially in highly urbanized river basins with the extensive economic development and anthropogenic activities threaten these critical but ecologically fragile regions. In this study, field investigations of BPs in the waters of the entire Qinhuai River Basin (QRB) were conducted in June (before the annual flood period) and August (after the annual flood period) 2023. The Qinhuai River, an important primary tributary of the lower Yangtze River, is located in eastern China and the QRB is characterized by a high population density and dense urbanization. Thirty-two sites were sampled for six types of BPs known to be ubiquitous in the surface water of the QRB. Significant differences in the concentrations of those BPs were found. Specifically, the concentration of total BPs (ΣBPs) was significantly higher before than after the flood period: 20.3-472 ng/L (mean = 146 ng/L) and 14.1-105 ng/L (mean = 35.9 ng/L), respectively. BPA was the main contributor to ΣBPs before the flood, and BPB followed by BPA after the flood. ΣBP concentrations were 12-241 % higher downstream than upstream of wastewater treatment plants (WWTPs). The results of a principal component analysis followed by multiple linear regression (PCA-MLR) suggested that untreated wastewater discharge from the WWTPs is an important source of BPs in the basin, with urban rainfall runoff as another potential source after the flood period. An assessment of the ecological risk of BPs, based on a calculation of the risk quotient, showed that BPA and BPS should be given due attention, and overall ecological risk of BPs pose a low risk to local algae but high and medium risks to invertebrates and fish, respectively.

Tissue-specific distributions of organic ultraviolet absorbents in free-range chickens and domestic pigeons from Guangzhou, China

The ecological risks of organic ultraviolet absorbents (UVAs) have been of increasing concern. Studies have found that these chemicals could be accumulated in terrestrial animals and pose toxicities. However, tissue distribution of UVAs in terrestrial species was far from well understood. In this study, free-range chickens and domestic pigeons were selected to investigate the occurrence and tissue distribution of UVAs. Total concentrations of eleven UVAs in muscles ranged from 778 to 2874 (mean 1413 ± 666) ng/g lipid weight, which were higher than those in aquatic species worldwide. Since low UVA concentrations in local environment were previously reported, the results implied the strong accumulation of UVAs in studied species. Brain, stomach and kidney were main target organs for studied UVAs, differentiating from the strong liver sequestration in aquatic species. The mean tissue-to-muscle ratios of 1.02-4.23 further indicated the preferential accumulation of target UVAs in these tissues. The tissue-to-blood ratios of benzophenone (BP), 2-ethylhexyl salicylate (EHS) and homosalate (HMS) in brain were 370, 1207 and 52.0, respectively, implying their preferential accumulation in brain. More research is needed to characterize the toxicokinetics and tissue distribution of UVAs in terrestrial wild species, in order to further understand their potential risks.

New insight into the bioaccumulation and trophic transfer of free and conjugated antibiotics in an estuarine food web based on multimedia fate and model simulation

The substantial utilization of antibiotics causes their "pseudo-persistence" in offshore environments. Published studies on antibiotic surveillance in food webs have primarily emphasized on parent forms; however, the compositions and concentrations of conjugated antibiotics in aquatic organisms remain largely unexplored. This study systematically examined the distribution characteristics and trophodynamics of free antibiotics and their conjugated forms in an estuarine food web. Total antibiotic levels differed insignificantly between the surface and bottom waters. The total mean values of free antibiotics in crabs, fish, shrimps, sea cucumbers, and snails varied from 0.77 to 1.4 ng/g (wet weight). The numbers and values of antibiotics rose in these biological samples after enzymatic hydrolysis. Conjugated antibiotics accounted for 23.8-76.9% of the total antibiotics in the biological samples, revealing that conjugated forms play a non-negligible role in aquatic organisms. More number of antibiotics exhibited bioaccumulation capabilities after enzymatic hydrolysis. In the food web, the free forms of anhydroerythromycin and conjugated forms of trimethoprim and ciprofloxacin underwent trophic dilution, whereas the free forms of trimethoprim and conjugated forms of ofloxacin underwent trophic amplification. The present work provides new insights into the bioaccumulation and trophic transfer of free and conjugated antibiotics in food webs.

Unveiling the toxic effects, physiological responses and molecular mechanisms of tobacco (Nicotiana tabacum) in exposure to organic ultraviolet filters

Exposure to organic ultraviolet (UV) filters has raised concerns due to their potential adverse effects on environments. However, their toxic mechanisms on plants remain elusive. In this study, using integrative physiological and transcriptomic approaches we investigated the physiological and molecular responses to three representative UV filters, namely oxybenzone (OBZ), avobenzone (AVB), and octinoxate (OMC), in an agricultural model plant tobacco. The exposure to UV filters disrupts the functionality of photosystem reaction centers and the light-harvesting apparatus. Concurrently, UV filters exert a suppressive effect on the expression of genes encoding Rubisco and Calvin-Benson cycle enzymes, resulting in a decreased efficiency of the Calvin-Benson cycle and consequently hampering the process of photosynthesis. Exposure to UV filters leads to significant generation of reactive oxygen species within tobacco leaves and downregulation of oxidoreductase activities. Moreover, UV filters promote abscisic acid (ABA) accumulation by inducing the expression of ABA biosynthesis genes whereas repress indole-3-acetic acid (IAA) biosynthesis gene expression, which induce leaf yellowing and slow plant growth. In summary, the organic UV filters exert toxic effects on tobacco growth by inhibiting chlorophyll synthesis, photosynthesis, and the Calvin-Benson cycle, while generating excessive reactive oxygen species. This study sheds light on the toxic and tolerance mechanisms of UV filters in agricultural crops.

Toxicity comparison of benzophenone-3 and its metabolite benzophenone-8 in different tissues of zebrafish

Benzophenone-3 (BP-3) is a commonly used ultraviolet absorber that has the potential to accumulate in organisms, leading to toxicity. Benzophenone-8 (BP-8) is one of the major metabolites of BP-3. In this study, zebrafish were exposed to different concentrations of BP-3 and BP-8 (1 μg/L, 30 μg/L, and 300 μg/L) to investigate their accumulation and toxic effects in various tissues, including zebrafish brain, gut, and liver. The analysis focused on neurotoxicity, oxidative damage, inflammation, and gene expressions. The results showed that both BP-3 and BP-8 accumulated in the tissues, with the highest concentration observed in the gut, followed by the liver and brain. BP-8 exhibited a stronger ability to accumulate. In the brain, exposure to 1 μg/L of BP-3 and BP-8 promoted cortisol production, while higher exposures (30 μg/L and 300 μg/L) inhibited acetylcholinesterase activity and suppressed cortisol production. In the gut, both BP-3 and BP-8 exposures disrupted oxidative stress, inflammatory immunity, and apoptosis functions. In the liver, BP-3 and BP-8 affected hepatic metabolism, oxidative stress, apoptosis, and inflammatory immunity. Comparing gene expression in the brain, gut, and liver, it was found that BP-3 and BP-8 had a lower effect on gene expression in the brain, while the effect on the gut and liver was significantly higher. BP-8 generally had a higher effect than BP-3, which aligns with the observed accumulation pattern. These findings provide valuable insights for the risk assessment of BP-3 and BP-8 in the aquatic environment.

Transcriptomic profiles of brains in juvenile Atlantic cod (Gadus morhua) exposed to pharmaceuticals and personal care products from a wastewater treatment plant discharge

Pharmaceuticals and personal care products (PPCPs) are frequently detected in marine environments, posing a threat to aquatic organisms. Our previous research demonstrated the occurrence of neuroactive compounds in effluent and sediments from a wastewater treatment plant (WWTP) in a fjord North of Stavanger, the fourth-largest city in Norway. To better understand the influence of PPCP mixtures on fish, Atlantic cod (Gadus morhua) were caged for one month in 3 locations: site 1 (reference), site 2 (WWTP discharge), and site 3 (6.7 km west of discharge). Transcriptomic profiling was conducted in the brains of exposed fish and detection of PPCPs in WWTP effluent and muscle fillets were determined. Caffeine (47.8 ng/L), benzotriazole (10.9 ng/L), N,N-diethyl-meta-toluamide (DEET) (5.6 ng/L), methyl-1H-benzotriazole (5.5 ng/L), trimethoprim (3.4 ng/L), carbamazepine (2.1 ng/L), and nortriptyline (0.4 ng/L) were detected in the WWTP effluent. Octocrylene concentrations were observed in muscle tissue at all sites and ranged from 53 to 193 ng/g. Nervous system function and endocrine system disorders were the top enriched disease and function pathways predicted in male and female fish at site 2, with the top shared canonical pathways involved with estrogen receptor and Sirtuin signaling. At the discharge site, predicted disease and functional responses in female brains were involved in cellular assembly, organization, and function, tissue development, and nervous system development, whereas male brains were involved in connective tissue development, function, and disorders, nervous system development and function, and neurological disease. The top shared canonical pathways in females and males were involved in fatty acid activation and tight junction signaling. This study suggests that pseudopersistent, chronic exposure of native juvenile Atlantic cod from this ecosystem to PPCPs may alter neuroendocrine and neuron development.

Effects associated with exposure to the emerging contaminant octyl-methoxycinnamate (a UV-B filter) in the aquatic environment: a review

Given the increasing concern surrounding ultraviolet (UV) radiation-induced skin damage, there has been a rise in demand for UV filters. Currently, UV-filters are considered emerging contaminants. The extensive production and use of UV filters have led to their widespread release into the aquatic environment. Thus, there is growing concern that UV filters may bioaccumulate and exhibit persistent properties within the environment, raising several safety health concerns. Octyl-methoxycinnamate (OMC) is extensively employed as a UV-B filter in the cosmetic industry. While initially designed to mitigate the adverse photobiological effects attributed to UV radiation, the safety of OMC has been questioned with some studies reporting toxic effects on environment. The aim of this review to provide an overview of the scientific information regarding the most widely used organic UV-filter (OMC), and its effects on biodiversity and aquatic environment.

Application of passive sampling device for exploring the occurrence, distribution, and risk of pharmaceuticals and pesticides in surface water

Pharmaceuticals and pesticides are compounds of high concern in surface waters around the world. However, few studies have used passive sampling methods to screen and detect these compounds in natural waters. In this study, a self-developed passive sampler was employed to measure pharmaceuticals and pesticides in the rivers of Nanjing, China. A total of 41 pharmaceuticals and 11 pesticides were detected, among which antibiotic and insecticide were the predominant classes, respectively. Valproic acid, caffeine and triclosan from the pharmaceuticals, and isoprocarb and imidacloprid from the pesticides were found frequently with high concentrations. At most sampling sites, the concentration ratios of caffeine versus carbamazepine exceeded 10, and even above 50, indicating relatively poor efficiency of wastewater treatment, or possibly the direct discharge of raw sewage, or other unknown source of pollution. It was found that the concentrations and ecological risks in the northern area of Yangtze River were higher than those in the southern area of Yangtze River, implying that economic development and population density were not the main contributors to the discovered pollution. The total concentration of pharmaceuticals and pesticides in Qinhuai River increased gradually with the direction of water flow, demonstrating the success of water diversion project in flushing and scouring pollutants.

Estimation of the riverine input of organic ultraviolet filters (OUVFs) from the Pearl River Estuary to the South China Sea during the early Covid-19 pandemic

Organic ultraviolet filters (OUVFs) are functional ingredients used in cosmetics to protect skin from the harmful effects of ultraviolet (UV) radiation. This study presents recent findings on the distribution of OUVFs in the Pearl River Estuary (PRE), located in southern China. This investigation was conducted during the early stages of the Covid-19 pandemic when the stay-at-home policy was implemented. Analysis revealed the presence of OUVFs in both the surface and bottom water samples collected from eight major outlets of the Pearl River. The OUVFs were detected in both the dissolved phase and suspended particulate matter, with a total concentration ranging from 7.19 ± 6.54 to 20.5 ± 9.62 ng/L. Notably, OUVFs' concentrations in the study period were significantly lower compared to those reported before the pandemic. This implies that effective reduction of OUVF emissions can be achieved through usage reduction combined with the management of direct discharge and appropriate treatment by urban wastewater treatment facilities. During the study period, the annual release of OUVFs was approximately 12.6 kg/1000 people/year, with the greatest contribution from the Hu Men outlet. Consequently, it is imperative to consider the potential ecological risks associated with the release of OUVFs from the PRE into the marine environment, particularly with the potential for an accompanying rebound in risk upon the lifting of restrictions on outdoor activities in the post Covid-19 time.

Parabens and their metabolite in a marine benthic-dominated food web from the Beibu gulf, South China Sea: Occurrence, trophic transfer and health risk assessment

Parabens are of particular concern due to their ubiquity in aquatic environments and endocrine-disrupting effects. However, information on their bioaccumulation and trophic magnification is limited. In the present study, we performed a comprehensive survey to investigate the occurrence, bioaccumulation and trophic magnification of parabens and their metabolite 4-hydroxybenzoic acid (4-HB) in a marine food web from the Beibu Gulf, South China Sea. Results showed that methylparaben (MeP) and 4-HB were the predominant target pollutants in marine organisms, with their concentrations being in the range of 0.18-13.77 and 13.48-222.24 ng/g wet weight, respectively. The bioaccumulation factors (BAFs) for target analytes were all lower than 5000, suggesting negligible bioaccumulation. However, the biota-sediment accumulation factors (BSAFs) for MeP and 4-HB were 4.51 and 3.21, respectively, which indicates significant bioaccumulation from the sediment. Furthermore, the estimated trophic magnification factor (TMF) was 2.88 for MeP, suggesting its biomagnification along the food web. In contrast, a lower TMF of 0.45 was found for 4-HB, suggesting trophic dilution along the food web. The hazard quotients (HQs) for parabens were far less than 1 in all organisms, suggesting low risks for humans through consuming marine organisms from the Beibu Gulf. This study provides substantial data on the fate and trophic transfer of parabens in a subtropical marine ecosystem.

Organic UV absorbents in the deepwater redfish (Sebastes mentella) from the St. Lawrence Estuary and Gulf: Distribution and human health risk assessment

UV absorbents (UVAs), such as organic UV filters (UVFs) and benzotriazole UV stabilizers (BZT-UVs), are used in a wide range of consumer and industrial products and they are contaminants of emerging concern in the environment. However, their occurrence and fate in the deep-sea environments are inadequately understood. This study investigated the occurrence and distribution of five UVFs and ten BZT-UVs in the muscle (n = 127) of 2019-collected deepwater redfish (Sebastes mentella) from the St. Lawrence Estuary and Gulf (SLEG) (Canada) to better understand the accumulation of these contaminants in deep-sea fish. Small redfish (<30 cm) tended to have higher concentrations of UVAs in the muscle than that of larger specimens (>30 cm). The UVF 2-hydroxy-4-methoxybenzophenone (BP3) was the most frequently detected (present in 34 % of all samples) target UVA, with concentrations as high as 413 ng/g (dry weight). According to the δ15N and δ13C data, pelagic-eating redfish, and individuals with lower trophic levels had higher lipid content and accumulated more BP3 in their muscles. Four BZT-UVs were detected in redfish muscle, but the detection frequency was lower than 30 %. The estimated hazard quotient for these contaminants was <2.3 × 10-2 for general Canadian populations, indicating that they are unlikely to pose health risks to humans through redfish consumption. Factors influencing UVAs bioaccumulation in redfish, as well as the effects UVAs may have on deep-sea species, should be researched further.

Occurrence, Distribution, and Trophic Transfer of Pharmaceuticals and Personal Care Products in the Bohai Sea

The ubiquitous presence of pharmaceuticals and personal care products (PPCPs) in environments has aroused global concerns; however, minimal information is available regarding their multimedia distribution, bioaccumulation, and trophic transfer in marine environments. Herein, we analyzed 77 representative PPCPs in samples of surface and bottom seawater, surface sediments, and benthic biota from the Bohai Sea. PPCPs were pervasively detected in seawater, sediments, and benthic biota, with antioxidants being the most abundant PPCPs. PPCP concentrations positively correlated between the surface and bottom water with a decreasing trend from the coast to the central oceans. Higher PPCP concentrations in sediment were found in the Yellow River estuary, and the variations in the physicochemical properties of PPCPs and sediment produced a different distribution pattern of PPCPs in sediment from seawater. The log Dow, but not log Kow, showed a linear and positive relationship with bioaccumulation and trophic magnification factors and a parabolic relationship with biota-sediment accumulation factors. The trophodynamics of miconazole and acetophenone are reported for the first time. This study provides novel insights into the multimedia distribution and biomagnification potential of PPCPs and suggests that log Dow is a better indicator of their bioaccumulation and trophic magnification.

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

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

Single and mixture toxicity evaluation of avobenzone and homosalate to male zebrafish and H295R cells

Avobenzone and homosalate are widely used in sunscreens to provide ultraviolet (UV) protection, either as single compounds or in combination. Some UV filters exhibit estrogenic or anti-androgenic activities, however, studies regarding their interactions and toxicity in mixtures are limited. In this study, the effect of the toxicity of a binary mixture comprising avobenzone (0.72 μg L-1) and homosalate (1.02 and 103 μg L-1) on steroid hormone biosynthesis were investigated using male zebrafish and human adrenocortical carcinoma (H295R) cells. In fish exposed to homosalate, a significant decrease in the gonadosomatic index, testosterone level, and transcription of several genes (e.g, hsd3b2, cyp17a1, and hsd17b1) and a significant increase in the hepatosomatic index, liver steatosis, 17β-estradiol level, and transcription of vtg gene were observed. These results suggest that estrogenic and anti-androgenic effects of homosalate were mediated by the steroidogenic pathway. The presence of 0.72 μg L-1 of avobenzone augmented the anti-androgenic responses in male fish. The testosterone level in the H295R cells were significantly decreased after they were exposed to homosalate alone or in combination with avobenzone, which is consistent with observations in male zebrafish. Further studies need to be conducted to understand the endocrine disrupting properties of long-term exposure to substances typically used in sunscreens.

Insights in Pharmaceutical Pollution: The Prospective Role of eDNA Metabarcoding

Environmental pollution is a growing threat to natural ecosystems and one of the world's most pressing concerns. The increasing worldwide use of pharmaceuticals has elevated their status as significant emerging contaminants. Pharmaceuticals enter aquatic environments through multiple pathways related to anthropogenic activity. Their high consumption, insufficient waste treatment, and the incapacity of organisms to completely metabolize them contribute to their accumulation in aquatic environments, posing a threat to all life forms. Various analytical methods have been used to quantify pharmaceuticals. Biotechnology advancements based on next-generation sequencing (NGS) techniques, like eDNA metabarcoding, have enabled the development of new methods for assessing and monitoring the ecotoxicological effects of pharmaceuticals. eDNA metabarcoding is a valuable biomonitoring tool for pharmaceutical pollution because it (a) provides an efficient method to assess and predict pollution status, (b) identifies pollution sources, (c) tracks changes in pharmaceutical pollution levels over time, (d) assesses the ecological impact of pharmaceutical pollution, (e) helps prioritize cleanup and mitigation efforts, and (f) offers insights into the diversity and composition of microbial and other bioindicator communities. This review highlights the issue of aquatic pharmaceutical pollution while emphasizing the importance of using modern NGS-based biomonitoring actions to assess its environmental effects more consistently and effectively.

Occurrence and ecological risk assessment of organic UV filters in coastal waters of the Iberian Peninsula

This study aimed to assess the presence of 21 UVFs and metabolites in coastal regions of the Iberian Peninsula, to evaluate their environmental risk, and identify possible influential factors affecting their measured concentrations. Sampling was carried out in spring and summer to assess possible seasonal variations. UVFs were detected in 43 of the 46 sampling sites. Only 5 were found above LOD: BP4, OC, BP3 and metabolites BP1 and BP8. Samples collected in Mar Menor had the greatest variety of compounds per sample and the highest cumulative concentrations. The risk was characterized using Risk Quotients (RQ). BP1 showed a Low environmental Risk in 2 sites while for OC the RQ indicated a Moderate Risk in 22 points. The variables that contribute most to the variation are population density, sampling season, whether it was an open bay or not, and level of urbanization. The presence of WWTPs had a lower influence.

Profiling of the spatiotemporal distribution, risks, and prioritization of pharmaceuticals and personal care products in coastal waters of the northern Yellow Sea, China

Pharmaceuticals and personal care products (PPCPs) have aroused global concerns due to their ubiquitous occurrence and detrimental effects. The spatiotemporal distributions of 64 PPCPs and their synergetic ecological risks were comprehensively investigated in the seawater of Yantai Bay, and 1 H-benzotriazole (BT), ethenzamide, phenazone, propyphenazone, 4-hydroxybenzophenone and N, N'-diphenylurea were first determined in the seawater of China. Fifty-six PPCPs were detected and their concentrations were 27.5-182 ng/L, with BT contributing around 58.0%. Higher PPCP concentrations were observed in winter and spring, with the concentrations of antioxidants, analgesic/anti-inflammatory drugs and human-used antibiotics significantly higher in winter, while those of aquaculture-used antibiotics and UV filters significantly higher in summer, which was closely related with their usage patterns. Positive correlations were observed for PPCP concentrations between surface and bottom water, except summer, during which time the weak vertical exchange and varied environmental behaviors among different PPCPs resulted in the distinct compositions and concentrations. Terrestrial inputs and mariculture resulted in higher PPCP concentrations in the area located adjacent to the coast and aquaculture bases. The PPCP mixtures posed medium to high risk to crustaceans, and bisphenol A was identified as a high-risk pollutant that needs special attention.

Phytoplankton Biological Pump Controls the Spatiotemporal Bioaccumulation and Trophic Transfer of Antibiotics in a Large Subtropical River

The spatiotemporal bioaccumulation, trophic transfer of antibiotics, and regulation of the phytoplankton biological pump were quantitatively evaluated in the Pearl River, South China. The occurrence of antibiotics in organisms indicated a significant spatiotemporal trend associated with the life cycle of phytoplankton. Higher temporal bioaccumulation factors (BAFs) were found in phytoplankton at the bloom site, while lower BAFs of antibiotics in organisms could not be explained by phytoplankton biomass dilution but were attributed to the low bioavailability of antibiotics, which was highly associated with distribution coefficients (R2 = 0.480-0.595, p < 0.05). Such lower BAFs of antibiotics in phytoplankton at higher biomass sites hampered the entry of antibiotics into food webs, and trophic dilutions were subsequently observed for antibiotics except for ciprofloxacin (CFX) and sulfamerazine (SMZ) at sites with blooms in all seasons. Distribution of CFX, norfloxacin (NFX), and sulfapyridine (SPD) showed further significant positive relationships with the plasma protein fraction (R2 = 0.275-0.216, p < 0.05). Both mean BAFs and trophic magnification factors (TMFs) were significantly negatively correlated with phytoplankton biomass (R2 = 0.661-0.741, p < 0.05). This study highlights the importance of the biological pump in the regulation of spatiotemporal variations in bioaccumulation and trophic transfer of antibiotics in anthropogenic-impacted eutrophic rivers in subtropical regions.

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

Pharmaceuticals and microplastics constitute potential hazards in aquatic systems, but their combined effects and underlying toxicity mechanisms remain largely unknown. In this study, a simultaneous characterization of bioaccumulation, associated metabolomic alterations and potential recovery mechanisms was performed. Specifically, a bioassay on Mediterranean mussels (Mytilus galloprovincialis) was carried out with polyethylene microplastics (PE-MPLs, 1 mg/L) and citalopram or bezafibrate (500 ng/L). Single and co-exposure scenarios lasted 21 days, followed by a 7-day depuration period to assess their potential recovery. PE-MPLs delayed the bioaccumulation of citalopram (lower mean at 10 d: 447 compared to 770 ng/g dw under single exposure), although reaching similar tissue concentrations after 21 d. A more limited accumulation of bezafibrate was observed overall, regardless of PE-MPLs co-exposure (<MQL-3.2 ng/g dw). Metabolic profiles showed a strong effect of pharmaceuticals, generally independent of PE-MPLs co-exposure. Alterations of the citrate cycle (bezafibrate exposure) and steroid and prostaglandin metabolism (citalopram and bezafibrate exposures) were highlighted. PE-MPLs alone also impacted metabolic pathways, such as neurotransmitters or purine metabolism. After depuration, relevant latent or long-lasting effects were demonstrated as, for instance, the effect of citalopram on neurotransmitters metabolism. Altogether, the observed molecular-level responses to pharmaceuticals and/or PE-MPLs may lead to a dysregulation of mussels' reproduction, energy metabolism, and/or immunity.

Antidepressant pharmaceuticals in aquatic systems, individual-level ecotoxicological effects: growth, survival and behavior

The growing consumption of antidepressant pharmaceuticals has resulted in their widespread occurrence in the environment, particularly in waterways with a typical concentration range from ng L^-1 to μg L^-1. An increasing number of studies have confirmed the ecotoxic potency of antidepressants, not only at high concentrations but also at environmentally relevant levels. The present review covers literature from the last decade on the individual-level ecotoxicological effects of the most commonly used antidepressants, including their impact on behavior, growth, and survival. We focus on the relationship between antidepressants physico-chemical properties and dynamics in the environment. Furthermore, we discuss the advantages of considering behavioral changes as sensitive endpoints in ecotoxicology, as well as some current methodological shortcomings in the field, including low standardization, reproducibility and context-dependency.

Bioaccumulation and trophic transfer of antibiotics in the aquatic and terrestrial food webs of the Yellow River Delta

Antibiotic pollution caused by aquaculture industries is a common problem in the wetland of the Yellow River Delta (YRD). Aquatic and terrestrial food webs coexist and interact in wetlands. However, there are few comparative studies on antibiotics in these two food webs. This study investigated the occurrence, bioaccumulation, and trophic transfer of 19 antibiotics in the aquatic and terrestrial food webs of the YRD, and discussed the effects of physicochemical parameters in different food webs. The total concentrations of antibiotics in aquatic organisms and terrestrial organisms ranged from 11.61 to 63.08 ng/g dry weight (dw) and 4.21-9.11 ng/g dw, respectively. BAF (bioaccumulation factor), BSAF_a (biota sediment accumulation factor), and BSAF_t (biota soil accumulation factor) were used to explore the bioaccumulation capacity of antibiotics. The calculation results of these three factors showed that fluoroquinolones (FQs) had the highest bioaccumulation capacity. As for the trophic transfer, the total concentrations of antibiotics were biodiluted in the aquatic food web while biomagnified in the terrestrial food web. Physicochemical parameters of the antibiotics showed that log K_ow (octanol-water partition coefficient)/log D_ow (pH-dependent distribution coefficient) and log K_oa (octanol-air partition coefficient) were good predictors for antibiotic bioaccumulation in the aquatic and terrestrial organisms of the YRD, respectively. In addition, the increasing log D_ow and log K_oa led to a rise of TMF (trophic magnification factor) in the aquatic food web while a decrease of TMF in the terrestrial food web. Overall, these results provide insights into the mechanisms on bioaccumulation and trophic transfer of antibiotics in different food webs.

Comparison of developmental toxicity of benzophenone-3 and its metabolite benzophenone-8 in zebrafish

Benzophenone-3 (BP-3) as one of frequently used organic UV filters has been considered an emerging pollutant due to its toxicities. Benzophenone-8 (BP-8) is one of the main metabolites of BP-3 in organisms. Current reports show that BP-8 may be more toxic than BP-3. However, difference of their toxicities on embryonic development has rarely been reported. In this study, zebrafish embryos were chosen as the target organism to explore the developmental toxicities of BP-3 and BP-8. Non-targeted metabolomic analysis was performed to compare their modes of action. Results showed that BP-8 exposures led to higher bioaccumulation and lower hatching rate of zebrafish larvae than BP-3. Both BP-8 and BP-3 exposures caused behavioral abnormalities of zebrafish larvae, but no significant difference was found between them. At the metabolome level, 1 μg/L BP-3 and 1 μg/L BP-8 exposures altered neuroactive ligand-receptor interaction pathway and FoxO signaling pathway, respectively, which might be involved in the abnormal behaviors in zebrafish larvae. For higher exposure groups (30 and 300 μg/L), both BP-3 and BP-8 exposures changed metabolism of cofactors and vitamins of zebrafish larvae. Exposure of BP-3 altered the metabolism by pantothenate and CoA biosynthesis pathway, while BP-8 exposure changed riboflavin metabolism and folate biosynthesis. The above results indicated different modes of action of BP-3 and BP-8 in zebrafish embryonic development. This study sheds new light to biological hazards of BP-3 due to its metabolism in aquatic organisms.

Bioaccumulation as a method of removing psychoactive compounds from wastewater using aquatic plants

Since WWTPs are not able to eliminate all psychoactive pharmaceuticals, these compounds become a part of the aquatic ecosystem. Our results indicate that compounds such as codeine or citalopram are eliminated with low efficiency (<38%), and compounds such as venlafaxine, oxazepam, or tramadol even with almost no efficiency. Lower elimination efficiency may be caused by the accumulation of these compounds in the wastewater treatment process. This study is focused on the possibility to remove problematic psychoactive compounds using aquatic plants. HPLC-MS analysis of the leaf extract obtained from studied plants showed that the amount of accumulated methamphetamine was highest in Pistia stratiotes and lower in the leaves of Limnophila sessiliflora and Cabomba caroliniana. However, tramadol and venlafaxine were accumulated considerably only in Cabomba caroliniana. Our study demonstrates that especially these three compounds - tramadol, venlafaxine, and methamphetamine, are accumulated in aquatic plants and can be removed from the aquatic environment. In our study was also observed that helophytic aquatic plants show a higher ability to remove psychoactive compounds from wastewater. Iris pseudacorus showed the best results in selected pharmaceuticals removal with no bioaccumulation effect in leaves or roots.

Trophodynamic of endocrine disrupting compounds in the aquatic food webs: Association with hydrophobicity and biota metabolic rate

Increasing concentration of endocrine disrupting compounds (EDCs) are released into the aquatic environment, resulting in irreversible effects on the endocrine and reproductive systems of biota. How the liver enzymes affect metabolic rate of these compounds and thus their structure-related trophic transfer in aquatic food webs remains largely unknown. In this study, the concentrations of seven common EDCs were measured in 15 species of fish, 7 invertebrate species and plankton collected from Liuxi River to Pearl River, South China. The mean ΣEDC concentrations generally were found to increase as follows: plankton (29.59 ng g^-1 dw) < invertebrate species (50.69 ng g^-1 dw) < fish (122.56 ng g^-1 dw), with 4-nonylphenol (4-NP) and bisphenol S (BPS) as the predominant components. Trophic magnification factors (TMFs) values were >1.0 ranged from 1.30 (BPS) to 4.07 (4-NP), indicating trophic magnification potential. Measurement of metabolism and activities of microsomal CYP450 enzymes were performed in the fish liver microsomes of Hypophthalmichthys molitrix ([TL] = 2.27), Cirrhinus mrigala (TL = 3.87) and Odontamblyopus rubicundus (TL = 4.73). TMFs were significantly negatively correlated with the obtained in vitro biotransformation clearance rates (CL _{in vitro}) of EDCs and CYP450 enzymes activities. A multiple linear regression model indicated that biotransformation clearance is a more powerful predictor for TMFs than the hydrophobicity (Kow) to drive changes in the studied aquatic food web trophodynamics.

A novel role of various hydrogen bonds in adsorption, desorption and co-adsorption of PPCPs on corn straw-derived biochars

The effect of various hydrogen bonds with different strength on the environmental behaviors of PPCPs remains unclear. In this study, three pharmaceutical pollutants including clofibric acid (CA), sulfamerazine (SMZ), and acetaminophen (ACT) with different functional groups and pK_a, were selected as representative of PPCPs to investigate the pivotal role of hydrogen bonds in adsorption/desorption and co-adsorption behaviors of PPCPs on two corn straw-derived biochars prepared at 300 °C (BCs-300) and 600 °C (BCs-600), respectively. The results indicated that charge-assisted hydrogen bond (CAHB) and ordinary hydrogen bond (OHB) with different intensities were the pivotal mechanisms responsible for the adsorption of three PPCPs on biochars, which was further confirmed by FTIR, but their immobilization effects of PPCPs on biochars were completely different. Compared with OHB formed between CA and BCs-600, the stronger CAHB (formed between CA and BCs-300, and SMZ/ACT and BCs-300/BCs-600) with covalent bond characteristics that derived from the smaller |ΔpK_a| (<5.0), resulted in the greater adsorption capacity (Q_s) and affinity (K_f) of the three PPCPs on BCs-300 (Q_s ≥ 195 μmol·g^-1, K_f ≥ 1.9956) than that on BCs-600 (Q_s ≤ 92 μmol·g^-1, K_f ≤ 0.5192), thereby making the better immobilization effect of PPCPs by biochar. In addition, in the coexisting systems, either SMZ coexisting with CA/ACT on BCs-300, or ACT coexisting with CA/SMZ on BCs-600, both implied that when the |ΔpK_a| between the target PPCPs and biochar is smaller than that between the coexisting compound and biochar, the target PPCPs can preferentially occupy the shared hydrogen bond sites on the biochar surface, and hard to be replaced by the coexisting compound. This work not only expand the application of designed biochar as engineering adsorbents to control and removal of the specific PPCPs in the environment, but also facilitate accurate assessment of the environmental risk of co-existing PPCPs.

Distribution, Bioaccumulation, and Risks of Pharmaceutical Metabolites and Their Parents: A Case Study in an Yunliang River, Nanjing City

The occurrence, bioaccumulation, and risks of 11 pairs of pharmaceutical metabolites and their respective parents were investigated in the water, sediment, and fish of an urban river in Nanjing city, China. The results showed that most of the target metabolites and their parents were detected in all water samples, with concentrations ranging from 0.1 ng/L to 72.9 ng/L. In some cases, the concentrations of metabolites in water were significantly higher than their parents, with fold changes reaching up 4.1 in the wet season and 6.6 in the dry season, while in sediment and fish, a lower concentration was observed in most cases. A lowered concentration of detected pharmaceuticals was observed in the dry season when compared to the wet season due to the seasonal variation in pharmaceutical consumption and overflow effluent. The bioaccumulation of pharmaceuticals in different fish tissues were detected with a descending order of overall concentration as gill > brain > muscle > gonad > intestine > liver > blood. In addition, the concentrations of both metabolites and their parents also decreased along the river in two seasons. However, the concentration rates of metabolites and their parents were significantly altered along the river in both water and sediment. The relatively high concentration proportions of the detected pharmaceuticals in water suggested that pharmaceuticals were more likely to apportion in water than in sediment, especially for the metabolites. Meanwhile, the rates of the metabolite/parent pairs between fish and water/sediment were generally lower, indicating the higher excretion capacity of metabolites from fish than their parents. Most of the detected pharmaceuticals had no impact on aquatic organisms. However, the presence of ibuprofen posed a medium risk to fish. Compared to the parents, metabolites showed a relatively low risk value but a high contribution to the total risk. It highlights that metabolites in the aquatic environments cannot be ignored.

Neuroactive pharmaceuticals in estuaries: Occurrence and tissue-specific bioaccumulation in multiple fish species

Contamination of surface waters by pharmaceuticals is an emerging problem globally. This is because the increased access and use of pharmaceuticals by a growing world population lead to environmental contamination, threatening non-target species in their natural environment. Of particular concern are neuroactive pharmaceuticals, which are known to bioaccumulate in fish and impact a variety of individual processes such as fish reproduction or behaviour, which can have ecological impacts and compromise fish populations. In this work, we investigate the occurrence and bioaccumulation of 33 neuroactive pharmaceuticals in brain, muscle and liver tissues of multiple fish species collected in four different estuaries (Douro, Tejo, Sado and Mira). In total, 28 neuroactive pharmaceuticals were detected in water and 13 in fish tissues, with individual pharmaceuticals reaching maximum concentrations of 1590 ng/L and 207 ng/g ww, respectively. The neuroactive pharmaceuticals with the highest levels and highest frequency of detection in the water samples were psychostimulants, antidepressants, opioids and anxiolytics, whereas in fish tissues, antiepileptics, psychostimulants, anxiolytics and antidepressants showed highest concentrations. Bioaccumulation was ubiquitous, occurring in all seven estuarine and marine fish species. Notably, neuroactive compounds were detected in every water and fish brain samples, and in 95% of fish liver and muscle tissues. Despite variations in pharmaceutical occurrence among estuaries, bioaccumulation patterns were consistent among estuarine systems, with generally higher bioaccumulation in fish brain followed by liver and muscle. Moreover, no link between bioaccumulation and compounds' lipophilicity, species habitat use patterns or trophic levels was observed. Overall, this work highlights the occurrence of a highly diverse suite of neuroactive pharmaceuticals and their pervasiveness in waters and fish from estuarine systems with contrasting hydromorphology and urban development and emphasizes the urgent need for toxicity assessment of these compounds in natural ecosystems, linked to internalized body concentration in non-target species.