[Pollution Characteristics and Multilevel Risk Assessments of Antibiotics in the Urban Rivers of Beijing, China].

To comprehensively assess the pollution characteristics and ecological risks of antibiotics in the rivers in Beijing, the concentrations of 35 common antibiotics belonging to four categories were quantified by using solid phase extraction combined with high-performance liquid chromatography-tandem mass spectrometry. The ecological risks of antibiotics were evaluated using the methods of risk quotient (RQ) and joint probability curves (JPCs). The results showed that a total of 33 antibiotics were detected in the surface water of ten rivers in Beijing, and the total concentrations of antibiotics ranged from N.D. to 1 573.57 ng·L-1. Sulfamethoxazole showed the highest concentration (N.D.-160.04 ng·L-1), followed by sulfadiazine (0.09-147.90 ng·L-1) and ofloxacin (0.28-94.72 ng·L-1). There were 16 antibiotics with a detection frequency greater than 50.0 %. The RQ method showed that there were 12 antibiotics with potential ecological risks. Tetracycline, clarithromycin, and trimethoprim showed the highest risks, with RQs of 3.99, 1.86, and 1.01, respectively. The risks of antibiotics at the outlets of wastewater treatment plants were higher than those in mainstream rivers. The PNEC exceedance rates of tetracycline, clarithromycin, and trimethoprim were above 2.3 %. Based on JPCs, the maximum risk product of clarithromycin was 1.66 %, and it showed low risks to 0.3 %-7.0 % of species. The risks of other antibiotics could be ignored. The detection frequency, distribution of concentrations, most sensitive species, and species sensitivity distribution of antibiotics had important impacts on the ecological risk assessment. Using the multilevel ecological risk assessment strategy can effectively avoid inadequate protection and overprotection and is also conducive to the hierarchical and zoning management of antibiotics throughout the region.

[Occurrence Distribution and Risk Assessment of Organophosphate Esters in A Typical Area of the Estuary in the Yellow River Basin].

As a type of emerging pollutant, organophosphate esters (OPEs) have the characteristics of toxicity, persistence, and bioaccumulation. Due to their wide use in production and life, OPEs pose potential risks to ecosystems when they enter the environment. In this study, the concentrations of 14 species of OPEs in surface water were determined using UPLC-MS/MS, and the spatial distribution of the OPEs in the surface water of the estuary of the Yellow River basin was further analyzed. The pollution sources were analyzed using correlation analysis and principal component analysis, and the ecological risk was evaluated. The results indicated that the concentration of Σ14OPEs in surface water ranged from 183.81 to 1674.52 ng·L-1, with an average concentration of 638.25 ng·L-1. Tris(2-chloroethyl) phosphate (TCEP) and tris(1-chloro-2-propanyl) phosphate (TCPP) were the main OPEs. The Xiaoqing River flowing through the urban area differed from the main stream of the Yellow River and other branches in terms of OPEs composition characteristics, which showed a greater impact from human activities. The distribution of Σ14OPEs showed an obvious regional pattern, with a trend of increasing and then decreasing along the direction of the Yellow River inlet. The results of source analysis revealed that human activities such as industrial wastewater discharge from different industries, transportation, and atmospheric deposition were the sources of OPEs in surface water. The ecological risk assessment results indicated that TCEP posed a high risk to aquatic organisms in the main stream of the Yellow River, Xiaoqing River, and Zhimai River, and tri-n-butyl phosphate (TnBP) and triphenyl phosphate (TPhP) posed a low risk at some sites.

[Pollution Level and Risk Assessment of OPEs in Typical River Basins of China].

Organophosphate esters(OPEs), as a substitute for brominated flame retardants, are widely used in production and life, and their environmental pollution and toxic effects have attracted widespread attention. In this study, the concentrations and distribution characteristics of OPEs in seven major drainage basins of China were sorted out. The average daily dose of OPEs in Chinese adults, adolescents, and children was calculated to assess the health risks, and the reliability of the results was evaluated using Monte Carlo simulation. The toxic effect concentrations of 12 OPEs on aquatic organisms were investigated, and the species sensitivity distribution(SSD) curve was constructed to assess the ecological risk. The results showed that the 5th percentile concentration of ΣOPEs in the seven drainage basins was 52.61 ng·L-1 under the low exposure scenario. The median concentration of ΣOPEs in the seven basins was 499.74 ng·L-1, with trichloroethyl phosphate(TCEP), triethyl phosphate(TEP), and triethyl phosphate(1,3-dichloro-2-propyl) esters(TDCP) as the main contaminants. Under the high exposure scenario, the 95th percentile concentration of ΣOPEs in the seven basins was 1904.4 ng·L-1, 3.8 times that of the intermediate exposure scenario, and the Yangtze River Basin had the highest ΣOPEs concentration under the high exposure scenario. The health risk assessment showed that the non-carcinogenic risk of OPEs exposure through drinking water was within acceptable limits for different populations. Trimethyl phosphate(TMP), triisobutyl phosphate(TiBP), and TCEP were the main contributors to cancer risk. The results of ecological risk assessment showed that TCEP had medium ecological risk at the high exposure level, tributyl phosphate(TnBP) had medium ecological risk under the intermediate exposure scenario, and there was higher ecological risk under the high exposure scenario. Triphenyl phosphate(TPhP) had a risk quotient greater than 1 under the low, intermediate, and high exposure scenarios, and there was a high ecological risk, which requires special attention.

Concentrations and sources of PAHs in surface sediments of the Fenhe reservoir and watershed, China.

Sixteen PAHs in surface sediments at 28 sites throughout Fenhe reservoir and watershed were measured. The ∑PAHs concentrations ranged from 539.0 to 6281.7 with the mean of 2214.8ng/g. The 2-3 rings PAHs, contributing 55 percent to ∑PAHs, were the dominant species. Twenty-eight sites were grouped into three segments: Fenhe principal stream, estuaries of main branch streams, and Fenhe reservoir. ∑PAHs was highest in the estuaries of main branch streams. The ecological risk assessment was studied by biological thresholds. The results showed levels of PAHs might cause mild but not acute adverse biological effects. In addition, PAHs ratios, PCA/MLR and hierarchical clustering analysis were applied to evaluate the possible sources. Coal combustion (35 percent), diesel and gasoline emissions (29 percent and 16 percent, respectively) might be the important sources. For sites in Fenhe reservoir, the major sources were complex, while other two segments were mainly influenced by coal combustion source.

Source and risk assessment of PCBs in sediments of Fenhe reservoir and watershed, China.

The concentrations of polychlorinated biphenyls (PCBs) in sediments from the Fenhe reservoir and watershed were detected at 28 sites in wet and dry seasons. The ∑(123)PCBs ranged from n.d. to 126.49 ng g(-1) dw. The dominated congeners were tri-PCBs (34.29%) and tetra-PCBs (24.05%). In the Fenhe reservoir, ∑(123)PCBs presented a decreasing trend, while percentages of low chlorinated congeners showed an increasing trend. For the temporal variations, PCBs homologues profiles of sediment samples and spatial distribution of ∑(123)PCBs for the two periods were similar (with CD = 0.021 and r(2) = 0.999 respectively), although PCBs concentrations in the wet season were significantly higher than in the dry season. PCA was applied to analyze the possible sources for PCBs, suggesting that PCBs might be mainly influenced by Aroclor 1016 and 1242. Compared with 3 established sediment quality guidelines, levels of PCBs in sediments of the investigated watershed might have a potential biological impact, especially in the wet season.

[Qualitative and quantitative detections of pyrethroid pesticides by terahertz time-domain spectroscopy].

Pyrethroids pesticides are broad-spectrum insecticides which were used to control variety of pests, and were mainly used to hygienic insecticides and agricultural pest control. The room-temperature terahertz spectra of b-cypermethrin, 1-cyhalothrin and deltamethrin were investigated by terahertz time-domain spectroscopy (THz-TDS) technology. The three pyrethroids pesticides were easily discriminated according to the absorption spectra within 0.2-2.2 THz. We employed SLR and PLS method to perform the quantitative analysis of the mixture of deltamethrin in polyethylene. The PLS method provides better result than SLR method. The detection limit of deltamethrin content in the mixture can be down to 2.0%, and the maximum value of absolute error was 0.8%. The root mean square error was 0.55%. This result proved that the THz-TDS technique is quite potential for pesticide molecular discrimination and content determination.

[Comparison of Health Risk from Sources of Perfluoroalkyl Substances in Taihu Lake for Different Years].

Pollution characteristics and spatial distributions of perfluoroalkyl substances (PFASs) in surface water samples were investigated in Taihu Lake in 2010 and 2019, respectively. A hybrid model based on the positive matrix factorization (PMF) and the health risk assessment model were employed for quantifying the contributions of sources to PFASs concentrations and the source risks. The method contained two stages:1 the sources of PFASs were apportioned using the PMF model, and 2 the contribution of health risks from each source was quantitively estimated. Three factors (source categories) were extracted using PMF, including:coating industry sources, textile and electroplating sources, and fluoride-processing industry sources. Their contributions to PFASs concentration were 29.59%, 25.68%, and 44.72% for 2010 and 67.69%, 10.26%, 22.05%, for 2019, respectively. The health risk of PFASs in the water assessed by the health risk assessment (HRA) model was 4.56E-07 for 2010 and 2.69E-07 for 2019, which was lower than 1E-06. The source contributions to health risks estimated by the PMF-HRA hybrid model were:64.86% (2010) and 92.48% (2019) for textile and electroplating sources, 31.30% (2010) and 5.04% (2019) for coating industry sources, and 3.84% (2010) and 2.48% (2019) for fluoride-processing industry sources. For the two years, the concentrations of PFOA and PFOS were reduced significantly, indicating the effective control of their emissions during the past ten years in Taihu Lake. However, it was also shown that the concentrations of PFBS and PFHxS were increased. These findings suggest that the above short chain-PFCs species should be the focus for further control and management, and their health risks should be studied in future research.

Mechanical Force-Induced Blue-Shifted and Enhanced Emission for AIEgens.

Mechanochromic (MC) luminescence of organic molecules has been emerging as a promising smart material for optical recording and memory devices. At the same time, pressure-induced blue-shifted and enhanced luminescence are rarely reported now. Herein, a series of cyanostilbene-based AIEgens with different substituents were synthesized to evaluate the influence of morphology transformation and push-pull electronic effect on the MC luminescence. Among these luminophores, compound 1 with one cyano group and diethylamino group was more susceptible to mechanical stimuli and obtained blue-shifted and enhanced fluorescence in response to anisotropic grinding. Powder X-ray diffraction patterns indicated that the MC behaviors were ascribed to the solid-state morphology transition from crystal-to-crystal. Analysis of crystal structures revealed that loose molecular packing is a key factor for high high-contrast MC luminescence. The smart molecular design, together with the excellent performance, verified that luminophores with twisted structures are ideal candidates for MC luminogens.

[Pollution Characteristics and Risk Assessment of Organophosphate Esters in Rivers and Water Body Around Taihu Lake].

To explore the pollution characteristics, potential sources, and ecological and health risk of organophosphate eaters (OPEs) in the surface water of Taihu Lake, water samples from 18 surrounding rivers were collected, as well as 11 water samples from Taihu Lake. The concentrations of 13 OPEs in the water were determined using UPLC-MS/MS, and the spatial distribution of the OPEs in surface water of Taihu Lake basin was further analyzed. The results indicate that, in addition to tripropyl phosphate (TPrP), 2-ethylhexyl diphenyl phosphate (EHDPP), and tricresyl phosphate (TCrP), ten OPEs were detected in all the water samples, the total concentration (ΣOPEs) ranged from 152.5 ng·L-1 to 2524 ng·L-1, and the concentration median value was 519.2 ng·L-1. Tri(chloropropyl) phosphate (TCPP) and tri(2-chloroethyl) phosphate (TCEP) were the dominant OPEs, with the concentration ranges of 73.7-1753.9 ng·L-1 (medium value:204.6 ng·L-1) and 43.9-313.5 ng·L-1 (medium value:131.3 ng·L-1), respectively. The ΣOPEs decreased from the northwest region to the southeast, which corresponds to the economic and industrial development. The results of the source identification reveal that the wastewater discharge from electronics and textile enterprises, construction materials, and vehicular and marine traffic emissions may be the principal sources of the OPEs in Taihu Lake. The ecological risk assessment results indicate that only TCPP, tri(dichloropropyl) phosphate (TDCP), and triphenyl phosphate (TPhP) in some sites had a low risk. The health risk assessment reveals that there were no risks based on water intake, but the long-term risk of OPEs to the aquatic ecosystem and surrounding residents still need attention.

[Organ-Specific Accumulation and Toxicokinetics of Ephedrine in Adult Zebrafish (Danio rerio)].

Ephedrine (EPH) is an alkaloid commonly used to relieve nasal congestion caused by colds, allergic rhinitis, rhinitis, and sinusitis, and to control bronchial asthma. It is also be used as a raw material in the manufacture of methamphetamine. Although the distribution of EPH in surface waters has been widely studied, its uptake, internal distribution, and toxicokinetic processing in exposed organisms have not been well investigated. In this study, we investigated the uptake, disposition, and toxicokinetics of EPH in zebrafish (Danio rerio) in a semi-static exposure system. EPH was consistently detected in zebrafish biological samples, with the highest concentrations of 84.97 ng·g-1 detected in the brain tissue of fish in the high treatment group. Over the 14-d exposure period, the relative abundance of mean concentrations of EPH in biological samples generally followed the order of brain > ovary > liver > intestine > muscle. The uptake rate constants (Ku), elimination rate constants (Ke), and half-lives of EPH in the biological tissues were in the ranges 0.23-570.31 L·(kg·d)-1, 1.22-6.11 d-1, and 0.12-0.57 d, respectively. The observed bioconcentration factor (BCFo) and kinetically-derived bioconcentration factor (BCFk) were similar, ranging 0.24-337.33 L·kg-1 and 0.13-316.43 L·kg-1, respectively. These results are helpful for understanding the behavior of psychoactive substances in aquatic organisms and have directive significance for studying their toxicity and ecological risks to aquatic organisms.