Search

In the past decade, organophosphate esters (OPEs) undergo rapid increase in production and use. Meanwhile, owing to their additive property, OPEs exhibit liability to escape from related products and therefore ubiquity in various environments. Moreover, numerous researches verify their bioavailability and negative effects on biota and human, hence their occurrence and associated risks have caught much concern, particularly those in aquatic systems. So far, however, OPEs in water are generally investigated as a whole, their phase distribution and behavior in waterbodies are incompletely characterized. We examined 25 OPEs in water (including dissolved and particulate phases), sediment, and sediment core samples from the Lian River, which flows through the Guiyu e-waste recycling zone and Shantou specific economic zone in South China. Compared to most global waterbodies, the Lian River showed high or ultrahigh OPE levels in both water and sediments, particularly in the reaches surrounded by e-waste recycling and plastic-related industries, which were the top two greatest OPE sources. Non-industrial and agriculture-related anthropogenic activities also contributed OPEs. Sediment core data suggested that OPEs have been present in waters in Guiyu since the 1960s and showed a temporal trend consistent with the local waste-recycling business. The phase distribution of OPEs in the Lian River was significantly correlated with their hydrophobicity and solubility. Owing to their wide range of physicochemical properties, OPE congeners showed significant percentage differences in the Lian River water and sediments. Generally, OPEs in water reflect their dynamic real-time inputs, while those in sediment signify their accumulative deposition, which is another cause of their phase distribution disparities in the Lian River. The physicochemical parameters of OPEs first imposed negative and then positive influences on their dissolved phase-sediment distribution, indicating the involvement of both the adsorption of dissolved OPEs and the deposition of particle-bound OPEs. [Display omitted] • OPEs showed both high levels but diverse profiles in the river water and sediments. • E-waste recycling and plastic-related industries were the top two OPE sources. • Temporal trend of OPEs in Guiyu waters matched the local waste recycling history. • Phase distribution of OPEs in the river was controlled by their K OW and solubility. • Sediment OPEs were contributed by both their dissolved and particle-bound forms. [ABSTRACT FROM AUTHOR]

Emission of antibiotics into riverine environments affects aquatic ecosystem functions and leads to the development of antibiotic resistance. Here, the profiles of forty-four antibiotics and eighteen antibiotic resistance genes (ARGs) were analyzed in two large rivers of the Pearl River System. In addition, the risks of ecotoxicity and resistance selection posed by the antibiotics were estimated. As compared to the reservoirs, the river sections close to the urban and livestock areas contained more antibiotics and ARGs. Seasonal variations of antibiotics (higher in the dry season) and relative ARGs (normalized by 16S rRNA gene, higher in the wet season) were found in the water, but not in the sediment. Sulfonamide resistance genes were the most prevalent ARGs in both river water and sediment. Antibiotic concentration was correlated with ARG abundance in the water, indicating that antibiotics play a critical role in ARG spread. In addition, oxytetracycline was the most abundant antibiotic with concentrations up to 2030 ng/L in the water and 2100 ng/g in the sediment respectively, and posed the highest risks for resistance selection. Oxytetracycline, tetracycline and sulfamethoxazole were expected to be more ecotoxicologically harmful to aquatic organisms, while ofloxacin, enrofloxacin, norfloxacin, chlortetracycline, oxytetracycline and tetracycline posed ecotoxicological risks in the sediment. The Nanliujiang river with intensive livestock activities was contaminated by antibiotics and ARGs and faced high ecotoxicological and resistance selection risks. Collectively, these findings reflect the impacts of anthropogenic activities on the spread of antibiotic resistance in large river basins. [Display omitted] • Tetracyclines were the major antibiotics in both river waters and sediments. • Sulfonamide resistance genes were prevalent in the rivers except reservoirs. • Antibiotics were the major drivers of antibiotic resistance in large river basins. • OTC produced the most serious ecological risks to the rivers. • Nanliujiang river faced the most antibiotic resistance and ecological risks. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the emission and multimedia fate as well as potential risks of triclosan (TCS) in all of 58 basins in China. The results showed that the total usage of TCS in whole China was 100 t/year, and the discharge to the receiving environment was estimated to be 66.1 t/year. The predicted TCS concentrations by the level III fugacity model were within an order of magnitude of the reported measured concentrations. TCS (90.8 %) was discharged into the water compartment and 9.2 % to the soil compartment. The TCS concentration levels in east China were found generally higher than in west China. In addition, the input flux for TCS to seawater was largely attributed to the seasonal variations in advection flows. Preliminary risk assessment showed that medium to high ecological risks for TCS would be expected in the eastern part of China due to the high population density. [ABSTRACT FROM AUTHOR]

Perfluoroalkyl substances (PFASs) have received great attention from the public and scientific community due to their potential adverse impacts on the ecosystem and human health. We investigated the occurrence and distribution of 16 PFASs from 2 classes of PFASs-perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids-in the archived surface sediments of five major rivers (Yellow River, Hai River, Liao River, Zhujiang River, and Dongjiang River) in northern and southern China. The study was also performed during the wet and dry seasons. Perfluorooctanoic acid and perfluorooctane sulfonic acid were the most frequently detected (detection frequency = 100 and 63 %, respectively) in the sediments of the five rivers; the concentrations ranged from 0.08 to 0.99 ng/g dry weight (dw) and were lower than the limit of detection (

Antibiotic susceptibility, detection of sul gene types and presence of class 1, 2 and 3 integrons and gene cassettes using PCR assays were investigated in 3456 Escherichia coli isolates obtained from 38 sampling sites of the Dongjiang River catchment in the dry and wet seasons. 89.1% of the isolates were resistant and 87.5% showed resistance to at least three antibiotics. sul2 was detected most frequently in 89.2% of 1403 SXT-resistant isolates. The presence of integrons (class 1 and 2) was frequently observed (82.3%) while no class 3 integron was found. In these integrons, 21 resistance genes of 14 gene cassette arrays and 10 different families of resistance genes were identified. Three gene cassette arrays, aac(6'')-Ib-cr-aar-3-dfrA27-aadA16, aacA4-catB3-dfrA1 and aadA2-lnuF, were detected for the first time in surface water. The results showed that bacterial resistance in the catchment was seriously influenced by human activities, especially discharge of wastewater. [Copyright &y& Elsevier]

The distribution and occurrence of 15 antibiotics in surface water of the Pearl River System (Liuxi River, Shijing River and Zhujiang River) and effluents of four wastewater treatment plants (WWTPs) were investigated in two sampling events representing wet season and dry season by using rapid resolution liquid chromatography-electrospray tandem mass spectrometry (RRLC-MS/MS) in positive ionization mode. Only eight antibiotics (sulfadiazine, sulfapyridine, sulfamethazine, sulfamethoxazole, trimethoprim, roxithromycin, erythromycin-H2O and norfloxacin) were detected in the water samples of the three rivers and the effluents. The detection frequencies and levels of antibiotics in the dry season were higher than those in the wet season. This could be attributed to the dilution effects in the wet season and relatively lower temperature in the dry season under which antibiotics could persist for a longer period. The levels of the detected antibiotics in different sites are generally in a decreasing order as follows: Shijing River ≥ WWTP effluent ≥ Zhujiang River ≥ Liuxi River. Risk assessment based on the calculated risk quotients showed that only erythromycin-H2O and roxithromycin detected in the Pearl Rivers might have adverse effects on aquatic organisms. [ABSTRACT FROM AUTHOR]

• DGT and Chemcatcher were employed for in situ sampling of EDCs in Rivers. • Passive sampling provided higher concentrations than grab sampling. • The effect of diffusive boundary layer on passive sampling should not be ignored. • DGT is more quantitative while Chemcatcher is more sensitive. • DGT is promising for assessing the exposure and risks of EDCs in Rivers. The occurrence of endocrine disrupting chemicals (EDCs) in the aquatic environment is a global concern. In this study, we employed two different passive samplers Diffusive Gradients in Thin-films (DGT) and Chemcatcher for in situ measurement of 8 phenolic EDCs in the East River of the Pearl River system over one-year. These data were assessed alongside results from traditional grab sampling. Six chemicals (4tOP, 4NP, BPA, E1, EE2 and DES) were regularly detected in the water samples, of which the three phenols (i.e. 4tOP, 4NP and BPA) were in all samples and at high concentrations (0.4–1040 ng/L for 4tOP, 2.6–58500 ng/L for NP and 11.4–123300 ng/L for BPA). Fewer target chemicals were detected in both passive samplers, with only 4tOP, 4NP and BPA found in most samplers; E1 and DES were occasionally measurable above detection limits. The higher (by about a factor of 2–3) measurements provided by DGT compared to Chemcatcher could be attributed to the effect of the diffusive boundary layer on Chemcatcher uptake or the strong adsorption of target chemicals on the Chemcatcher PES filter. The temporal trends of EDC monthly loadings indicated that they were from different sources and that WWTPs were not effective in EDC removal and/or there was still some untreated wastewater discharged into the rivers. [ABSTRACT FROM AUTHOR]

Bisphenol (BP) analogues are widely used as industrial materials and various product additives and are inevitably released into environment. However, knowledge on the sources of different BPs, especially those from urban rainfall runoff to the receiving rivers is very limited. In this study, 15 BPs were determined in surface water, sediments, wastewater treatment plant (WWTP) and rainfall runoff samples in the Pearl River region, South China. Eleven BPs were detected in surface water and sediments of the Pearl Rivers. BPA was the dominant compound up to 2080 ng/L in surface and 1970 ng/g in sediments, followed by BPF, BPS, BPTMC and BPAF. In WWTPs, 10, 9 and 8 BPs were detected in influents, effluents and excess sludges, respectively, with total BPs (ΣBPs) concentrations in effluents still at thousands ng/L, suggesting incompletely removal of BPs. Five BPs were detected in urban rainfall runoff samples, with the ΣBPs concentrations up to 7740 ng/L. Mass loads of ΣBPs from the rainfall runoff (5800 kg/y) were almost equivalent to the source from WWTPs (7370 kg/y) in the region, implying that the urban rainfall runoff was a potential source for BPs into the receiving river. The calculated estrogenic activity contributed by BPs showed low to median risks in sources and receiving rivers. But BPs are always as mixtures with other potential endocrine disrupting chemicals (EDCs) which probably pose high estrogenic activity risks. Hence, effective measures should be taken to decrease the input of EDCs from sources to receiving rivers. Image 1 • 15 Bisphenol (BP) analogues in river, WWTPs and rainfall runoff were investigated. • BPA was the dominant, followed by BPF, BPS, BPTMC and BPAF in most inputs. • The mean ΣBPs in street and courtyard runoff were 2410 and 232 ng/L, respectively. • The mass load of BPs from rainfall runoff was almost equal to WWTP effluents. • BPs posed low to median estrogenic risks in the Pearl River Delta region. This study showed the wide detections of bisphenol analogues from different sources to the Pearl River system, and emphasizes the importance of considering urban rainfall runoff as a potential source of bisphenols for the receiving rivers. [ABSTRACT FROM AUTHOR]

• Global microbiome data were integrated into AMR assessment in the Pearl River. • The river had a higher AMR level than global rivers, with WWTPs and landfills as major sources. • Detection of risk rank I and emerging ARGs highlighted AMR risk in some river reaches. • Pathogen-related families were predominant ARG-carrying bacteria in river water and sediment. • Co-sharing of ARGs across taxonomic ranks implied their transfer potentials in the community. Rivers are important in spreading antimicrobial resistance (AMR). Assessing AMR risk in large rivers is challenged by large spatial scale and numerous contamination sources. Integrating river resistome data into a global framework may help addressing this difficulty. Here, we conducted an omics-based assessment of AMR in a large river (i.e. the Pearl River in China) with global microbiome data. Results showed that antibiotic resistome in river water and sediment was more diversified than that in other rivers, with contamination levels in some river reaches higher than global baselines. Discharge of WWTP effluent and landfill waste drove AMR prevalence in the river, and the resistome level was highly associated with human and animal sources. Detection of 54 risk rank I ARGs and emerging mobilizable mcr and tet(X) highlighted AMR risk in the river reaches with high human population density and livestock pollution. Florfenicol-resistant floR therein deserved priority concerns due to its high detection frequency, dissimilar phylogenetic distance, mobilizable potential, and presence in multiple pathogens. Co-sharing of ARGs across taxonomic ranks implied their transfer potentials in the community. By comparing with global genomic data, we found that Burkholderiaceae, Enterobacteriaceae, Moraxellaceae and Pseudomonadaceae were important potential ARG-carrying bacteria in the river, and WHO priority carbapenem-resistant Enterobacteriaceae, A. baumannii and P. aeruginosa should be included in future surveillance. Collectively, the findings from this study provide an omics-benchmarked assessment strategy for public risk associated with AMR in large rivers. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: We investigated two commonly used antimicrobial agents triclosan (TCS) and triclocarban (TCC) in the Pearl River system in China (i.e., Liuxi, Zhujiang and Shijing Rivers) and four sewage effluents during dry and wet seasons. The median values for TCS and TCC were the highest in the surface water and sediments of the Shijing River, followed by the Zhujiang River and Liuxi River. Screening level risk assessment using the risk quotient (RQ) method showed that TCS and TCC in surface water posed median risks in the Zhujiang and Liuxi Rivers (RQs: 0.28–0.62 for TCS, and 0.15–0.80 for TCC) and high risks in the Shijing River (RQs: 5.15–9.55 for TCS, and 3.32–5.83 for TCC). Higher risks (RQs: 3.63–28.47 for TCS, and 3.13–24.54 for TCC) were found in the sediments than in surface water of the Pearl River system. The four sewage effluents and Shijing River as well as other urban streams in Guangzhou metropolitan area were identified as the sources of the two compounds in the main river Zhujiang River. The mass inventories of TCS and TCC in the Pearl River system indicate that the sediments are not only an important sink but also a potential source for the two compounds in surface water. [Copyright &y& Elsevier]

[Display omitted] • Metagenomics is applied to reveal airborne microbiome and resistome. • Plasmids are the main drivers of horizontal transfer of airborne ARGs. • Diverse CRISPR-Cas systems promote frequent virus-host interactions in the air. • High-risk ARGs are identified in the air of pharmaceutical factories. Antimicrobial resistance is considered to be one of the biggest public health problems, and airborne transmission is an important but under-appreciated pathway for the spread of antibiotic resistance genes (ARGs) in the environment. Previous research has shown pharmaceutical factories to be a major source of ARGs and antibiotic resistant bacteria (ARB) in the surrounding receiving water and soil environments. Pharmaceutical factories are hotspots of antibiotic resistance, but the atmospheric transmission and its environmental risk remain more concerns. Here, we conducted a metagenomic investigation into the airborne microbiome and resistome in three pharmaceutical factories in China. Soil (average: 38.45%) and wastewater (average: 28.53%) were major contributors of airborne resistome. ARGs (vanR / vanS , bla OXA, and CfxA) conferring resistance to critically important clinically used antibiotics were identified in the air samples. The wastewater treatment area had significantly higher relative abundances of ARGs (average: 0.64 copies/16S rRNA). Approximately 28.2% of the detected airborne ARGs were found to be associated with plasmids, and this increased to about 50% in the wastewater treatment area. We have compiled a list of high-risk airborne ARGs found in pharmaceutical factories. Moreover, A total of 1,043 viral operational taxonomic units were identified and linked to 47 family-group taxa. Different CRISPR-Cas immune systems have been identified in bacterial hosts in response to phage infection. Similarly, higher phage abundance (average: 2451.70 PPM) was found in the air of the wastewater treatment area. Our data provide insights into the antibiotic resistance gene profiles and microbiome (bacterial and non-bacterial) in pharmaceutical factories and reveal the potential role of horizontal transfer in the spread of airborne ARGs, with implications for human and animal health. [ABSTRACT FROM AUTHOR]

Antibiotics are increasingly used and released into the marine environment due to the rapid development of mariculture, resulting in spread of antibiotic resistance. The pollution, distribution, and characteristics of antibiotics, antibiotic resistance genes (ARGs) and microbiomes have been investigated in this study. Results showed that 20 antibiotics were detected in Chinese coastal environment, with predominance of erythromycin-H 2 O, enrofloxacin and oxytetracycline. In coastal mariculture sites, antibiotic concentrations were significantly higher than in control sites, and more types of antibiotics were detected in the South than in the North of China. Residues of enrofloxacin, ciprofloxacin and sulfadiazine posed high resistance selection risks. β -Lactam, multi-drug and tetracycline resistance genes were frequently detected with significantly higher abundance in the mariculture sites. Of the 262 detected ARGs, 10, 26, and 19 were ranked as high-risk, current-risk, future-risk, respectively. The main bacterial phyla were Proteobacteria and Bacteroidetes, of which 25 genera were zoonotic pathogens, with Arcobacter and Vibrio in particular ranking in the top10. Opportunistic pathogens were more widely distributed in the northern mariculture sites. Phyla of Proteobacteria and Bacteroidetes were the potential hosts of high-risk ARGs, while the conditional pathogens were associated with future-risk ARGs, indicating a potential threat to human health. [Display omitted] • 20 antibiotics and 262 ARGs were detected in mariculture of coastal China. • Antibiotic residues could pose resistance selection risks. • β-Lactam, multi-drug and tetracycline resistance genes were frequently detected. • Proteobacteria and Bacteroidetes were the potential hosts of high-risk ARGs. • The results suggest potential health risks associated with the coastal mariculture. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tire additives and transformation products are ubiquitous in urban water system. • 1,3-Diphenylguanidine and some transformation products are the dominant compounds in most samples. • 6PPD-Quinone is firstly reported in surface water and drinking water treatment plant in China. • Surface runoff and wastewater treatment plants as sources of tire additives in urban water systems. • 6PPD-Quinone and N , N' -Di-2-naphthyl-p-phenylenediamine displayed high ecological risks in some sites of surface water. Tire wear particles (TWPs) enter road surface with the friction between tires and road surfaces. Under the volatilization, leaching, and transformation action on TWPs by sunlight and rain, tire additives are released into urban water systems, such as surface rainfall runoff, wastewater treatment plants (WWTPs), receiving surface waters, and drinking water treatment plant (DWTP). In this study, we investigated the occurrence of 23 tire additives and their transformation products in the urban water system of the Pearl River Delta region, South China. Nineteen target compounds were detected in the surface runoff, with 1,3-Diphenylguanidine (DPG) showing highest maximum concentration of 58780 ng/L. Benzothiazole and its transformation products are detected at the frequency of 100 % with the total concentrations of 480–42160 ng/L. The antioxidant derivative N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-Q) was also detected up to 1562 ng/L, which was considerably higher than that of the parent compound 6PPD (the maximum concentration of 7.52 ng/L). Eleven and 8 compounds were detected in WWTPs influents and effluents, respectively, with removal rates of − 62–100 %. Seventeen compounds were detected in the receiving Zhujiang and Dongjiang rivers, while 9 compounds were detected in drinking water sources and DWTP samples. Road runoff, with total concentrations of target compounds up to 79200 ng/L, is suggested as the main non-point source for receiving rivers, while WWTPs effluents are the point sources due to incomplete removal of target compounds after accepting the initial runoff. 6PPD-Q and other 10 compounds displayed median to high ecological risks in surface waters, and the human daily intake of tire additives was estimated to be 2.63 × 10−8-3.16 × 10−5 mg/(kg d) via drinking water. This is the first report of the 6PPD-Q and 1,3-Diphenylurea levels in surface waters in China. [ABSTRACT FROM AUTHOR]

Climbazole is an antidandruff active ingredient commonly used in personal care products, but little is known about its environmental fate. The aim of this study was to evaluate the fate of climbazole in water, sediment, soil and air compartments of the whole China by using a level III multimedia fugacity model. The usage of climbazole was calculated to be 345 t in the whole China according to the market research data, and after wastewater treatment a total emission of 245 t was discharged into the receiving environment with approximately 93% into the water compartment and 7% into the soil compartment. The developed fugacity model was successfully applied to estimate the contamination levels and mass inventories of climbazole in various environmental compartments of the river basins in China. The predicted environmental concentration ranges of climbazole were: 0.20–367 ng/L in water, and 0.009–25.2 ng/g dry weight in sediment. The highest concentration was mainly found in Haihe River basin and the lowest was in basins of Tibet and Xinjiang regions. The mass inventory of climbazole in the whole China was estimated to be 294 t, with 6.79% in water, 83.7% in sediment, 9.49% in soil, and 0.002% in air. Preliminary risk assessment showed high risks in sediment posed by climbazole in 2 out of 58 basins in China. The medium risks in water and sediment were mostly concentrated in north China. To the best of our knowledge, it is the first report on the emissions and multimedia fate of climbazole in the river basins of the whole China. [ABSTRACT FROM AUTHOR]

Abstract: Triclosan (TCS) and triclocarban (TCC) are two commonly used personal care products. They may enter into aquatic environments after consumption and pose potential risks to aquatic organisms. We investigated the occurrence and fate of TCS and TCC in five large rivers (the Liao River, Hai River, Yellow River, Zhujiang River and Dongjiang River) in China, and compared the monitoring data with the predicted results from Level III fugacity modeling. TCS and TCC were detected in the five large rivers with the detection frequencies of 100% or close to 100% in surface water and sediments of almost every river. TCS and TCC were found at concentrations of up to 478 ng/L and 338 ng/L in surface water, and up to 1329 ng/g and 2723 ng/g in sediments. Cluster analysis indicated that the sites with higher concentrations were usually located in or near urban area. Meanwhile, principal component analysis also suggested that the mass inventories of TCS and TCC in water and sediment were significantly influenced by the factors such as the total or untreated urban domestic sewage discharge at river basin scale. The concentrations and mass inventories from the fugacity modeling were found at the same order of magnitude with the measured values, suggesting that the fugacity modeling can provide a useful tool for evaluating the fate of TCS and TCC in riverine environments. Both monitoring and modeling results indicated that the majority of mass inventories of TCS and TCC were stored into sediment, which could be a potential pollution source for river water. The wide presence of TCS and TCC in these large rivers of China implies that better controlling of urban domestic sewage discharge is needed. [Copyright &y& Elsevier]

Wide use of various chemicals has resulted in water pollution, which has become a global environmental concern. So far limited information is available on what chemicals in our water. Here we investigated the occurrence and profiles of organic chemicals in the North River, South China by applying non-target screening analysis with high resolution mass spectrometry. A total of 402 organic chemicals belonging to eleven categories were identified in the North River, with notable presence of industrial chemicals, pharmaceuticals and pesticides. Among these detected chemicals, over half of the tentatively identified compounds were rarely reported in the surface water, with a few compounds, e.g., sisomicin, simeton, 2-methyl-4,6-dinitrophenol, xanthurenic acid and indole-3-carboxylic acid that have never been documented in the North River before, while the metabolites like 4-acetamidoantipyrine were also observed. The maximum concentration of the identified chemicals in the North River was above 300 ng/L (Sulfamonomethoxine). Principle component analysis results of the obtained dataset showed significant seasonal distribution, which could be linked to variations in wastewater discharge, river dilution and anthropogenic activities such as pesticide spray. Agricultural activities in the upper reaches led to detection of various pesticides in the river basin, especially in the wet season. The findings from this study demonstrated the widespread presence of chemicals in our waterway, and further retrospective analysis would reveal more information about chemicals of emerging concern. [Display omitted] • Non-target analysis was performed to identify organic chemicals in the North River. • A total of 402 organic chemicals was identified in the water. • Industrial chemicals, pharmaceuticals and pesticides were predominant in the river. • >50% of the identified compounds have not been reported in the river before. • This study demonstrates the widespread presence of chemicals in our waterway. [ABSTRACT FROM AUTHOR]

Poly- and perfluoroalkyl substances (PFASs) are contaminants of global concern. Studies in Pearl River, south China have focused on the delta area, while the upstream contributions are unclear. Here, we systematically investigated the fate, trends and potential sources of 57 PFASs in river water, sediment and fish of the North and West Rivers of the Pearl River system. Perfluorooctanoic acid (PFOA), Perfluorooctanesulfonic acid (PFOS) and 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2Cl-PFESA) were frequently found compounds in waters, sediments and fish, suggesting their wide usage in this area and potential for bioaccumulation. Waters showed a higher ∑PFASs in the wet season compared to the dry season, but sediments did not. The North River contributed higher PFAS loads to the Pearl River Delta. Our results also reflect the current shift in PFAS usage from legacy substances to alternatives. This study, for the first time, reports data on PFASs in two upstream rivers of the Pearl River and on alternative PFASs such as PFESA in this area, which can better the understanding of their use, fate, risk assessment and further controls and management. [Display omitted] • Legacy and alternative PFASs were investigated in two river systems, South China. • PFOA, PFOS and 6:2 Cl-PFESA were the most frequently detected compounds. • PFAS profiles in surface water differed between rivers and sampling seasons. • Legacy PFASs are being replaced by alternative PFASs at Pearl River Basin. [ABSTRACT FROM AUTHOR]

• We investigated the fate of 40 steroid hormones in two swine farms. • 31 and 22 target steroids were detected in the wastewater and feces. • The two integrated WWTPs are effective in removing steroids. • The contribution of some steroids by sows was higher than byhumans. Steroid hormones are endocrine-disrupting chemicals that can cause adverse effects even at trace levels. The information about steroid hormones in animal wastes is still very limited. Here we investigated the occurrence and fate of fourteen androgens, twenty-one progestogens, and five glucocorticoids in Farm Luo Cheng (LC) and Farm Shui Tai (ST) with integrated wastewater treatment systems (WTSs) in South China. These two integrated systems have four stages: primary treatment (primary sedimentation tank), secondary biological treatment (biogas digester and up-flow anaerobic sludge reaction bed (UASB)), third-stage disinfection process, and fourth-stage dilution and further biodegradation process (oxidation fish ponds/lagoons). A total of 31 target steroid hormones were detected in the wastewater of the two swine farms, with concentrations ranging from 0.12 ng/L (medroxyprogesterone acetate, MPA) to 11,200 ng/L (5α-dihydroprogesterone, 5α-DHP). A total of 22 target steroid hormones were detected in feces, of which 19 were detected in Farm LC and 17 in Farm ST. Some of these detected steroids were synthetic chemicals, which might be parent chemicals from exogenous addition or their metabolites, or transformation products from other natural steroids. The steroids excretion of sows in swine farms were estimated, with some steroids such as androstenedione (AED, 41.5 μg/d), epiandrosterone (EADR, 268 μg/d), progesterone (P, 661 μg/d), and 5α-DHP (982μg/d) having much higher values than those from human bodies. Both WTSs in the swine farms could effectively remove the target steroid hormones, with the removal rates of most targets exceeding 90%. In comparison, the anaerobic digester-A2/O (anaerobic-anoxic-oxic)-lagoon system performed better in removing steroids than the up-flow anaerobic sludge reaction bed (UASB)-two-stage series (A/O)2-oxidation fish ponds system. However, there were still 22 steroid hormones, including 14 synthetic ones detected in the effluent, with the risk quotients of most synthetic steroids exceeding 1, showing high risks to aquatic organisms. The findings from this study showed that there is a wide presence of steroid hormones, especially some synthetic steroids in animal wastes, posing potential ecological risks, and these steroids should be removed before discharge to the environment. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Swine farm wastewaters (SFWs) led to elevated steroid levels in the environment. • SFWs resulted in masculinization, defeminization and feminization in fish. • Steroid hormones in waters accounted for 53.4% of adverse effects in fish. • The adverse effects in fish from the ponds corroborated those from the rivers. Swine farm wastewaters (SFWs) are generally discharged either directly into nearby rivers or into fish ponds as a source of fertilizer/food for aquaculture in China. SFWs contain various contaminants including steroid hormones. However, there is an extreme paucity of data on their effects in fish populations. Here we investigated the endocrine disrupting effects of SFWs in G. affinis from 2 rivers (7 sites) and 2 fish ponds (2 sites) receiving SFWs and a reference site in Guangdong Province, China. In this study, a total number of 3078 adult western mosquitofish (Gambusia affinis) were collected and the sex ratio was determined. In addition, secondary sexual characteristics were examined and the transcriptional levels of target genes were analyzed. The results showed the mosquitofish populations had a significant increase in male-to-female ratio from 7 sites (including 2 fish ponds) among the 9 sampling sites. The hemal spines of females were masculinized at most sites while the hemal spines of males were feminized at approximately half of the sites (including 2 fish ponds). Significant reduction in vitellogenin (Vtg) mRNA expression was observed in females from 2 sites (including RS7) while elevated Vtg mRNA expression was noticed in males from 2 sites along the rivers (including RS7). Redundancy analysis showed that androgens in the water samples were closely related with male-to-female ratio in the mosquitofish populations and the masculinized hemal spines of females. The findings from this study demonstrated that discharge of SFWs could result in occurrence of both masculinized females and feminized males in mosquitofish population. [ABSTRACT FROM AUTHOR]

Pharmaceutical plant sites play a significant role in the dissemination of antibiotic resistance genes (ARGs) into the environment. It is imperative to comprehensively monitor of ARGs across various environmental media at these sites. This study focused on three pharmaceutical plants, two located in North China and one in South China. Through metagenomic approaches, we examined the composition, mobility potential, and bacterial hosts of ARGs in diverse media such as process water, groundwater, topsoil, soil cores, and pharmaceutical fermentation residues across diverse environmental matrices, including topsoil, soil cores, process water, groundwater, and pharmaceutical fermentation residues. We identified a wide array of ARGs, comprising 21 types and 740 subtypes, with process water exhibiting the highest abundance and diversity. Treatment processes varied in their efficacy in eliminating ARGs, and the clinically relevant ARGs should also be considered when evaluating wastewater treatment plant efficiency. Geographical distinctions in groundwater ARG distribution between northern and southern regions were observed. Soil samples from the three sites showed minimal impact from pharmaceutical activity, with vancomycin-resistance genes being the most prevalent. High levels of ARGs in pharmaceutical fermentation residues underscore the necessity for improved waste management practices. Metagenomic assembly revealed that plasmid-mediated ARGs were more abundant than chromosome-mediated ARGs. Metagenome-assembled genomes (MAGs) analysis identified 166 MAGs, with 62 harboring multiple ARGs. Certain bacteria tended to carry specific types of ARGs, revealing distinct host-resistance associations. This study enhances our understanding of ARG dissemination across different environmental media within pharmaceutical plants and underscores the importance of implementing strict regulations for effluent and residue discharge to control ARG spread., 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.)

To understand the contamination characteristics and ecological risk of antibiotics in contaminated fields of pharmaceutical plants， samples of the surface soil， soil column， wastewater treatment process water， ground water， and residue dregs were collected from two typical antibiotic pharmaceutical plants in South and North China. A total of 87 commonly used antibiotics were quantified using ultrasound extraction-solid phase extraction and ultra-high performance liquid chromatography-mass spectrometry. The results showed that a total of 31 antibiotics of five classes were detected in all types of samples， and the maximum concentrations at each sampling point in the surface soil， soil column， residue dregs， wastewater treatment process water， and groundwater were 420 ng·g -1 ， 595 ng·g -1 ， 139 ng·g -1 ， 1 151 ng·L -1 ， and 6.65 ng·L -1 ， respectively. Most of the antibiotics were found in the surface soil， showing a decreasing trend with the depth of the soil column. The ecological risk assessment indicated that sulfamethazine， sulfaquinoxaline， tetracycline， chlorotetracycline， and D-sorbitol were at higher risk. Improving the efficiency of antibiotic removal from pharmaceutical wastewater and preventing production shop leaks are effective measures of controlling antibiotic contamination into and around fields in pharmaceutical plants.

China's takeaway food industry is growing rapidly, and bringing unprecedented demand for plastic packaging, which results in serious plastic pollution and increasing emissions of plasticizers of phthalate esters (PAEs) and greenhouse gases (GHGs). This study assesses the current and future situation of plastic usage for takeaway food packaging in China, and also analyzes the PAEs and GHG emissions brought by these plastics under different scenarios. From 2010 to 2020, the plastic usage grew from 2.92 to 101 × 10 4 tons, and brought 112-3845 kg PAEs and 43.6-1438 kt CO 2 e GHG emissions. Their distribution exhibited a clear 'two-line' pattern: higher features mostly located in Beijing-Guangzhou and Beijing-Shanghai railways. The socio-economic factors model performed better than the growth rate model for plastic usage prediction from 2021 to 2060. It is predicted that 40.6 Mt. plastic would be consumed in 2060, and they will bring 155 tons PAEs and 37.0 Mt. CO 2 e GHGs. At that time, biodegradable plastic replaced or plastic cycling cannot significantly contribute to national carbon reduction, unless using a temperature change of 2 °C scenario. Our work improves the understanding of PAEs and GHG emission from plastic pollution, and provides insight into long-term dynamics in the plastics management of takeaway food industry., 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 © 2023 Elsevier B.V. All rights reserved.)

As the nexus where rivers and oceans meet, estuaries are vulnerable to microplastic (MP) pollution derived from rivers. However, few studies have focused on the pollution status of MPs in small estuarine areas. Here, the abundance and characteristics of MPs in surface water and sediment samples from a small estuary, the Wanquan River estuary, were studied. The average abundance of MPs was 6573 ± 2659 n/m 3 in surface water and 1065 ± 696 n/kg dw in sediment samples from the Wanquan River estuary. Most of the MPs in water samples and sediments were red (92.9 % and 88.1 %) fragments (87.4 % and 95.5 %) with sizes <1.0 mm (90.8 % and 92.4 %) made up of antifouling paint particles (APPs) (83.5 % and 89.8 %), respectively. A significant positive correlation (p < 0.01) was found between the concentration of Cu 2+ and the abundance of APPs in sediment samples from the Wanquan River estuary. The APPs in the sediments can act as a continuous source of toxic chemicals (e.g., Cu 2+ ) to marine environments. The results of this study expand our knowledge about MP pollution in small estuaries, and the ecological risk of APPs in the Wanquan River estuary to aquatic organisms should not be ignored., 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 © 2023 Elsevier Ltd. All rights reserved.)

As a class of common emerging pollutants, per- and polyfluoroalkyl substances (PFASs) and their alternatives have been widely detected in various environmental matrices, exhibiting a great threat to the ecological environment and human health. Nevertheless, changes in biomolecular structure and function of duckweed caused by PFASs and their alternatives remain unknown thus far. Herein, the effects of four PFASs, including two common legacy PFASs (perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA)) and two PFASs alternatives (perfluorobutane sulfonic acid (PFBS) and 1H,1H,2H, 2H-perfluorooctane sulfonic acid (6:2 FTS)) on duckweed (Lemna minor) at biochemical level were investigated with Fourier transform infrared spectroscopy (FTIR). Although no obvious inhibitions were observed in the growth of L. minor with PFASs exposure at three levels of 1 μg L -1 , 100 μg L -1 , and 10 mg L -1 , significant structural and functional alterations were induced at the biochemical level. In response to PFASs exposure, lipid peroxidation, proteins aggregation and α-helix to β-sheet transformation of the protein conformation, as well as changes of DNA conformations were detected. Moreover, alterations in lipid, protein, and DNA were proved to be concentration-related and compound-specific. Compared to the two legacy PFASs (PFOS and PFOA), alternative ones exhibited greater effects on the biological macromolecules of L. minor. The findings of this study firstly reveal structural and functional alterations in L. minor induced by PFASs exposure, providing further understanding of their toxicity effects., 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 © 2022 Elsevier Ltd. All rights reserved.)

Landfills are the main destination of many urban wastes containing per- and polyfluoroalkyl substances (PFAS), and PFAS may leach out from the waste and contaminate the surrounding groundwater. Here we investigated the occurrence of PFAS in leachate and surrounding groundwater from three landfills in Guangzhou, China by using a combined target and non-target approach. Non-target screening showed that a total of 651 PFAS with 96 classes were identified, including 17 legacy PFAS and 637 emerging PFAS. The quantitative target analysis of some PFAS revealed that the average removal rate of PFAS from the raw leachates were ranged between 62 % and 99 %. Statistical analysis and source analysis suggested that landfill leachate was a major source of PFAS in the groundwater within the landfills and downstream sites. The results from the combined target and non-target analyses demonstrated that PFAS in landfills could leach into the surrounding groundwater, and may affect the sustainable use of groundwater as a source of drinking water and pose a potential risk to 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 © 2022 Elsevier B.V. All rights reserved.)

Increasing use of feed and medicine in mariculture could cause negative environmental impacts such as habitat modification, microbial disease development and antibiotic resistance. Here we investigated contamination of antibiotics and antibiotic resistance genes (ARGs), and composition of microbial community in grouper mariculture systems in Hainan province, China. Results showed detection of various antibiotic residues with the dominance of fluoroquinolones and tetracyclines in the six grouper cultivation systems. The concentrations of the detected antibiotics in the grouper mariculture water were significantly higher than those in the original seawater. Some of the detected antibiotics such as enrofloxacin, ciprofloxacin, ofloxacin, oxytetracycline and erythromycin in the mariculture water and/or sediment would pose high resistance selection risks. Sulfonamides resistance genes sul1 and sul2 were found to be predominant in water and sediment, while tetracycline resistance genes were prevalent in fish gill and gut. The dominant bacterial phyla in water and sediments were Bacteroides, Actinomycetes, and Proteobacteria, while the dominant ones in fish gill and gut were the Proteobacteria. Genera of Vibrio and Mycobacterium in the core microbiota were important zoonotic pathogens, and there was a significant positive correlation between Vibrio and ARGs. Phyla of Proteobacteria, Actinomyces, and Cyanobacteria were positively correlated to ARGs, indicating that these microorganisms are potential hosts of ARGs. The putative functions of microbiome related to antibiotic resistance and human diseases were significantly higher in fish than in the mariculture environment. This study suggests that mariculture system is a reservoir of ARGs, and the use of antibiotics in mariculture could induce the increase of antibiotic resistance and the prevalence of opportunistic pathogens., 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 © 2021 Elsevier B.V. All rights reserved.)

Anthropogenic activities have inevitably impacted riverine ecosystems, yet their overall contribution to the assemblage of bacterial communities at a large river basin scale remains unclear. In this study, 16S amplicon sequencing was implemented to investigate the bacterial ecosystems in paired water and sediment of North River and West River basins in South China., which contains various anthropogenic environments (e.g., rural/urban area, mining area and livestock area). Subsequently, the links between bacterial community and various types of emerging pollutants in river water were analyzed. The results show that the bacterial assemblage of water and sediment had their own properties that the bacterial community of sediment were mainly affected by seasonal properties, while the bacterial community of water were affected by both seasons and anthropogenic activities. Therein, the aquatic bacterial compositions and abundances were driven by changes in temperature, dissolved oxygen and the emerging pollutants. The dominant phyla Proteobacteria and Firmicutes exhibited adaptability to the mining-affected regions, therein many clades (e.g., Beijerinckiaceae, Acetobacteraceae and Mycobacteriaceae) were also prevalent in the livestock-affected and densely-populated regions. In addition, these two phyla presented associations to the antibiotic resistance in water. The levels of antibiotics, relative antibiotic resistance gens (ARGs) and non-antibiotic pharmaceuticals (NAPs) were closely related to bacterial community composition, diversity and functional diversity, indicating their drive in shifting bacterial communities. Collectively, this work provides a basis for understanding the contribution of anthropogenic activities in shifting bacterial community at a large river basin scale. Further, the results provide new insights for expansion of ecological 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 © 2021 Elsevier B.V. All rights reserved.)

The extensive usage of organic ultraviolet filters (UV filters) and benzothiazoles (BTs) has caused continuous and widespread pollution in the aquatic environment. This study investigated the occurrence of nine organic UV filters and eight BTs in the surface water and sediment of two major drinking water source rivers in the Pearl River Basin (PRB). The detection frequencies of six organic UV filters and seven BTs were above 50% in surface water, while eight target compounds were as high as 100%. Composition profiles revealed that 2-Hydroxybenzothiazole (2-OH-BTH, 1112 ng/L) and 2-Mercaptobenzothiazole (2-SH-BTH, 426.3 ng/L) were the predominant compounds in surface water, while Octyl 4-methoxycinnamate (OMC, maximum concentration, 68.3 ng/g) and UV-329 (18.8 ng/g) were predominant in sediment. Significant positive correlations were observed between water quality parameters (temperature, total phosphorus (TP) and total nitrogen (TN)) and organic UV filters (UV-327 and UV-P), indicating the domestic discharge. The calculated annual flux of targets compounds indicated that West River (WR) promoted more BTs and UV filters to the PRB than North River (NR) (BTs: WR22, 88,517 kg/year; NR13, 15,660 kg/year; UV filters: WR22, 28,332 kg/year; NR13, 1128 kg/year). Significant relationship between the Gross Domestic Product (GDP) and annual flux of BTs (R 2 = 0.96, p < 0.001), and UV filters (R 2 = 0.88, p < 0.001) in the rivers were found by regression analysis. UV-329 was detected with medium risk (RQ > 0.1) in all WR surface water samples, and 2-SH-BTH was detected with high risk (RQ > 1) in half of the WR sediment samples. This study provides the first time reports on the organic UV filters and BTs in two major rivers in the Pearl River Basin, and further showed that these two types of contaminants are ubiquitous and with potential risks in surface water and sediment of PRB., 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 © 2021 Elsevier B.V. All rights reserved.)

Benzodiazepines (BZDs) are one of the most widely prescribed psychoactive drugs, however their persistence in the receiving environment has raised great concerns about their potential ecological risks. Here we investigated the occurrence, fate and mass loading of 17 BZDs and their 3 transformation products in 11 wastewater treatment plants (WWTPs) in Guangdong province, China. A total of 10 BZDs and 1 transformation product were found in the WWTPs influents, effluents and excess sludge, with concentrations reaching up to 44.5 ng/L (clozapine), 27.1 ng/L (oxazepam) and 62.9 ng/g (clozapine), respectively. The overall removal efficiency varied widely from negative to complete removal in these 11 WWTPs. Mass balance analysis of two representative WWTPs (WWTP A and WWTP B ) with different treatment processes showed that their removals were mainly attributed to the sludge adsorption and biodegradation/biotransformation. The total usage of detected BZDs was estimated to be 185 kg/y in Guangdong province, China, while the total emission was 143 kg/y. Based on sewage epidemiology method, the total back-estimated consumption and emissions of BZDs and their transformation products in one district of Guangzhou (WWTP C service area) were 1012 mg/d/1000 people and 10.1 mg/d/1000 people, respectively. The findings from this study demonstrate the persistence of BZDs in WWTPs and also provide basis for further investigation into the potential ecological risks from this group of chemicals., 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 © 2020 Elsevier B.V. All rights reserved.)

Antibiotics used for human and veterinary purposes are released into the environment, resulting in potential adverse effects, including the development and spread of antibiotic resistant bacteria. Here we investigated the dynamic fate of 36 antibiotics in a large river basin Dongjiang in South China, and discussed their potential antibiotic resistance selection risk. Based on the usage, excretion rate, wastewater treatment rate, human population and animal numbers the emissions of 36 frequently detected antibiotics were estimated for the Dongjiang River Basin. The total usage of the 36 antibiotics in the basin was 623.4 tons, which included 37% for human use and the rest for veterinary purposes. After being metabolized and partially treated, the amount of antibiotics excreted and released into the environment decreased to 267.6 tons. By allocating the high-precision antibiotic discharge inventory to 42 sewage plants and 17 livestock farms, an improved GREAT-ER (Geography referenced Regional Exposure Assessment Tool for European Rivers) model for the Dongjiang River Basin, with a well calibration river flow network based on the SWAT (Soil and Water Assessment Tool), was established to simulate the dynamic fate of 36 antibiotics. The simulation results showed that antibiotics contaminated >50% of the river sections. The modelled concentrations in water were almost within an order of magnitude of the measured concentrations. Antibiotic contamination in the dry season was obviously higher than that in the wet season. The concentrations of the antibiotics were always higher at the discharge zones and lower reaches of the river basin than the other reaches. The antibiotic resistance risk assessment showed that 23 out of the 36 antibiotics (nearly 65%) could pose high risks in the river basin. For those river reaches with high risks, the risk levels could mostly be reduced to low risk levels with a certain distance (15 km) from the pollution source. Therefore, more attention should be paid to those impact zones in term of antibiotic resistance., 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 © 2020 Elsevier B.V. All rights reserved.)

Domestic wastewaters are an important source of endocrine disrupting chemicals in the receiving aquatic environment. Most rural domestic wastewaters (RDWs) in China have been directly discharged into the aquatic environment without any treatment. Here we studied the effects of RDWs on the western mosquitofish (Gambusia affinis) from two rural rivers receiving untreated RDWs. Mosquitofish samples were collected at 5 sampling sites along two rivers during dry and wet seasons. Sex ratios, secondary sex characteristics and transcriptional levels of target genes related to the endocrine system in adult females and males were determined. In parallel, various pollutants including steroid hormones, phenolic compounds, pesticides, polycyclic aromatic hydrocarbons (PAHs) and heavy metals were measured in the water samples at all sites. The results showed that the androgenic effects in the fish were evidenced by significant increase in male to female ratio in fish populations at two sampling sites and by the presence of modified hemal spines in females at four sampling sites when compared to the reference site. The males from the two rivers had increased Vtg mRNA expressions with a maximal 6.2-fold increase relative to the reference site and a delayed development of hemal spines. The redundancy analysis (RDA) showed that some physiological parameters were related to steroid hormones, phenolic compounds and PAHs. The findings from this study suggest that RDWs can lead to masculinization in females and feminization in males., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We used a hybrid precipitation method to simultaneously extract and analyze 24 personal care products (PCPs), including 16 biocides, 4 synthetic musks, and 4 benzotriazoles, in the plasma of fish. The method's performance was validated for plasma samples with and without β-glucuronidase/aryl-sulfatase hydrolysis. The recoveries were in the range of 70-120% for most of the PCPs, except N,N-diethyl-3-methylbenzamide (DEET), clotrimazole (CTZ), miconazole and itraconazole at spiking concentration of 20 and 5 ng/mL. The quantification limits ranged between 0.89 and 17.9 ng/mL (hydrolyzed plasma) and 0.85-18.5 ng/mL (non-hydrolyzed plasma), except CTZ at 77.5 ng/mL and 76.3 ng/mL. Totally, 13 PCPs were detected in plasma samples of fish collected from the Yangtze River, with a maximum concentration of 58.4 ng/mL (galaxolide). Compounds with the phenol hydroxyl groups of parabens or triclosan in hydrolyzed plasma showed higher concentrations than those in unhydrolyzed plasma with the ratio of conjugation (glucuronides + sulfates) forms up to 86%. The median values for the logarithm of bioaccumulation factors were between 1.39 and 4.15, which were 2-3 orders of magnitude higher than the theoretical logarithm of bioconcentration factors. Using the fish plasma model, the effect ratios (effect concentration/measured plasma concentration ratios) of tonalide, galaxolide, benzotriazole, triclosan, and DEET reached 0.35, 4.15, 3.78, 7.52, and 9.24, respectively. These are recognized as priority chemicals for further risk assessment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Steroid hormones and biocides are regarded as emerging contaminants in rural wastewater in China, owing to their widespread occurrence and adverse effects on both aquatic organisms and humans. Constructed wetlands (CWs) are an alternative technology for cost-effective and efficient decentralized rural sewage treatment. In this study, an integrated constructed wetland (ICW) system was built and used to treat a typical rural wastewater mixture composed of domestic sewage and livestock wastewater from a small village. As expected, five steroid hormones (ADD, AED, 19-NTD, T, and P) and four biocides (DEET, TCS, CBD, and MP) were detected in the influent in concentrations ranging from 30.5 ± 1.25 ng/L to 105 ± 5.14 ng/L and from 63.4 ± 2.85 ng/L to 515 ± 19.7 ng/L, respectively. The ICW system effectively removed the detected steroid hormones (97.4 ± 0.09%) and biocides (92.4 ± 0.54%). Based on the measured concentrations, the total pollution loadings of the detected steroid hormones and biocides in the influent were calculated to be 2330 ± 26.5 μg/day and 5710 ± 196 μg/day, which decreased to 60.8 ± 1.44 μg/day and 433 ± 25.6 μg/day in the final effluent. The risk quotients for these steroid hormones and biocides in the effluent from the ICW system were lower than those from reported wastewater treatment plants, indicating that CWs are a promising technology for removing contaminants including steroid hormones and biocides in rural wastewater, although additional efforts are required to optimize and improve the design of CWs before the steroid hormones and biocides present in the effluent can be safely and directly discharged into the environment., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Natural and synthetic steroid hormones have been detected in swine farm wastewaters (SFWs) and receiving waters. However, little is known on their potential endocrine disrupting effects on fish population in receiving rivers. Here we investigated the concentrations of androgens and estrogens in the SFWs and the receiving waters. In addition, the endocrine disrupting effects of SFWs on wild western mosquitofish (Gambusia affinis) were also analyzed by assessing the sex ratio, secondary sex characteristics and transcriptional expression of genes related to the endocrine system. Chemical analysis showed the maximum concentration of total androgens reached 1375.7 ng L -1 in the SFWs and 1020.8 ng L -1 in receiving river waters. A total of 3552 adult G. affinis were collected from the Lianhe River (Guangdong, China), which was heavily impacted by SFWs, before and after the Ban of Swine Farming (BSF) in the river basin. The results showed the presence of male-biased G. affinis populations and masculinized anal fins and hemal spines of females at all contaminated sites prior to BSF. In addition, the transcription of vitellogenin (vtg) was inhibited by SFWs by 99.9% in the females from one sampling site. In contrast, the adverse effects on the females were significantly decreased after BSF. Redundant and path analyses showed that skewed sex ratios of fish populations, masculinized secondary sex characteristics of females and the decrease of vtg transcripts of females were well correlated with the concentrations of androgens in the receiving waters. The findings from this study suggest that SFW can cause masculinization effects of wild G. affinis populations., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

A total of 21 progestagens were screened in animal wastes and environmental samples from two representative swine farms and surrounding environments of South China using ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) to assess the effectiveness of simple lagoon (and digester) treatment. The results showed that 11, 8 and 8 of 21 target progestagens were detected with the minimum concentration of 2.31 ng/L and maximum of 6150 ng/L in the water samples, with the minimum of 1.36 ng/L and maximum of 98.3 ng/L in the suspended particles, and with the minimum of 1.57 ng/g dry weight (dw) and maximum of 3310 ng/g dw in the solid samples, respectively. Trace levels (a few ng/L or ng/g levels) of dydrogesterone, 5α-dihydroprogesterone, norgestrel and progesterone were found in samples from nearby surface waters and vegetable fields impacted by animal wastes. The residual progestagens at the reported levels may still pose potential risks to aquatic organisms such as fish in the receiving aquatic environments. This finding suggests that swine wastewater and feces could lead to contamination of some detectable progestagens in the surrounding environments. Significant reduction in total progestagen concentrations were observed from the fresh swine wastewaters to the fish ponds, indicating effective removal of these compounds by the lagoon (and digester) treatment. In addition, the biogas digesters provided high removal of the progestagens in the waste streams. This low-cost and eco-friendly treatment system should be promoted in developing countries with concentrated animal operations., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The aim of this study was to investigate the contamination profiles of tetracycline, sulfonamide, and macrolide resistance genes, as well as integrons in sediments of Dongjiang River basin of South China by real time quantitative polymerase chain reaction. sul2 was the most abundant resistance gene, with the average concentration of 6.97×10(8) copies/g and 1.00×10(8) copies/g in the dry and wet seasons, respectively, followed by ermF, sul3, sul1, intI1, tetA, ermB, tetX, tetM, tetQ, tetO, tetW, tetS, ermC, and tetB. The abundance of intI2 gene was the lowest in the sediment samples. Significant correlations existed between the ARGs and sediment properties as well as metals (Cu and Zn) and corresponding antibiotic classes, suggesting that the contamination of ARGs is related to chemical pollution of the sediments in the river basin. Principal component analysis showed distinct groupings of the sampling sites, reflecting that human activities are the key player in the dissemination of ARGs in the catchment environment., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Biocides are widely formulated in household and personal care products. We investigated the distribution and ecological risks of 16 household biocides in aquatic environments of a highly urbanized region in South China, evaluated triclosan as a chemical indicator for this group of household chemicals, and proposed a novel approach to predict the environmental occurrence and fate of these household biocides by using triclosan usage data and a level-III fugacity model. Eleven biocides were quantitatively detected at concentrations up to 264 ± 15.3 ng/L for climbazole in surface water, and up to 5649 ± 748 ng/g for triclocarban in sediment of four rivers in the region. The distribution of biocides in the aquatic environments was significantly correlated with environmental variables such as total nitrogen, total phosphorus and population. Domestic sewage in the region was the dominant pollution source for most biocides such as azole fungicides (fluconazole, climbazole, clotrimazole, ketoconazole, miconazole, and carbendazim) and disinfectants (triclosan and triclocarban). Preliminary risk assessment showed high ecological risks posed by two biocides carbendazim and triclosan in river waters. Mostly important, triclosan was found to be a reliable chemical indicator to surrogate household biocides both in water and sediment based on the correlation analysis. In addition, the fugacity modeling could provide simulated concentrations comparable to the monitoring results. Therefore, with the usage data of the chemical indicator triclosan and correlation formula with other biocides, this model can be applied for predicting the occurrence and fate of various household biocides in a catchment., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

This study investigated antibiotic resistance profiles including antibiotic resistance frequencies, resistance genes and resistance patterns in Escherichia coli strains isolated from traditional and integrated aquaculture systems in South China by using antibiotic susceptibility testing and real time polymerase chain reaction (PCR) technique. The E. coli isolates were found to be resistant to at least one antibiotic among 12 antibiotics. Higher resistance frequencies to ampicillin, sulfamethoxazole, trimethoprime, streptomycin and tetracycline were found compared to the rest antibiotics. Among the 10 tetracycline resistance genes detected in the resistant isolates, the most prevalent tetracycline resistance genes were tetA, tetW and tetB with the frequency of 69.7%, 63.5% and 21.9%, respectively. Three sulfonamide resistance genes were detected in these resistant isolates, with their detection frequencies in the following order: sul2 (55.3%) > sul3 (28.2%) > sul1 (6.2%). Four resistance genes mainly encoding extended-spectrum β-lactamases (ESBLs) were detected in these resistant isolates, with the detection frequencies of blaTEM (28.4%) > blaOXA (9.7%) > blaCTX (9.3%) > blaCARB (5.2%) > blaSHV (0.0%). It was found that the integrated aquaculture system exhibited generally higher prevalence of antibiotic resistance than the traditional aquaculture system. An integrated aquaculture system could facilitate development of bacterial resistance and spread of the antibiotic resistance genes, and consequently become an important reservoir of resistance genes.

Estrogenic activity risks in the Pearl River system (Liuxi River, Zhujiang River and Shijing River) in South China were assessed by combined chemical analysis and recombinant yeast estrogen screen (YES) bioassay for surface waters and sediments collected in both dry and wet seasons. The xenoestrogens 4-tert-octylphenol, 4-nonylphenol and bisphenol A were detected at almost every sampling site at concentrations of several ng L(-1) (ng g(-1)) to tens of μg L(-1) (μg g(-1)) in surface waters (and sediments). The estrogens estrone and 17β-estradiol were also detected in most of the samples with concentrations from several ng L(-1) (ng g(-1)) to tens of ng L(-1) (ng g(-1)) in surface waters (and sediments). However, synthetic estrogens diethylstilbestrol and 17α-ethinylestradiol were only detected at a few sites. The 17β-estradiol equivalents (EEQ) screened by the YES bioassay were in the range of 0.23-324 ng L(-1) in surface waters and from not detected to 101 ng g(-1) in sediments. Shijing River displayed one to two orders of magnitude higher levels for both measured chemical concentrations and estrogenic activities than the Zhujiang River and the Liuxi River. A risk assessment for the surface waters showed high risks for the downstream reaches of the Liuxi River and the upstream to midstream reaches of the Zhujiang River and the Shijing River. Higher estrogenic risks were observed in the wet season than in the dry season for surface waters, probably due to the input of runoff and direct overflow of small urban streams during heavy rain events. Only small variations in estrogenic risk were found for the sediments between the two seasons, suggesting that sediments are a sink for these estrogenic compounds in the rivers.

Ten nonsteroidal antiinflammatory drugs (NSAIDs), two blood lipid regulators (BLRs), and two antiepileptic drugs (AEDs) were analyzed in the Pearl River system in China (i.e., Liuxi, Zhujiang, and Shijing Rivers) and four sewage effluents during the dry and wet seasons, and the environmental risks they posed were assessed. Eight pharmaceuticals were detected in the rivers and effluents, including five NSAIDs (salicylic acid, ibuprofen, diclofenac, mefenamic acid, and naproxen), two BLRs (clofibric acid and gemfibrozil), and one AED (carbamazepine). The median concentrations for the eight pharmaceuticals ranged from 11.2 to 102 ng/L. Seasonal variations were not obvious for most pharmaceuticals in the three rivers, except for salicylic acid and clofibric acid in the Zhujiang River, and diclofenac in the Zhujiang and Shijing Rivers. However, spatially considerable variations in the concentrations were observed for the eight pharmaceuticals in all three rivers. For most of the pharmaceuticals, the effluents from the four wastewater treatment plants and Shijing River water were found to be the major discharge sources for the Zhujiang River, but with additional discharge sources from some small urban streams in the wet season. Diclofenac in the Shijing River was the only pharmaceutical that had a risk quotient (RQ) >1, indicating a high risk to aquatic organisms in the river. Although higher RQs were calculated for the mixture of the pharmaceuticals in each river, the risk rating remained the same for the three rivers with the RQ being >1 only in Shijing River., (Copyright 2010 SETAC.)

Objective: To investigate the clinical features and changes in the incidence of skin cancer in two hospitals located in western China., Methods: The patients diagnosed pathologically as skin cancer from 1981 to 2000 were retrospectively collected from the two hospitals. Clinical data of patients with skin cancer were collected and analyzed., Results: (1) Of the 1 905 patients with skin cancer, squamous cell carcinoma accounted for 29.4%(560 patients), basal cell carcinoma 28.0% (534), and cutaneous malignant melanoma(CMM) 16.0% (305). (2) There were 591 patients with skin cancer diagnosed between 1980 and 1990, and 1 314 between 1991 and 2000, and accounted for 0.34% and 0.58% of all biopsy cases, respectively. The number of total biopsy patients increased 1.6% every year during the 20 years. The number of biopsy patients with skin cancer and with CMM increased 3.5% and 3.9% every year,respectively. (3) Of the 305 CMM patients, 63.3% located on the acra. These patients were elder, and have a higher rate of trauma and a higher incidence in the male than that in patients with CMM located on the other sites. (4) Of the 305 CMM patients, 64 (21%) had history of trauma at the primary onset sites, and 47 (15.4%) had history of small congenital nevi at the primary sites., Conclusion: There are some differences in the clinical features such as location and age between the skin cancer patients in our study and those in white population. The incidence of skin cancer in the two hospitals had been increasing in the 20 years (between 1981 and 2000). Both trauma and small congenital nevi are important risk factors of CMM.