Occurrence and Removal of Organic Micropollutants in Landfill Leachates Treated by Electrochemical Advanced Oxidation Processes
In recent years, electrochemical advanced oxidation processes have been shown to be an effective alternative for the removal of refractory organic compounds from water. This study is focused on the effective removal of recalcitrant organic matter (micropollutants, humic substances, etc.) present in municipal solid waste landfill leachates. A mixture of eight landfill leachates has been studied by the electro-Fenton process using a Pt or boron-doped diamond (BDD) anode and a carbon felt cathode or by the anodic oxidation process with a BDD anode. These processes exhibit great oxidation ability due to the in situ production of hydroxyl radicals (OH), a highly powerful oxidizing species. Both electrochemical processes were shown to be efficient in the removal of dissolved total organic carbon (TOC) from landfill leachates. Regarding the electro-Fenton process, the replacement of the classical anode Pt by the anode BDD allows better performance in terms of dissolved TOC removal. The occurrence and removal yield of 19 polycyclic aromatic hydrocarbons, 15 volatile organic compounds, 7 alkylphenols, 7 polychlorobiphenyls, 5 organochlorine pesticides, and 2 polybrominated diphenyl ethers in landfill leachate were also investigated. Both electrochemical processes allow one to reach a quasicomplete removal (about 98%) of these organic micropollutants.
(Environmental Science and Technology. vol. 49, n° 0013-936X, pp. 12187-12196, 31/08/2026)
UPEM, IRSTEA, UR HBAN, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Is the toxicity of pesticide mixtures on river biofilm accounted for solely by the major compounds identified?
Pesticides are present as a cocktail of compounds at low concentrations in water bodies. Nevertheless, studies assessing the toxic effects of pesticide mixtures at realistic environmental concentrations are still scarce. Polar Organic Chemical Integrative Sampler (POCIS) allows the concentration of several organic chemicals from large volumes of natural water [1]. This high pre-concentration of compounds makes POCIS a powerful tool to assess extract toxicity via biological testing and therefore to study the impact of realistic mixtures . PE can be used as a black box with the advantages of dealing with mixtures “as they came”; this approach gives an estimation of an integrative measure of the toxic potential of a group of compounds including unknown toxicants without using an a priori approach. With this protocol, the global toxicity of the extract is assessed although the compounds responsible for the observed toxicity are not identified. The present study aimed to characterize the effects of long-term and low-dose exposure to POCIS extracts in a context of contamination by cereal crops on a natural biofilm community and to evaluate whether the effects observed due to exposure to PE were explained by the major compounds identified in the extracts [2].
(pp. 2, 31/08/2026)
UR EABX, IRSTEA, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Herbicide toxicity on river biofilms assessed by pulse amplitude modulated (PAM) fluorometry
The use of Rapid light curves (RLCs) as a toxicity endpoint for river biofilms was examined in this studyand compared to "classical fluorescence parameters" i.e. minimal fluorescence (F0), optimal and effectivequantum yields of photosystem II (Fv/Fmand PSII). Measurements were performed after exposure tofive concentrations of diuron (from 0.3 to 33.4 g L-1), its main degradation product (DCPMU) (from1.0 to 1014 g L-1) and norflurazon (from 0.6 to 585 g L-1) with the lowest exposure concentrationscorresponding to levels regularly encountered in chronically contaminated sites. Biofilm responses wereevaluated after 1, 5, 7 and 14 days of exposure to the different toxicants.Overall, the responses of both "classical fluorescence parameters" and RLC endpoints were highly timedependent and related to the mode of action of the different compounds. Interestingly, parameters cal-culated from RLCs (ETRmaxand Ik) were useful early markers of pesticide exposure since they revealedsignificant effects of all the tested toxicants from the first day of exposure. In comparison, classicalfluorescence endpoints (F0and Fv/Fm) measured at day 1 were only affected in the DCPMU treatment.Our results demonstrated the interest of RLCs as early markers of toxicant exposure particularly whenworking with toxicants with less specific mode of action than PSII inhibitors.
(Aquatic Toxicology. vol. 165, n° 0166-445X, pp. 160-171, 31/08/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CESAM, CNRS
Pervasive multidecadal variations in productivity within the Peruvian Upwelling System over the last millennium
There is no agreement on the pluri-decadal expression of El Ni~ noeSouthern Oscillation (ENSO) in the Pacific over the last millennium. Marine records from the Peruvian margin indicate humid conditions (El Ni~ no-like mean conditions) over the Little Ice Age, while precipitation records from the eastern equatorial Pacific infer arid conditions (La Ni~ na-like mean conditions) for the same period. We here studied diatom assemblages, nitrogen isotopes, and major and minor elements at the lamination level in three laminated trigger cores located between 11 S and 15 S on the Peruvian shelf within the oxygen minimum zone (OMZ) to reconstruct precipitation and ocean productivity at the multiannual to multidecadal timescales over the last millennium. We respected the sediment structure, thus providing the first records of the mean climatic conditions at the origin of the lamination deposition, which ones represent several years. Light laminations were deposited under productive and dry conditions, indicative of La Ni~ na-like mean conditions in the system, while dark laminations were deposited under non-productive and humid conditions, representative of El Ni~ no-like mean conditions. La Ni~ na-like mean conditions were predominant during the Medieval Warm Period (MWP; 1000e600 years BP) and Current Warm Period (CWP; 150 years BP to present), while El Ni~ no-like mean conditions prevailed over the Little Ice Age (LIA; 600e150 years BP). We provide evidence for persistent multidecadal variations in productivity over the last millennium, which were disconnected from the mean climate state. Multidecadal variability has been stronger over the last 450 years concomitantly to increased variability in the NAO index. Two intervals of strong multidecadal variability were also observed over the MWP, congruent to decreased solar irradiance and increased volcanic activity.
(Quaternary Science Reviews. vol. 125, n° 0277-3791, pp. 78-90, 31/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CAU
Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species
The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood P7PCB concentrations (range: 61e115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood P7PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood P7PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure.
(Environmental Pollution (1970). vol. 197, n° 0013-9327, pp. 173-180, 31/08/2026)
CEBC, INRA, ULR, CNRS, NINA, NINA, NINA, NILU, TOXEN, UQAM, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UC
Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation
Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effects, contaminants gradually accumulated in eels during their somatic growth phase (yellow eel stage) would be remobilized during their reproductive migration leading to potential toxic events in gonads. The aim of this study was to investigate the effects of organic and inorganic contaminants on the gonad development of wild female silver eels. Female silver eels from two sites with differing contamination levels were artificially matured. Transcriptomic analyses by means of a 1000 candidate gene cDNA microarray were performed on gonads after 11 weeks of maturation to get insight into the mechanisms of toxicity of contaminants. The transcription levels of several genes, that were associated to the gonadosomatic index (GSI), were involved in mitotic cell division but also in gametogenesis. Genes associated to contaminants were mainly involved in the mechanisms of protection against oxidative stress, in DNA repair, in the purinergic signaling pathway and in steroidogenesis, suggesting an impairment of gonad development in eels from the polluted site. This was in agreement with the fact that eels from the reference site showed a higher gonad growth in comparison to contaminated fish.
(Chemosphere. vol. 139, n° 0045-6535, pp. 303--309, 31/08/2026)
BOREA, UNICAEN, NU, MNHN, IRD, SU, CNRS, UA, IBIS, ULaval, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, µVIS X-ray Imaging Centre, UR EABX, IRSTEA, INRS, LPTC, UB, CNRS, ISM, UB, INC-CNRS, CNRS
Divergent biophysical controls of aquatic CO2 and CH4 in the World's two largest rivers
Carbon emissions to the atmosphere from inland waters are globally significant and mainly occur at tropical latitudes. However, processes controlling the intensity of CO2 and CH4 emissions from tropical inland waters remain poorly understood. Here, we report a data-set of concurrent measurements of the partial pressure of CO2 (pCO2) and dissolved CH4 concentrations in the Amazon (n = 136) and the Congo (n = 280) Rivers. The pCO2 values in the Amazon mainstem were significantly higher than in the Congo, contrasting with CH4 concentrations that were higher in the Congo than in the Amazon. Large-scale patterns in pCO2 across different lowland tropical basins can be apprehended with a relatively simple statistical model related to the extent of wetlands within the basin, showing that, in addition to non-flooded vegetation, wetlands also contribute to CO2 in river channels. On the other hand, dynamics of dissolved CH4 in river channels are less straightforward to predict and are related to the way hydrology modulates the connectivity between wetlands and river channels.
(Scientific Reports. vol. 5, n° 2045-2322, pp. 15614, 31/08/2026)
ULiège, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, KU Leuven, UENF
Spatial and seasonal contrasts of sedimentary organic matter in floodplain lakes of the central Amazon basin
(Biogeosciences Discussions. vol. 12, n° 1810-6277, pp. 8747 - 8787, 31/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISEM, Cirad, IRD, EPHE, PSL, UM, CNRS, BOME, MNHN, UPMC, CNRS, IRD [Burkina Faso]
Differences in brain gene transcription profiles advocate for an important role of cognitive function in upstream migration and water obstacles crossing in European eel
Background: European eel is a panmictic species, whose decline has been recorded since the last 20 years. Among human-induced environmental factors of decline, the impact of water dams during species migration is questioned. The main issue of this study was to pinpoint phenotypic traits that predisposed glass eels to successful passage by water barriers. The approach of the study was individual-centred and without any a priori hypothesis on traits involved in the putative obstacles selective pressure. We analyzed the transcription level of 14,913 genes. Results: Transcriptome analysis of three tissues (brain, liver and muscle) from individuals sampled on three successive forebays separated by water obstacles indicated different gene transcription profiles in brain between the two upstream forebays. No differences in gene transcription levels were observed in liver and muscle samples among segments. A total of 26 genes were differentially transcribed in brain. These genes encode for, among others, keratins, cytokeratins, calcium binding proteins (S100 family), cofilin, calmodulin, claudin and thy-1 membrane glycoprotein. The functional analysis of these genes highlighted a putative role of cytoskeletal dynamics and synaptic plasticity in fish upstream migration. Conclusion: Synaptic connections in brain are solicited while eels are climbing the obstacles with poorly designed fishways. Successful passage by such barriers can be related to spatial learning and spatial orientation abilities when fish is out of the water.
(BMC Genomics. vol. 16, n° 1471-2164, pp. 10 p., 31/08/2026)
UR EABX, IRSTEA, Unipd, JCU, EDF R&D LNHE, EDF R&D, EDF [E.D.F.], EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Environmental concentrations of benz[a]anthracene induce developmental defects and DNA damage and impair photomotor response in Japanese medaka larvae.
Benz[a]anthracene (BaA) is a ubiquitous polycyclic aromatic hydrocarbon found in numerous aquatic ecosystems. However, ecotoxicological data in aquatic organisms are scarce. To remedy this lack of data, Japanese medaka (Oryzias latipes) embryos were exposed to BaA and toxic effects were investigated at multiple toxicological endpoints. Japanese medaka embryos were incubated onto BaA-spiked artificial sediment for 9 days at low or moderate environmental concentrations ranging from 0.9 to 12µgg(-1) dw. BaA-exposed embryos exhibited significant tachycardia. BaA exposure was also shown to increase CYP1A activity in the hepato-biliary tissue as well as craniofacial deformities and DNA damage in pro-larvae. The photomotor response of BaA-exposed larvae was reduced in comparison to the control group. According to this set of tests, the lowest tested and observed effect concentration (LOEC) for Japanese medaka early life stages was equivalent to 0.92µgg(-1) dw of BaA. This concentration fall into the range of concentrations frequently encountered in sediments of polluted aquatic ecosystems. Taking into consideration these results, BaA represents a threat for fish early life stages in particular those developing onto or into contaminated sediments.
(Ecotoxicology and Environmental Safety. vol. 113C, n° 0147-6513, pp. 321-328, 31/08/2026)
UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPGP, INRA, Biosit : Biologie - Santé - Innovation Technologique, BE, IFREMER