In this work, the contributions of triclosan and its metabolite methyl triclosan to the overall acute toxicity of wastewater were studied using Vibrio fischeri. The protocol used in this paper involved various steps. First, the aquatic toxicities of triclosan and methyl triclosan were determined for standard substances, and the 50% effective concentrations (EC(50)) were determined for these compounds. Second, the toxic responses to different mixtures of triclosan, methyl triclosan, and surfactants were studied in different water matrices, i.e., Milli-Q water, groundwater and wastewater, in order to evaluate (i) the antagonistic or synergistic effects, and (ii) the influence of the water matrices. Finally, chemical analysis was used in conjunction with the toxicity results in order to assess the aquatic toxicities of triclosan and its derivative in wastewaters. In this study, the toxicities of 45 real samples corresponding to the influents and effluents from eight wastewater treatment works (WWTW) were analyzed. Thirty-one samples were from a wastewater treatment plant (WWTP) equipped with two pilot-scale membrane bioreactors (MBR), and the influent and the effluent samples after various treatments were characterized via different chromatographic approaches, including solid-phase extraction (SPE), liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), and SPE coupled to gas chromatography-mass spectrometry (GC-MS). The toxicity was determined by measuring the bioluminescence inhibition of Vibrio fischeri. In order to complete the study and to extrapolate the results to different WWTPs, the toxicity to V. fischeri of samples from seven more plants was analyzed, as were their triclosan and methyl triclosan concentrations. Good agreement was established between the overall toxicity values and concentrations of the biocides, indicating that triclosan is one of the major toxic organic pollutants currently found in domestic wastewaters.
"Results from Goldstein et al. (2014) provide sufficient evidence that although the parent compound was not detected accumulation of metabolites in the fruit may occur. Metabolites, such as methyl-triclosan derived from triclosan or epoxy-carbamazepine derived from carbamazepine, are potentially more toxic than the parent compound and have been found at significantly higher concentrations than the parent compounds (Farré et al., 2008; Goldstein et al., 2014; Malchi et al., 2014). Hence, PPCP metabolism warrants discussion in assessing human health risk of crops and certain PPCPs should have an additional uncertainty factor, especially if the PPCP's metabolites possess higher biological activity than that of the parent compound. "
"e l s e v i e r . c o m / l o c a t e / s c i t o t e n v hydroxy-ibuprofen at 26% and carboxy-ibuprofen at 43% of applied therapeutic dose (Lishman et al., 2006; Farré et al., 2008). Also a major contribution to environmental concentration of non-metabolized and metabolized form of ibuprofen is medical waste that has not been properly managed (household, hospital or industrial production waste) and untreated municipal wastewater. "
[Show abstract][Hide abstract] ABSTRACT: A new system for monitoring toxicity TOXcontrol® (MicroLAN BV, The Netherlands) has been used to assess the toxicity of a selection of priority or emergent compounds in the laboratory. In this study, inhibition curves and EC50 - Effective Concentration causing 50% inhibition - of selected compounds (including pesticides, pharmaceuticals, surfactants and metals commonly detected in surface or drinking waters) were determined. This new technology is based on the measurement of Vibrio fischeri bioluminescence inhibition (ISO 11348). The main advantage of this equipment, compared to other laboratory assays, is the fully automation of the procedure. The instrument can be operated online in a simple, rapid and reproducible way. The variability of the results obtained with the TOXcontrol® biomonitoring system has been studied. A comparison with standardised technology based in V. fischeri (Microtox®) and additional test with Daphnia magna for selected organic compounds is presented. The results show that the methodology based on the TOXcontrol® system being validated is accurate and reproducible enough enabling this system to be used as an on-line automatic alert system to detect abnormal concentrations of toxic compounds.
Science of The Total Environment 06/2012; 440. DOI:10.1016/j.scitotenv.2012.05.043 · 4.10 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.