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Based on sampling from Xiaoqing River of China and elimination experiments, this study first investigated spatial/seasonal profiles and fates of phenylmethylsiloxanes (PMSs), as modified products of dimethylsiloxanes (DMSs), in natural waterbody. Overall, the average water (6.7 ng/L) and sediment (28.5 ng/g dw) concentrations of total six cis-/trans- isomers of 2,4,6-triphenyl-2,4,6-trimethylcyclotrisiloxanes (P3) and 2,4,6,8-tetraphenyl-2,4,6,8-tetramethylcyclotetrasiloxanes (P4) in river segments located in industrial areas were respectively 7.37 and 6.13 times higher than those near residential areas, indicating that industrial activities may have larger contribution to PMSs emission than living activities. Compared with paired DMSs with same Si number, PMSs had lower hydrolysis but faster photolysis, and these two pathways influenced isomeric differences in river water: (1) slower hydrolysis of trans-isomers (t 1/2 = 45.6-334 h) than cis-isomers (t 1/2 = 38.1-251 h) might cause actual cis/trans ratios (0.18 for P3 and 0.092 for P4) lower than theoretical values (0.33 for P3 and 0.14 for P4) in water, especially in acidic (pH=6.1-6.3) and alkaline (pH=8.0-8.4) segments; (2) faster indirect photolysis of trans-isomers (t 1/2 = 54.7-177 h) than cis-isomers (t 1/2 = 73.4-191 h) might lead to larger mean cis/trans ratios in summer (0.31 for P3) with stronger illumination than those in winter (0.08 for P3). The Σ(P3 + P4) concentrations in 140 mussels (Anodonta woodiana) from 14 sites of the Xiaoqing River were

Polycyclic aromatic hydrocarbons (PAHs) are a class of organic pollutants widely present in various environmental media. Some PAHs have carcinogenic, teratogenic, and mutagenic effects. Urban lakes are severely polluted by PAHs due to human activities. Longyang Lake (LL) and Moshui Lake (ML), which serve as entry lakes for Wuhan's "Six Lakes Connectivity" project, were chosen as the study areas to learn about the migration of PAHs. Water flows from LL to ML through the Mingzhu River. Multi-Media Mass Balance Model (MMBM) and fugacity fractions (ff) were used to characterize the migration of PAHs under the hydrological connectivity project. Compared to ff, the MMBM can describe the migration of PAHs in a more detailed and quantitative way. The concentration of PAHs in water of LL decreased from 36.5 ng L -1 to 26.59 ng L -1 over 43 days, while those in ML increased from 46.8 ng L -1 to 198.25 ng L -1 over 141 days. Sediment takes a longer time to decrease to stabilization. The concentration of PAHs in the sediment of LL decreased from 932 ng g -1 to 0.95 ng g -1 over 13.33 years, while those in ML decreased from 4812 ng g -1 to 1.04 ng g -1 over 16.96 years. The stabilized concentrations were consistently lower than the observed concentrations and fell below the modeled stabilized concentrations obtained in the unconnected case (2170 ng L -1 in water and 40.81 ng g -1 in sediment). The MMBM showed that PAHs in the lake are mainly exported through runoff. However, modeling results indicated that upstream LL did not increase total PAHs concentrations in the ML because the output from ML was significantly higher. Sediment parameters sensitively influenced the results of the model. Although the simulation results showed reductions of PAHs pollution in two lakes under the hydrological connectivity project, long-term monitoring results are needed to optimize the model., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microplastics (MPs) and polycyclic aromatic hydrocarbons (PAHs) have been found in all environment matrices and are of concern worldwide. In this study, PAHs were determined in Baiyangdian Lake, China, and the effects of MPs on the migration of PAHs at the lake interfaces were analyzed. The average abundances of detected MPs were 9595 items m -3 for water and 1023 items kg -1 for sediment. The detected MPs were polyamide 6, polypropylene, polyethylene, and polyethylene terephthalate. The average Σ 16 PAHs in the water, sediment, and air were 1338 ng L -1 , 751 ng g -1 dry weight, and 395 ng m -3 , respectively. At the air-water interface, naphthalene, and phenanthrene volatilized from water to air, whereas benzo(b)fluoranthene, benzo(k)fluoranthene, and dibenzo(a,h)anthracene deposited from air to water. The fugacity fraction between sediment and bottom water ranged from 0.88 to 0.99, which indicated net volatilization at the water-sediment interface. The adsorption capacities of the four MPs for the PAHs ranged from 39.4 to 99.8 μg g -1 with a desorption efficiency range of 0.01%-44.3% under oscillation. According to the distribution of PAHs on the MPs, the exchange fluxes of PAHs at the water-air and sediment-water interfaces were recalculated. The results showed that the MPs could increase deposition of the PAHs from air to the water (ΔF A-W : -221 × 10 -2 to -0.01 × 10 -2  ng m -2  d -1 ) and the volatilization of PAHs from sediment to water (ΔF W-S : -79.7 × 10 5 to 180 × 10 5  ng m -2  d -1 ), which suggests that MPs increase the risk of PAHs in water and to aquatic organisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Organophosphate esters (OPEs) are emerging pollutants and used extensively in industrial production as alternative to the traditional flame retardants. This study investigated the contamination characteristics and health risks of OPEs in 104 mollusks from 15 cities along the coastal region of South China. Σ8OPEs ranged from 48.2 to 1937 ng/g dw, with a mean value of 295 ng/g dw. TDCIPP, TCPP, and TCEP were the dominant OPEs. Different spatial distributions were observed, with higher concentrations in Guangdong Province. A statistically positive but non-significant linear correlation was found between the trophic level of mollusk and OPEs concentration. The trophic magnification factors were >1, suggesting that OPEs have the potential to biomagnify in mollusks. OPEs in mollusks pose low non-carcinogenic and carcinogenic risks to consumers. This study provides an important basis for managing the safety risks associated with OPEs in mollusks., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Offshore sediment serves as an important sink for traditional organophosphate esters (TOPEs) originating from terrestrial sources. However, the contamination characteristics of novel OPEs (NOPEs) and their hydrolyzed and hydroxylated transformation products (Di- and OH-OPEs) in marine sediment are still unknown. In this study, 34 OPE-associated contaminants were measured in six offshore sediment cores (71 samples) collected from Eastern China. The total concentrations of Σ 15 TOPEs, Σ 3 NOPEs, Σ 9 Di-OPEs, and Σ 7 OH-OPEs in surface sediments were 3.16-73.4, n.d.-16.3, 4.48-21.4, and 0.14-0.42 ng g -1 , respectively. NOPE compounds, such as tris(2,4-di-tert-butylphenyl) phosphate and its diester product, exhibited high contamination levels, primarily due to their high hydrophobicity and extensive industrial applications. Additionally, atmospheric transportation, along with wet and dry deposition and ocean currents, plays a crucial role in their distribution in offshore sediment. The location conditions and historical usage also influenced the vertical distributions of OPE-associated contaminants in sediment cores. Notably, a concentration peak of bis(2,4-di-tert-butylphenyl) phosphate (B2,4DtBPP) was dating back to 1940s, indicating the early usage of antioxidant tris(2,4-di-tert-butylphenyl) phosphite. Furthermore, a risk quotient (RQ) model was employed to assess the ecological risks posed by OPEs. Generally, the acute toxicity-based predicted no-effect concentrations for studied compounds were 1 to 2 orders of magnitude lower than those based on chronic toxicity. NOPEs and B2,4DtBPP exhibited high ecological risks, with maximum RQ values of 1570-4877 based on acute toxicity and 93.4-197 based on chronic toxicity. Notably, ΣRQ values for NOPEs were significantly higher than those of TOPEs (Mann-Whitney U test, p < 0.001), indicating their severe ecological risks in offshore sediment. Therefore, given the continuous input and considerable persistence of NOPEs in offshore sediment, their toxic effects and mechanisms warrant thorough investigation. This study provides the first evidence for the occurrence, temporal trends, and potential risks of NOPEs in marine sediment environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Oxygenated polycyclic aromatic hydrocarbons (OPAHs) have garnered significant scientific attention due to their heightened toxicity and mobility compared to their parent PAHs. This study investigated the occurrence of 11 OPAHs and 16 PAHs within agricultural ditch sediment of Guangzhou City, China. The ΣPAH and ΣOPAH concentrations ranged from 63.8-3955 ng/g and 16.5-522 ng/g, respectively. Notably, concentrations were elevated during the rainy season, attributed to intensified atmospheric deposition and surface runoff during the rainy season. Spatially, Pearson correlation and path analysis disclosed a linkage between OPAHs and high-molecular-weight PAHs and adjacent agricultural practices, whereas low-molecular-weight PAHs were associated with human and industrial operations. This disparity was linked to the restricted mobility of high-molecular-weight PAHs, rendering them particularly susceptible to proximal sources. Diagnostic ratios and principal component analysis-multiple linear regression (PCA-MLR) implicated fossil fuel combustion and vehicle emissions as major contributor to the sedimentary OPAHs and PAHs. Further correlations between estimated source contributions and water quality, strengthened by spatial interpolation, clearly identified agricultural activities, and atmospheric deposition associated with traffic emissions and fossil fuel combustion as primary contributor to sedimentary OPAHs and PAHs. Secondary sources encompassed coal combustion, road runoff, and wastewater from both industrial and shipping activities. The risk quotients (RQs) for PAH and OPAH mixtures indicated moderate to high ecological hazards. This study demonstrated the importance of employing the integrated approach, combining PCA-MLR, diagnostic ratios, and correlation of source contributions with water quality in precisely delineating the origins of OPAHs and PAHs in agricultural ditch sediment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

This study investigated 17 organophosphate esters (OPEs) in the surface sediments of Hangzhou Bay and the East China Sea. The mean concentration of ∑OPEs in Hangzhou Bay (235.3 ng/g) was slightly lower than that in the East China Sea (273.5 ng/g), with detected analytes dominated by Diethyl phosphate, Tris(2-chloropropyl) phosphate, and Tris(1-chloro-2-propyl) phosphate. Based on principal component analysis and cluster analysis for the source apportionment of OPEs, the results indicated that the high levels of OPEs in the East China Sea close to Yangtze River estuary can be attributed to a significant large-scale OPEs production site located along the southern Yellow Sea and the western coast of the East China Sea. Furthermore, the risk assessment conducted on aquatic organisms indicated the non-ecological risk of OPEs. However, future research should focus on the potential composite impacts of OPEs on the water systems and human health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microplastics (MPs) pollution has emerged as a global concern. To mitigate the potential threats by MPs, particularly to coastal regions, it is crucial to comprehend the environmental behavior of MPs and their affiliated chemicals. In the present study, we collected floating MPs using a Manta net (0.33 mm mesh size) in a one-year sampling event in 2022 from the eight major estuaries in the Pearl River Delta, China, and also from five coastal sites in August and December in the same year. Nineteen linear alkylbenzenes (∑ 19 LAB) and 16 polycyclic aromatic hydrocarbons (∑ 16 PAH) affiliated with MPs were measured. The mean concentrations of MPs-affiliated ∑ 19 LAB and ∑ 16 PAH were 6710 (range: 3400-12300) and 5310 (range: 817-19,600) ng g -1 , respectively, at the estuarine sites, and were 4920 (range: 2400-7600) and 2610 (range: 911-7890) ng g -1 , respectively, at the coastal sites. Significant correlations were found between logarithmic MPs-water partition coefficients (log K pw ) and logarithmic suspended particulate matter-water partition coefficients (log K d ) values for LABs and PAHs, indicating analogous partitioning dynamics for MPs and suspended particulate matter with water. The annual riverine outflows were 1170 and 414 g for ∑ 19 LAB and ∑ 16 PAH, respectively. Although the riverine outflows of LABs and PAHs carried by MPs remain negligible compared to those by suspended particulate matter, an upward trend was identified between 2018 and 2022. Notably, the riverine input of LABs and PAHs carried by suspended particulate matter to the coastal ocean decreased from 2005/2006 to 2022, due to a combination of improved technological processes and energy structures., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The bioaccumulation of organochlorine pesticides (OCPs) in aquatic organisms has been extensively explored in recent years due to associated ecological risks and potential threats to human health through food. This study aims to assess the bioaccumulation of organochlorine pesticides (OCPs) in 18 freshwater fish species from the Pearl River Delta, China. The observed OCP concentrations ranged from 0.69 to 43.15 ng/g wet weight, indicating low to moderate pollution levels. A linear mixed-effects model revealed the contribution of the feeding habits and geographic distributions at 58.67 and 0.67 % of OCP accumulation, respectively. Bottom-dwelling carnivorous fish species exhibited greater OCP residue levels than those in the upper layers of the freshwater. Estuarine organisms showed higher Dichlorodiphenyltrichloroethane (DDT) residue levels than those inland species. On the other hand, although there were no direct carcinogenic or exposure risks associated with OCPs in the study area, potential related hazards were observed. Consumers are, therefore, advised to select fish species from the middle and upper delta rather than bottom fish, shellfish, and shrimp. The current research provides valuable guidance for aquatic food consumption., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Per- and polyfluoroalkyl substances (PFAS) are widespread, highly persistent, and bio-accumulative compounds that are increasingly found in the sediments of aquatic systems. Given this accumulation and concerns regarding the environmental impacts of PFAS, their influence on sedimentary bacterial communities remains inadequately studied. Here, we investigated the concentrations of 17 PFAS in sediments from six urban lakes in Nanjing, China, and assessed their effects on the diversity, composition, potential interactions, and assembly mechanisms of sedimentary bacterial communities. Sediment concentrations of PFAS ranged from 4.70 to 5.28 ng·g -1 dry weight. The high concentrations of the short-chain perfluorobutanesulfonic acid (PFBS) suggested its substitution for the long-chain perfluorooctanesulfonic acid (PFOS). As alternatives to long-chain PFAS, short-chain PFAS had similar effects on bacterial communities. The short-chain perfluoropentanoic acid (PFPeA) and the long-chain perfluorotridecanoic acid (PFTrDA) were the most important PFAS related to the ecological patterns of the co-occurrence network and may alter the composition of the sedimentary bacterial communities in the urban lakes. The Anaerolineaceae family represented as keystone bacteria within the PFAS-affected bacterial co-occurrence network. Deterministic processes (65.9 %), particularly homogeneous selection (63.2 %), were the dominant process driving bacterial community assembly. PFAS promoted the phylogenetic clustering and influenced the community dispersal capabilities to shape bacterial community assembly. This study provides a comprehensive analysis of PFAS distribution in sediments across six urban lakes in Nanjing and provides novel insights into the effects of PFAS on sedimentary bacterial communities. Further research is required to elucidate the mechanisms underlying the impacts of PFAS on microbial communities and to evaluate their broader ecological consequences., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The occurrence and trophic transfer of polycyclic aromatic hydrocarbons (PAHs) in aquatic ecosystems is vital to assess ecological risks. PAHs concentrations were analyzed in seawater, sediment, plankton, and marine species (15 fish species, 8 invertebrate species, 3 marine mammals), collected from Liaodong Bay (China). Bioaccumulation and biomagnification were calculated to demonstrate the biotransfer pattern of PAHs from the environmental matrix to high-level predators through the food web. Total PAHs concentrations ranged from 81.2 to 197.6 ng/L in seawater, 51.4-304.8 ng/g (dw) in sediment, and 65.3 to 28,885 ng/g (lw) in all biota samples. Three- and four-ring PAHs constituted major components (>81% in each case) of PAH congener profiles. Lower biota-sediment accumulation factors (BSAFs) and bioaccumulation factors (BAFs) values indicated limited bioaccumulation of PAHs within marine organisms. Also, 77% of biomagnification factors (BMF TL ) values of PAHs in spotted seal and finless porpoise were >1, whereas opposite transfer patterns of PAHs were observed in food webs with trophic values of 1.5-3.5 and 3.0-4.0; that is, trophic dilution (trophic magnification factor (TMF) < 1) and trophic magnification (TMF >1), respectively. This study provides novel insights into the importance of TL span for trophodynamics of PAHs within food webs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Synthetic musks (SMs) commonly used in personal care products can accumulate in the estuarine environment, but influencing factors on their distribution at large-scale region remain largely unexplored. Herein, surface sediment samples from 18 main estuaries of China and two river outlets in the Yangtze River Estuary were collected to discern the spatial and temporal variations of SMs. Moreover, fourteen influencing factors consisting of natural and anthropogenic parameters were scrutinized and their significance were analyzed by using Spearman's rank correlation and Random Forest. The widespread distribution of SMs were observed in Chinese estuarine sediments with the levels ranging from < reporting limit to 28 ng g -1 on a basis of dry weight (mean: 3.5 ng g -1 ). Predominated polycyclic musks shared similar sources both spatially and temporally. Positive correlation was found between SMs and total organic carbon in sediments, whereas the SM distribution was strongly influenced by regional anthropogenic activities. Regional population density was the primary influencing factor, followed by gross domestic product per unit area and wet deposition of particulate matters. A good correlation between SMs and water quality category indicated SMs could serve as an indicator for water quality. To the best of our knowledge, this is the first study to identify the main influencing factors on SM distribution in estuarine sediments, aiming to better understand the distribution and fate of emerging organic chemicals in the estuarine environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Current researches on pesticides in wetlands are limited in terms of screening and quantification of many types of pesticides. Understanding the spatial and temporal dynamics, distribution patterns, and environmental risks of pesticides in multiple media is important for wetland ecological conservation. In this study, 222 pesticides were determined in multimedia samples collected simultaneously from the Songhua Wetland during four seasons. Concentrations of target pesticides in water, ice, sediment and soil ranged from 94.1 to 7445 ng/L, 62.6-953 ng/L, 0.82-50.2 ng/g dw, and 4.32-146 ng/g dw. Large spatial differences (p < 0.05) in pesticide concentrations in ice were found. However, there were no significant differences in the spatial and temporal distribution of pesticides in water, sediment, and soil (p > 0.05), suggesting that there were no correlation between the spatial and temporal use of pesticides. The dynamic exchange of pesticides between water-ice indicated that most pesticides were more enriched in water. However, there were still some pesticides (Dichlorvos and Biphenyl) that showed a stronger tendency to transfer from water to ice. Sediment-water exchange suggested that sediment is a source of secondary releases of most pesticides in wetland ecology, but is a sink for Biphenyl and Oxadiazon. The correlation between concentration ratios and fugacity fraction supported this finding. Most individual pesticides in wetland water and ice had shown low or moderate ecological risk conducted using risk quotient. The cumulative toxic effects of multiple pesticides had a high potential to pose a threat to wetland aquatic organisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Perfluoroalkyl acids (PFAAs), renowned for their exceptional physical and chemical properties, are ubiquitous in urban and rural environments. Despite their widespread usage, more knowledge is needed concerning their accumulation and transfer mechanisms within the aquatic food webs of urban fringe lakes, especially across rural-urban and seasonal scales. This study investigated the tissue distribution, bioaccumulation, biomagnification, associated human health risks, and potential risk mitigation strategies of 15 PFAAs within the food web of Luoma Lake, a prototypical urban fringe lake. All targeted PFAAs were detected in samples, with ∑PFAA concentrations ranging from 116.97 to 564.26 ng/g dw in muscles and 26.96-1850.95 ng/g dw in viscera. Spatial variations revealed significantly higher ∑PFAA concentrations in the muscles from the urban subregion (∑PFAA: 359.66 ± 76.48 ng/g dw) compared to the rural subregion (∑PFAA: 328.86 ± 87.51 ng/g dw). Seasonal fluctuations impacted PFAA concentrations in fish and crustacean muscles but exhibited negligible effects on bivalve muscles. Spatial variations only influenced PFAA concentrations in specific viscera (gill, liver, kidney), while seasonal changes had minimal effects on viscera. The organisms demonstrated varying bioaccumulation capacities, with crustaceans displaying the highest bioaccumulation potential, followed by crustaceans and fish. Both spatial and seasonal variations modulated the bioaccumulation patterns of PFAA in muscles, whereas bioaccumulation in viscera was only influenced by seasonal factors. Notably, PFAA biomagnification along the food web was exclusively governed by spatial distribution, remaining unaffected by seasonal changes. The human health risk assessment underscored the potential adverse health impacts of PFOS and PFOA, particularly on young children (aged 2 to <6 years). This study further proposed comprehensive recommendations for mitigating PFAA-induced health risks, encompassing source control, selective consumption, pre-cooking treatments, and strategic cooking method selection. This research provides crucial insights into the ecological behaviors and health implications of PFAA in urban fringe lakes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Microplastics can act as vectors of chemical contaminants in aquatic environments, but the extent to which this phenomenon contributes to chemical exposure in marine organisms remains poorly understood. We investigated the occurrence of microplastics and emerging contaminants (ECs), including antibiotics and per- and polyfluoroalkyl substances (PFAS) in 14 marine fish species. Microplastics were detected in all marine fish species, mainly in the gastrointestinal tract. Fluoroquinolones and tetracyclines were the dominant antibiotics in fish muscles with maximum concentrations of 24.84 and 26.95 ng g -1 ww, while perfluorooctanesulfonic acid (PFOS, 0.039-0.95 ng g -1 ww) was the dominant component in the PFAS profile. Fish with more microplastics had significantly higher concentrations of fluoroquinolones and perfluoroalkyl acids than fish with less microplastics (p < 0.05), but the correlation was not observed in other chemicals. Structural equation modeling revealed the contribution of microplastics in fish on the level of ECs contamination. The health quotient value indicated the low health risk of single compounds via fish consumption to humans; however, the combined risk of microplastics and ECs still needs to be considered. This work highlights the link between microplastics with associated ECs ingested by aquatic organisms and the human health risk of consuming polluted seafood., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Progestins (PGs) are a group of emerging contaminants with endocrine disrupting effects. Despite their large amounts of use and excretion, investigations have been limited to several compounds in the aqueous phase, and the occurrences and distribution of numerous PGs in different matrices remain unclear. In this study, water, suspended particulate matter and sediment samples from rivers in the Yellow River Delta (YRD), China were investigated over two seasons to elucidate the occurrences, sources, and ecological risks of 55 natural and synthetic PGs. 40 PGs were detected with concentrations varied from not detected (ND) to 146 ng/L in water, ND to 251 ng/g dry weight (dw) in SPM, and ND-173 ng/g dw in sediment. The less-studied natural metabolites were the predominant PGs in all samples. 54-96 % of the PGs were concentrated in the aqueous phase, and SPM was also an important carrier, especially for hydrophobic compounds. Anthropogenic activities and environmental conditions together affected the spatiotemporal distribution of PGs. Animal sources, including aquaculture and animal husbandry, contributed most (42.3 %) to the total PGs, followed by treated sewage (32.9 %) and industrial sources (24.7 %). The risk assessment suggested that PGs posed moderate to high risks to aquatic organisms, especially the fish., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study aimed to examine the distribution of poly- and perfluoroalkyl substances (PFAS) in 15 marine fish species from the northern Bohai Sea, investigate their sources of contamination, and evaluate the benefits-risks associated with the concurrent consumption of fish fatty acids and PFAS. The ∑PFAS concentrations in fish ranged from 9.38 to 262.92 ng·g -1 (dry weight). The highest PFAS levels were found in the viscera and gills, while the lowest levels were found in the muscles. Industrial effluents and sewage treatment plant discharges were the primary sources of PFAS contamination. The individual PFAS concentrations in fish were insignificantly correlated with their trophic levels (p > 0.05). However, the concentrations of hexafluoropropylene oxide dimer acid (HFPO-DA) or long-chain PFAS (C > 8) significantly increased with fish size (e.g., total length, weight) and lipid content (p < 0.001). The benefit-risk analysis suggests that HPFO-DA poses a higher health risk than perfluorooctanoic acid (PFOA) in fish (p < 0.05). Long-term consumption of contaminated fish may significantly increase human serum PFOA concentration and kidney cancer risk (p < 0.05). Daily consumption of 5 g (wet weight) muscle from Ditrema temmincki and Konosirus punctatus is recommended to meet the requirements for fatty acid supplementation without posing health risks., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Studying the impacts of land use and river network structure on perfluoroalkyl acids (PFAAs) footprint in rivers is crucial for predicting the fate of PFAAs in aquatic environments. This study investigated the distribution, ecological risks, sources and influence factors of 17 PFAAs in water and sediments of rivers from hills to plain areas. The results showed that the detection frequencies were higher for short-chain PFAAs than long-chain PFAAs in water, whereas an opposite pattern was found in sediments. The concentration of ∑PFAAs ranged from 59.2 to 414 ng/L in water and from 1.4 to 60.1 ng/g in sediments. Perfluorohexanoic acid and perfluorooctanoic acid were identified as the main pollutants in the river. The average concentrations of PFAAs were higher in the aquaculture areas (water: 309.8 ng/L; sediments: 43.27 ng/g) than in residential areas (water: 206.03 ng/L; sediments: 11.7 ng/g) and farmland areas (water: 123.12 ng/L; sediments: 9.4 ng/g). Environmental risk assessment showed that PFAAs were mainly low risk or no risk in water, but were moderate risk and even high risk in sediments, especially for perfluorooctane sulfonate. Source apportionment found that PFAA sources were mostly from industry, wastewater discharge, and surface runoff. Dissolved oxygen, chemical oxygen demand, water system circularity, network connectivity and organic matter were significantly correlated to PFAA concentration, indicating that the physicochemical properties and river network might directly influence the environmental behavior of PFAAs. The built-up area was positively correlated with PFAAs. These findings indicated that a comprehensive understanding of the influences of land use and river network structure on PFAAs in rivers is essential for managers to formulate effective PFAA control strategies., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study investigated the occurrence status, sources, and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in sediments from three typical mangrove areas in Guangxi Province, China. Results showed that the PAH content in the three studied regions ranged from 39.76 ng·g -1 to 164.93 ng·g -1 , and the average concentration was 92.87 ng·g -1 . The PAHs that were detected were mainly 3-ring and 4-ring. The source of PAHs, as traced by the diagnostic ratio method and principal component analysis, was mainly from combustion. The toxicity risk assessment showed that the content of all PAHs was lower than the Effects Range Low (ERL), and the potential ecological risk was low. The toxicity equivalent (TEQ BaP ) content ranged from 4.75 ng·g -1 to 19.20 ng·g -1 , with an average of 12.08 ng·g -1 . Overall, the ecological risk of PAHs in mangrove sediments in Guangxi is considered low., Competing Interests: Declaration of competing interest All authors declare there are no conflicts of interest regarding the publication of this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Environmental occurrence and risks of novel synthetic phenolic antioxidants (SPAs) remain largely unclear. By using a typical algae (Chlorella pyrenoidosa) as model organism, we evaluated the ecological risks of both traditional and novel SPAs, based on their concentrations in water, sediment, and soil collected from the Yangtze River Delta, China. Detection frequencies (DFs) of 10 novel SPAs were 25-100% in water, 3-100% in sediment, and 0-100% in soil, with geometric means (GMs) of 2700 ng/L, 1270 ng/g, and 2440 ng/g, respectively. For 8 traditional SPAs, DFs were 50-100% (GM: 680 ng/L), 3-100% (534 ng/g), and 47-100% (2240 ng/g) in water, sediment, and soil, respectively. AO3114 was the main pollutant in water, while AO1010 dominated in sediment and soil. Notably, low-molecular-weight SPAs showed migration behavior from sediment to water. Four SPAs (AO626, AO1035, AO1098, and AO1076) showed dose- and time-dependent toxicity on Chlorella pyrenoidosa. As time progressed, sediment-released SPAs became more toxic than those in water. Two SPAs (AO1135 and BHT-Q) posed high risks (RQ W  > 1) to green algae, daphnia, and fish. The SPA mixture exhibited high risks (RQ mix  > 1) to these organisms, increasing with the trophic level. This research holds valuable guidance for further SPA risk assessments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Brominated flame retardants (BFRs) and their substitutes are prevalent in the environment, especially near industrial point sources. In non-point source pollution areas, it is crucial to investigate the seasonal pollution characteristics to identify the pollution sources. In this study, compositional profiles, seasonal variations, and ecological risks of legacy BFRs and novel BFRs (NBFRs) in the water and sediment from the Tuojiang River located in southwest China were investigated. The results indicated that ΣBFRs ranged from not detected (n.d.) to 42.0 ng/L in water and from 0.13 to 17.6 ng/g in sediment, while ΣNBFRs ranged from n.d. to 15.8 ng/L in water, and from 0.25 to 6.82 ng/g in sediment. A significant seasonal variation was observed in water and sediments with high proportions of legacy BFRs (median percentage of 68.8% and 51.3% in water and sediment) in the dry season, while NBFRs (median percentage of 53.2% and 71.6% in water and sediment) exhibited predominance in the wet season. This highlighted the importance of surface runoff and atmospheric deposition as important sources of NBFRs in aquatic environments. Moreover, there were high ratios of decabromodiphenyl ethane (DBDPE) and BDE-209 (average: 1.38 and 2.76 in dry and wet season) in sediments adjacent to the residual areas, indicating a consumption shift from legacy BFRs to NBFRs in China. It was observed that legacy BFRs showed higher ecological risks compared to NBFRs in both water and sediment environments, with BDE-209 posing low to medium risks to sediment organisms. This study provides better understanding of contamination characteristics and sources of legacy BFRs and NBFRs in non-point source pollution areas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This study argued for the first time that 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) and perfluorooctanesulfonic acid (PFOS) might have different tissue distribution mechanisms in wild fish species. Nine emerging and legacy per- and polyfluoroalkyl substances (PFASs) were detected in the water and wild fish tissues samples collected from the Qiantang River. Perfluorooctanoic acid (213 ng/L) was the predominant PFAS contaminant, and the other contaminants included perfluorohexanoate (19 ng/L), perfluorobutanoate (199 ng/L) and hexafuoropropylene oxide dimer acid (55 ng/L), which are the main fluorinated alternatives used in various industries located along the Qiantang River. Furthermore, PFOS (742 ng/g) and 6:2 Cl-PFESA (9.0 ng/g) were the predominant PFAS contaminants detected in the fish tissue samples. The differences in the potential molecular mechanism of the tissue distribution of PFOS and 6:2 Cl-PFESA in wild fish species are discussed. Additionally, we hypothesize that phospholipid partitioning is the primary mechanism underlying the tissue distribution of PFOS, and that a specific protein-binding mechanism is involved in the tissue distribution of 6:2 Cl-PFESA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Antibiotics play an essential role in the aquaculture industry, but their overuse and weak degradability inevitably lead to light to severe residues in natural and aquaculture environments. Most studies were interested in the occurrence, distribution, and ecological risks of a limited number of antibiotics in natural environments (rivers, lakes, and coastal regions) with a minor focus on antibiotic presence in either water, sediments, or organisms in aquaculture environments located in specific regions. In this study, we conducted a comprehensive investigation into the occurrence and distribution of up to 32 antibiotics [including 15 quinolones (QNs) and 17 sulfonamides (SAs)] in organisms and their corresponding environmental matrices from 26 freshwater aquaculture ponds in Northeast Zhejiang, China. A total of 13, 9, 7, and 7 antibiotics were detected in pond water, sediments, feeds, and aquaculture organisms, respectively, with concentration ranges of 0.6-92.2 ng/L, 0.4-1169.3 ng/g dw,

Bisphenols, bisphenol A diglycidyl ether (BADGE), and bisphenol F diglycidyl ether (BFDGE) are commonly used as raw materials or additives in the production of several industrial and consumer products. However, information regarding the occurrence and distribution of these industrial chemicals in freshwater ecosystem is limited. In this study, four bisphenols, six BADGEs, and three BFDGEs were determined in abiotic and biotic samples collected from the Dongjiang River basin in southern China. Among the four bisphenols, BPA was widely present in all samples analyzed including surface water (median: 1.81 ng/L), sediment (3.1 ng/g dw), aquatic plants (3.69 ng/g dw), algae (7.57 ng/g dw), zooplankton (6.17 ng/g dw), and fish muscle (5.28 ng/g dw). Among the nine BADGEs and BFDGEs analyzed, BADGE, BADGE•H 2 O, BADGE·HCl·H 2 O and BADGE•2H 2 O was found in all sample types. Although the median concentration of BADGE•2H 2 O in surface water was below LOQ, this compound was found at median concentrations of 2.61, 3.59, 1.03, 1.69, and 49.8 ng/g dw in sediment, plants, algae, zooplankton, and fish muscle, respectively. Significant positive linear correlations were found among logarithmic transformed concentrations of BPA, BADGE, BADGE•H 2 O, BADGE•HCl•H 2 O, and BADGE•2H 2 O in sediment. The bioconcentration factor (logBCF) values of BADGE, BADGE•H 2 O, BADGE•HCl, BADGE•HCl•H 2 O, BADGE•2H 2 O, and BADGE•2HCl in fish, plants, algae, and zooplankton were > 3.3 L/kg (wet weight), indicating that these chemicals possess moderate bioaccumulation potential. The estimated daily total intake of bisphenols and BADGEs through fish consumption was 75.1 ng/kg bw/day for urban adult residents. The study provides baseline information on the occurrence of bisphenols, BADGEs, and BFDGEs in a freshwater ecosystem., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Historical chlor-alkali production has led to substantial concentrations of persistent organic pollutant residues in the environment. This study systematically investigated the distribution of polycyclic aromatic hydrocarbons (PAHs), chlorinated/brominated-PAHs (Cl/Br-PAHs), polychlorinated naphthalenes (PCNs), and hexachlorobutadiene (HCBD) in sediment, lotus (Nelumbo nucifera), and fish samples from Ya-Er Lake, which is a site in China with historical chlor-alkali contamination. The average concentrations [(4.97-1.47) × 10 3  ng/g dry weight (dw)] of these pollutants in backfill sediments, which were dredged from the lake after chlor-alkali production stopped, were 2.68-70.87 times those in fresh lake sediments (0.622-218 ng/g dw) and reported concentrations in other areas. Correlation analyses indicated that Cl-PAHs, Br-PAHs, and PCNs likely originated from halogenation of parent PAHs in the study area, and the chlorination ratios were larger than those of bromination. The Cl (1/2/3) -PAHs/PAHs and Br (1) -PAHs/PAHs ratios were higher than those for PAHs with more halogen atoms. This contamination extended into the biota, with notable pollutant burdens found in lotus (Nelumbo nucifera, 0.305-77.3 ng/g dw) and even higher concentrations in fish (2.20-345 ng/g lipid weight). Estimated biological soil accumulation factors revealed significant enrichment in lotus organs (mean: 7.19) and fish muscle (mean: 10.65), especially the latter, which highlighted bioaccumulation and potential food chain transfer risks. The estimated daily intakes of PAHs, Cl/Br-PAHs, and HCBD through fish consumption currently pose negligible risks, while dietary intake of PCNs may present health concerns. Continuous monitoring and impact assessments are crucial for developing appropriate risk management strategies to safeguard public health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Parabens, bisphenols (BPs), and triclosan (TCS) are common environmental phenols widely applied in industrial products, pharmaceuticals, and personal care products. They are endocrine disruptors and pervade the natural environment, causing significant detrimental impacts on ecosystems, including marine habitats. Therefore, in this study, 40 samples comprising coral polyps, algae, and sediments were collected from Sanya, Hainan Province, China, in which the presence and compositional profiles of parabens, BPs, and TCS were examined to identify their fate in the oceans. The results unveiled the ubiquitous occurrence of at least one paraben or bisphenol in all samples, with TCS detected in over 80% of cases. Notably, coral samples contained the most contaminants (median concentration: 9.42 ng/g dry weight-dw), followed by sediment samples (5.95 ng/g dw) and algal samples (3.58 ng/g dw). Attributed to their broadest application, methylparaben (MeP) and propylparaben (PrP) emerged as the primary paraben constituents. MeP displayed the highest median concentration in coral samples (4.42 ng/g dw), probably related to its high-water solubility and the filtration mechanism employed by the coral polyps during seawater intake. Intriguingly, bisphenol P (BPP) superseded bisphenol A (BPA) as the dominant bisphenol, especially in the algal samples, probably owing to the lipophilic character of BPP and the enhanced biodegradability of BPA within aquatic environments. The highest concentration of TCS (3.44 ng/g dw) was found in the sediment samples, associated with its long half-life in the sediments. Furthermore, the correlation between multiple parabens and TCS implies their co-use to augment antimicrobial efficacy. Future research should prioritize the examination of these phenols in diverse marine environmental media. Corresponding toxicological experiments should be conducted to visualize their transport dynamics, degradation byproducts, and toxicity to marine biota to gain insights into the risks they pose to the marine ecosystem., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The COVID-19 pandemic has profoundly impacted human activities and the environment globally. The lockdown measures have led to significant changes in industrial activities, transportation, and human behavior. This study investigates how the lockdown measures influenced the distribution of polycyclic aromatic hydrocarbons (PAHs) in the sediments of Chaohu Lake, a semi-enclosed lake. Surface sediment samples were collected in summer of 2020 (lockdown have just been lifted) and 2022 and analyzed for 16 priority PAHs. The range of ΣPAHs concentrations remained similar between 2020 (158.19-1693.64 ng·g -1 ) and 2022 (148.86-1396.54 ng·g -1 ). Among the sampling sites, the west lake exhibited similar PAHs concentrations characteristics over the two years, with higher levels observed in areas near Hefei City. However, the east lake exhibited increased ΣPAHs concentrations in 2022 compared to 2020, especially the area near ship factory. PAHs source analysis using principal component analysis-multiple linear regression (PCA-MLR) revealed an increased proportion of petroleum combustion sources in 2022 compared to 2020. The isotope analysis results showed that organic matter (OM) sources in the western lake remained relatively stable over the two years, with sewage discharge dominating. In contrast, the eastern lake experienced a shift in OM sources from sewage to C3 plants, potentially contributing to the increased PAH levels observed in the eastern lake sediments. Ecological risk assessment revealed low to moderate risk in both 2020 and 2022. Health risk evaluation indicated little difference in incremental lifetime cancer risk (ILCR) values between the two years, with only benzo[a]pyrene (BaP) posing a high risk among the carcinogenic PAHs. Children generally faced higher health risks compared to adults. This study reveals pandemic-induced changes in PAH pollution and sources in lake sediments, offering new insights into the impact of human activities on persistent organic pollutants, with implications for future pollution control strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Aniline accelerators and antioxidants (AAs) are high-production-volume industrial additives that have recently attracted emerging concern given their ubiquity in environmental compartments and the associated (eco)toxic effects. Nonetheless, available information on the multi-media behavior of AAs and their transformation products (TPs) remains scarce. Therefore, we determined the residues of twenty-four AA(TP)s in paired dissolved phases (i.e., filtered water), suspended particulate matter (SPM), and sediment samples collected from the Yangtze River Estuary (YRE), a highly urbanized estuary in the East China. The median total concentrations of targeted compounds were 0.73 ng/g dw, 34.4 ng/L, and 39.6 ng/L in sediments, surface and bottom water, respectively. Diphenylamine (DPA) was the most abundant congener in SPM, while 1,3-diphenylguanidine (DPG) and dicyclohexylamine (DChA) dominated in the dissolved phases and sediments. Various anthropogenic emissions and (a)biotic degradation may collectively shape the matrix-specific accumulation patterns and spatial trends of these compounds across the YRE. However, the vertical patterns of AA(TP)s were obscure, probably due to the estuarine hydrodynamics and/or the modest sample size. The SPM fractions of AA(TP)s in water (Ф: 7.9-100%) and the sediment sorption coefficients (K OC : 0.01-6.56) both positively correlated with their hydrophobicity as indicated by the octanol-water partition coefficient (K OW ). Moreover, risk quotients implied moderate to high aquatic toxicity posed by several AA(TP)s at certain YRE sites. The estimated total annual fluxes of our analytes transported via water and sediments towards the East China Sea were 5.90-365.5 tons and 4.23-1,100 kg, respectively. This work provides a systematic investigation of multi-media processes and ecological risks of AA(TP)s in a highly-urbanized estuary, contributing to holistic comprehension of these emerging contaminants in estuarine environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Enhanced anthropogenic activity strength has altered the watershed particulate transport and material cycle resulting in organic pollutant deposition changes in Dongting Lake associated with unclear ecological risk. In the present study, dual biomarkers i.e. n-alkanes and polycyclic aromatic hydrocarbon (PAHs) were applied in the 210 Pb-dated sediment cores for traceability of centennial organic pollutants in the lake mouth area. The partial least squares path model and risk quotients method were used to explore the controlling pathways and ecological risk. The results show a range of sedimentary organic carbon (C), nitrogen (N), and phosphorus (P) was at 1.76-185.66, 0.97-89.80, and 0.01-0.97 g m -2  yr -1 with total reserves of 51.68, 18.44, and 0.27 t ha -1 , respectively, over the past 179 years. The presence of PAHs rapidly increased by 2.47 fold from 535.60 ng g -1 , while PAHs and carcinogenic PAHs (ΣCPAHs) burial fluxes increased by about 6 and 5 folds, respectively. Accompanied by anthropogenic activities and climate change, the exotic sources gradually becoming predominant. The n-alkane diagnostic ratios indicated a shift of organic matter (OM) from autotrophic bacteria, algae, and phytoplankton-derived sources to macrophyte and terrestrial plants. The exotic origins rose to approximately 73.61 %, while endogenous sources decreased to 26.39 %. The direct effects of anthropogenic activities and their indirect negative impacts on climate and sedimentary structure are the key ways for sediment material loading. The nutrient accumulation in sediments coincides with the lake's eutrophication history over the past decades. The ΣCPAHs accounted for about 89.37 ± 17.14 % of the total TEQ, reflecting a strong ecological risk. The contribution of anthropogenic activities such as fuel usage, fertilizer application, hard pavement coverage, and OM loss from the ecosystem to the sources of organic pollutants and their component types may be a focus of attention in the middle reaches of the Yangtze River plain lake., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Polycyclic aromatic hydrocarbons (PAHs) are highly concerning environmental pollutants due to their toxicity, persistence, and bioaccumulation. In this paper, concentrations and compositions of 16 United States Environmental Protection Agency (USEPA) priority control PAHs in the fish collected from four lakes in central and eastern China were analyzed. 18 species of fish were collected from four typical lakes, namely Taihu Lake, Danjiangkou Reservoir, Yuncheng Salt Lake, and Nansi Lake. Quantitative analysis of PAHs were carried out with gas chromatograph/mass spectrometer, and 13 out of 16 PAHs were identified, with the main components being pyrene, chrysene, naphthalene, and benzo(b)fluoranthene. The accumulation of PAHs in fish from Taihu Lake, Danjiangkou Reservoir, Yuncheng Salt Lake, and Nansi Lake was 28.75-47.27, 26.60-31.93, 33.56-39.30, and 27.22-43.01 ng·g -1 , respectively. The toxic equivalents of high-cyclic PAHs in fish of the four lakes were significantly higher than those of low-cyclic and middle-cyclic PAHs (P < 0.05). In Taihu Lake, Danjiangkou Reservoir, and Nansi Lake, the toxicity equivalents were predominantly contributed by benzo[a] pyrene (BaP), while in Yuncheng Salt Lake, dibenzo(a,h) anthracene (DahA) was the main contributor. The residents in central and eastern China exposed to PAHs had a negligible non-cancer risk (non-carcinogenic risk values <1) and a potential low cancer risk. It was noteworthy that the Pleuronichthys cornutus and Lateolabrax japonicus from Yuncheng Salt Lake could pose carcinogenic risks (>10 -4 ) to humans, with benzo[b]fluoranthene (BbF) having the highest risk contribution rate. Source analysis indicated that the main source of PAHs in fish was combustion sources. BaP, DahA, and BbF could become potential pollutants of concern in the field of ecotoxicology. The results of this study on PAHs bioaccumulation, pollution characteristics, sources and health risks in fish from four lakes would provide a scientific basis for local governments to formulate targeted environmental management policies, pollution control measures, and public health strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Polybrominated diphenyl ethers (PBDEs) and their alternatives (e.g., dechlorane plus (DPs) and decabromodiphenyl ethane (DBDPE)) are ubiquitous in various environmental media. However, limited data is available on these chemicals in edible fish species from the wide-open South China Sea (SCS). In the present study, ten legacy PBDEs and three substitutions (DBDPE and two DPs) were analyzed in 16 wild fish species sampled from the open SCS to investigate their spatial and species-specific variations. The results showed that the total concentrations of PBDEs, DBDPE, and DPs in fish samples were in the range of 1.69-47.6, not detected (nd) to 21.0, and nd to 3.80 ng/g lipid weight (lw), respectively. BDEs 47, 209 and 100 were the dominant target PBDE congeners, representing 49.2%, 17.2% and 9.93% of the total PBDE concentrations, respectively. Higher concentrations of PBDEs, DBDPE, and DPs were found in fish species from the Wanshan Archipelago compared to those from the Mischief Reef and the Yongxing Island, suggesting the significant influence of anthropogenic activities. Species-specific differences in levels of PBDEs were observed, with the order of bathydemersal > demersal > pelagic ≈ reef-associated > benthopelagic species. The average f anti value of all fish samples was 0.68, suggesting commercial DP products as a contamination source. The levels of PBDEs, DPs, and DBDPE in fish samples were relatively low compared with those from other locations around the globe. Finally, the health risks concerning the ingestion of BDEs 47, 99, 153 and 209 via fish consumption collected from the SCS are negligible., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The construction of dams has caused disruptions to river connectivity, leading to alterations in the deposition of hydrophobic organic contaminants in reservoir sediments. Further investigation is warranted to explore the impact of cascade reservoirs with differing hydrological characteristics on polycyclic aromatic hydrocarbons (PAHs) distribution in sediment. This study examines the presence of 30 PAHs in the sediments collected from six cascade reservoirs situated in the Wujiang River basin during January and July 2017. The results showed that Σ30 PAHs ranged from 455-3000 ng/g dw (mean 1030 ng/g dw). Anthropogenic activities and reservoir hydrology determined the distribution trend of PAHs in sediments, with an overall increase from upstream to midstream and then a decrease downstream. The PAH levels were highly linked to the secondary industry (P < 0.05). This was further supported by the relationship between the PAH emissions from coal combustion and traffic sources analyzed by the positive matrix factorization model and economic parameters in the wet season (P < 0.01). At the same time, reservoir age (RA) showed a positive correlation with PAH concentrations (P < 0.05), while hydraulic retention time (HRT) exhibited a negative correlation with PAH levels (P = 0.03). The relationship between total organic carbon (TOC) and PAHs in stream sediments worldwide was nonlinear (P < 0.01), with PAH concentrations initially rising and then falling as TOC levels increased. Concerns regarding carcinogenic risk were raised due to contributions from coal and vehicular sources, with the risk increasing with RA., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The widespread existence and persistence of antibiotics in the aquatic environment, and their extensive ecological risks, have attracted considerable attention. The objective of this study was to evaluate the occurrence and distribution of 25 antibiotics in environmental and biological samples from Poyang Lake Basin in China. SPE-HPLC-MS/MS was used to quantify the concentrations in different matrices. The total concentrations ranged from 144 to 933 ng/L in the water and 346 to 1154 ng/g in the sediment. In the spatial distribution analysis of this basin, the concentrations in the Ganjiang River were generally higher than those in Poyang Lake. The seasonal distribution in the wet and dry seasons showed comparatively higher concentrations during the dry season than the wet season. Additionally, antibiotics were found in various hydrophytes and animals, and the bioconcentration factor values followed the order: emergent plants > floating plants > submerged plants and benthic organisms > ducks > fish. Moreover, correlations among different matrices showed that antibiotics in viviparid snails were significantly positively correlated with those in ducks, and negatively correlated with those in carps, indicating the transmission relationship through the food chain. The results showed the trophic transfer of antibiotics in the food web and their potential environmental impacts on Poyang Lake Basin need constant attention., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Benzotriazoles are a class of ultraviolet absorbents which absorb UV ranging from 280 to 400 nm and are widely used in personal care products and industrial production. Their residues in environmental matrices have received great concern in recent years, but most studies have focused on pollution in water and few have examined BUVs in marine sediments. In this study, we investigated the occurrence, potential sources, and ecological risk of 15 types of BUVs in the sediments of Bohai Sea in China for the first time. The total concentrations of the 15 BUVs ranged from 0.139 to 4.125 ng/g dw with a median concentration of 0.340 ng/g. UV-327 and UV-360 were predominant among the BUV congeners, accounting for 22.6% and 17.7% of the total concentration of Σ 15 BUVs, respectively. The detection frequencies of the BUV congeners generally exceeded 95%, reflecting the wide use and persistence of these chemicals. The concentrations of the BUV congeners in this study were one order of magnitude lower than those in other areas. Moreover, the distributions of BUVs presented a decreasing gradient from nearshore to offshore, indicating that coastal input was the main influencing factor. Two potential primary sources, plastic manufacturing and domestic wastewater, were identified via principle component analysis. The ecological risks of BUVs to aquatic organisms in the sediments were evaluated using the risk quotient (RQ) method. Generally, the risk to aquatic organisms from exposure to BUVs in Bohai Sea could be considered low at the measured concentrations. While our study provides important new insight into the ecological risks of BUVs in the estuary, further research on the pollution levels and toxicity risks of BUVs in Bohai Sea should be conducted to better understand the ecological effect of these pollutants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A total of 32 surface sediment samples were collected from the East China Sea (ECS) to investigate the distribution of polycyclic aromatic hydrocarbons (PAHs) in the surface sediments and evaluate their sources. The content of PAHs in the ECS surface sediments ranged from 2.3 ng/g to 57.8 ng/g. The source analysis revealed that the combustion of such fuels as petroleum is the main contribution source of PAHs in the ECS surface sediments, and oil spill is another important contribution source. The study also showed that the content of PAHs in the ECS surface sediments is low and does not cause adverse ecological risks., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The distribution characteristics and risk levels of PAHs in surface sediment in the Honghai Bay of China are studied in this paper. The results showed that the concentration of total PAHs in this area ranged from 100.65 ng·g -1 to 241.31 ng·g -1 , with an average concentration of 158.83 ng·g -1 . The tricyclic PAHs were the main components in the detected PAHs. PAH pollution levels in this region were low and moderate as compared with adjacent areas. Traceability results showed that the sediment PAHs mainly originate from coal and biomass combustion. PAHs concentrations at some stations were above the Environmental Quality Reference Level. The PAHs toxicity and ecological risk level in surface sediments in the area was determined to be low to moderate by toxicity equivalence testing and risk entropy value assessment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Knowledge about sediment levels and sources of persistent organic pollutants (POPs) in Lanzhou section Yellow River remains limited. Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) levels in 12 sediment samples from this region were measured by GC/MS. OCPs concentrations ranged from 85.6 to 202 ng/g, while PCBs levels varied between 3.08 and 32.3 ng/g. Our findings demonstrated a significant correlation between these pollutants and total organic matter (TOC), highlighting TOC's role in pollutants distribution. Notably, OCPs and PCBs levels were higher in the eastern section, following the water flow direction. The primary OCPs components were hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), whereas PCBs were dominated by perchlorinated compound. Source identification indicated that OCPs primarily originated from historical residues and recent applications, while industrial activities as significant PCBs sources. Sediment quality guidelines and health risk assessments indicated negligible environmental risk. This study providing valuable insights on sediment pollution control and management strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

As a group of emerging contaminants of global concern, tire additives and their transformation products (TATPs) are causing a severe threat to aquatic ecosystems, particularly the highly lethal effects of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q) on certain fish species. Yet, the contamination status of TATPs in the lake ecosystems remains largely uncharacterized. This study conducted the first nationwide monitoring of the distribution characteristics of TATPs in 208 lake sediments collected from five lake regions across China. All the 13 TATPs were identified in lake sediments, with the total levels varying between 1.4 and 1355 ng/g, and 4-hydroxydiphenylamine (4-OH-PPD) as the most dominant. The total levels of TATPs decreased in the following order: Yunnan-Guizhou Plateau > Inner Mongolia-Xinjiang Region, Eastern Plain > Qinghai-Tibet Plateau, and Northeast Plain (p < 0.05). The geographical distribution of TATPs in lake sediments was significantly driven by total organic carbon content, temperature, and population density. N,N'-di-2-naphthyl-p-phenylenediamine, 6PPD-Q, N,N'-diphenyl-p-phenylenediamine, and 4-OH-PPD belonged to high-priority contaminants. Our study emphasizes that emerging pollutant TATPs place significant pressure on lake ecosystems and deserve urgent attention., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Contaminant accumulation in organisms can be influenced by both biological traits and environmental conditions. However, delineating the main factors affecting contaminant burdens in organisms remains challenging. Here, we conducted an initial investigation into the impact of diet and habitat on the accumulation of short- (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in Indo-Pacific humpback dolphins (2003-2020, n = 128) from the Pearl River Estuary (PRE), a highly polluted estuary in China. The detected levels of SCCPs (5897 ± 3480 ng g -1 lw) and MCCPs (13,960 ± 8285 ng g -1 lw) in blubber samples of humpback dolphin are the highest among recorded values marine mammals. Both SCCPs and MCCPs exhibited biomagnification factor values exceeding 1, suggesting their biomagnification potential within the dolphins and their diet. Quantitative diet analysis using the dolphin fatty acid signatures revealed that humpback dolphins inhabiting the western PRE consumed a larger proportion of carnivorous fish than those from the eastern PRE. However, spatial analysis showed that humpback dolphins in the western PRE contained lower SCCP/MCCP concentrations than those from the eastern PRE. Based on these findings we suggest that, compared to diet differences, spatial variations of SCCPs/MCCPs in humpback dolphins may be predominantly influenced by their space-use strategies, as the eastern PRE is closer to the pollutant discharge source and transfer routes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Organic ultraviolet filters (OUVFs) are extensively incorporated into both cosmetic items and industrial products and have been commonly found in water ecosystems. This study aims to examine the environmental levels, sources, ecological and human health risks of 14 commonly used OUVFs both in coastal water and beach deposit samples collected from the nearshore regions of Hainan Island and the South China Sea. This is first study highlighting the contamination of OUVFs in Hainan Island and utilizing economic and tourism data to confirm the potential source of OUVF pollution in costal aquatic and coastal ecosystem. Along the coastal tourist regions of Hainan Island, the median concentrations in coastal waters and beach deposits of these OUVFs fall within the range from 1.2 to 53.2 ng/L and 0.2-17.0 ng/g dw, respectively. In coastal water and beach deposit, the concentration of BP-3 was the highest, with median concentrations of 53.2 ng/L and 17.0 ng/g dw, respectively. Regarding human health risks, the daily intake of all 14 OUVFs through swimming was found to be 40-48 ng/kg/day. Ecological risk assessment indicates that BP-3 presents a medium risk for marine microalgae with a concurrent low risk for corals. The correlation analysis underscores a substantial interrelation of OUVFs in both coastal waters and beach deposits with various economic indicators, including annual rainfall, overnight tourists, total hotel rooms (unit), room occupancy rate, and sewage treatment capacity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Organophosphate esters (OPEs), increasingly used as alternatives to brominated flame retardants, are ubiquitous in the global aquatic environment. Despite their potential toxicological impact on ecosystems, community-level risk assessments for OPEs in sediments remain scarce. This study investigated OPE occurrences and composition characteristics in the Bohai Sea's sediments and appraised both individual and joint ecological risks posed by characteristic OPE homologs using ten commonly used species sensitivity distribution (SSD) models, integrating acute-to-chronic conversion and phase equilibrium partitioning. OPEs were detected across all sediment samples, with total concentrations ranging from 0.213 ng/g dry weight (dw) to 91.1 ng/g dw. The predominant congeners included tri-n-butyl phosphate (TnBP), triisobutyl phosphate (TiBP), tri(2-ethylhexyl) phosphate, tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(1, 3-dichloro-2-propyl) phosphate (TDCIPP), and triphenylphosphine oxide. Best-fit SSD models varied among TnBP, TiBP, TCEP, TCPP, and TDCIPP, demonstrating Sigmoid, Burr III, Sigmoid, Burr III, and Burr III, respectively. The same parametric model demonstrated variability in the fitting process for different OPE congeners, which also happened to the fitting results of ten parametric models for the same specific characteristic congener, underscoring the necessity of employing multiple models for precise community-level risk assessments. Hazard concentrations for a 5% cumulative probability were 0.116 mg/L, 2.88 mg/L, 1.30 mg/L, 1.44 mg/L, and 1.85 mg/L for each respective congener. The resulting risk quotients (RQ) and overall hazard index (HI) were selected as criteria to assess the individual and joint ecological risks of OPEs in sediments from the Bohai Sea, respectively. RQ and HI were both below 0.1, indicating a low risk to the local ecosystems. Multi-model SSD analysis could provide refined data for community-level risk evaluation, offering valuable insights for the development of evidence-based environmental standards and pollution control strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Polybrominated diphenyl ethers (PBDEs) and their substitutes, novel brominated flame retardants (NBFRs), are ubiquitously present in the aquatic environment of electronic waste (e-waste) dismantling region, leading to their inevitable absorption and accumulation by aquatic organisms, which can be transferred to human via directly aquatic product consumption or through food chain, thereby posing potential health risks. This study focused on fish samples from Guiyu and its surrounding areas, and found the total PBDEs concentrations were 24-7400 ng/g lw (mean: 1800 ng/g lw) and the total NBFRs concentrations were 14 to 2300 ng/g lw (mean: 310 ng/g lw). Significant positive correlations were found among PBDE congeners, among different NBFRs, and between NBFRs and commercial PBDEs that they replace. ΣPBDEs and ΣNBFRs in the intestine were 620-350,000 and 91-81,000 ng/g lw (mean: 83000 and 12,000 ng/g lw, respectively), significantly exceeding those in the gills, where ΣPBDEs and ΣNBFRs were 14-37,000 and 39-45,000 ng/g lw (mean: 9200 and 2400 ng/g lw, respectively). The ΣPBDEs and ΣNBFRs showed no non-carcinogenic risks to the target population through dietary intake. Despite the significantly higher daily intake of decabromodiphenyl ethane (DBDPE) compared to decabromodiphenyl ether (BDE209), the non-carcinogenic risk associated with BDE209 remained higher than that of DBDPE. Our findings can assist researchers in understanding the presence of BFRs in aquatic organisms, inhabiting e-waste dismantling areas, and in evaluating the associated health risks posed to humans through dietary exposure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The exploration of sediment pollution caused by PAHs and its impact on microbial communities can provide valuable insights for the remediation of sediments. The spatial distribution of PAHs and their impact on the microbial community within the Pearl River Estuary were investigated in this study. The findings revealed that the total concentration ranges of 16 PAHs were between 24.26 and 3075.93 ng/g, with naphthalene, fluorene, and phenanthrene potentially exerting adverse biological effects. More PAHs were found to accumulate in subsurface sediments, and their average accumulation rates gradually decreased as the number of rings in PAHs increased, ranging from 180 % for 2-ring to 36 % for 6-ring. The phyla Proteobacteria, Bacteroidetes, Actinobacteria, and Chloroflexi were found to dominate both surface and subsurface sediments The correlation between microbial genera and PAHs contents was weak in sediments with low levels of PAHs contamination, while a more significant positive relationship was observed in sediments with high levels of PAHs contamination. The physicochemical properties of sediments, such as pH, soil structure and Cu significantly influence bacterial community composition in highly contaminated sediments. Additionally, the network analysis revealed that certain bacterial genera, including Novosphingobium, Robiginitalea and Synechococcus&#95;CC9902, played a pivotal role in the degradation of PAHs. These findings are significant in comprehending the correlation between bacterial communities and environmental factors in intertidal ecosystems, and establish a scientific foundation for bioremediation of intertidal zones., Competing Interests: Declaration of competing interest The authors declare that they do not have any commercial or financial relationships that could cause a potential conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis asiaeorientalis) is the only freshwater cetacean found in China. However, per- and polyfluoroalkyl substances (PFASs) risks in YFPs remain unclear. In this study, legacy PFASs, their precursors and alternatives, were determined in YFP muscles (n = 32), liver (n = 29), kidney (n = 24), skin (n = 5), and blubbers (n = 25) collected from Poyang Lake (PL) and Yangtze River (YR) between 2017 and 2023. Perfluorooctane sulfonic acid (PFOS) was the predominant PFAS in all YFP tissues, with a median hepatic concentration of 1700 ng/g wet weight, which is higher than that in other finless porpoises worldwide. PFOS, chlorinated polyfluorinated ether sulfonates (Cl-PFESAs), and perfluoroalkane sulfonamides concentrations in YFP livers from PL were significantly higher than those from YR (p < 0.05); however, the opposite was observed for hexafluoropropylene oxide acids. Biomagnification and trophic magnification factors (BMF and TMF, respectively) of most PFASs in the YFP food web were > 1. Perfluoroheptane sulfonic acid had the highest BMF value (99), followed by 6:2 Cl-PFESA (94) and PFOS (81). The TMF muscle and TMF liver values of the total PFASs were 3.4 and 6.6, respectively, and were significantly positively correlated with the fluorinated carbon chain length (p < 0.01). In addition, up to 62 % of the hazard quotients for 6:2 Cl-PFESA were > 1, which was higher than that of PFOS (48 %), suggesting a high hepatotoxicity of 6:2 Cl-PFESA to YFPs. Bioaccumulation and biotoxicity of legacy and emerging alternatives in aquatic organisms continue to be a concern, especially for underscoring the vulnerability of the long-lived and endangered species., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

As emerging organic contaminants, Polyhalogenated carbazoles (PHCZs) have caused wide concerns due to their wide distribution in the environment and dioxin-like toxicity. Nevertheless, research on the distribution and formation mechanisms of PHCZs in polluted environment of printing and dyeing plants is lacking. Here, 11 PHCZs were detected in samples from the Cao'e River, China, a typical river heavily polluted by printing and dyeing. The PHCZs concentrations in the soil, sediment, and water samples were 8.3-134.5 ng/g (median: 26.3 ng/g), 17.7-348.8 ng/g (median: 64.2 ng/g), and 1.2-41.4 μg/L (median: 4.8 μg/L), respectively. 3,6-dichlorocarbazole was the dominant congener, proved by both analysis results and formation mechanisms. PHCZ migration patterns in water-sediment systems indicated that highly halogenated PHCZs tend to be transferred to sediment. Furthermore, PHCZs are persistent, can undergo long-range transport, and pose high risks to aquatic organisms by models. PHCZs released from dye production into environment can be form through halogenation of carbazole or PHCZs formed during the dye synthesis, heating of halogenated indigo dyes, and photolysis of highly halogenated PHCZs. This is the first comprehensive study to reveal the impact of printing and dyeing plant activities on PHCZs in the environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Taking Liangshui River, the reclaimed water-receiving river in Beijing, as the research area, the types, detection frequencies, and concentrations of 16 antibiotics in water and sediment were analyzed, and their temporal-spatial variation and occurrence characteristics were discussed. The results showed that nine and 13 target antibiotics were detected in the water and sediment of Liangshui River, with the antibiotic concentration ranges of ND-116.68 ng·L -1 and ND-235.42 ng·g -1 , respectively. The main antibiotics in water were ofloxacin and clarithromycin, and the main antibiotic in sediment was ofloxacin. The total concentration of antibiotics in water and sediment showed a gradual decrease from the upstream to the downstream in the Liangshui River mainstream, and the concentration of antibiotics in tributaries was higher than that in the mainstream. The inflow of tributaries had an obvious impact on the antibiotic concentration in water for the Liangshui River but had little impact on its sediment. The total concentration of antibiotics in water and sediment during the dry season was generally higher than that during the wet season. The detected antibiotics with the highest concentration were quinolones in water during the wet season and macrolides in the dry season. Quinolones had the highest concentration in sediment in both seasons. The ecological risk assessment results showed that clarithromycin had a low risk in water in the dry season and sediment in both seasons, whereas the other antibiotics had no risk. The combined ecological risk and the most sensitive trophic level ecological risk assessment showed that all sampling sites had low risk or no risk, and the risk of the dry season was generally greater than that of the wet season. The risk values of some sampling points were close to the medium risk threshold during the dry season, which requires further attention.

The impact of polycyclic aromatic hydrocarbons (PAHs) on the marine food web is crucially understudied in the primary trophic system. We evaluated the seasonal dynamics of PAHs in microplankton in a polluted environment (Taiwan), northeastern South China Sea. Replicate size-fractionated microplankton (55-1000 μm) were freeze-dried, and PAHs were extracted with a 1:1 v/v ratio of acetone: n-hexane, then analyzed using GC-MS. Total PAHs ranged between 68 and 2548 ng/g dw in microplankton, greatest during spring (130-2548 ng/g), followed by autumn (135-772 ng/g) and summer (44-423 ng/g). Spatial distribution varied through seasons but was higher in the southern part (S6 > S4 > S5 > S2 > S3 > S1 > S7), dominated by higher-ring PAHs from mixed pyrogenic and petrogenic sources. PAHs are significantly correlated with environmental factors, especially in colder seasons and lower salinity areas. Suspended matter and plankton influenced PAH transport and partitioning seasonally. Plankton's PAHs seasonal changes and environmental influences are revealed in an anthropic environment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Dechloranes, including dechlorane 602 (Dec 602), dechlorane 603 (Dec 603), dechlorane 604 (Dec 604), dechlorane plus (DP, including syn- and anti-DP) and mirex, were determined in marine food web from Dalian Bay, Northeast China to investigate their occurrence andtrophic transfer. In all organisms, the detection rates were Dec 602 (99%) > mirex (95%) > Dec 603 (92%) > anti-DP (91%) > syn-DP (82%) > Dec 604 (9.6%). The concentrations were 0.92-16 ng/g lipid weight (lw) for mirex, 0.53-2.3 ng/g lw for syn-DP, 1.1-4.5 ng/g lw for anti-DP, 0.19-5.0 ng/g lw for Dec 602, 0.26-1.9 ng/g lw for Dec 603 and 0.020-0.33 ng/g lw for Dec 604. Significant positive relationships (p < 0.0001) were observed between lipid normalized concentrations and trophic levels for mirex (R 2  = 0.80) and Dec602 (R 2  = 0.82) in food webs, with the calculated TMFs values of 3.09 and 3.39, respectively, indicating the trophic magnification potential of these compounds. For syn-DP, anti-DP, Dec 603 and Dec 604, the similar significant relationships were not found, suggesting that these chemicals do not trophic magnification nor trophic dilution in the food web. With low log K OW values for mirex (7.01) and Dec 602 (8.05), these two compounds have the highest magnifications potentials, while the magnification potential of Dec 603, Dec 604 and DP dramatically decreased because of their extremely big log K OW values (higher than 10). The observed fractional abundance of anti-DP (f anti ) ranged of 0.58-0.69, closing to the one in Chinese industrial products, indicating DP isomers had not undergone significant differences of physicochemical or biological process in the studied food web., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The extensive utilization of per- and polyfluoroalkyl substances (PFASs) has led to their pervasive presence in the environment, resulting in contamination of aquatic products. Prolonged exposure to PFASs has been linked to direct hepatic and renal damage, along with the induction of oxidative stress, contributing to a spectrum of chronic ailments. Despite the recent surge in popularity of red swamp crayfish as a culinary delicacy in China, studies addressing PFASs' exposure and associated health risks from their consumption remain scarce. To address this gap, our study investigated the PFASs' content in 85 paired edible tissue samples sourced from the five primary red swamp crayfish breeding provinces in China. The health risks associated with dietary exposure were also assessed. Our findings revealed widespread detection of PFASs in crayfish samples, with short-chain perfluoroalkyl carboxylic acids (PFCAs) exhibiting the highest concentrations. Notably, the total PFAS concentration in the hepatopancreas (median: 160 ng/g) significantly exceeded that in muscle tissue (5.95 ng/g), as did the concentration of every single substance. The hazard quotient of perfluorohexanesulfonic acid (PFHxS) via consuming crayfish during peak season exceeded 1. In this case, a potential total non-cancer health risk of PFASs, which is mainly from the hepatopancreas and associated with PFHxS, is also observed (hazard index>1). Thus, it is recommended to avoid consuming the hepatopancreas of red swamp crayfish. Greater attention should be paid to governance technology innovation and regulatory measure strengthening for short-chain PFASs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)