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Bioécologie

Articles avec #ecotoxicologie

Adverse Outcome Pathways, Molecular Screening and Toxicogenomics

13 Septembre 2017,

Publié par Bioécologie

The OECD launched a new programme on the development of Adverse Outcome Pathways (AOP) in 2012. An AOP is an analytical construct that describes a sequential chain of causally linked events at different levels of biological organisation that lead to an adverse health or ecotoxicological effect (see figure below). AOPs are the central element of a toxicological knowledge framework being built to support chemical risk assessment based on mechanistic reasoning.

Adverse Outcome Pathways, Molecular Screening and Toxicogenomics

The Causal Analysis/Diagnosis Decision Information System: CADDIS

29 Août 2017,

Publié par Bioécologie

The Causal Analysis/Diagnosis Decision Information System, or CADDIS, is a website developed to help scientists and engineers in the Regions, States, and Tribes conduct causal assessments in aquatic systems. It is organized into five volumes.

The Causal Analysis/Diagnosis Decision Information System: CADDIS

Open Letter from Dr. Christopher Portier on His Review of the Carcinogenicity of Glyphosate European Union Authorities

31 Mai 2017,

Publié par Bioécologie

Executive Summary: The European Food Safety Agency IEFSA) and the European Chemical Agency IEChA) have completed their assessments of the carcinogenic potential of glyphosate and concluded that the evidence does not support a classification for glyphosate. The raw data for the animal cancer studies for glyphosate have been released, and a reanalysis of these data show eight instances where significant increases in tumor response following glyphosate exposure were not included in the assessment by either EFSA or EChA. This suggests that the evaluations applied to the glyphosate data are scientifically flawed, and any decisions derived from these evaluations will fail to protect public health. I ask that the evaluations by both EFSA and EChA be repeated for all toxicological endpoints and the data underlying these evaluations be publicly released.

You can read the full letter by clicking here

Airparif : surveillance de la qualité de l'air de Paris et de toute l'Ile-de-France

9 Décembre 2016,

Publié par Bioécologie

La surveillance de la qualité de l'air ambiant est assurée en France par des associations indépendantes comme Airparif (type loi de 1901), chargées pour le compte de l'État et des pouvoirs publics, de la mise en œuvre des moyens de surveillance.

Créée en 1979, Airparif est agréée par le ministère de l'Environnement pour la surveillance de la qualité de l'air sur l'ensemble de l'Ile-de-France.

En savoir plus ici et suivre la qualité de l'air ici

La pollution de l'air en France : 48 000 morts par an !

9 Décembre 2016,

Publié par Bioécologie

La pollution de l’air due aux particules fines est responsable de 48 000 morts chaque année en France, dont plus de 34 000 seraient évitables, selon une étude de Santé Publique France.

En savoir plus ici

Découvrez ici la carte de France de la pollution atmosphérique.

Crédit photo : Damián Bakarcic

Crédit photo : Damián Bakarcic

The Copernicus Atmosphere Monitoring Service (CAMS)

24 Novembre 2016,

Publié par Bioécologie

The Copernicus Atmosphere Monitoring Service (CAMS) provides continuous data and information on atmospheric composition. The service describes the current situation, forecasts the situation a few days ahead, and analyses consistently retrospective data records for recent years.

Read more...

Emission of spherical cesium-bearing particles from an early stage of the Fukushima nuclear accident

29 Juin 2016,

Publié par Bioécologie

Abstract

The Fukushima nuclear accident released radioactive materials into the environment over the entire Northern Hemisphere in March 2011, and the Japanese government is spending large amounts of money to clean up the contaminated residential areas and agricultural fields. However, we still do not know the exact physical and chemical properties of the radioactive materials. This study directly observed spherical Cs-bearing particles emitted during a relatively early stage (March 14–15) of the accident. In contrast to the Cs-bearing radioactive materials that are currently assumed, these particles are larger, contain Fe, Zn, and Cs, and are water insoluble. Our simulation indicates that the spherical Cs-bearing particles mainly fell onto the ground by dry deposition. The finding of the spherical Cs particles will be a key to understand the processes of the accident and to accurately evaluate the health impacts and the residence time in the environment.

(a) A Cs-bearing particle partially embedded within a carbon paste. (b) The same Cs-bearing particle as a) but measured the next day. The particle shows a spherical shape. (c) An elemental mapping (Cs) of the particle (a). (d) The EDS spectrum of the particle a) (black line). The red line shows the spectrum from the glass substrate. The Cs in the particle shows multiple peaks. (e) An elemental mapping of the other elements within the area. O, Si, Cl, Mn, Fe, and Zn are possibly coexistent with Cs within the particle.

(a) A Cs-bearing particle partially embedded within a carbon paste. (b) The same Cs-bearing particle as a) but measured the next day. The particle shows a spherical shape. (c) An elemental mapping (Cs) of the particle (a). (d) The EDS spectrum of the particle a) (black line). The red line shows the spectrum from the glass substrate. The Cs in the particle shows multiple peaks. (e) An elemental mapping of the other elements within the area. O, Si, Cl, Mn, Fe, and Zn are possibly coexistent with Cs within the particle.

Internal structure of cesium-bearing radioactive microparticles released from Fukushima nuclear power plant

28 Juin 2016,

Publié par Bioécologie

Abstract

Microparticles containing substantial amounts of radiocesium collected from the ground in Fukushima were investigated mainly by transmission electron microscopy (TEM) and X-ray microanalysis with scanning TEM (STEM). Particles of around 2 μm in diameter are basically silicate glass containing Fe and Zn as transition metals, Cs, Rb and K as alkali ions, and Sn as substantial elements. These elements are homogeneously distributed in the glass except Cs which has a concentration gradient, increasing from center to surface. Nano-sized crystallites such as copper- zinc- and molybdenum sulfide, and silver telluride were found inside the microparticles, which probably resulted from the segregation of the silicate and sulfide (telluride) during molten-stage. An alkali-depleted layer of ca. 0.2 μm thick exists at the outer side of the particle collected from cedar leaves 8 months after the nuclear accident, suggesting gradual leaching of radiocesium from the microparticles in the natural environment.

Read more here

(a) Element maps of NWC-1 acquired by STEM-EDS with a STEM Dark-field (DF) image at the same area, and (top) TEM Bright-field image in which the rectangle indicates the area analyzed by STEM-EDS. The thin area around the top of the particle which was not observed in Fig. 1a was formed by a further thinning process by FIB. (b) Element maps and images of CB-8 with the same framing as in (a).

(a) Element maps of NWC-1 acquired by STEM-EDS with a STEM Dark-field (DF) image at the same area, and (top) TEM Bright-field image in which the rectangle indicates the area analyzed by STEM-EDS. The thin area around the top of the particle which was not observed in Fig. 1a was formed by a further thinning process by FIB. (b) Element maps and images of CB-8 with the same framing as in (a).

L'or noir de l'Amérique - Un film sur le pétrole de schiste dans le Dakota du Nord

13 Mai 2016,

Publié par Bioécologie

Un documentaire réalisé par Pierre-Emmanuel Luneau-Daurignac (52’). Ce documentaire a été diffusé sur La Chaîne Parlementaire (LCP, France). Cette chaîne de télévision a été créée en 1999 par l’Assemblée nationale et le Sénat français.

Synopsis :

"En 2009, la découverte d’un gigantesque gisement de pétrole de schiste dans le Dakota du Nord sonne comme une bonne nouvelle pour l’Amérique en crise. Plus de 16 000 puits pompent aujourd’hui le sol du Dakota du Nord. Les Etats-Unis devraient devenir le premier producteur de pétrole d’ici à 2020, devant la Russie et l’Arabie Saoudite, remettant ainsi en cause une bonne partie de l’équilibre géostratégique de la planète. Mais alors que l’argent et le pétrole coulent à flots, d’autres voix se font entendre : celles des fermiers de la région dont le bétail dépérit à vue d’œil, celles des habitants des petites villes dont l’eau potable s’irise soudain. Le réalisateur est parti enquêter sur ce nouveau Far West et ses acteurs, avec en toile de fond les enjeux économiques gigantesques des hydrocarbures de schiste, mais aussi les enjeux de santé publique…"