Comprehensive investigation and risk assessment of organic contaminants in Yellow River Estuary using suspect and nontarget screening strategies

Data mining-based screening of prevalent mixture systems in aquatic environments: A case study of antibiotics in the Yangtze River Basin

Chemical pollution in real-world environment often involves exposure to combinations of thousands of chemicals. However, due to the vast number of possible combinations, it is nearly impossible to conduct comprehensive mixture toxicity tests and risk assessments for all of them. This study applied frequent itemset mining, a technique traditionally used in market basket analysis, to develop a prevalent mixture system screening (PMSS) method for identifying combinations that frequently co-occur in the environment. PMSS enables efficient data mining of chemical concentrations, allowing for the identification of a small number of prevalent mixture systems from numerous theoretical possibilities. In this study, 16 antibiotics were detected in the Linjiang River and the Xuebu River. Using the PMSS method, 48 prevalent antibiotic combinations (PACs), primarily ranging from binary to septenary combinations, were identified in the Xuebu River and the Linjiang River. The PACs in the surface water presented acceptable ecological risks, whereas the PACs in the sediments exhibited moderate to even high ecological risks. Therefore, targeted risk management measures should be developed for the sediments to reduce the potential harm to benthic organisms. Additionally, a case study demonstrates the application of identified PACs in mixture design. This study provides essential methodological and material support for advancing research on mixture toxicity evaluation and risk assessment.

Occurrence, Sources, and Prioritization of Per- and Polyfluoroalkyl Substances (PFASs) in Drinking Water from Yangtze River Delta, China: Focusing on Emerging PFASs

As regulations ban legacy PFASs, many emerging PFASs are being developed, leading to their release into the aquatic environment and drinking water. However, research studies on these emerging PFASs in drinking water are limited, and current standards only cover a few legacy PFASs, leaving many emerging PFASs unregulated and their toxicity unknown. Therefore, a machine learning-based suspect screening combined with target screening was employed to comprehensively identify and quantify both legacy and novel PFASs in drinking water from the Yangtze River Delta, and their potential sources of contamination were determined through pollutant profile analysis. A total of 30 PFASs were identified, including 16 legacy and 14 novel PFASs, categorized into 11 classes. Quantitative and semi-quantitative analyses revealed that the maximum concentrations of 30 PFASs ranged from Collapse

Key Words

• drinking water
• per- and polyfluoroalkyl substances
• prioritization
• risk assessment
• suspect screening

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MESH Headings

• Drinking Water/analysis
• Drinking Water/chemistry
• Water Pollutants, Chemical/analysis
• China
• Rivers/chemistry
• Fluorocarbons/analysis
• Environmental Monitoring

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Grants

• GWVI-11.1-41 Key Subject Projects of Shanghai's Three-year Action Plan for Strengthening the Construction of Public Health System (2023-2025)
• 22YF1443800 Shanghai Science and Technology Commission Qixing plans to sail special projects.
• 21DZ1202100 Shanghai 2021 "Science and Technology Innovation Action Plan" Social Development Science and Technology Key Project

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Affiliation(s)

Zixin Qian School of Public Health, Fudan University, Shanghai 200032, China; (Z.Q.); (Z.Z.) Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Chao Feng Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Yuhang Chen Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Yuanjie Lin Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Ziwei Liang Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Hailei Qian Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Jingxian Zhou Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Jinjing Ma Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Yue Jin Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Dasheng Lu Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Guoquan Wang Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Ping Xiao Shanghai Municipal Center for Disease Control and Prevention, State Environmental Protection Key Laboratory of Environmental Health Impact Assessment of Emerging Contaminants, Shanghai 200336, China; (C.F.); (Y.C.); (Y.L.); (Z.L.); (H.Q.); (J.Z.); (J.M.); (Y.J.); (G.W.); (P.X.)
Zhijun Zhou School of Public Health, Fudan University, Shanghai 200032, China; (Z.Q.); (Z.Z.)

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Collaborators Collapse

Constraining the composition and biochemical activity of organic carbon in a large eutrophic estuary using size-fractionated analysis

The presence of refractory dissolved organic carbon (RDOC) can result in the misestimation of organic pollution, and documentation regarding the characteristics of organic carbon (OC) and its relationship with pollution is limited. This study employed physical separation, biological incubation, and chemical analysis to examine the size-fractionated composition and bioavailability of OC in the Yangtze River Estuary, one of the most polluted estuarine areas in China. Results revealed that OC chemical features were highly diverse, with RDOC constituting approximately 65.8% ± 9.2% of dissolved organic carbon (DOC). During incubation, less than 10% of CHO molecules (molecules composed solely of carbon, hydrogen and oxygen atoms) identified by ultra-high resolution mass spectrometry were degraded. A significant positive linear relationship between OC and RDOC in size-fractionated OC indicated greater recalcitrance in smaller size fractions. The OC present in the >0.45 μm fraction was notably important for labile OC, including the particulate fraction of OC, which is relevant to chemical oxygen demand (COD) assessments. Excluding RDOC allows for a more accurate estimation of the contribution of labile OC to COD, as represented by the equation: CODLabile = 0.47 × CODBulk - 0.03. Approximately 0.44 ± 0.10 Gt of refractory OC, including 0.31 ± 0.07 Gt of RDOC, is transported annually into the ocean via rivers. This linear relationship of COD reveals an overestimation in current assessments of organic pollution and a neglect of RDOC's role in carbon preservation, thereby necessitating a revision of the COD evaluation practices in estuaries. This study highlights the differentiated impacts of refractory and labile OC on the quantification of OC pollution in a large eutrophic estuary.

Spatiotemporal distribution and fate of typical pesticides in the Bohai Sea and surrounding rivers, China

Pesticide leakage has lasting and profound effects on the stability and health of marine ecosystems. To explore the occurrence, distribution, and fate of typical pesticides in marine environments, three sampling campaigns were conducted in the Bohai Sea and surrounding rivers. Atrazine was the most pronounced pesticide, with a high concentration and detection frequency in both seawater and sediment. The presence of typical organophosphorus pesticides (OPs) was significantly lower than historical levels. Pesticide concentrations decreased from inshore to offshore. Furthermore, the spatiotemporal distribution characteristics of the pesticides highlighted the agricultural patterns and differences in pesticide use. Environmental factors and physicochemical properties jointly determined the behaviors and fates of pesticides in the marine environment. Sediment served as both a sink for widely used atrazine and a source of restricted OPs. Although some pesticides have been restricted or banned, such as dimethoate and chlorpyrifos, the risks caused by their long-term use and environmental accumulation cannot be ignored and the normalized monitoring of typical pesticides is necessary in the marine environment.

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.

Chemical profiling of organic contaminants in rural surface waters combining target and non-target LC-HRMS/MS analysis

The pollution of natural waters by contaminants of emerging concern (CECs) is one of the pressing problems due to their global distribution and potential negative effects on the environment and human health. In rural areas with lower population density and limited industrial development, less contamination is expected. However, the lack of wastewater treatment plants (WWTPs) or their poor removal efficiency can lead to significant input of pollutants. In this context, 11 streams of rural areas in the Guadalquivir River basin, southeast of Spain, were studied over two years to obtain an overview of the origin and distribution of contaminants. A target method using solid-phase extraction and liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) was developed for the analysis of 316 compounds in surface waters. A total of 78 target analytes were detected, comprising pesticides, pharmaceuticals, personal care products (PCPs), transformation products (TPs), and industrial chemicals. The flame retardant tributyl phosphate (16-3572 ng L-1) was detected in all samples, followed by caffeine (30-8090 ng L-1) and the analgesic tramadol (3-1493 ng L-1). The target approach was combined with a non-target analysis (NTA) strategy to obtain an overall perspective of the chemical profile of unexpected or unknown compounds in the samples. Up to 79 contaminants were tentatively identified, and 12 of them were finally confirmed with standards. Most of the contaminants determined by NTA were pharmaceuticals and their TPs. The results indicated that most of CECs have an urban origin despite traditional agriculture is the main economic activity in this region. Moreover, the absence of WWTPs in small towns is significant, as contamination levels at these sites were comparable to or higher than those in larger populations with sewage treatments.

Occurrence of micropollutants in surface waters: Monitoring of Portuguese Lima and Douro River estuaries and interconnecting northwest coast

This study monitored the occurrence of 34 MPs in 2 Portuguese estuaries and adjacent coastal area using solid-phase extraction and liquid chromatography-tandem mass spectrometry, covering: (i) an extensive monitoring study area; (ii) a multi-class group of organic MPs, including some outlined in European Union guidelines for water protection; (iii) a year-long monitoring campaign including different seasons; (iv) samples collected at both flood and ebb tide; and (v) samples taken from the water surface and bottom at each sampling point. Results showed that a specific group of compounds prevailed in the monitored areas, with concentrations depending on season, tide, and location. In general, the MPs found more frequently were isoproturon and perfluorooctanesulfonic acid, along with pharmaceuticals trimethoprim, acetaminophen, tramadol, diclofenac, and ketoprofen, which were mostly detected at higher concentrations. Although most MPs have been detected at very low levels, their persistent and widespread presence highlights the need for mitigation measures and effective water treatment solutions able to address them.

Global Trends and Hotspots in Non-Targeted Screening of Water Pollution Research: Bibliometric and Visual Analysis

Non-targeted screening (NTS) technology has been showing significant potential in identifying contaminants of emerging concern (CECs) in water and has attracted great attention in academia in recent years. It is a method that analyzes samples without pre-selecting substances, enabling the detection and identification of unknown compounds, which is crucial for environmental health and public protection. This study uses the Bibliometrix package in R 4.4.1 and CiteSpace 6.3.R1 software to statistically analyze 589 relevant publications from the Web of Science Core Collection from 2007 to 2024. Our work concentrates on NTS of water bodies; thus, articles that only analyze water sediments without analyzing the water were not considered for inclusion. By conducting a quantitative analysis and visualizing the publication trends, countries, authors, journals, and keywords, the present study identifies research hotspots, compositions, and paradigms within this field, trying to analyze the horizontal and vertical development trends and structural evolution of the research area. The research found that the application of NTS in water pollution studies has progressed through three phases: theoretical exploration, rapid development, and steady progress. From the national level, China leads with the highest number of publications (131), followed by Germany (105), Spain (50), and the United States (39). The top three authors by publication volume are J. Hollender, Nikolaos S. Thomaidis, and Emma L. Schymanski, while the top three by citation count are J. Hollender, Emma L. Schymanski, and M. Krauss. However, international collaboration between countries and researchers still remains an area for improvement. Science of the Total Environment is the journal with the highest number of publications (81), and Environmental Science & Technology holds the highest number of citations. Research on NTS methodologies, suspect screening, and health risk assessments are hot topics in the academic community. Future research is expected to be multidisciplinary, with emerging hotspots likely to focus on including the identification of novel pollutants through NTS, toxicity assessments of biotransformed compounds, and the health impacts and mechanisms of related compounds.

Ecosystem risk-based prioritization of micropollutants in wastewater treatment plant effluents across China

Identifying priority pollutants in wastewater treatment plant (WWTP) effluents is crucial for optimizing monitoring efforts, improving regulations, and developing targeted mitigation strategies. Despite the presence of numerous trace organic pollutants in WWTP effluents, a comprehensive prioritization scheme is lacking, hindering effective control. This study screened 216 micropollutants, including pharmaceuticals, pesticides, and industrial chemicals, which had been detected in effluents from 46 WWTPs across China. A multi-criteria prioritization method was developed, considering exposure potential based on median concentrations and detection frequencies, as well as hazard potential determined by persistence, bioaccumulation, in vitro toxicity, and in vivo toxicity. Pollutants with low exposure or hazard potential were filtered out, and a priority index was calculated to rank the remaining 59 substances. The top 15 priority pollutants included regulated persistent organic pollutants like perfluorooctanoic acid and their alternatives such as perfluorobutane sulfonate, pesticide transformation products, and emerging contaminants such as bisphenol A, which are not currently regulated in WWTP effluents. This study provides a systematic approach to identify priority pollutants and generates a guiding framework for monitoring, regulation, and control of both well-recognized and overlooked contaminants in WWTP effluents.

Spatiotemporal variations and priority ranking of emerging contaminants in nanwan reservoir: A case study from the agricultural region in huaihe river basin in China

The presence of emerging contaminants (ECs) in drinking water sources is an increasing concern, yet limited data exists on their occurrence and risk in the upper Huaihe River Basin, an important agricultural region in Central China. This study investigated 70 ECs, including pesticide and antibiotics in surface water from drinking water source areas in Nanwan Reservoir along the upper reaches of the Huaihe River Basin to prioritize the ECs based on ecological risk and health risk assessment. A total of 66 ECs were detected in the surface water at least once at the selected 38 sampling sites, with concentrations ranging from 0.04 to 2508 ng/L. Ecological risk assessment using the risk quotient (RQ) method revealed high risks (RQ > 1) from 7 ECs in the dry season and 15 ECs in the wet season, with triazine pesticides as the main contributors. Non-carcinogenic risks were below negligible levels, but carcinogenic risks from neonicotinoid and carbamate pesticides and macrolide antibiotics were concerning for teenagers. Ciprofloxacin exhibited a high level of resistance risk during the wet season. A multi-indicator prioritization approach integrating occurrence, risk, and chemical property data ranked 6 pesticides and 3 antibiotics as priority pollutants. The results highlight EC contamination of drinking water sources in this agriculturally-intensive region and the need for targeted monitoring and management to protect water quality.

Ubiquitous nanocolloids suppress the conjugative transfer of plasmid-mediated antibiotic resistance in aqueous environment

Nanocolloids (Nc) are widespread in natural water environment, whereas the potential effects of Nc on dissemination of antibiotic resistance remain largely unknown. In this study, Nc collected from the Yellow River in Henan province was tested for its ability to influence the conjugative transfer of resistant plasmid in aqueous environment. The results revealed that the conjugative transfer of RP4 plasmid between Escherichia coli was down-regulated by 52%-91% upon exposure to 1-10 mg/L Nc and the reduction became constant when the dose became higher (20-200 mg/L). Despite the exposure of Nc activated the anti-oxidation and SOS response in bacteria through up-regulating genes involved in glutathione biosynthesis and DNA recombination, the inhibition on the synthesis and secretion of extracellular polysaccharide induced the prevention of cell-cell contact, leading to the reduction of plasmid transfer. This was evidenced by the decreased bacterial adhesion and lowered levels of genes and metabolites relevant to transmembrane transport and D-glucose phosphorylation, as clarified in phenotypic, transcriptomics and metabolomics analysis of E. coli. The significant down-regulation of glycolysis/gluconeogenesis and TCA cycle was associated with the shortage of ATP induced by Nc. The up-regulation of global regulatory genes (korA and trbA) and the reduction of plasmid genes (trfAp, trbBp, and traG) expression also contributed to the suppressed conjugation of RP4 plasmid. The obtained findings remind that the role of ubiquitous colloidal particles is nonnegligible when practically and comprehensively assessing the risk of antibiotic resistance in the environment.

Ecological implications and drivers of emerging contaminants in Dongting Lake of Yangtze River Basin, China: A multi-substance risk analysis

Emerging contaminants (ECs) are increasingly recognized as a global threat to biodiversity and ecosystem health. However, the cumulative risks posed by ECs to aquatic organisms and ecosystems, as well as the influence of anthropogenic activities and natural factors on these risks, remain poorly understood. This study assessed the mixed risks of ECs in Dongting Lake, a Ramsar Convention-classified Typically Changing Wetland, to elucidate the major EC classes, key risk drivers, and magnitude of anthropogenic and natural impacts. Results revealed that ECs pose non-negligible acute (30% probability) and chronic (70% probability) mixed risks to aquatic organisms in the freshwater lake ecosystem, with imidacloprid identified as the primary pollutant stressor. Redundancy analysis (RDA) and structural equation modeling (SEM) indicated that cropland and precipitation were major drivers of EC contamination levels and ecological risk. Cropland was positively associated with EC concentrations, while precipitation exhibited a dilution effect. These findings provide critical insights into the ecological risk status and key risk drivers in a typical freshwater lake ecosystem, offering data-driven support for the control and management of ECs in China.

Plastic protective nets: A significant but neglected "reservoir" for priority chemicals as revealed by composition analysis

As chemical-intensive products, plastics are potential sources of emerging contaminants and pose risks to the ecosystem. However, knowledge on the inventory and emissions of chemicals in plastics remains scarce, prohibiting the lifecycle assessment of their environmental exposure. Herein, full compositions of plastic protective nets (PPNs, one globally used plastics) were analyzed via nontarget screening with mass spectrometry, optical emission spectrometry, infrared spectroscopy and thermogravimetric analysis. Nontarget screening identified 861 non-polymeric organic chemicals, which were classified by network-like similarity analysis into 9 communities, dominated by phthalates (PAEs), aliphatic/oxalic esters and branched alkanes. Notably, around 80.8% (696) of the chemicals were first observed in plastics, suggesting aplenty plastic additives have previously been overlooked. Quantification results indicated PPNs contained higher levels of priority chemicals, including detrimental lead (1.17 × 104 ng/g), benzotriazoles ultraviolet stabilizers (6.66 × 103 ng/g) and PAEs (1.87 × 104 ng/g) than other plastics commonly reported. Emission projections revealed that dibutyl phthalate in PPNs had an annual release (1.83 × 103 kg) comparable to that from greenhouse films in China. These findings suggest PPNs are a significant but neglected "reservoir" for priority chemicals, which could inform future research on resolving plastic compositions, so as to promote sound chemical management.

Non-target analysis for water characterization: wastewater treatment impact and selection of relevant features

Non-target analyses were conducted to characterize and compare the molecular profiles (UHPLC-HRMS fingerprint) of water samples from a wastewater treatment plant (WWTP). Inlet and outlet samples were collected from three campaigns spaced 6 months apart in order to highlight common trends. A significant impact of the treatment on the sample fingerprints was shown, with a 65-70% abatement of the number of features detected in the effluent, and more polar, smaller and less intense molecules found overall compared to those in WWTP influent waters. Multivariate analysis (PCA) associated with variations of the features between inlets and outlets showed that features appearing or increasing were correlated with effluents while those disappearing or decreasing were correlated with influents. Finally, effluent features considered as relevant to a potentially adverse effect on aqueous media (i.e. those which appeared or increased or slightly varied from the influent) were highlighted. Three hundred seventy-five features common with the 3 campaigns were thus selected and further characterized. For most of them, elementary composition was found to be C, H, N, O (42%) and C, H, N, O, P (18%). Considering the MS2 spectra and several reference MS2 databases, annotations were proposed for 35 of these relevant features. They include synthetic products, pharmaceuticals and metabolites.

Association between co-exposure to phenols, phthalates, and polycyclic aromatic hydrocarbons with the risk of frailty

The phenomenon of population aging has brought forth the challenge of frailty. Nevertheless, the contribution of environmental exposure to frailty remains ambiguous. Our objective was to investigate the association between phenols, phthalates (PAEs), and polycyclic aromatic hydrocarbons (PAHs) with frailty. We constructed a 48-item frailty index using data from the National Health and Nutrition Examination Survey (NHANES). The exposure levels of 20 organic contaminants were obtained from the survey circle between 2005 and 2016. The association between individual organic contaminants and the frailty index was assessed using negative binomial regression models. The combined effect of organic contaminants was examined using weighted quantile sum (WQS) regression. Dose-response patterns were modeled using generalized additive models (GAMs). Additionally, an interpretable machine learning approach was employed to develop a predictive model for the frailty index. A total of 1566 participants were included in the analysis. Positive associations were observed between exposure to MIB, P02, ECP, MBP, MHH, MOH, MZP, MC1, and P01 with the frailty index. WQS regression analysis revealed a significant increase in the frailty index with higher levels of the mixture of organic contaminants (aOR, 1.12; 95% CI, 1.05-1.20; p < 0.001), with MIB, ECP, COP, MBP, P02, and P01 identified as the major contributors. Dose-response relationships were observed between MIB, ECP, MBP, P02, and P01 exposure with an increased risk of frailty (both with p < 0.05). The developed predictive model based on organic contaminants exposure demonstrated high performance, with an R2 of 0.9634 and 0.9611 in the training and testing sets, respectively. Furthermore, the predictive model suggested potential synergistic effects in the MIB-MBP and P01-P02 pairs. Taken together, these findings suggest a significant association between exposure to phthalates and PAHs with an increased susceptibility to frailty.

Priority control sequence of 34 typical pollutants in effluents of Chinese wastewater treatment plants

The identification of the priority control sequence of pollutants in effluents of wastewater treatment plants (WWTPs) has important implications for the management of water quality. This study chose 34 typical pollutants based on their representativeness and detection rates in municipal wastewater. The occurrence frequency and concentration of these pollutants in 168 Chinese WWTP effluents were measured at the national level. The data on in vitro toxicity (67 assays) and in vivo toxicity (216 species) for target pollutants were obtained from the public toxicity database and our experimental data. An environmental health prioritization index (EHPi) method was proposed to integrate the occurrence frequency, concentration, removal rate, and in vitro and in vivo toxicity to determine the priority control sequence of target pollutants. Ethynyl estradiol, 17β-estradiol, estrone, diclofenac, and atrazine were the top 5 pollutants identified by the EHPi score. Several pollutants with high EHPi scores showed spatial differences. Besides the EHPi method which was from the single pollutant perspective, the combined toxicity of pollutants (300 pairs of binary combinations) was also measured based on in vitro toxicity assays to evaluate the key pollutants from the pollutant-pollutant interacting perspective. The pollutants (such as ofloxacin and acetaminophen) that could have significant synergetic effects with many other pollutants are worthy of prior attention. This study shed new light on the identification of the priority control sequence of pollutants in WWTP effluents. The results provide meaningful data for the effective management and control of wastewater water quality.