Papers - Co author by Jean-Luc Loizeau
An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is u... more An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is used here to
study long-term contamination by 137Cs atmospheric deposition and the fate of this radioisotope when
associated with various agricultural practices: fallow land, KCl, NH4(NO3), superphosphate fertilizers,
horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is
supposed to move downward by convectional mechanisms, is checked using samples from control plots
which had been neither amended, nor cultivated since 1928. This simple model presents the advantage
of depending on only two parameters: a, a proportional factor allowing the historical atmospheric 137Cs
fluxes to be reconstructed locally, and k, an annual loss coefficient from the plow horizon. Another
pseudo-unknown is however necessary to run the model: the shape of historical 137Cs deposition, but
this function can be easily computed by merging several curves previously established by other surveys.
A loss of w1.5% per year from the plow horizon, combined with appropriate fluxes, provides good
concordance between simulated and measured values. In the 0–25 cm horizon, the residence half time is
found to be w18 yr (including both migration and radioactive decay). Migration rate constants are also
calculated for some plots receiving continuous long-term agricultural treatments. Comparison with the
control plots reveals significant influence of amendments on 137Cs mobility in these soils developed from
a unique genoform.
Papers by Jean-Luc Loizeau
History of TCEs in the Vidy Bay, Lake Geneva
Poster.-- Cost Action TD 1407 Final Meeting: Technology Critical Elements – Sources, Chemistry an... more Poster.-- Cost Action TD 1407 Final Meeting: Technology Critical Elements – Sources, Chemistry and Toxicology, April 2-3 2019, Zagreb (Croatia)
Urban Sources of Micropollutants: from the Catchment to the Lake
Micropollutants in Large Lakes, 2018
Metabolic, cellular and molecular effects of carbamazepine and methylmercury after single and combined exposures in Dreissena polymorpha
Social Science Research Network, 2022
Chemosphere 299 (2022) 134306
Environmental Pollution, May 1, 2022
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Journal of Seismology, 2018
The Valais is the most seismically active region of Switzerland. Strong damaging events occurred ... more The Valais is the most seismically active region of Switzerland. Strong damaging events occurred in 1755, 1855, and 1946. Based on historical documents, we discuss two known damaging events in the sixteenth century: the 1524 Ardon and the 1584 Aigle earthquakes. For the 1524, a document describes damage in Ardon, Plan-Conthey, and Savièse, and a stone tablet at the new bell tower of the Ardon church confirms the reconstruction of the bell tower after the earthquake. Additionally, a significant construction activity in the Upper Valais churches during the second quarter of the sixteenth century is discussed that however cannot be clearly related to this event. The assessed moment magnitude Mw of the 1524 event is 5.8, with an error of about 0.5 units corresponding to one standard deviation. The epicenter is at 46.27 N, 7.27 E with a high uncertainty of about 50 km corresponding to one standard deviation. The assessed moment magnitude Mw of the 1584 main shock is 5.9, with an error of about 0.25 units corresponding to one standard deviation. The epicenter is at 46.33 N and 6.97 E with an uncertainty of about 25 km corresponding to one standard deviation. Exceptional movements in the Lake Geneva wreaked havoc along the shore of the Rhone delta. The large dimension of the induced damage can be explained by an expanded subaquatic slide with resultant tsunami and seiche in Lake Geneva. The strongest of the aftershocks occurred on March 14 with magnitude 5.4 and triggered a destructive landslide covering the villages Corbeyrier and Yvorne, VD.
Medium- and Long-Term Effects of Estrogenic Contaminants on the Middle River Po Fish Community as Reconstructed from a Sediment Core
Archives of Environmental Contamination and Toxicology, 2016
Recent studies showed that endocrine active compounds (EDs) capable to induce fish gonadal histop... more Recent studies showed that endocrine active compounds (EDs) capable to induce fish gonadal histopathologies, plasma vitellogenin and thyroid disruption, are transported by the River Lambro to the River Po, potentially affecting the fish community of the main Italian river. To assess whether fish relative abundance, composition and health were impaired by the River Lambro, a 3-year survey was undertaken in the main river. Results showed that the tributary supports in the River Po a denser fish community (+43 %), with a higher total biomass (+35 %). The survey also showed niche- and sensitivity-dependent effects, so that three benthopelagic species (bleak, topmouth gudgeon, and bitterling) were, for example, more abundant downstream from the tributary (up to 3.4×), but their sizes were significantly smaller. The present fish community was then compared with that described 30 years before in the same area of the Po River. This comparison highlighted that some fish species have disappeared and many have severely declined. To better evaluate this contrast, a sediment core of the Lambro tributary was analysed for the time trends of natural estrogens (E1, E2, E3), bisphenol A and alkylphenols. The results showed that during the last 50 years the River Lambro has been exposed to high estrogenic activities (16.1 ± 9.3 ng E2 equivalents/g), which inevitably affected also the River Po. In addition, at the time of the previous survey, six species of the main river had skewed sex ratios toward all-female populations, providing evidence that EDs and particularly (xeno)estrogens were already affecting the long-term viability of fish populations. Estrogens thus can be ascribed among the causal factors of fish qualitative and quantitative decline of the River Po, although long-term effects have been likely mitigated by nonconfinement of fish populations and nutrient enrichment.
Sedimentology, 1994
ABSTRACTThe qualities of a laser diffraction grain size analyser, the Coulter LS‐100 (range claim... more ABSTRACTThe qualities of a laser diffraction grain size analyser, the Coulter LS‐100 (range claimed by the manufacturer: 0·4–900 μm in a single measurement), are evaluated on sediments of fluvial and lacustrine origin.Accuracy and resolution of measurement on standard latex spheres are excellent. Reproducibility of the results on natural sediments appears to be satisfactory, but the method underestimates the fraction of clay particles with an efficiency of detection (36–70%) proportional to the clay content determined from pipette analysis. This efficiency is somewhat higher than those reported from other instruments of the same generation.Comparison of the Coulter LS‐100 with other sizing techniques shows good agreement with the sieving method but some differences appear with the electroresistance particle technique: median and mean size values measured by the Coulter Counter TA1 are systematically lower than those obtained by the Coulter LS‐100. Analyses show good correlation with...
Environmental Science: Processes & Impacts
The formation and dynamic partitioning of As species in the water column of a large oligo-mesotro... more The formation and dynamic partitioning of As species in the water column of a large oligo-mesotrophic lake is driven by biological processes.
Benthic communities can inform about the contamination of large lakes surface sediments: A case-study in Lake Geneva
HAL (Le Centre pour la Communication Scientifique Directe), Sep 23, 2018
La dernière évaluation globale de la contamination des sédiments superficiels du Léman (métaux et... more La dernière évaluation globale de la contamination des sédiments superficiels du Léman (métaux et nutriments) ayant été effectuée en 1988, une nouvelle campagne de prélèvements et d'analyses était nécessaire pour évaluer l'état actuel des sédiments superficiels vis-à-vis des micropolluants métalliques et organiques. Cette étude se base sur l'analyse des paramètres sédimentologiques et des métaux trace sur 80 sites, du phosphore et de ses formes chimiques sur 50 sites, de 54 substances réparties en 12 groupes de micropolluants organiques (HAP, PCB, pesticides, …) sur 31 sites, et de 24 substances peu documentées pour le Léman (dioxines, PFOS, retardateurs de flamme bromés, ...) sur 5 sites pour une étude exploratoire. De plus, des tests écotoxicologiques basés sur la croissance et la mortalité de l'ostracode Heterocypris incongruens ont été menés sur 30 sites afin de confronter les résultats avec les teneurs en micropolluants. La plupart des substances recherchées sur les 80 et 31 sites ont été détectées. Pour les métaux, les concentrations présentent généralement des valeurs deux à trois fois plus élevées que les teneurs naturelles, sauf pour le mercure qui est jusqu'à 20 fois plus concentré. Les teneurs en métaux sont similaires à celles mesurées en 1988, excepté le mercure qui montre une nette diminution générale des concentrations. Concernant les micropolluants organiques, la répartition de leurs teneurs suit deux tendances principales : soit une augmentation avec l'éloignement de l'embouchure du Rhône (DDT, PCB, …), soit une répartition assez homogène sur l'ensemble du lac mais avec des teneurs parfois plus fortes près des côtes (PBDE, Endosulfan, …). Les concentrations médianes des principaux groupes de substances sont de : HAP 781 µg/kg ; 7 PCBi 8.78 µg/kg ; DDT 2.87 µg/kg ; HCH 0.86 µg/kg ; 7 PBDEi 0.12 µg/kg. L'étude exploratoire sur 5 sites a révélé la présence de dioxines et furanes, d'hexabromocyclo-dodécane et de composés perfluorés. Le site de la Baie de Vidy au large de Lausanne reste le point le plus contaminé du lac, tant pour les métaux que la plupart des substances organiques, avec : Hg 2.44 µg/kg ; Cd 1.47 µg/kg ; HAP 3214 µg/kg ; 7 PCBi 79.07 µg/kg ; 7 PBDEi 2.70 µg/kg ; DDT 9.01 µg/kg ; HCH 0.83 µg/kg. Les test écotoxicologiques ont permis de classer les sites en trois catégories, avec 13 sites considérés comme présentant une bonne qualité des sédiments, 10 sites de classe moyenne et 7 de classe mauvaise. Une première approche de la toxicité potentielle des sédiments pour les organismes benthiques à partir des données chimiques indique que les sédiments ne devraient pas induire de toxicité importante, excepté sur le site de la Baie de Vidy. Les résultats des tests sur ostracode révèlent une situation différente, dont la signification reste à explorer.
Minerals
The radioactivity associated with artisanal and small-scale gold mining activities (ASM) carried ... more The radioactivity associated with artisanal and small-scale gold mining activities (ASM) carried out along the Ulindi River, in the eastern Democratic Republic of the Congo, was evaluated by gamma-ray spectrometry and inductively coupled plasma–mass spectrometry of soil and sediment samples. The results revealed that activity concentrations of 238U (up to 3127 ± 98 Bq kg−1), 226Ra (up to 2710 ± 89 Bq kg−1) and 232Th (up to 2142 ± 162 Bq kg−1) were 71- to 89-fold higher than the worldwide average concentrations reported by UNSCEAR in soils. Primordial radionuclides are, thus, present in high concentrations in deposits of gold in that region and the average ambient effective radiation dose rate was determined at 8.4 mSv y−1 (range 0.5 to 40 mSv y−1). This area may be classified as a natural high background radiation area (HBRA). The radiation risk for artisanal miners and population members manipulating those geological materials were assessed through radiological parameters. such as ...
Bird watching in the wetlands of the Ukrainian part of the
1. Birds as indicators of biodiversity and environment quality In nature, birds are usually among... more 1. Birds as indicators of biodiversity and environment quality In nature, birds are usually amongst the vertebrate animals which are relatively easy and also fascinating to observe because of their ability to move in the air. They are one of the best-known classes of animals, with a well-established systematic classification. In many regions, cohorts of amateur bird-watchers and societies record species occurrence, creating large databases that can be used by scientists and environmental managers. For example, since 2002 the Pan-European Common Bird Monitoring Scheme (http://www.ebcc.info/) gathers data from 21 European
Bird watching in the wetlands of the Ukrainian part of the
1. Birds as indicators of biodiversity and environment quality In nature, birds are usually among... more 1. Birds as indicators of biodiversity and environment quality In nature, birds are usually amongst the vertebrate animals which are relatively easy and also fascinating to observe because of their ability to move in the air. They are one of the best-known classes of animals, with a well-established systematic classification. In many regions, cohorts of amateur bird-watchers and societies record species occurrence, creating large databases that can be used by scientists and environmental managers. For example, since 2002 the Pan-European Common Bird Monitoring Scheme (http://www.ebcc.info/) gathers data from 21 European
Journal of Paleolimnology, 2018
Anthropogenic eutrophication can initiate vast and persistent ecosystem state changes in lakes. S... more Anthropogenic eutrophication can initiate vast and persistent ecosystem state changes in lakes. Such changes may be characterized by increased phytoplankton taxa variability, which can affect the effectiveness and time of lake recovery mechanisms. Lake Morat in Switzerland has undergone intense eutrophication in the 20 th century (phosphorous concentrations up to 150 μg L-1) caused by excessive nutrient loadings from agricultural intensification and urbanization. Phosphorous reduction measures since 1986, such as the ban of phosphates in detergents and decreased use of fertilizers in agriculture, have resulted in total phosphorous concentrations up to 20 μg L-1 today. Despite this drastic reduction of total phosphorous, total biomass production stays high. We investigate historical changes in the phytoplankton community during the eutrophication and re-oligotrophication periods by comparing historical limnological data with sediment pigment concentrations measured by HPLC and other geochemical proxies in a radiodated sediment core. For the last 90 years, we identified four major trophic state changes in Lake Morat. The first period (AD 1924-1937) is characterized by low pigment concentrations and nutrient inputs, with good oxygen conditions. This section represents trophic conditions before the intensive eutrophication phase. The second period (AD 1937-1970) revealed an abrupt increase in pigment concentrations with higher primary production, cyanobacteria dominance and reduced oxygen levels. Oscillaxanthin indicated a Planktothrix rubescens dominance (AD 1954-1970) with concentrations up to 800 nmol g-1 OM. Their decline after AD 1970 suggests the initiation of an intense eutrophication phase (AD 1970-1983) associated with the dominance of other cyanobacteria species, higher total phosphorous inputs, and intense anoxia. In the restoration period (AD 1983-2014), there was a shift in the phototrophic community from cyanobacteria to green algae dominance, yet some cyanobacteria species remain present. Rapid phytoplankton community changes were identified in the studied period, yet overall primary production response was low. Limnological data revealed a delay of phosphorous reduction due to phosphorous recycling from the sediments. The observation of complex lake ecosystem reactions to prolonged eutrophication and subsequent reoligotrophication, as shown by the paleolimnological and limnological data in this study, emphasize the importance of careful lake management to revert eutrophication back to historical reference biomass values.
Dreissena polymorpha is a bivalve promising for biomonitoring in freshwater ecosystems thanks to ... more Dreissena polymorpha is a bivalve promising for biomonitoring in freshwater ecosystems thanks to its abundance and high filtration activity allowing rapid uptake of toxicants and identification of their negative effects. Nonetheless, we still lack knowledge on its molecular responses to stress under realistic scenario, e.g. multi-contamination. Carbamazepine (CBZ) and Hg are ubiquitous pollutants sharing molecular toxicity pathways, e.g. oxidative stress. A previous study in zebra mussels showed their co-exposure to cause more alterations than single exposures, but molecular toxicity pathways remained unidentified. D. polymorpha was exposed 24h (T24) and 72h (T72) to CBZ (6.1±0.1 µg L-1), MeHg (430±10 ng L-1) and the co-exposure (6.1±0.1 µg L-1 CBZ and 500±10 ng L-1 MeHg) at concentrations representative of polluted areas (~10x EQS). RedOx system at the gene and enzyme level, the proteome and the metabolome were compared. The co-exposure resulted in 108 differential abundant proteins (DAPs), as well as 9 and 10 modulated metabolites at T24 and T72, respectively. The co-exposure specifically modulated DAPs and metabolites involved in neurotransmission, e.g. dopaminergic synapse and GABA. CBZ specifically modulated 46 DAPs involved in calcium signaling pathways and 7 amino acids at T24. MeHg specifically modulated 55 DAPs proteins involved in the cytoskeleton remodeling and hypoxia-induced factor 1 pathway, without altering the metabolome. Single and co-exposures commonly modulated proteins and metabolites involved in energy and amino acid metabolisms, response to stress and development. Concomitantly, lipid peroxidation and antioxidant activities were unchanged, supporting that D. polymorpha tolerated experimental conditions. The co-exposure was confirmed to cause more alterations than single exposures. This was attributed to the combined toxicity of CBZ and MeHg. Altogether, this study underlined the necessity to better characterize molecular toxicity pathways of multi-contamination that are not predictable on responses to single exposures, to better anticipate adverse effects in biota and improve risk assessment.
Sediment-bound Contaminant Transport Dynamics in and Around Vidy Bay
EPFL Press eBooks, Mar 14, 2018
Que nous raconte l’étude des sédiments d’un lac ?
L’analyse des longues series de donnees (plus de 50 ans) peut expliquer les trajectoires d’evolut... more L’analyse des longues series de donnees (plus de 50 ans) peut expliquer les trajectoires d’evolution des systemes lacustres et definir certaines conditions environnementales passees. Les archives sedimentaires permettent de reconstituer l’histoire des lacs sur le long terme (de 100 a 10 000 ans).
Au regard des temps géologiques, les lacs sont pour la plupart éphémères et disparaissent en quel... more Au regard des temps géologiques, les lacs sont pour la plupart éphémères et disparaissent en quelques milliers ou dizaines de milliers d'années, remplis par l'accumulation de sédiments. La formation des grands lacs alpins est essentiellement l'héritage des nombreuses périodes glaciaires qui ont touché les Alpes depuis le début du quaternaire, il y a environ 2,6 millions d'années. L'évolution des formes lacustres que l'on connait actuellement résulte essentiellement de la dernière glaciation, celle dite du Würm (il y a entre-110 000 et-14 000 ans) et de la période post-glaciaire.
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Papers - Co author by Jean-Luc Loizeau
study long-term contamination by 137Cs atmospheric deposition and the fate of this radioisotope when
associated with various agricultural practices: fallow land, KCl, NH4(NO3), superphosphate fertilizers,
horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is
supposed to move downward by convectional mechanisms, is checked using samples from control plots
which had been neither amended, nor cultivated since 1928. This simple model presents the advantage
of depending on only two parameters: a, a proportional factor allowing the historical atmospheric 137Cs
fluxes to be reconstructed locally, and k, an annual loss coefficient from the plow horizon. Another
pseudo-unknown is however necessary to run the model: the shape of historical 137Cs deposition, but
this function can be easily computed by merging several curves previously established by other surveys.
A loss of w1.5% per year from the plow horizon, combined with appropriate fluxes, provides good
concordance between simulated and measured values. In the 0–25 cm horizon, the residence half time is
found to be w18 yr (including both migration and radioactive decay). Migration rate constants are also
calculated for some plots receiving continuous long-term agricultural treatments. Comparison with the
control plots reveals significant influence of amendments on 137Cs mobility in these soils developed from
a unique genoform.
Papers by Jean-Luc Loizeau