An integrated approach for chemical water quality assessment of an urban river stretch through Effect-Based Methods and emerging pollutants analysis with a focus on genotoxicity

Exposure to emerging water contaminants and human health risk: Cytotoxic and genotoxic effects of caffeine and diethyltoluamide (DEET) on eukaryotic cells

The presence of emerging pollutants in aquatic ecosystems due to human activities poses substantial concerns. While many studies explore detection and removal techniques for these compounds, conventional treatment methods often fail to address emerging pollutants. Moreover, there is a lack of legislation defining safe thresholds for these substances in water. Consequently, caffeine and N,N-diethyl-meta-toluamide (DEET) persist in surface waters, including treated sources, with limited understanding of their genomic effects on human cells. This study aimed to assess the cytotoxic and genotoxic effects of caffeine and DEET, individually and in combination, at concentrations detected in drinking water, using HepG2 cells. Additionally, through systems biology, we sought to understand the underlying molecular mechanisms of both substances. Cytotoxicity was evaluated using MTT and Trypan Blue assays, while genotoxicity was assessed using the comet assay. The chemoproteomic interaction network was constructed using STITCH and STRING databases, with subnetworks analyzed using Cytoscape plugins (MCODE, CentiScaPe, and BiNGO). Both compounds reduced HepG2 cell viability in a dose-dependent manner in both assays. Caffeine and DEET also induced DNA damage at all tested concentrations, including in co-exposure. Proteins related to the inflammatory response, signaling pathways, and xenobiotic metabolism were the main hub-bottlenecks of the chemoproteomic interaction network. These findings underscore the urgent need for further investigations into the presence of emerging pollutants in drinking water and their potential risks to human health.

Retrieve water quality parameters of urban rivers from hyperspectral images through feature interaction based two-stage method fused with spectral unmixing and spatial relatedness

Monitoring water quality through efficient quantification of water quality parameters (WQPs) is of paramount importance to environmental management of urban rivers. Unmanned aerial vehicle (UAV) remote sensing techniques posed a great opportunity for visualizing spatial distributions of WQPs concentrations with higher flexibility and monitoring frequency compared to satellite remote sensing techniques, assisting to trace potential contamination sources and prevent water quality from degradation. However, current methods of water quality monitoring usually involved large masses of water samples as training data to keep calculation accuracy every time their study area changed, increasing financial cost and incurring time delay in monitoring and evaluating water quality. This study proposed a UAV-based two-stage multidirectional fusion with probabilistic matrix factorization (TSMF-PMF) method in unified framework, to effectively quantify WQPs including chemical oxygen demand (COD), biochemical oxygen demand (BOD), and turbidity from UAV hyperspectral images. TSMF-PMF established feature interaction and outlier feedback module, ensuring relatively high calculation stability with less training samples. The experimental results showed that TSMF-PMF achieved good performance on predicting concentrations of WQPs with coefficient of determination (R2) and mean absolute percentage error (MAPE) ranging from 0.82 to 0.91 and from 5.35 % to 10.23 %. This study established theoretical and technical foundation to optimize environmental management scheme of urban rivers and provided an application demonstration.

Chemical contaminants and environmental stressors induced teratogenic effect in aquatic ecosystem - A comprehensive review

Aquatic environments, including marine and freshwater ecosystems, are vital for ecological balance and biodiversity. The rising global demand for aquaculture products necessitates increased production, with intensified aquaculture practices posing significant environmental risks. This review explores the pathways through which chemical pollutants, heavy metals, pharmaceuticals, and environmental stressors induce teratogenic effects in aquatic species. The review highlights the impact of pesticide include triazine herbicides, organophosphate and organochlorine insecticides, and carbamates on aquatic life, emphasizing their interference with endocrine systems and developmental processes. Heavy metals like mercury, lead, cadmium, arsenic, and chromium are noted for their persistence and bioaccumulative properties, disrupting cellular and hormonal functions. Pharmaceuticals, including NSAIDs, antibiotics, and chemotherapeutic agents, exert teratogenic effects by disrupting physiological and developmental pathways. Environmental stressors includes temperature fluctuations, salinity variations, pH changes, and oxygen level imbalances exacerbate the teratogenic impact of pollutants. This review highlights the importance of comprehensive environmental management and understanding these complex interactions is essential for formulating efficient strategies to safeguard the effective measures to protect aquatic ecosystems and the biodiversity.

Emerging pollutants in the aquatic environments: A review of genotoxic impacts

Urbanization and industrial growth have negatively impacted water quality, raising concerns about emerging aquatic pollutants. Despite advancements in water treatment, these substances persist, endangering aquatic life and human health. Although research has focused on the physiological effects of these pollutants, their genetic damage potential remains poorly understood. This systematic review aimed to consolidate existing knowledge on the genotoxic potential of emerging aquatic pollutants. A comprehensive search was conducted across major databases, encompassing articles published from 2001 to 2022. The review primarily focused on research articles that evaluated genotoxicity in environmental samples containing emerging pollutants, as well as in vitro studies using various concentrations of these substances. Fourteen articles were included in the review, with pharmaceutical compounds, personal care products, disinfection byproducts, and industrial chemicals being the most extensively investigated classes. Other notable pollutants included metals, cyanotoxins, antiseptics, pesticides, and caffeine. All these pollutants classes were found to cause DNA damage, either in vitro at specific concentrations or in complex environmental mixtures. The comet assay was the most frequently used method, owing to its sensitivity and practicality in assessing DNA damage. For some pollutants, different responses were observed when comparing in vitro and in vivo studies, emphasizing the need for studies employing both approaches. However, the limited number of available articles underscores the necessity for further research on the genotoxic potential of emerging pollutants. More research is required to clarify mutagenicity, DNA repair kinetics, and cumulative effects of pollutants, which are critical for shaping policies and ensuring safe water quality. A greater knowledge about these pollutants will enable better understanding risk mitigation, ultimately protecting public health and ecosystems.

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.

Metabolomic and sphingolipidomic profiling of human hepatoma cells exposed to widely used pharmaceuticals

Pharmaceutical compounds have become one of the main contaminants of emerging concern (CECs) due to their high usage and increased release into the environment. This study aims to assess the effects caused by three widely consumed hepatotoxic pharmaceutical compounds: an antibiotic (amoxicillin), an antiepileptic (carbamazepine), and an antidepressant (trazodone), on human health when indirectly exposed to toxicologically relevant concentrations (30, 15, and 7.5 μM for amoxicillin and carbamazepine, and 4, 2, and 1 μM for trazodone). A combination of semi-targeted metabolomic and targeted sphingolipid analyses was chosen to unravel the metabolic alterations in human hepatic cells exposed to these CECs at three concentrations for 24 h. HepG2 hepatoma cells were encapsulated in sodium alginate spheroids to improve the physiological relevance of this in vitro approach. Statistical analysis was used to identify the most affected metabolites and sphingolipids for each drug exposure. The results revealed small but significant changes in response to carbamazepine and trazodone exposures, affecting sphingolipid, glycerophospholipid precursors, and amino acid metabolism. Under both drug treatments, a decrease in various ceramide species (related to cell signaling) was observed, along with reduced taurine levels (related to the biosynthesis of bile acid conjugates) and carnitine levels (suggesting an impact on energy production). These and other drug-specific changes indicate that cellular functions in liver cells might be altered under low doses of these CECs, potentially affecting the health of other organs.

Predicting micropollutant removal through nanopore-sized membranes using several machine-learning approaches based on feature engineering

Predicting the efficacy of micropollutant separation through functionalized membranes is an arduous endeavor. The challenge stems from the complex interactions between the physicochemical properties of the micropollutants and the basic principles underlying membrane filtration. This study aimed to compare the effectiveness of a modest dataset on various machine learning tools (ML) tools in predicting micropollutant removal efficiency for functionalized reverse osmosis (RO) and nanofiltration (NF) membranes. The inherent attributes of both the micropollutants and the membranes are utilized as input factors. The chosen ML tools are supervised algorithm (adaptive network-based fuzzy inference system (NF), linear regression framework (linear regression (LR)), stepwise linear regression (SLR) and multivariate linear regression (MVR)), and unsupervised algorithm (support vector machine (SVM) and ensemble boosted tree (BT)). The feature engineering and parametric dependency analysis revealed that characteristics of micropollutants, such as maximum projection diameter (MaxP), minimal projection diameter (MinP), molecular weight (MW), and compound size (CS), exhibited a notably positive impact on the correlation with removal efficiency. Model combination with key variables demonstrated high prediction accuracy in both supervised and unsupervised ML for micropollutant removal efficiency. An NF-grid partitioning (NF-GP) model achieved the highest accuracy with an R 2 value of 0.965, accompanied by low error metrics, specifically an RMSE and MAE of 3.65. It is owed to the handling of the complex spatial and temporal aspects of micropollutant data through division into consistent subsets facilitating improved identification of rejection efficiency and relationships. The inclusion of inputs with both negative and positive correlations introduces variability, amplifies the system responsiveness, and impedes the precision of predictive models. This study identified key micropollutant properties, including MaxP, MinP, MW, and CS, as crucial factors for efficient micropollutant rejection during real-time filtration applications. It also allowed the design of pore size of self-prepared membranes for the enhanced separation of micropollutants from wastewater.

High-Throughput Transcriptomics of Water Extracts Detects Reductions in Biological Activity with Water Treatment Processes

The presence of numerous chemical contaminants from industrial, agricultural, and pharmaceutical sources in water supplies poses a potential risk to human and ecological health. Current chemical analyses suffer from limitations, including chemical coverage and high cost, and broad-coverage in vitro assays such as transcriptomics may further improve water quality monitoring by assessing a large range of possible effects. Here, we used high-throughput transcriptomics to assess the activity induced by field-derived water extracts in MCF7 breast carcinoma cells. Wastewater and surface water extracts induced the largest changes in expression among cell proliferation-related genes and neurological, estrogenic, and antibiotic pathways, whereas drinking and reclaimed water extracts that underwent advanced treatment showed substantially reduced bioactivity on both gene and pathway levels. Importantly, reclaimed water extracts induced fewer changes in gene expression than laboratory blanks, which reinforces previous conclusions based on targeted assays and improves confidence in bioassay-based monitoring of water quality.

In situ detection of the genotoxic potential as one of the lines of evidence in the weight-of-evidence approach-the Joint Danube Survey 4 Case Study

Environmental studies which aim to assess the ecological impact of chemical and other types of pollution should employ a complex weight-of-evidence approach with multiple lines of evidence (LoEs). This study focused on in situ genotoxicological methods such as the comet and micronucleus assays and randomly amplified polymorphic DNA analysis as one of the multiple LoEs (LoE3) on the fish species Alburnus alburnus (bleak) as a bioindicator. The study was carried out within the Joint Danube Survey 4 (JDS4) at nine sites in the Danube River Basin in the Republic of Serbia. Out of nine sampling sites, two were situated at the Tisa, Sava, and Velika Morava rivers, and three sites were at the Danube River. The three additionally employed LoEs were: SumTUwater calculated based on the monitoring data in the database of the Serbian Environmental Protection Agency (SEPA) (LoE1); in vitro analyses of JDS4 water extracts employing genotoxicological methods (LoE2); assessment of the ecological status/potential by SEPA and indication of the ecological status for the sites performed within the JDS4 (LoE4). The analyzed biomarker responses in the bleak were integrated into the unique integrated biomarker response index which was used to rank the sites. The highest pollution pressure was recorded at JDS4 39 and JDS4 36, while the lowest was at JDS4 35. The impact of pollution was confirmed at three sites, JDS4 33, 40, and 41, by all four LoEs. At other sampling sites, a difference was observed regarding the pollution depending on the employed LoEs. This indicates the importance of implementing a comprehensive weight-of-evidence approach to ensure the impact of pollution is not overlooked when using only one LoE as is often the case in environmental studies.

From city to sea: Spatiotemporal dynamics of floating macrolitter in the Tiber River

Rivers are undoubtedly the main pathway of waste dispersed in the environment that from land reaches oceans and seas increasing the amount of marine litter. Major cities are a great source of riverine litter as large urbanization can originate pressure on the integrated waste management resulting in litter entering the rivers. Within this study, we aim to investigate the dynamic of floating riverine macrolitter (items >2.5 cm) in the city of Rome before it reaches the sea by assessing the composition, amount, and seasonal trends of litter transported from the urban centre to the main river mouth of Tiber River. Visual surveys for a whole year (March 2021-February 2022) were conducted from two bridges, Scienza Bridge (in the city) and Scafa Bridge (at the main river mouth) and followed JRC/RIMMEL protocol for riverine litter monitoring. Overall, similar litter composition was observed from the city centre to the mouth with a prevalence of plastic material, mainly related to fragmentation process (i.e. plastic pieces) and single use items, mainly in food and beverage sectors. An extrapolated annual loading of 4 × 10⁵ items/year was estimated at the main mouth of Tiber River. The litter flux seems to be influenced by the seasonal variability and hydrometeorological parameters. The frequency of size classes decreases with increasing size in both sites, and more than half of the recorded items were below 10 cm. Specific categories belonging to "other plastics" have been reported related to anti-Covid-19 behaviour such as face masks and beverage sector, e.g. bottle lids and rings. The main colour of plastics was white, suggesting weathering process of floating riverine litter. This study contributes to increasing knowledge of the origin, composition and spatiotemporal dynamics of riverine floating litter from the city and entering the sea.

Eco-Friendly Engineered Nanomaterials Coupled with Filtering Fine-Mesh Net as a Promising Tool to Remediate Contaminated Freshwater Sludges: An Ecotoxicity Investigation

The use of eco-friendly engineered nanomaterials represents a recent solution for an effective and safe treatment of contaminated dredging sludge. In this study, an eco-designed engineered material based on cross-linked nanocellulose (CNS) was applied for the first time to decontaminate a real matrix from heavy metals (namely Zn, Ni, Cu, and Fe) and other undesired elements (mainly Ba and As) in a lab-scale study, with the aim to design a safe solution for the remediation of contaminated matrices. Contaminated freshwater sludge was treated with CNS coupled with a filtering fine-mesh net, and the obtained waters were tested for acute and sublethal toxicity. In order to check the safety of the proposed treatment system, toxicity tests were conducted by exposing the bacterium Aliivibrio fischeri and the crustacean Heterocypris incongruens, while subtoxicity biomarkers such as lysosomal membrane stability, genetic, and chromosomal damage assessment were performed on the freshwater bivalve Dreissena polymorpha. Dredging sludge was found to be genotoxic, and such genotoxicity was mitigated by the combined use of CNS and a filtering fine-mesh net. Chemical analyses confirmed the results by highlighting the abetment of target contaminants, indicating the present model as a promising tool in freshwater sludge nanoremediation.

Ecotoxicological assessment of water and sediment river samples to evaluate the environmental risks of anthropogenic contamination

Several studies have shown the issue of effluent discharges as a source of contamination into waterways. Still, the impact of chemical pollutants on sediment is less well understood, especially from an ecotoxicological perspective, even though it is known that chemicals from industrial processes are frequently released into river systems. Therefore, here we compared water-sediment samples collected in high-anthropogenic urban area and low-anthropogenic peri-urban area. We have used physicochemical parameters, genotoxicity assay, bioindication and acute and surviving chronic toxicity tests - in an integrated biological assessment. Results suggest no acute toxicity related to exposure to samples from both areas. Still, samples collected in the high-anthropogenic urban area were associated with chronic toxicity effects in D. magna. Heavy metals Pb, Cu, and Cr were found in all samples. Even having all averages below the allowed level as determined by CONAMA (Resolution 420-Class 2), the Water Quality Index (WQI) score showed us that samples from high-anthropogenic sites were identified as "Poor," and samples from low-anthropogenic sites were identified as "Good." Ephemeroptera, Plecoptera, and Odonata, which are very sensitive organisms, were largely absent in high-anthropogenic areas, showing that it is likely to be associated with WQI. Therefore, careful consideration should be applied to monitoring effluent discharges using predictive tests, considering the environmental risks of sediment contamination and its consequences on the total environment.

Two constructed wetlands within a Mediterranean natural park immersed in an agrolandscape reduce most heavy metal water concentrations and dampen the majority of pesticide presence

The water concentrations of 12 heavy and other metals/metalloids were analyzed seasonally along two horizontal-flow constructed wetlands (CWs) (Tancat Mília-TM and Tancat l'Illa-TLI) located within the Mediterranean Albufera de València Natural Park during 2020-2021. A wide-scope screening of pesticides present in waters was also performed. The two CWs were created to improve water quality and increase biodiversity. They currently receive effluent waters from two different tertiary-treatment wastewater plants, and the water flows along the CWs before being discharged into the main lagoon and a smaller lagoon in TM and TLI, respectively. TLI manages to reduce (Mn) or maintain the concentration of most of the studied elements (Zn, Ni, Hg, Cr, Fe Cd, Cu) at the same level as outside (67%). Only Al, Pb, B, and As remain at a higher concentration. TM also reduces Zn and Cu and keeps the concentration of Cr, Cd, and Hg (representing 42%). Al, Pb, B, and As remain at higher concentrations, as in TLI, but Ni, Fe, and Mn are also at higher concentrations. Although both CWs vary in their ability to remove elements, no risks to human health or the environment have been detected due to the low metal concentration in their outlets, all of them (except Hg) below the legal limits for environmental quality in the European Union. With the detection of 71 compounds in water in each CW area (26 herbicides, 26 insecticides, and 19 fungicides in TLI, and 29 herbicides, 23 insecticides, and 19 fungicides in TM), we also provide evidence of the impact of pesticides, which depends on the application method (helicopter, tractor), originated from areas with high agricultural pressure (chiefly rice crops) on systems (mainly TM) created to preserve biodiversity. Nevertheless, both systems provide crucial environmental services in water quality in this agrolandscape.

Pesticides in surface freshwater: a critical review

The objective of this study was to critically review studies published up to November 2021 that investigated the presence of pesticides in surface freshwater to answer three questions: (1) in which countries were the studies conducted? (2) which pesticides are most evaluated and detected? and (3) which pesticides have the highest concentrations? Using the Prisma protocol, 146 articles published from 1976 to November 2021 were included in this analysis: 127 studies used grab sampling, 10 used passive sampling, and 9 used both sampling techniques. In the 45-year historical series, the USA, China, and Spain were the countries that conducted the highest number of studies. Atrazine was the most evaluated pesticide (56% of the studies), detected in 43% of the studies using grab sampling, and the most detected in passive sampling studies (68%). The compounds with the highest maximum and mean concentrations in the grab sampling were molinate (211.38 µg/L) and bentazone (53 µg/L), respectively, and in passive sampling, they were oxyfluorfen (16.8 µg/L) and atrazine (4.8 μg/L), respectively. The levels found for atrazine, p,p'-DDD, and heptachlor in Brazil were higher than the regulatory levels for superficial water in the country. The concentrations exceeded the toxicological endpoint for at least 11 pesticides, including atrazine (Daphnia LC₅₀ and fish NOAEC), cypermethrin (algae EC50, Daphnia and fish LC₅₀; fish NOAEC), and chlorpyrifos (Daphnia and fish LC₅₀; fish NOAEC). These results can be used for planning pesticide monitoring programs in surface freshwater, at regional and global levels, and for establishing or updating water quality regulations.