Estrogenic and AhR activities in dissolved phase and suspended solids from wastewater treatment plants
UMR 5569 Hydrosciences Montpellier, Université Montpellier 1, Av. Charles Flahault, 34060 Montpellier, France. Science of The Total Environment
(Impact Factor: 4.1).
03/2010; 408(12):2608-15. DOI: 10.1016/j.scitotenv.2010.02.034
The distribution of estrogen receptor (ERalpha) and Aryl Hydrocarbon Receptor (AhR) activities between the dissolved phase and suspended solids were investigated during wastewater treatment. Three wastewater treatment plants with different treatment technologies (waste stabilization ponds (WSPs), trickling filters (TFs) and activated sludge supplemented with a biofilter system (ASB)) were sampled. Estrogenic and AhR activities were detected in both phases in influents and effluents. Estrogenic and AhR activities in wastewater influents ranged from 41.8 to 79 ng/L E(2) Eq. and from 37.9 to 115.5 ng/L TCDD Eq. in the dissolved phase and from 5.5 to 88.6 ng/g E(2) Eq. and from 15 to 700 ng/g TCDD Eq. in the suspended solids. For both activities, WSP showed greater or similar removal efficiency than ASB and both were much more efficient than TF which had the lowest removal efficiency. Moreover, our data indicate that the efficiency of removal of ER and AhR activities from the suspended solid phase was mainly due to removal of suspended solids. Indeed, ER and AhR activities were detected in the effluent suspended solid phase indicating that suspended solids, which are usually not considered in these types of studies, contribute to environmental contamination by endocrine disrupting compounds and should therefore be routinely assessed for a better estimation of the ER and AhR activities released in the environment.
Available from: Cristina Ávila
- "Among the most well known effects, it has been reported that triclosan impairs algal growth and develops bacterial resistance (Orvos et al., 2002) whereas pharmaceutical mixtures containing carbamazepine, ibuprofen, and clofibric acid have also been found to be toxic for algae (Cleuvers, 2003). Estrogenicity has already been demonstrated for many contaminants such as natural and synthetic hormones and alkylphenols commonly detected in wastewaters (Dagnino et al., 2010). Although the removal of EOCs may be partially achieved by the application of conventional wastewater treatment plants (WWTPs) combined to advanced tertiary treatment processes (Rosal et al., 2010), their high cost limits the widespread application of these treatment technologies. "
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ABSTRACT: The capacity of a hybrid constructed wetland (CW) system consisting of two vertical flow (VF) CWs working alternatively (3m(2)), one horizontal flow (HF) CW (2m(2)) and one surface flow (FWS) CW (2m(2)) in series to eliminate 13 emerging organic contaminants (EOCs) under three different hydraulic loading rates (HLRs) (0.06, 0.13 and 0.18m d(-1) considering the area of the two VF beds) was studied through a continuous injection experiment. General toxicity, dioxin-like activity, antimicrobial activity and estrogenicity were also measured under the highest hydraulic loading rate. The hybrid system was highly efficient on the removal of total injected EOCs (except for antibiotics, 43±32%) at all three HLRs (87±10%). The removal efficiency in the hybrid CW system showed to decrease as the HLR increased for most compounds. The VF wetlands removed most of the injected EOCs more efficiently than the other two CWs, which was attributable to the predominant aerobic degradation pathways of the VF beds (70±21%). General toxicity was reduced up to 90% by the VF beds. Estrogenicity and dioxin-like activity were similarly reduced by the VF and the HF wetlands, whereas antimicrobial activity was mainly removed by the FWS wetland. Bearing this in mind, this injection study has demonstrated that the use of hybrid CW systems is a suitable wastewater technology for removing EOCs and toxicity even at high HLRs.
Available from: Xiaoyan Ma
- "Therefore, sample pretreatment is often required for isolating and/or concentrating the target toxic substances and eliminating the interference. When organic substances are the targets of ecotoxicity test, liquid–liquid extraction (Pérez et al., 2009), resin adsorption (Reginatto et al., 2009) and solid-phase extraction (SPE) (Dagnino et al., 2010; Smital et al., 2011) are the common pretreatment methods for effective extraction of organic substances and elimination of all inorganic interferences. If heavy metals become the target substances, passive sampling can effectively concentrate the metals ions by utilizing diffusive gradient in thin-films (Roig et al., 2011). "
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ABSTRACT: Luminescent bacterial test is a fast and sensitive method for acute toxicity assessment of water and wastewater. In this study, an improved toxicity testing method was developed using the freshwater luminescent bacteria Vibrio qinghaiensis sp.-Q67 that involved pretreatment of water samples with reverse osmosis (RO) to eliminate the interferences caused by nutrients in concentrated samples and to improve the reliability and sensitivity of the analysis. Because water samples contain low concentrations of several target toxic substances, rapid acute toxicity testing method that is commonly employed does not achieve enough sensitivity. The proposed RO pretreatment could effectively enrich organic and inorganic substances in water samples to enable a more effective and sensitive toxicity evaluation. The kinetic characteristics of toxicity of raw sewage and secondary effluent were evaluated based on the relative luminescence unit (RLU) curves and time-concentration-effect surfaces. It was observed that when the exposure time was prolonged to 8-h or longer, the bacteria reached the logarithmic growth stage. Hence, the stimulating effects of the coexisting ions (such as Na(+), K(+), NO3(-)) in the concentrated samples could be well eliminated. A 10-h exposure time in proposed Q67 test was found to quantitatively evaluate the toxicity of the organic and inorganic pollutants in the RO-concentrated samples.
Available from: Anne Lespine
- "Ivermectin was tested for its ability to activate rodent transcription factors (murine CAR, murine PXR and rat AhR) by using three different reporter cell lines (HG 5 LN-mCAR, HG 5 LNmPXR and H4IIE XRE-LUC) in which PXR, CAR and AhR agonists or antagonists induced or repressed luciferase gene expression. Activation was measured in these cells in the presence of increased concentrations of ivermectin from 10 À8 M to 3.3 Â 10 À6 M. The vehicle alone (DMSO) was used as negative control (luciferase activity baseline set to 1) and known reference effectors were used as positive control, as already described . Results are presented in Table 2. "
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ABSTRACT: Ivermectin is widely used in human and veterinary medicine for the control of helminth infections. Ivermectin is known to interact with P-glycoprotein (P-gp/MDR1), being a good substrate and a potent inhibitor, however, the influence of ivermectin on the expression of the transporter has not been investigated. Expression of P-glycoprotein was investigated in cultured mouse hepatocytes acutely exposed to ivermectin. The two P-glycoprotein murine isoforms, Mdr1a and Mdr1b, mRNA levels were assessed by real-time RT-PCR. Ivermectin induced a clear time- and concentration-dependent up-regulation of Mdr1a and Mdr1b mRNA levels (as early as a 12-h exposure and up to 2.5-fold at 10μM). Moreover, ivermectin-treated cells displayed enhanced cellular efflux of the P-glycoprotein substrate calcein that was inhibited by the P-glycoprotein blocker valspodar, providing evidence that the ivermectin-induced P-glycoprotein was functional. The mechanisms underlying these effects were investigated. Ivermectin-mediated Mdr1 mRNA induction was independent of the two nuclear receptors CAR and PXR, which are known to be involved in drug transporters regulation. Moreover, by using reporter cell lines that detects specific ligand-activated transcription factors, we showed that ivermectin did not displayed CAR, PXR or AhR ligand activities. However, studies with actinomycin D revealed that the half-life of Mdr1a and Mdr1b mRNA were significantly prolonged by two-fold in ivermectin-treated cells suggesting a post-transcriptional mode of ivermectin regulation. This study demonstrates for the first time that ivermectin induces P-glycoprotein overexpression through post-transcriptional mRNA stabilization, thus offering insight into the mechanism of reduced therapeutic efficacy and development of ivermectin-resistant parasites.
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