Determination of estrogens and estrogenic activities in water from three rivers in Tianjin, China

Studies on estrogenic disrupting compounds （EDCs） occurrence and identification of main responsible compounds in river water discharged into the sea are of significance. In the present research, we screened estrogenic activities of 10 river water samples from 3 main rivers discharged into Bohai Sea in Tianjin using a recombinant two-hybrid yeast assay and chemical analysis by gas chromatography-mass spectrometry. All sample extracts induced significant estrogenic activity, with 17^-estradiol equivalents （EEQ） of raw water ranging from 5.72 to 59.06 ng/L. Six most concerned EDCs in the fiver water samples including estrone, 17（5-estradiol, 17ct-ethinylestradiol, estriol, diethylstilbestrol and estradiol valerate were determined, with their concentrations up to 50.70, 31.40, 24.40, 37.20, 2.56, and 8.47 ng/L, respectively. Through causality analysis by comparing the EEQ values of yeast assay and chemical analysis, 17ct-ethinylestradiol and 17[3-estradiol were identified as the main contributors to the estrogenic effects of the river samples, accounting for the whole estrogenic activities （62.99% to 185.66%）, and estrogen antagonistic compounds might presented in the heavy polluted water samples. The proposed approach using both chemical analysis and bioassay could be used for identification and evaluation of the estrogenic activity of EDCs in river water.

Comparative toxicity study of a novel non-ionic surfactant,vanillin ethoxylates, and nonylphenol ethoxylates in Chinese hamster ovary cells in vitro

Surfactants such as alkylphenol polyethoxylates(APEOs) and nonylphenol ethoxylates(NPEOs) are commonly used worldwide, but the majority of these compounds, together with their metabolites, have been reported to induce severe biological toxicity. Here, we evaluated for the first time the cytotoxicity,genotoxicity and mitochondrial damage in Chinese hamster ovary(CHO-K1) cells caused by a novel non-ionic surfactant, vanillin ethoxylates(VAEOs), an alternative to APEOs. In parallel, the same in vitro bioassays were conducted on NPEOs along with their metabolic byproducts 4-nonylphenol(4-NP) and vanillin. The results showed that the cytotoxic potency order was NPEOs > 4-NP > VAEOs>vanillin using CCK-8 assays. Also, 4-NP showed potential direct DNA damage in SOS/umu tests, whereas NPEOs, VAEOs and vanillin showed no positive result with and without S9 addition. In addition, none of the test compounds showed obvious genotoxic effects with low olive tail moment value using comet assays. However, all test compounds were shown to cause mitochondrial impairment by increasing mitochondrial mass and decreasing mitochondrial membrane potential in a concentration-dependent manner. And further analysis of reactive oxygen species(ROS) and mitochondrial superoxide(MNSOD)measurement showed that mitochondrial impairment was induced by oxidative stress with intracellular ROS and MNSOD overproduction. It's worth noting that VAEOs and vanillin cause relative lower cytotoxic, genotoxic and mitochondrial damage effects than NPEOs and 4-NP, indicating that VAEOs have the potential to substitute NPEOs as suitable surfactants. Take together, this study elucidates the toxicity profiles of VAEOs and NPEOs relatively comprehensively, and further toxicity analyses are suggested in the population, community and ecosystem.

Fish forewarning of comprehensive toxicity in water environment based on Bayesian sequential method

Environmental impact of pollutants can be analyzed effectively by acquiring fish behavioral signals in water with biological behavior sensors. However, a variety of factors, such as the complexity of biological organisms themselves, the device error and the environmental noise, may compromise the accuracy and timeliness of model predictions. The current methods lack prior knowledge about the fish behavioral signals corresponding to characteristic pollutants, and in the event of a pollutant invasion, the fish behavioral signals are poorly discriminated. Therefore, we propose a novel method based on Bayesian sequential,which utilizes multi-channel prior knowledge to calculate the outlier sequence based on wavelet feature followed by calculating the anomaly probability of observed values. Furthermore, the relationship between the anomaly probability and toxicity is analyzed in order to achieve forewarning effectively. At last, our algorithm for fish toxicity detection is verified by integrating the data on laboratory acceptance of characteristic pollutants. The results show that only one false positive occurred in the six experiments, the present algorithm is effective in suppressing false positives and negatives, which increases the reliability of toxicity detections, and thereby has certain applicability and universality in engineering applications.

In vitro agonistic and antagonistic endocrine disrupting effects of organic extracts from waste water of different treatment processes

Effluents from wastewater treatment plant （WWTP） have been reported to have a broad spectrum of endocrine disrupting compounds （EDCs）. The majority of studies have focused on the occurrence of estrogenic activity, while ignoring nuclear hormone receptors （NRs） pathways. In the present study, a battery of in vitro yeast bioassays and a cell bioassay, including antagonistic and agonistic effects on estrogen receptor （ER）, androgen receptor （AR）, progesterone receptor （PR）, estrogen- related receptor （ERR） and aryl hydrocarbon receptor （AHR）, were conducted to evaluate the removal efficien- cies of EDCs by different treatment processes of a WWTP located in Beijing. Estrogenic, anti-estrogenic, anti- androgenic, anti-progesteronic, anti-ERR and the activa- tion of AHR activities were detected in samples from all treatment processes and the receiving water. The concen- tration of estrogenic contaminants with estradiol （E2） equivalent concentrations ranged from 0.82 x 10-9 to 3.54 x 10 9g Ee_EQ.L-1. The concentration of anti-estrogenic contaminants with 4-hydroxytamoxifen （4-OHT） equiva- lent concentrations ranged from 1.24 × 10-6 to 2.36 x 10-6 g 4-OHT-EQ.L-1. The concentration of anti-androgenic contaminants ranged from 2.21 x 10-s to 3.52 × 10-6g flutamide-EQ. L-1. The concentration of anti-progesteronic contaminants ranged from 3.15 x 10^-5 to 2.71 x 10^-4g RU486-EQ. L-1. The concentration of anti-ERR contami- nants ranged from 7.09 x 10-5 to 6.50 x 104 g 4-OHT-EQ × L^-10. The concentration of AHR activators ranged from 1.7 × 10-10 to 3.4 × 10^-10g TCDD-EQ-L-1. These processes including secondary clarifier, coagulation, as well as coal and sand filtration could eliminated 67.2% of estrogenic contaminants, 47.0% of anti-estrogenic contaminants, 98.3% of anti-androgenic contaminants, 88.4% of anti- progesteronic contaminants, 65.4% of anti-ERR contami- nants and 46.9% of AHR activators. WWTP effluents contain multiple receptor disruptors may have very complex adverse effects on exposed organisms.

Estrogen-related receptor γ disruption of source water and drinking water treatment processes extracts

Environmental chemicals in drinking water can impact human health through nuclear receptors. Additionally, estrogen-related receptors （ERRs） are vulnerable to endocrine-disrupting effects. To date, however, ERR disruption of drinking water potency has not been reported. We used ERRy two-hybrid yeast assay to screen ERRy disrupting activities in a drinking water treatment plant （DWTP） located in north China and in source water from a reservoir, focusing on agonistic, antagonistic, and inverse agonistie activity to 4-hydroxytamoxifen （4-OHT）. Water treatment processes in the DWTP consisted of pre-chlorination, coagulation, coal and sand filtration, activated carbon filtration, and secondary chlorination processes. Samples were extracted by solid phase extraction. Results showed that ERRγ antagonistic activities were found in all sample extracts, but agonistic and inverse agonistic activity to 4-OHT was not found. When calibrated with the toxic equivalent of 4-OHT, antagonistic effluent effects ranged from 3.4 to 33.1 μg/L. In the treatment processes, secondary chlorination was effective in removing ERRy antagonists, but the coagulation process led to significantly increased ERRy antagonistic activity. The drinking water treatment processes removed 73.5 % of ERRy antagonists. To our knowledge, the occurrence of ERRy disruption activities on source and drinking water in vitro had not been reported previously. It is vital, therefore, to increase our understanding of ERRγ disrupting activities in drinking water.

Spatio-temporal characteristics of genotoxicity in the Yangtze River under the background of COVID-19 pandemic

The global spread of viruses can lead to the release of large amounts of disinfectants or antiviral drugs into the water environment.The resulting disinfection byproducts(DBPs)and residual antiviral drugs,acting as genotoxic substances or their precursors,may pose risks to aquatic animals and drinking water sources;however,to date,no studies have analyzed the changes in genotoxicity in the Yangtze River before and after the epidemic.In the present study,water and sediment samples from the Yangtze River were collected during different seasons,just before and after the outbreak of COVID-19,and were assessed using the SOS/umu test(with and without liver S9).The results indicated that water samples exhibited more pronounced genotoxicity than did sediments,with direct genotoxicity being the primary factor.Additionally,there were significant regional differences,with notably greater genotoxicity observed in the upper Yangtze River than in the lower reaches before the COVID-19 epidemic.However,this trend was reversed six to ten months later,suggesting the accumulation of DBPs or antiviral drugs after the COVID-19 pandemic.Moreover,the risk quotient indicated that 65%of the water samples posed a high risk for Paramecium caudatum,whereas 71%of the samples posed a medium risk for Danio rerio,thereby representing a potential threat to the ecological security of the Yangtze River.In conclusion,this study,at the basin scale,revealed the impacts of COVID-19 on the Yangtze River,highlighting the need to prevent DBPs and pharmaceutical pollution during similar events in the future.