Mutagenicity, health risk, and disease burden of exposure to organic micropollutants in water from a drinking water treatment plant in the Yangtze River Delta, China

Comprehensive monitoring and prioritizing for contaminants of emerging concern in the Upper Yangtze River, China: An integrated approach

Contaminants of emerging concern (CECs) in aquatic environments can adversely impact ecosystems and human health even at low concentrations. This study assessed the risk of 162 CECs, including neonicotinoid pesticides, triazine pesticides, carbamate pesticides, psychoactive substances, organophosphate esters, antidepressants, per- and polyfluoroalkyl substances, and antibiotics in 10 drinking water sources and two tributaries (Jialing and Wujiang Rivers) of the Upper Yangtze River in Chongqing, China. Target screening detected 156 CECs at 0.01-2218.2 ng/L, while suspect screening via LC-QTOF-MS identified 64 CECs, with 13 pesticides, 29 pharmaceuticals and personal care products, and 2 industrial chemicals reported for the first time in the Yangtze River Basin. Risk quotient-based ecological risk assessment revealed that 48 CECs posed medium to high risks (RQ > 0.1) to aquatic life, with antibiotics (n = 20) as the main contributors. Non-carcinogenic risks were below negligible levels, but carcinogenic risks from neonicotinoids, triazines, antidepressants, and antibiotics were concerning. A multi-criteria prioritization approach integrating occurrence, physico-chemical properties, and toxicological data ranked 26 CECs as high priority. This study underscores the importance of comprehensive CEC screening in rivers and provides insights for future monitoring and management strategies.

Assessment of dynamics and variability of organic substances in river bank filtration for prioritisation in analytical workflows

Bank filtration supports the growing global demand for drinking water amidst concerns over organic micropollutants (OMPs). Efforts to investigate, regulate and manage OMPs have intensified due to their documented impacts on ecosystems and human health. Non-targeted analysis (NTA) is critical for addressing the challenge of numerous OMPs. While identification in NTA typically prioritises compounds based on properties like toxicity, considering substance quantity, occurrence frequency and exposure duration is essential for comprehensive risk management. A prioritisation scheme, drawing from intensive sampling and NTA of bank filtrate, is presented and reveals significant variability in OMP occurrence. Quasi-omnipresent substances, though only 7% of compounds, accounted for 44% of cumulative detections. Moderately common substances, constituting 31% of compounds, accounted for 50% of cumulative detections. Rare compounds, comprising 61%, contributed only 6% to cumulative detections. The application of suspect screening for 31 substances to the dataset yielded results akin to NTA, underscoring NTA's value. Correlation between both methods demonstrates the efficacy of high-resolution mass spectrometry-based NTA in assessing temporal and quantitative OMP dynamics.

Phthalate esters in clothing: A review

Phthalate esters (PAEs) are widely used as plasticizers to enhance the flexibility and durability of different consumer products, including clothing. However, concerns have been raised about the potential adverse health effects associated with the presence of phthalates in textiles, such as endocrine disruption, reproductive toxicity and potential carcinogenicity. Based on examination of more than 120 published articles, this paper presents a comprehensive review of studies concerning the phthalate content in clothing and other textile products, with special emphasis on those conducted in the last decade (2014-2023). The types and role of PAEs as plasticizers, the relevant legislation in different countries (emphasizing the importance of monitoring PAE levels in clothing to protect consumer health) and the analytical methods used for PAE determination are critically evaluated. The review also discusses the models used to evaluate exposure to PAEs and the associated health risks. Finally, the study limitations and challenges related to determining the phthalate contents of textile products are considered.

Occurrence and Health Risks of Organic Micropollutants in Tap Water in Dalian

Organic micropollutants (OMPs) in tap water may pose risks to human health. Previous studies on the potential health risks of OMPs in tap water may have underestimated the potential health risks of OMPs due to their limited coverage in target pollutants and incomplete toxicity data. In this study, tap water samples were collected in 37 sampling sites in Dalian, China. More than 1,200 target pollutants were screened by combining screening analysis and target analysis. A total of 93 OMPs were detected, with concentration summation ranging from 157 to 1.7 × 104 ng/L among different sampling sites. A total of 17 OMPs (12 agrochemicals, 3 pharmaceuticals and personal care products, and 2 other compounds) were detected in over 80% of the sampling sites. Especially, imidacloprid, tebuconazole, and atrazine-desethyl were found in all the sampling sites. Computational toxicology models were adopted to predict the missing toxicity threshold values of the identified chemicals. Noncarcinogenic risks were estimated to be negligible among all the sampling sites, while carcinogenic risks at six sites were above 10-6 but below 10-4, indicating non-negligible risks. Griseofulvin contributed the most to the carcinogenic risk. This study offers valuable insights that can guide future initiatives to safeguard tap water safety.

Bacterial worth in genotoxicity assessment studies

Bacterial-based genotoxicity test systems play a significant role in the detection and evaluation of genotoxicity in vitro and have gained importance due to attributes like wide applicability, speed, high sensitivity, good reproducibility, and simplicity. The Salmonella microsomal mutagenicity assay was created by Ames and colleagues at the beginning of the 1970s, and it was based on the fundamental notion that in auxotrophic bacterial strains with inhibited growth, a mutant gene would revert to its original state on exposure to genotoxicants. This is the most successful and widely used in vitro genotoxicity test. Later, a number of additional test systems that incorporated DNA repair mechanisms including the bacterial SOS response were created. Genetic engineering has further provided significant advancement in these test systems with the development of highly sophisticated bacterial tester strains with significantly increased sensitivity to evaluate the chemical nature of hazardous substances and pollutants. These bacterial bioassays render an opportunity to detect the defined effects of compounds at the molecular level. In this review, all the aspects related to the bacterial system in genotoxicity assessment have been summarized and their role is elaborated concerning real-time requirements and future perspectives.

Construction of Pt@BiFeO3 Xerogel-Supported O-g-C3N4 Heterojunction System for Enhanced Visible-Light Activity towards Photocatalytic Degradation of Rhodamine B

Synthetic organic pigments from the direct discharge of textile effluents are considered as colossal global concern and attract the attention of scholars. The efficient construction of heterojunction systems involving precious metal co-catalysis is an effective strategy for obtaining highly efficient photocatalytic materials. Herein, we report the construction of a Pt-doped BiFeO₃/O-g-C₃N₄ (Pt@BFO/O-CN) S-scheme heterojunction system for photocatalytic degradation of aqueous rhodamine B (RhB) under visible-light irradiation. The photocatalytic performances of Pt@BFO/O-CN and BFO/O-CN composites and pristine BiFeO₃ and O-g-C₃N₄ were compared, and the photocatalytic process of the Pt@BFO/O-CN system was optimized. The results exhibit that the S-scheme Pt@BFO/O-CN heterojunction has superior photocatalytic performance compared to its fellow catalysts, which is due to the asymmetric nature of the as-constructed heterojunction. The as-constructed Pt@BFO/O-CN heterojunction reveals high performance in photocatalytic degradation of RhB with a degradation efficiency of 100% achieved after 50 min of visible-light irradiation. The photodegradation fitted well with pseudo-first-order kinetics proceeding with a rate constant of 4.63 × 10^-2 min^-1. The radical trapping test reveals that h⁺ and ^•O₂^- take the leading role in the reaction, while the stability test reveals a 98% efficiency after the fourth cycle. As established from various interpretations, the considerably enhanced photocatalytic performance of the heterojunction system can be attributed to the promoted charge carrier separation and transfer of photoexcited carriers, as well as the strong photo-redox ability established. Hence, the S-scheme Pt@BFO/O-CN heterojunction is a good candidate in the treatment of industrial wastewater for the mineralization of organic micropollutants, which pose a grievous threat to the environment.

Occurrence, spatial distribution, and potential risks of organic micropollutants in urban surface waters from qinghai, northwest China

Lack of knowledge on the destiny of organic micropollutants (OMPs) in the Tibetan Plateau region of China prevents the public from being aware of the need for protecting these unique aquatic ecosystems that are precious water resources and source areas of the Yellow River. To address this knowledge gap, this study systematically investigated the multi-residue analysis, distribution, and potential risks of six types of OMPs, namely, neonicotinoid pesticides (NEOs), fungicides, organophosphate esters (OPEs), organophosphorus pesticides (OPPs), psychoactive substances (PSs), and antidepressants (ADs), in surface waters of major cities in Qinghai. A total of 31 compounds, consisting of 8 NEOs, 1 fungicide, 12 OPEs, 2 OPPs, 5 PSs, and 3 ADs, were detected in >50% of the sites, showing their ubiquitous nature in the study area. Results showed that the total OMP concentration in surface water was 28.3-908 ng/L, and OPEs were the dominant composition (48.6%-97.4%). The risk quotient values of the detected diazinon and dursban regularly exceeded 1 for aquatic organisms at all sampling sites, indicating moderate-high chronic ecological risk. The joint probability curves showed that dursban and NEOs have higher risk levels than other OMPs. Although the results of the non-carcinogenic total hazard quotient of the OMPs in the surface water was less than 1 in all age groups and the carcinogenic risk was lower than the negligible risk level, the potential risks to children and infants were considerably greater and should not be underestimated. In addition to pollutant concentration and exposure duration, ingestion rate and body weight (BW) are also important factors affecting health risk, with BW having a negative effect. To the best of the authors' knowledge, this report is the first to describe OMP pollution in Qinghai, and the results provide new insight into the ecological security of the water resources of the Tibetan Plateau.

Seasonal variability, predictive modeling and health risks of N-nitrosamines in drinking water of Shanghai

The prevalence of carcinogenic N-nitrosamines in drinking water is of significant concern. In the present study, eight N-nitrosamines from three representative drinking water treatment plants (DWTPs) in Shanghai, China were monitored for an entire year to evaluate their seasonal variability, probabilistic cancer risk and the resulting disease burden. The possibility of employing routinely monitored water quality parameters as predictors of N-nitrosamines was also examined. The results showed that the Taipu River-fed reservoir suffered more serious N-nitrosamine contamination than the Yangtze River-fed reservoirs. Winter witnessed higher levels of N-nitrosamines in both source and finished water. N-nitrosamine concentrations increased from source water to finished water in autumn or winter, but no spatial variations were observed in summer. The total lifetime cancer risk (LCR) posed by N-nitrosamines in finished water was within the acceptable range (1.00 × 10^-6 to 1.00 × 10^-4), with N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) being the main contributors. Winter and autumn were found to have higher total LCR values. The average individual disability-adjusted life years (DALYs) lost was 4.43 × 10^-6 per person-year (ppy), exceeding the reference risk level (1.00 × 10^-6 ppy). Liver cancer accounted for 97.1 % of the total disease burden, while bladder and esophagus cancers made a little contribution (2.9 %). A multiple regression model was developed to estimate the total N-nitrosamines in finished water as a function of water quality parameters, and the R² value was 0.735. This study not only provides fundamental data for public health policy development, but also reveals the necessity to incorporate a seasonal control strategy in DWTPs to minimize the associated health risks induced by N-nitrosamines.

Priority screening of contaminant of emerging concern (CECs) in surface water from drinking water sources in the lower reaches of the Yangtze River based on exposure-activity ratios (EARs)

Surface water provides ecological services such as drinking water supply. However, contaminants of emerging concern (CECs) are rising concerns because they are ubiquitously detected in surface water and pose potential risks to the aquatic environment and human health. This study investigated the occurrence of 165 CECs in surface water from drinking water source areas along the lower reaches of the Yangtze River to prioritize the CECs and to estimate potential biological activity based on exposure-activity ratio (EAR). A total of 70 CECs were detected in the surface water at least once at the selected 17 sampling sites, and their concentrations ranged from 0.592 to 4650 ng/L. Twenty-four CECs were detected at each site, and these were mostly pharmaceutical and personal care products and pesticides. Sucralose, 1H-benzotriazole and carbendazim were the most common CECs with high median concentrations in the study area. Specifically, sucralose, an artificial sweetener, was presented at each site with the highest median concentration (3010 ng/L), which indicated that anthropogenic inputs are an important source of contaminants. Medroxyprogesterone and trenbolone were identified as the priority contaminants of interest, with maximum EAR_chemical values of 0.389 and 0.183, respectively. Among all the sites, the higher cumulative EAR_mixture value was found from Nantong City (0.765), which indicated that this site could have a relatively greater potential for biological effects, and these effects were mainly due to medroxyprogesterone and trenbolone. In regard to the bioactivity of all detected CECs, nuclear receptors showed the greatest potential bioactivity in this region, particularly androgen receptor-mediated bioactivity, which is most likely affected organisms residing in the source water area. These results suggest that the drinking water sources from the studied region are contaminated with CECs, and highlight the prioritization of future monitoring and research to protect source waters.

Removal of micropollutants through bio-based materials as a transition to circular bioeconomy: Treatment processes involved, perspectives and bottlenecks

The recent increase in micropollutant levels in water bodies is a growing concern globally. The generation of new materials and techniques for wastewater treatment often involves the release of hazardous wastes and the utilization of energy related to it. This can be resolved by the synthesis of bio-based materials through the use of already released wastes and naturally occurring components, adding their value as reusable resources. These bio-based materials find wide applications for micropollutant elimination and energy tapping due to the presence of various functional groups, large surface area, high stability, and reusability. The processes involved in micropollutant elimination through biomaterials generally include adsorption and degradation. These treatment processes are suggested to depend on various operational parameters like pH, temperature, dose, reaction time, presence of other contaminants, ions, etc. in the system, which may influence the process efficiency. Understanding the potential of bio-based materials many steps can be taken towards its large-scale application to upgrade wastewater treatment plants for micropollutant elimination. Furthermore, the recent advances of bio-based materials in energy storage and conversion have widened its scope for implementation in a circular bioeconomy. The bottlenecks towards such a transition and future recommendations are also presented and discussed.

Removal of organic micropollutans by adsorptive membrane

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

A perspective review on medicinal plant resources for their antimutagenic potentials

Mutagens present in the environment manifest toxic effects and are considered as serious threat for human health and healthcare. Recent reports reveal that medicinal plant resources are being explored for identifying potent antimutagenic as well as cancer preventing agents. There is mounting evidence that cancer and other mutation-related diseases can be prevented with the use of medicinal pant resources including crude extracts, active fractions, phytochemicals, and pure phytomolecules. These medicinal plant resources possessing antimutagenic potentials have been shown to target molecular mechanisms underlying the mutagenic impacts. Technological advents and high-throughput screening/activity methods have revolutionized this field, though several potent plants and their active principles have been reported as effective antimutagens. The translational success rate needs to be improved, but the trends are encouraging. In this review, we present the current understandings and updates on various mutagens in the environment, toxicities related/attributed to them, the resultant mutations (and cancer), and how medicinal plants come to the rescue. A perspective review has been presented on whether and how medicinal plant resources can be an effective approach for addressing mutagens in the environment. An account of medicinal plant resources used as antimutagenic agents has been given along with the underlying mechanism of action and their therapeutic potential in various models of cancer. Recent success stories, current challenges, and future prospects are discussed.

Bioremediation of 27 Micropollutants by Symbiotic Microorganisms of Wetland Macrophytes

Background: Micropollutants in bodies of water represent many challenges. We addressed these challenges by the application of constructed wetlands, which represent advanced treatment technology for the removal of micropollutants from water. However, which mechanisms specifically contribute to the removal efficiency often remains unclear. Methods: Here, we focus on the removal of 27 micropollutants by bioremediation. For this, macrophytes Phragmites australis, Iris pseudacorus and Lythrum salicaria were taken from established wetlands, and a special experimental set-up was designed. In order to better understand the impact of the rhizosphere microbiome, we determined the microbial composition using 16S rRNA gene sequencing and investigated the role of identified genera in the micropollutant removal of micropollutants. Moreover, we studied the colonization of macrophyte roots by arbuscular mycorrhizal fungi, which are known for their symbiotic relationship with plants. This symbiosis could result in increased removal of present micropollutants. Results: We found Iris pseudacorus to be the most successful bioremediative system, as it removed 22 compounds, including persistent ones, with more than 80% efficiency. The most abundant genera that contributed to the removal of micropollutants were Pseudomonas, Flavobacterium, Variovorax, Methylotenera, Reyranella, Amaricoccus and Hydrogenophaga. Iris pseudacorus exhibited the highest colonization rate (56%). Conclusions: Our experiments demonstrate the positive impact of rhizosphere microorganisms on the removal of micropollutants.

Dysregulation of fatty acid metabolism associated with esophageal inflammation of ICR mice induced by nitrosamines exposure

Nitrosamines, as ubiquitous environmental carcinogens with adverse impact on human health, were crucial inducers of esophageal cancer (EC). Esophageal inflammation (EI) was an important biological process and considered to be associated with the progression of EC. However, the underlying regulatory mechanism of EI process caused by nitrosamines exposure remained largely unclear. In this study, a metabolomics approach based on mass spectrometry was utilized to explore the effect of nitrosamines exposure to ICR mice. Also, the changes of pivotal metabolic enzyme levels, urinary nitrosamines and histopathological analysis were evaluated. The results showed that nitrosamines exposure was intimately interrelated with EI process in mice. Metabolomics profiling analysis indicated that nitrosamines caused significant alterations of metabolic pathway predominantly enriched in fatty acid metabolism. Targeted metabolomics analysis revealed that nitrosamines promoted decomposition of fatty acids and facilitated fatty acid β-oxidation (FAO) of mice. The significant increase of carnitine palmitoyltransferase 1 (CPT1) and downregulation of acetyl-CoA acyltransferase 2 (ACAA2) would promote FAO in EI process induced by nitrosamines. Additionally, the exposure levels of more than half of nitrosamines in urine were correlated with inflammatory fatty acid biomarkers. Overall, this study found that EI triggered by nitrosamines may be associated with the promotion of FAO, and provided novel insights for evaluating the underlying mechanism of environmental pollutant-caused toxicity based on metabolomics.

Urinary Volatomic Expression Pattern: Paving the Way for Identification of Potential Candidate Biosignatures for Lung Cancer

The urinary volatomic profiling of Indian cohorts composed of 28 lung cancer (LC) patients and 27 healthy subjects (control group, CTRL) was established using headspace solid phase microextraction technique combined with gas chromatography mass spectrometry methodology as a powerful approach to identify urinary volatile organic metabolites (uVOMs) to discriminate among LC patients from CTRL. Overall, 147 VOMs of several chemistries were identified in the intervention groups-including naphthalene derivatives, phenols, and organosulphurs-augmented in the LC group. In contrast, benzene and terpenic derivatives were found to be more prevalent in the CTRL group. The volatomic data obtained were processed using advanced statistical analysis, namely partial least square discriminative analysis (PLS-DA), support vector machine (SVM), random forest (RF), and multilayer perceptron (MLP) methods. This resulted in the identification of nine uVOMs with a higher potential to discriminate LC patients from CTRL subjects. These were furan, o-cymene, furfural, linalool oxide, viridiflorene, 2-bromo-phenol, tricyclazole, 4-methyl-phenol, and 1-(4-hydroxy-3,5-di-tert-butylphenyl)-2-methyl-3-morpholinopropan-1-one. The metabolic pathway analysis of the data obtained identified several altered biochemical pathways in LC mainly affecting glycolysis/gluconeogenesis, pyruvate metabolism, and fatty acid biosynthesis. Moreover, acetate and octanoic, decanoic, and dodecanoic fatty acids were identified as the key metabolites responsible for such deregulation. Furthermore, studies involving larger cohorts of LC patients would allow us to consolidate the data obtained and challenge the potential of the uVOMs as candidate biomarkers for LC.

Micropollutant transformation and toxicity: Electrochemical ozonation versus biological metabolism

Environmental water sources are constantly polluted by anthropogenic compounds, not always minimized by conventional water treatment methods to remove these compounds at the micro- and nano-range. The absolute concentrations of a suite of seven representative environmental micropollutants were compared pre- and post-treatment with both ozone and microbial biofilms, in terms of removal efficiencies and toxicity assays. Both synthetic micropollutant mixes and environmental water samples were evaluated. The study started with two representative micropollutants (carbamazepine, CBZ, and sulfamethoxazole, SMX), and broadened into a suite of pollutants, evaluating whole-sample eco-toxicological footprints. An ozone concentration of 4.24 ± 0.27 mg/L in tap water, resulted in an 87.9% and 96.5% removal of CBZ and SMX, respectively, within 1 min. Despite almost immediate removal of parent micropollutants by oxidation, endocrine disruption potential (anti-estrogenicity) of CBZ and SMX required up to 240 min of ozone treatment to show no assay effect. A broader suite of micropollutants in more complex environmental matrices showed scavenging of ozone (2.95 ± 0.17–0.25 ± 0.03 mg/L) and varying micropollutant recalcitrance to oxidation. Lower matrix pollution led to lower reduction in eco-toxicity. Microbial degradation of CBZ and SMX (56% and 70% versus 19% and 79%, respectively, in duplicate biofilms) by nutrient-limited biofilms showed less removal than ozonation, with marked variation due to the stochastic nature of biofilm sloughing. Microbial degradation of CBZ and SMX resulted in an increase of >90% in both estrogenicity and Aliivibrio inhibition. The results obtained from this study address a gap in understanding the removal efficiency of micropollutants, where the removal process often receives more attention than the comparative reduction of toxicological effects. This shift from a controlled laboratory environment to real-world scenarios also provided comparative insights into the removal of micropollutants and the eco-toxicity of the transformation by-products of each process.